ALBERT

Description: Abstract The research aims to evaluate the output of biogas and the concentration of CH4 and gaseous impurities such as CO2 and H2S in the process of digesting chicken manure without additives (experiment A) and with 10% of biochar additive (by mass of the dry load) (experiment B) under anaerobic and mesophilic conditions. It has been found that the average output of biogas from a particular amount of chicken manure (experiments A and B) obtained in the 45‐day experimental research is similar in both cases and reaches 12.88 l d–1 and 12.36 l d–1, respectively. However, the biochar additive increases CH4 concentration in biogas and reduces the concentration of gaseous impurities (CO2 and H2S) in biogas. The maximum concentration of CH4 in biogas obtained from a load of manure with biochar additive is higher than that in biogas obtained by using a load without a biochar additive, and reaches 72.0% and 68.5%, respectively. The average CO2 concentration, reaching 33.09% and 47.5%, respectively, in biogas obtained from the load with 10% of biochar additive is lower than that in biogas obtained from the manure load without an additive. The average concentration of H2S in the biogas obtained in experiment B is lower than that in experiment A and reaches 95.9 mg m–3 and 195.5 mg m–3, respectively. The biochar additive adsorbs gaseous impurities (CO2 and H2S) from biogas without adsorbing CH4. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Inorganic membranes can operate under harsh conditions. However, successful synthesis of inorganic membranes is still challenging, and its performance depends on many factors. This work reports the effect of dip‐coating duration, inlet pressure, and inlet flow rate on the flux, permeability, and selectivity of silica membranes. A silica membrane was prepared by the deposition of silica sol onto porous alumina support. The permeability test was conducted at 100 °C using a single gas of CO2 and CH4. The highest flux was observed at the maximum inlet pressure and inlet flow rate for the membrane prepared at the minimum dip‐coating duration. The neural network modeling of the membrane predicted permeabilities showed a considerably high validity regression (R ≈ 0.99) of the predicted data linked to the experimental sets. The separation factor (α) was the highest at the maximum dip‐coating duration. The synthesized silica membrane has potential for CO2/CH4 separation under harsh operating conditions. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The concentration of greenhouse gases (GHG)s and specifically CO2 continue to rise in the global environment including the atmosphere and the oceans. Oil and gas exploration in oceans and the increased probability of CO2 being destined for ocean storage have made the oceans much vulnerable to acidification and hence detrimental to the entire marine ecosystem. Offshore wind energy, along with other renewables, have the potential to lower the rate of CO2 absorption in the global eco system. Distant offshore wind farms are faced with the problem of dispatch of surplus wind power. Power‐to‐gas technology can be used to convert the offshore wind power into synthetic natural gas that can be transported through the existing network of offshore gas pipelines. The novel method has the capability to significantly reduce GHG emissions, solve the power dispatch problems of offshore wind farms, as well as reduce the oceanic environmental degradation. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Controlled release of carbon dioxide (CO2) into the soil and atmosphere is performed to test detection and monitoring tools, for which several field laboratories were established by a number of institutions worldwide. Numerical simulations of CO2 behavior in the shallow subsurface region are other forms of validation and verification of the leakage pathways and destinations. These studies aim to improve monitoring and verification of CO2 in case of unexpected leakages for public assurance. In this work, we present the results of a numerical modeling study conducted to simulate the injection of CO2 as carried out during a field test in Viamão, southern Brazil, where 20 kg day–1 of CO2 was pumped for 30 days through a vertical well 3 m below ground in an altered granitic soil. Multiphase flow simulations were performed with the TOUGH2/EOS7CA software for unsaturated porous media, using field data and injection parameters, including sensitivity tests to permeability direction, diffusivity, and boundary conditions. Results with increased horizontal permeabilities are in better agreement with the field observations. In this condition, mass balance calculations indicate approximately 90% of injected CO2 (20 kg day–1 during 30 days) remains in the soil after 180 days from injection start, consistent with the measured flow through the soil–atmosphere interface. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In order to utilize as much of the pore space for CO2 storage in high permeability thick saline aquifers, it is vital to investigate the interactions of injected CO2 with formation brine and rock. In order to quantify the displacement process, we investigate the dynamic storage efficiency factor (DSEF) for saline aquifers where pressure increase is minimal during the injection phase. Dimensionless numbers are derived from basic governing equations, constitutive equations, initial and boundary conditions using the inspection analysis. Then using the Hammersley sequence sampling, 178 numerical experiments are designed, and a compositional reservoir simulator is used to perform these simulations. In the next step, response surface regression analysis is used to establish a relationship between DSEF obtained from the numerical simulations and the corresponding dimensionless numbers. The simulation results show that for the studied conditions the underground dynamics is mostly influenced by the gravity number, followed by effective aspect ratio and dip numbers. The results from the response surface regression analysis are used to develop a correlation, which can be used to estimate the dynamic CO2 storage capacity of relevant zones. This study provides quantitative measures for the different competing mechanisms involved in underground displacement of fluids in CO2 geological storage, which can serve as a useful tool during planning phase of storage projects. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 4, Page 610-612, August 2019.

Description: Abstract The phase equilibria with the confinement effect could shift in nano‐pores, which could have a great impact on the recovery mechanisms of CO2 injection in tight oil reservoirs; this has not been systematically studied. In this paper, the confinement effect with property shift and capillarity effect is introduced into the flash calculation of confined fluids. The Soave modification of the Redlich–Kwong equation of state is extended by the molecular‐wall collision parameter to describe the shifted pressure–volume–temperature properties of confined fluid, and the Young–Laplace equation is applied to evaluate the capillary pressure. This developed model could effectively be applied for phase equilibrium calculation in tight porous media because of the verification of experimental results. A binary mixture is investigated to study the different effect of capillary pressure and property shift on phase equilibria. Subsequently, a typical hydrocarbon fluid from Middle Bakken tight oil reservoirs is studied with CO2 injection. Results illustrate that the confinement effect could play an increasingly important part in the phase equilibrium state. The CO2 solubility and mass transfer driving force in tiny pores would be greater than those in large pores under the same conditions. The gas phase saturation would be smaller with the same compositions, which could extend the single‐phase region of fluid flow in porous media. Furthermore, bubble‐point pressure, the minimum miscible pressure of CO2/hydrocarbon, and the viscosity of tight oil dissolved with CO2 both decrease with the pore size, which has a good influence on tight oil recovery. In general, the confinement effect could effectively reinforce the recovery mechanisms of CO2 injection, which is conducive to the enhancement of tight oil recovery. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Recent field experiments in Iceland and Washington State (USA) show that basalt formations may be favorable targets for carbon capture and sequestration (CCS) because CO2 mineralization reactions proceed rapidly. These results imply that there is tremendous opportunity for implementing CCS in large igneous provinces. However, the magnitude of this opportunity comprises commensurate levels of uncertainty because basalt reservoirs are characterized by highly heterogeneous, fracture‐controlled hydraulic properties. This geologic uncertainty is propagated as parametric uncertainty in quantitative risk models, thus limiting the efficacy of models to predict CCS performance attributes, such as reservoir integrity and storage potential. To overcome these limitations, this study presents a stochastic approach for quantifying the geomechanical performance attributes of CCS operations in a highly heterogeneous basalt reservoir. We utilize geostatistical reservoir characterization to develop an ensemble of equally probable permeability distributions in a flood basalt reservoir with characteristics of the Wallula Basalt Pilot Project. We then simulate industrial‐scale CO2 injections within the ensemble and calculate the mean and variance of fluid pressure over a 1‐year injection period. These calculations are combined with the state of stress in southeast Washington State to constrain the spatial extent at which shear failure, fracture initiation, and borehole breakdown may occur. Results from this study show that (i) permeability uncertainty alone causes injection pressure to vary over 25 MPa, (ii) shear failure is likely to occur at 7 times greater distances from the injection than the CO2 migrates, and (iii) joint initiation pressures are localized within the volume comprising the CO2 plume. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Despite political turmoil and intrigue, along with the inevitable financial uncertainty, the desire to overcome the obstacles that could hold back the innovation and implementation of technologies and projects to tackle climate change remains active. The recent climate change protests by school children are an indicator of not only the level of concern over climate issues, but what is also at stake if these obstacles allow progress to be derailed. The good news is that in the area of carbon capture utilisation and storage (CCUS), considered to be among the costliest, but necessary, weapons in the climate change mitigation arsenal, progress continues to be made. In this article, GHGS&T's Muriel Cozier rounds up some of the most recent developments. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract To investigate the flow field near fracture entrance and promote the development of sand fracturing with carbon dioxide as the working fluid, numerical simulation of multiphase flow was conducted with a 3D geological model considering the compressibility of carbon dioxide. The flow field of carbon dioxide alone was firstly investigated to lay the foundation for the analysis of multiphase flow, and then comparative analysis was conducted on the flow field of both the injecting sand from the pipe and the annulus. The results show that jet fracture with carbon dioxide can achieve a 4.46 MPa pressure boost at the fracture tip compared to the annulus pressure, which theoretically validates the feasibility of the mentioned technology. Sand fracturing can achieve a higher pressure boost in the cavity, while it needs greater pump pressure at the surface. Injecting sand from the annulus could decrease the need for pump pressure by 6.62 MPa at the condition of injecting 25% carbon dioxide from the annulus simultaneously, while the pressure difference between the cavity tip and the annulus decreases as a result. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Global warming and the greenhouse effect are two of the most important environmental problems. Carbon dioxide, methane, and nitrous oxide emissions are the main greenhouse gas emissions in wastewater treatment plants. In this study, the greenhouse gas emission sources in a wastewater treatment plant were determined. Direct (from fossil fuel combustion, methane emissions, and process emissions of the other greenhouse gases) and indirect emissions (primarily from electricity use) in the plant were monitored. The optimum influent characteristics and operating conditions have been defined by using Monte Carlo simulation to minimize the emissions. The results revealed that the highest direct greenhouse gas emission was observed in August with the value of 23.328 kg CO2‐eq d–1 and the lowest emission was 7.56 kg CO2‐eq d–1 measured in January. The aeration tank is a major source of greenhouse gas emissions. Indirect emission has occurred because of the anaerobic digester but the biogas has been cogenerated in the plant, so it has been ignored for the calculation. According to the simulation study, if the plant is operated under optimum operating conditions, it can emit the lowest amount of greenhouse gas emissions. The optimum removal values required for the minimum greenhouse gas emissions are 79% for chemical oxygen demand, 75% for biochemical oxygen demand, and 82% for total suspended solid. The optimum operating conditions for the aeration tank, which is the major source of emission, are 5.33 h of hydraulic retention time, 0.215 d of solid retention time, and 0.999 for food/microorganisms. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 4, Page 607-609, August 2019.

Description: The cover image is based on the Review Renewable absorbents for CO2 capture: from biomass to nature by Qingyao He et al., https://doi.org/10.1002/ghg.1902. Cover image © Feihong Liang.

Description: Abstract The economic feasibility of carbon dioxide (CO2) enhanced oil recovery (EOR) to offset CO2 capture costs from a coal‐fired power plant are evaluated for 36 source‐sink scenarios in Ohio; one of the top ten states for fossil‐fuel use and CO2 emissions in the United States. Six capture scenarios are examined for a representative 550 megawatt (MW) coal‐fired power plant, and three CO2‐EOR injection scenarios are evaluated for both East Canton oil field and Gore consolidated oil field. The potential costs and credits associated with CO2 storage related tax incentives are also considered. Power plant capture performance and costs integrated with field‐scale CO2‐EOR techno‐economics suggest that there are potentially feasible scenarios for capture, transport, and CO2‐EOR storage of 25%, 50%, and 90% of CO2 emissions, respectively, from a 550 MW power plant. Economically feasible outcomes exhibiting net present values of $2191, $1380, and $1940 million are estimated for the 25%, 50%, and 90% capture scenarios, respectively. On average, the 45Q tax credit for CO2 storage affords a $3–$7 per barrel decrease in the minimum oil price required to break‐even on the project. In all source‐sink scenarios qualifying as feasible, the CO2 capture costs incurred by the power plant are offset by revenue from CO2‐EOR and are not passed on to ratepayers during the 30‐year analysis time frame. The most economical outcome for supporting a commercial carbon capture, utilization, and storage project in Ohio is also identified, and the potential impact of CO2‐EOR operational strategy on source‐sink feasibility is discussed. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract A dynamically coupled mass, momentum, and heat transfer model was developed, which demonstrated the unstable behavior of CO2 movement inside porous sediment during high pressure injection and its transformation into solid hydrates. The presented mathematical model was solved using the implicit finite difference method, and through ordering the set of model equations, a complex integrated methodology could be established to analyze the CO2 hydrate nucleation procedure within P‐T equilibrium conditions. The results showed that the intrinsic permeability factor of the porous sediment had great influence on the pressure distribution. At 10−13 m2 intrinsic permeability, the formation pressure distribution became stable at an early stage of the hydrate growth process and remained stable afterwards. The overall hydrate covered length was 320 m due to the massive hydrate growth rate. When intrinsic permeability was reduced to 10−14 m2, it showed delay in pressure distribution and the overall hydrate covered length shifts to up to 310 m due to the delay in pressure distribution. Whereas at a 10−15 m2 intrinsic permeability factor, there was significant delay in pressure distribution so the injection pressure was not fully distributed even after 30 days of the induction process, which squeezed the hydrate covered length to 130 m. This pressure distribution had direct correlation with other parameter variations during the hydrate growth process, such as temperature distribution, hydrate growth rate, CO2 velocity, CO2 density, CO2 and H2O saturation, CO2 permeability, and interface boundary movement speed. Hence, the pressure distribution inside hydrate‐bearing sediment is the most dominant factor to enhance CO2 storage capacity but it does not give satisfactory results in extended formations. © 2019 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract As a water‐less fracturing mining technology, supercritical CO2 fracturing has attracted increasing attention in the mining industry. Based on detailed analysis of CO2 phase behavior in the whole process of supercritical CO2 fracturing, the whole cycle of supercritical CO2 fracturing was divided into the supercritical CO2 fracturing stage and the CO2 phase transition–induced fracturing stage, and according to the characteristics of each fracturing stage, the fracturing mechanism of supercritical CO2 was analyzed in stages, and the roles of the two stages in the life cycle of the entire supercritical CO2 fracturing process were obtained. Through the laboratory test of supercritical CO2 fracturing coal mass, the pressure–time curves during the whole process of supercritical CO2 fluid fracturing were analyzed, and the rationality and correctness of the supercritical CO2 fracturing staged analysis method proposed in this paper were verified. Based on the energy conservation theory and the state function equation of classical thermodynamics, the burst energy of the CO2 phase transition–induced fracturing stage was estimated. By comparing the trinitrotoluene equivalent of phase‐transition energy with the trinitrotoluene amount of explosive explosion, it was proved that the CO2 phase transition–induced fracturing stage was not negligible. The research results of this paper are of considerable significance for the full understanding of the supercritical CO2 fracturing mechanism. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract CO2 capture and storage (CCS) can be an important feature of a decarbonization strategy involving electricity generation. According to the recently revised Section 45Q tax credits, said credits will be provided for implementing CCS, which is motivating some United States (US) electricity generation companies to revisit their business strategies for CCS. This paper discusses alternative business models being considered by companies for undertaking CCS, including providing a ‘template’ for evaluating the cost‐effectiveness of CCS with Section 45Q tax credits and storage in saline reservoirs. Using stylized illustrative examples, the paper indicates how use of Section 45Q tax credits should be expected to change dispatch at an electricity generating unit. For situations similar to the examples, the paper suggests that Section 45Q tax credits may need to be modified to achieve its intended impact. Modifications can include extending the time period of tax credit availability beyond the current 12 years. In addition, continued R&D investments in CCS and specific support for first‐of‐a‐kind CCS demonstrations would be valuable complements for the deployment of the Section 45Q tax credit. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Growing interest in offshore geologic carbon sequestration (GCS) motivates evaluation of the consequences of subsea CO2 well blowouts. We have simulated a hypothetical major CO2 well blowout in shallow water of the Texas Gulf Coast. We use a coupled reservoir‐well model (T2Well) to simulate the subsea blowout flow rate for input to an integral model (TAMOC) for modeling CO2 transport in the water column. Bubble sizes are estimated for the blowout scenario for input to TAMOC. Results suggest that a major CO2 blowout in ≥50 m of water will be almost entirely attenuated by the water column due to CO2 dissolution into seawater during upward rise. In contrast, the same blowout in 10 m of water will hardly be attenuated at all. Results also show that the size of the orifice of the leak strongly controls the CO2 blowout rate. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Novel Mn‐doped CaO was prepared by the combustion method. The CO2 capture performance of Mn‐doped CaO, carbonated in the presence of steam and under severe calcination conditions (950°C and 70% CO2/30% N2) during calcium looping cycles, was investigated in a dual fixed‐bed reactor. The intercoupling effects of Mn and steam on CO2 capture by CaO were also studied. Doping of Mn in CaO by the combustion method greatly improved the CO2 capture capacity of CaO. The carbonation conversions of Mn‐doped CaO increased with increasing steam concentration from 0 to 15%. When the molar ratio of Mn/Ca was 0.75 : 100, Mn‐doped CaO achieved the highest CO2 capture capacity. Under severe calcination conditions, the carbonation conversion of Mn‐doped CaO, where the molar ratio of Mn to Ca = 0.75 : 100 in the presence of 15% steam, was about 0.4 after ten cycles (carbonation for 5 min at 650°C under 15% CO2/15% steam/N2), which was 4.38 times as high as that of the original CaO in the absence of steam. The cyclic CO2 capture capacities of CaO were improved by Mn and steam. Synergistic enhancement effects of Mn and steam on the CO2 capture capacities of CaO were also found. The effect of steam on the carbonation conversion of Mn‐doped CaO was stronger than that of the original CaO. Mn in the presence of steam showed a more positive effect on CO2 capture by CaO. X‐ray photoelectron spectroscopy analysis showed that doping of Mn in CaO enhanced the transport of electrons in the carbonation of CaO, which helped to increase the carbonation rate. When steam was present in the carbonation, Mn‐doped CaO possessed a more porous structure and smaller CaO grains than the original CaO during the cycles. Simulation calculations using periodic density functional theory (DFT) showed that CO2 molecules were easier to absorb on CaO owing to the doping of Mn and the presence of steam. The synergistic enhancement effects of Mn and steam on CO2 captured the performance of CaO. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Oil wells that intersect a potential CO2 storage zone in a depleted oil and gas field may provide leakage pathways. It is essential to estimate the field‐scale leakage risk associated with these wells. In this study, a risk‐based approach is used to estimate the risk of leakage. Existing reduced‐order models for well leakage are used to quantitatively estimate well leakage rates for cased‐cemented, cased‐uncemented, and open wellbores. For each existing well that intersects the storage zone, we introduce the well leakage index (WLI), which accounts for wellbore geometry, distance from the injection well, buffer layers between the storage zone and underground sources of drinking water, and the nature of storage zone boundary type. For an initial injection well location, the total site well leakage index (SWLI) is calculated, which is the summation of the WLI for all of the wells. Next, the injector location is varied areally and SWLI is calculated for a specified number of potential injector well locations in the storage zone area. Small values for the SWLI correspond to low well leakage potential, indicating where injection well locations can be considered. The developed criterion provides a means to systemically find the areas with highest and lowest well leakage potential for a storage zone. Due to the reduced order nature of the developed method, it should be a useful tool in the planning and execution phase of the CO2 geological sequestration process. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Geological carbon storage (GCS) refers to the technology of capturing man‐made carbon dioxide (CO2) emissions, typically from stationary power sources, and storing such emissions in deep underground reservoirs. GCS is an approach being explored globally as a defense mechanism against climate change projections, although it is not without its critics. An important focus has been recently placed on understanding the coupling between rock–fluid geochemical alterations and mechanical changes for CO2 storage schemes in saline aquifers. This article presents a review of the current state of knowledge regarding CO2‐induced geochemical reactions in subsurface reservoirs, and their potential impact on mechanical properties and microseismic events at CO2 storage sites. This review focuses, in particular, on the current state of the art in fluid–rock interactions within the GCS context. Key issues to be addressed include geochemical reactions and the alteration of transport and mechanical properties. Specific review topics include the swelling of clays, the prediction of dissolution and precipitation reaction rates, CO2‐induced changes in porosity and permeability, constitutive models of chemo–mechanical interactions in rock, and correlations between geochemical reactions and induced seismicity. The open questions in the field are emphasized, and new research needs are highlighted. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract An audit is not always something that an organisation looks forward to. Having procedures or expenditures critiqued by an independent body has the potential to be nerve‐wracking. But the scrutiny can often lead to better decisions for the future. In this article, GHGS&T's Muriel Cozier looks at the findings from the audit of the past 10 years of European Union's climate action. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Sequence SO2/CO2 capture technology will be more attractive as the control on secondary pollution is strengthened and the operating cost is decreased. The sulfation, pore, and fractal characteristics of a spent CaO‐based adsorbent are studied. The spent modified CaO/Ca12Al14O33 is used in this study. The effect of cyclic numbers in the calcium‐looping process on sulfation conversion and the pore characteristics of spent adsorbents is investigated. A model between the fractal dimension and the Brunner–Emmet–Teller (BET) specific surface area (SBET) of the spent CaO/Ca12Al14O33 is established. The sulfation reaction characteristic of spent adsorbents is also interpreted by the fractal mechanism. Results show that the sulfation conversions of spent CaO/Ca12Al14O33 are almost 10% higher than those of spent CaO at the same cyclic number. The sulfation reaction rate in the product layer diffusion‐controlled stage is much lower than that in the chemical reaction‐controlled stage. The spent CaO/Ca12Al14O33 adsorbents are mainly composed of meso‐ and macropores. The pore size distributions show that there are two peaks in the curves. The surface fractal dimension (D1) and the pore fractal dimension values of spent adsorbents show a trend that is similar to those of SBET and total pore volume, respectively. The relation between the D1 values of four different CaO‐based adsorbents and their SBET values is a quadratic function, and a higher D1 indicates an irregular surface of disordered fractals, which significantly affects the efficiency of the sulfation reaction. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The global warming and change in climatic conditions due to rising concentration of CO2 in atmosphere are the most important challenges of 21st century. Catalytic conversion of CO2 to methanol will not only check global warming but also provide an alternative source of fuel. The phase purity of solid catalysts has a considerable influence on the desired product selectivity. Reduction temperature is one of the most important parameters responsible for catalyst phase formation. Herein, the effect of a range of reduction temperatures between 100 and 600°C on the phase composition of Pd–Ga bimetallic catalyst and CO2 hydrogenation to methanol activity was investigated. X‐ray diffraction (XRD) analysis revealed the formation of different phases at different reduction temperatures. The variation in catalyst structure was also analyzed using field emission scanning electron microscope‐energy dispersive X‐ray spectroscopy (FESEM‐EDS), Brunaue–Emmett–Teller, H2 chemisorption, and transmission electron microscopy techniques. The influence of reduction temperature, pressure (1–25 bar), H2/CO2 ratio (3–9), and reaction temperature (150–250°C) on methanol and CO selectivity from CO2 hydrogenation at atmospheric pressure was also studied. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In the context of geologic carbon dioxide (CO2) sequestration, the storage effectiveness of a caprock–reservoir system is a function of the properties of both the caprock and reservoir – namely, the ability of the caprock to prevent upward leakage of CO2 (caprock sealing capability), the mechanical response of the reservoir and caprock (by evaluating in situ stress changes), and the extent and degree to which CO2 can be trapped over long periods of time. In this work, all three parameters were considered to evaluate the storage effectiveness of the Cambrian–Ordovician sequence of the Northern Appalachian Basin. We constructed a series of hydro‐mechanical models to investigate interactions between CO2 flow and geomechanical processes and to evaluate the three aspects of storage performance. Models were built to evaluate two scenarios: (1) single reservoirs with a single overlying caprock, and (2) systems comprising multiple reservoirs and multiple intermediate caprock units in addition to the primary (uppermost) caprock unit. The overall conclusion of the work is that focusing only on one aspect of storage effectiveness might not necessarily warrant long‐term CO2 storage. Results of the sensitivity analysis for the single caprock–reservoir system show that each storage effectiveness metric has its own control parameters. A comparison among three stacked caprock–reservoir systems in different parts of the study area shows that each location in the study area could be appropriate for one of the storage effectiveness metrics. Therefore, we conclude that the screening process to select the best site for CO2 sequestration should be based on an evaluation of all three metrics. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The hybrid process of carbonated low salinity waterflood (CLSWF) integrating low salinity waterflood (LSWF) and carbonated waterflood (CWF) is proposed as enhanced oil recovery (EOR) incorporating CO2 storage. Based on the understanding of the mechanisms of LSWF and CWF, the hybrid technology is simulated with a fully‐coupled model of fluid flow, geochemical reactions, and equation of state, which describes chemical interactions in the oil/brine/rock system. The comprehensive simulations confirm the synergetic effects of the hybrid CLSWF when compared to waterflooding (WF) and LSWF. In addition, optimum designs of cost‐efficient CLSWF securing CO2 storage are drawn via optimization and sensitivity studies. First, CLSWF enhances wettability modification effect, when compared to LSWF. In CLSWF, extensive mineral dissolution causes more cation exchange. Following the multicomponent ion exchange theory of the wettability modification mechanism, CLSWF produces more residual oil than LSWF with an increasing equivalent fraction of cation. Consequently, it enhances oil recovery by 6.9% and 2.5%, compared with WF and LSWF. Second, the interphase transport of CO2 introduces the oil viscosity reduction effect, which improves the injectivity of CLSWF. Lastly, it sequestrates 25% of the injected CO2 in the depleted reservoir via the solubility‐trapping mechanism. In optimization and sensitivity studies, the optimum design of CLSWF is determined to produce more oil recovery by 9.9% and more net present value by 35% over WF. In addition, 33% of the injected CO2 becomes sequestrated in the reservoirs. This study clarifies that hybrid CLSWF improves EOR, injectivity, and CO2 storage. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Fertilizer management and straw returning are effective measures to regulate greenhouse gas emissions and increase crop yields, which have attracted wide attention in agricultural production. To clarify the effect of Chinese milk vetch returning with nitrogen fertilizer on rice yield and greenhouse gas emissions in paddy field, field experiments were conducted during 2017–2018 and four treatments were proposed in this study, including the treatments with Chinese milk vetch returning plus different nitrogen fertilizer application amount, namely RA, RB, RC, and control CK (winter fallow without Chinese milk vetch returning). The results showed that treatments RA, RB, and RC significantly increased the early rice yield by 15.35%, 12.94%, and 15.35%, respectively (P〈0.05), and treatment RA had the best effect on the annual yield (P〈0.05) compared with control CK. Meanwhile, all the treatments with Chinese milk vetch returning plus nitrogen fertilizer increased the global warming potential, but the difference between RA, RB, and control CK was not significant (P〉0.05); the greenhouse gas intensity produced by RA was 11.76% lower than control CK. In summary, treatment RA, followed by RB, had the best effect in increasing rice production and reducing greenhouse gas emissions in paddy fields. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Two parameters that play the most important role in the appraisal of environmental risk performance at carbon dioxide (CO2) storage sites are the prospective impact of the pore pressure increase and CO2 saturation. In this context, this study investigates the spatiotemporal evolution of pressure buildup and CO2 saturation as a function of flow region's size, average porosity and permeability, and heterogeneity, as well as the injection rate and total volume of injected fluid. The practical importance of this study is to investigate the factors that affect the extent of pressure buildup and areal extent of CO2 plume both during and after injection, which will impact risk assessment as well as influence effective monitoring operations. This study pursues the above objective using two risk metrics that are based on numerical simulations and illustrated using representative models of three realistic storage sites with varying volumetric storage potential and geological settings, all with open geologic systems. The two metrics (the spatiotemporal extent of pressure buildup and CO2 saturation plume, respectively) used in this study are able to capture the geologic (structural and petrophysical) and operational complexities that cannot be incorporated into analytical or semianalytical solutions. The results of this study suggest that in addition to the average permeability, the areal extent of the pressure buildup during the injection period is strongly related to the injection rate, whereas the postinjection period may be more strongly influenced by the reservoir heterogeneity. The areal extent of the saturation plume during active injection is highly correlated to the mass of injected fluid, and the postinjection behavior is impacted by the shape of the reservoir–seal interface. These findings are consistent with other recent studies by the National Risk Assessment Partnership (NRAP) on characteristic reservoir behavior. The results have been used to generate pressure and saturation plume profiles (over time) that can be used to support risk‐based decision making. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Regional heterogeneity during low‐carbon economy development among provinces in China should be considered with more concerns by central government. Spatial coordination can bring more opportunities for underdeveloped provinces. Under this background, provincial low‐carbon economy transformation performance is evaluated during 2000–2016 and spatial characters are analyzed to supply detailed development information. Based on parametric input–output evaluation model and linear programming method, provincial low‐carbon economy transformation performance is evaluated. Spatial analysis methods such as Moran index, Moran scatter diagram, and Markov chain are implemented to analyze their spatial characters and dynamic trends. Main results are as follows: First, linear programing supplies reliable parameter results to evaluate the transformation performance. Mean value rises during 2000−2011 and there is a slight downward trend during 2013−2016. Economy transformation performance is still at lower medium level for most provinces nowadays and there is a long way to go further. Second, according to Markov chain results, more than 90% provinces exist as state self‐locking and less than 10% may exist as state jumping. Third, spatial correlation exists among provinces and ‘lower−lower’ type dominates with respect to low‐carbon economy transformation performance. They are mainly underdeveloped provinces in northwestern China. Absorbing greener production technology is the best choice for them. Yangtze River Delta provinces such as Shanghai, Jiangsu, and Zhejiang are of ‘higher–higher’ type. Regional cooperatives can exert lots of potentials and are beneficial to stimulate transformation performance. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The chemical absorption process for carbon dioxide (CO2) capture is a promising method to reduce greenhouse gas emissions in the energy industry. Worldwide applications of the CO2 chemical absorption process will consume plenty of chemical absorbents and have hazardous impacts on the environment. The development of renewable absorbents from biomass can not only fill the gap of absorbent production, but also provide a novel green approach to recycle the used absorbents into nature without additional pollution. In this review, we summarized several renewable absorbents available from biomass such as biomass ash slurries, alkanolamines, aqueous ammonia, and amino acid salts. The preparations, CO2 absorption capacities, advanced treatments, and applications of the renewable absorbents were also reviewed. Moreover, the advantages and challenges in the preparation of the renewable absorbents were discussed, as well as their CO2 absorption performance improvement. Finally, future research avenues into degradation and utilization of renewable absorbents in nature were suggested. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract We develop plume migration metrics based on spatial moment analysis methods that quantify the spatio‐temporal evolution of plumes at geologic CO2 storage sites. The metrics are generalized to handle any 3‐D scalar attribute field values. Within the geologic CO2 storage context, these can be parameters such as CO2 saturation, effective pressure, overpressure, dissolved CO2 concentration, total dissolved solids, pH, and other attributes that are critical for assessing risks. The metrics are comprehensive in that they can effectively handle and account for complex continuous and discontinuous plumes and intra‐plume migration. We demonstrate the metrics on simulated CO2 plumes injected into flat and tilted reservoirs with homogeneous and heterogeneous permeability fields. Using these idealized reservoir scenarios, we demonstrate the information that the metrics extract, showing that the metrics elucidate nuances in plume migration not apparent by standard approaches to the scalar fields values. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Description: Abstract Porous carbon fibers (PCFs) were prepared from porous polyacrylonitrile fibers by cross‐linking, oxidation, and carbonization. X‐ray diffraction patterns revealed that graphite structures as well as disordered carbon coexisted in the PCFs. Nitrogen content was more than 15.3 wt% with the variation of oxidation temperature, and a maximum value was obtained at 275°C. Nitrogen was quickly released with carbonization temperature. Compared with the fiber prepared at elevated carbonization temperatures, those owning high nitrogen contents deserved better carbon dioxide (CO2) adsorption performance in the simulated flue gas environment (10% CO2/90% N2). The CO2 adsorption had a better relationship with nitrogen content rather than specific surface area and pore volumes. Especially, nitrogen was very useful to enhance the CO2 adsorption of the fibers with low microporosity. The heat of CO2 adsorption was in the range of 39.8–54.6 kJ mol−1, which indicated good selectivity of CO2 adsorption. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Sulfur dioxide (SO2) and carbon dioxide (CO2) removals are of great significance for fossil fuel combustion, where they can be simultaneously captured by calcium‐based absorbents. Nevertheless, the CO2 uptake capacity declines with SO2 partial pressures. This paper aims at explaining the mechanisms of steam‐declined sulfation and steam‐enhanced carbonation by density functional theory calculations. CaO(001) surface is chosen as the absorbent, and the transition state is calculated to obtain the desorption barrier energy of the adsorbates. By analyzing the desorption of the adsorbate on pristine CaO(001) surface and the CaO(001) surface that has adsorbed other adsorbate, it can be concluded that SO2 adsorption inhibits CO2 adsorption since the barrier energy of CO2 desorption on SO2‐CaO(001) surface (24.15 kJ mol–1) is less than CO2 desorption on CaO(001) surface (129.52 kJ mol–1). By comparing the coadsorption energy of the two adsorbates with the sum of the adsorption energy of each adsorbate, it is practical that the H2O adsorption inhibits SO2 adsorption because the calculated coadsorption energy (−221.27 kJ mol–1) is larger than the sum of H2O adsorption energy (–100.00 kJ mol–1) and SO2 adsorption energy (−194.37 kJ mol–1). However, the calculated coadsorption energy of H2O and CO2 adsorption (−254.89 kJ mol–1) is less than the sum of CO2 adsorption energy (−144.23 kJ mol–1) and H2O adsorption energy (−100.00 kJ mol–1), indicating the promotion of CO2 adsorption. Steam in the adsorption process plays the roles of sulfation suppression and carbonation enhancement. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract CO2 storage in different geological formations has been recognized as one of the promising mitigation approaches to reduce the emission of CO2 into the atmosphere. There are many complex hydro‐chemo‐mechanical interactions (effective stress changes, water acidification, and mineral dissolution) that may take place in a storage site during or after injection, reducing the integrity of formations in the short or long term. Although there have been several studies carried out in the past to assess the feasibility of sandstones and limestone formations as a safe CO2 storage site, the effect of hydrological, mechanical, and chemical processes on the storage site integrity has not been deeply addressed. The aim of this study is to couple thermo‐hydro‐chemo‐mechanical processes upon CO2 injection and assess their impact on the key storage aspects of quartz‐rich sandstone and calcite‐rich limestone. A numerical model was built to simulate CO2 flooding into a saline aquifer with sandstone and limestone composition for 500 years. The results obtained indicated that geochemical activity and CO2 dissolution are significantly higher in limestone and may increase the porosity by ∼16%. During injection, a decrease in the reservoir strength was observed in both rock types upon exposure to CO2. A remarkable variation in the geomechanical characteristics was also revealed in the sandstone after injection. However, ground displacements (subsidence) of 0.0017 and 0.033 m were, respectively, observed in sandstone and limestone aquifers, at the end of 500 years. It is recommended to consider a high‐strength reservoir for carbon capture and storage (CCS) projects in order to reduce the likelihood of compaction. It was also found that both rock types have a good storage capacity, injectivity, and trapping potentials (the structural and dissolution trappings) to capture and hold CO2 in place. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The environmental problems caused by global warming have attracted close attention of governments and scientists all over the world. As the source and sink of atmospheric carbon dioxide, cropland soil plays an important role in the global carbon cycle. Paddy soil is a major component of global cropland, and there is growing research on its carbon sequestration potential. Based on the dynamic characteristics of soil carbon sequestration in cropland, this paper reviews and synthesizes the process and mechanism of soil carbon sequestration in cropland, discusses the driving factors of soil carbon sequestration in cropland from the perspective of crop management practices, and emphatically discusses the knowledge of soil carbon sequestration potential in paddy fields in China. The main conclusions are as follows: (1) The organic carbon content of cropland soil in China is obviously lower than the global average, and the current sequestration rate of paddy soil in China is obviously lower than the potential sequestration rate, which has great potential for carbon sequestration. Since the mid‐1980s, China's agricultural soil organic carbon (SOC) has been gradually increasing, especially the carbon sink effect of rice soil in southern China. (2) Soil and crop management practices such as conservation agriculture, irrigation, integrated nutrition management, straw returning, and crop rotation can improve input efficiency, increase SOC content in the soil carbon pool, and reduce greenhouse gas emissions. (3) The research on SOC fixation mechanism has entered the micro level of soil particles. The chemical protection mechanism of clay, the physical protection mechanism of aggregates, and the biological mechanism interact and influence each other. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Using a solid Na‐based sorbent is one potential option to decrease CO2 emission in coal‐fired power plants, and the CO2 sorption reactivity of Na2CO3/γ‐Al2O3 sorbent was improved by mechanically doping MgO into Na2CO3/γ‐Al2O3 in our previous study while the mechanism was not clear. In this paper, the CO2 sorption/desorption mechanisms of the promising MgO‐doped Na‐based sorbent prepared by the two‐step incipient wetness impregnation method were studied using a fixed‐bed reactor, together with characterizations of X‐ray fluorescence, nitrogen adsorption apparatus, field emission scanning electron microscopy, X‐ray diffraction, and thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG‐FTIR). Also, the sorption behaviors were well described with Avrami's fractional‐order kinetic model. Results demonstrated that MgO not only dispersed on γ‐Al2O3 but entered γ‐Al2O3’s lattice, leading to the formation of Mg‐Al mixed oxides for CO2 sorption. In addition, a new phase Mg6Al2CO3(OH)16·4H2O was produced during the CO2 sorption process, which plays a crucial role in facilitating the conversion of Na2CO3 to NaHCO3. The CO2 sorption capacity of MgO‐doped Na‐based sorbents is presumably determined by the trade‐off between microstructure and active component dispersion. The knowledge gained about the promotion mechanism of MgO provides fundamental direction for the synthesis of Mg–Al mixed oxides, supported with the developed microstructure for CO2 sorption enhancement of Na‐based sorbents. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Gravimetric techniques are used for monitoring the distribution and migration of CO2 stored in geological formations. Superconducting gravimeters (SGs), because of their high sensitivity, can enable continuous ground‐based monitoring of offshore CO2 storage. For offshore monitoring purposes, gravity stations should be located near the seashore to maximize the signal of interest. We observed gravity continuously with an SG near the seashore at the Tomakomai carbon dioxide capture and storage demonstration site in Japan to assess variation of the observed gravity and to evaluate the applicability of this technique for monitoring of large‐scale offshore storage. Strong noise caused by strong winds and ocean waves was removed by low‐pass filtering. The noise did not fundamentally affect long‐term gravity changes. The observed gravity was affected strongly by shallow groundwater level changes but the effects were sufficiently corrected by expressing their effects as a summation of linear functions of groundwater level changes. Considering all possible effects on gravity, the standard deviation of the gravity residuals during 85 days of observation was minimized to 7.5–8.2 nm s–2. Based on the model setting of the Tomakomai site, the estimated annual gravity changes caused by industrial‐scale injection (1 MtCO2 year–1) into a hypothetical offshore formation (1 km depth) were –2.8 to –3.3 nm s–2 under different saturation conditions. The estimated changes exceed the observed standard deviation in 2.3–2.9 years. These results suggest that injection‐induced gravity changes can be detected using SG within a few years. Therefore, the present ground‐based gravimetric technique can contribute to long‐term monitoring of offshore storage. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The main objective of this study is to investigate the relationship between the CO2 adsorption capacity and electrical resistivity of coal. The H‐Sorb 2600 high pressure gas adsorption analyzer is used to measure the CO2 sorption capacity in the temperature range of 25–55°C for anthracite coal. In addition, the TH2811D LCR meter is used to examine the electrical resistivity of raw coal samples and coal briquettes from 15°C to 65°C. The results indicate that there is a critical pressure threshold depending on the coal types and the pattern of changes in CO2 adsorption capacity changes when this threshold is exceeded. The electrical resistivity of raw coal samples decreases linearly and then slightly decreases at temperatures above 45°C and the electrical resistivity decreases approximately linearly from 15°C to 65°C for the coal briquettes due to lower compactness compared with the raw coal samples. The CO2 adsorption capacity has a power function with the electrical conductivity of the raw coal samples and coal briquettes. The power exponent of the power function is related to the porosity of coal. The results of the experiments indicate that it is effective to estimate the CO2 adsorption capacity of coal from the electrical conductivity. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Polymeric membrane technology applied to gas separation is seen as a valuable alternative to conventional systems due to its ease integrability with existing plant, its lower energy consumption, and its flexibility when scaling up. It constitutes a cheaper solution because, in accordance with the principles of process intensification strategy, realized with a reduced number of stages process. In this work, for the first time, a modified polylactic acid‐based polymer (PLA Easy Fil™ – White) was used to synthesize polymeric membranes for use in CO2 separation. This has the further advantage of adopting a biodegradable and non‐toxic material and environmental friendly. Dense symmetric PLA Easy Fil™ – White membranes (average thickness ∼ 27 μm) were prepared and characterized in terms of differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and Fourier‐transform infrared (FTIR) analyses and in single gas permeation tests to determine their perm‐selectivity at room temperature in the particular field of CO2/CH4 separation as an example of CO2 removal from raw natural gas or biogas. A CO2/CH4 ideal selectivity equal to 285 (corresponding to a CO2 permeability of 70 barrer) was obtained, overcoming the related Robeson's upper bound. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract This study examined the cost of adopting carbon capture and storage (CCS) as a technology when retrofitting current gas‐fired plants in Nigeria to reduce CO2 emissions. Studies show that Nigeria has abandoned or depleted oil fields; it has large coal reserves that are potential sites for CO2 storage. Five power plants with capacities of 1074, 675, 624, 480, and 191 MW were studied using the Integrated Environmental Control Model (IECM) 9.5. The IECM 9.5 was calibrated using available data and some default values to model the performance and cost of retrofitting the power plants. The transport and storage system chosen was pipeline and enhance oil recovery (EOR). The results show that net plant efficiency, CO2 emission rate, quantity of CO2 captured, and CCS energy penalty are 35.78 ± 1.69%, 0.0668 ± 0.0138 kg MWh−1, 0.4478 ± 0.0274 kg MWh−1, and 0.2588 ± 0.0386%, respectively. The results also show that total capital requirement, cost of electricity, and percentage increase in cost of electricity were 1888.2 ± 336.9 $ kW−1, 114.44 ± 10.15 $ MWh−1, and 52.04 ± 3.58%, respectively. In the same manner, the cost of CO2 avoided, cost of capture, and added cost of CCS were 84.442 ± 27.73 $ MWh−1, 60.02 ± 22.51 $ tonne−1, and 28.44 ± 10.16 $ MWh−1, respectively. Further analysis shows that it would be advantageous to retrofit 1074 MW plants because this has a 46.51% increase in cost, which is lower than the cost for the other retrofitted plants. The total CO2 emission rate dropped from 0.4282 ± 0.014 to 0.0668 ± 0.0138 kg MWh−1; this drop is significant as it shows that CCS can reduce the amount of CO2 emitted from Nigeria. The study recommends that CCS is a viable CO2 emission‐reduction alternative but incentives must be put in place to cushion the high cost of electricity. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Petroleum resource development is creating a global legacy of active and inactive onshore energy wells. Unfortunately, a portion of these wells will exhibit gas migration (GM), releasing fugitive gas (FG) into adjacent geologic formations and overlying soils. Once mobilized, FG may traverse the critical zone, impact groundwater, and emit to the atmosphere, contributing to greenhouse‐gas emissions. Understanding of GM and FG has increased in recent years but significant gaps persist in knowledge of (1) the incidence and causes of GM, (2) subsurface baseline conditions in regions of development required to delineate GM and FG, and (3) the migration, impacts, and fate of FG. Here we provide an overview of these knowledge gaps as well as the occurrence of GM and FG as currently understood in British Columbia (BC), Canada, a petroleum‐producing region hosting significant reserves. To address the identified knowledge gaps within BC, the Energy and Environment Research Initiative (EERI) at the University of British Columbia is implementing several field‐focused research projects including: (1) statistical analyses of regulatory data to elucidate the incidence and causes of GM, (2) characterization of regional hydrogeology and shallow subsurface conditions in the Peace Region of the Montney resource play, and (3) investigation of the migration, impacts, and fate of FG in the shallow subsurface through controlled natural‐gas release. Together, the EERI investigations will advance understanding of GM and FG, provide scientific data that can inform regulations, and aid development of effective monitoring and detection methodologies for BC and beyond. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Potential CO2 leakage from carbon capture and storage (CCS) facilities should be monitored and managed carefully. Biomonitoring technologies for CO2 leakage using plants could be very effective, especially in areas near transport pipelines, because of the extensive areas that they can cover. A greenhouse study was conducted to investigate whether early changes in plant parameters could be an effective indicator to detect leaked CO2. Corn (Zea mays), which was reported to be a CO2‐tolerant species, was selected to identify specific indicators of CO2 leakage. The mean soil CO2 concentration for soil treated with CO2 was 20–40%, which is similar to the concentration that could occur near transport pipelines through slow‐insidious seepage. In the soil treated with CO2, the number of yellow leaves at the canopy level was significantly increased from the sixth day of CO2 injection compared to the control. The chlorophyll content in green leaves was significantly reduced on the eighth day from CO2 injection. The soil water content in the treated soil was increased from the sixth day of injection due to reduced root adsorption. The results of this study implied that early changes in parameters of CO2‐tolerant species such as canopy‐level discoloration and chlorophyll content could be used as CO2‐specific indicators for the detection of soil CO2 leakage. We suggested that canopy‐level monitoring is a promising, useful technique for soil CO2 leakage in extensive areas, such as near CO2 transport pipelines. In addition, rhizosphere‐level parameters, such as soil water content, could be good subsidiary indicators together with the large‐scale collection of baseline data and statistical analysis. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Global climate change, especially global warming, has caused widespread concern in the international community. Increasing concentrations of greenhouse gases, such as carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) produced by human activities, are the main cause of global warming. According to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), agriculture is an important source of greenhouse gas emissions, so reduction of such emissions is of great significance to global climate change. There are many driving factors affecting agricultural greenhouse gas emissions. These factors are interrelated and interact with each other, so the mechanism of action is complicated. In this paper, first, the driving factors of agricultural greenhouse gas emissions and emission sources are introduced. Second, the factors influencing agricultural greenhouse gas emissions are analyzed and summarized. Third, to clarify the factors influencing agricultural greenhouse gas emissions, measures and countermeasures for reducing greenhouse gas emission are proposed, discussed, and compared. Finally, action mechanisms, action pathways, and long‐term reduction measures for agricultural greenhouse gases are described. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 1, Page 3-5, February 2019.

Description: Abstract The chlorinated tailing (CT) generated during titanium extraction from Ti‐bearing blast‐furnace slag contains 3–5 wt% chlorides, which are hazardous to the environment. In this paper, a process for simultaneous CO2 mineralization, dechlorination, and recovery of multiple value‐added products was proposed to fully utilize the CT. In this process, Ti, Al, Mg, and Ca are extracted in the form of their sulfates via roasting with recyclable (NH4)2SO4 followed by leaching with dilute H2SO4. Their extraction ratios are 83.1%, 87.4%, 89.4%, and 92.1%, respectively. The chlorides are simultaneously removed from the CT as gaseous HCl with a dechlorination ratio of 98.5%. Subsequently, 89.5% of the Al and 97.5% of the Ti in the leaching liquor are successively recovered as NH4Al(SO4)2·12H2O with a purity of 99 wt% and titanium‐rich material with TiO2 of 62.5 wt%. The CaSO4‐rich leaching residue and MgSO4‐rich leachate, after complete depletion of the Al and Ti, are separately carbonated with a mixed gas of CO2 and NH3 with total CO2 capacity up to 279.8 kg CO2 per tonne CT. The preliminary economic evaluation shows that income from selling products after the deduction of the cost of primary raw materials reaches 200 $/tonne CT. The proposed route therefore provides a cost‐efficient alternative for comprehensive utilization of the polluting CT. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In this research, the CO2 adsorption process was studied using modified activated alumina with a piperazine solution as a novel sorbent. Activated alumina was modified with a piperazine solution concentration in the range of 1–4 wt%. Adsorption experiments were performed to evaluate the operating parameters, including CO2 pressure in the range of 2–8 bar, adsorbent dosage in the range of 0.5–2 g, temperature in the range of 25–85°C and adsorbent mesh in the range of 200–800 micron. Maximum adsorption capacity (222.01 mg CO2/g modified activated alumina) was determined at a temperature of 25°C, pressure of 8 bar, and adsorbent dosage of 0.5 g, with a piperazine solution of 2 wt%. The results of the experiments showed that the rate of CO2 adsorption increases with increasing pressure and decreasing temperature. The Freundlich isotherm model with correlation coefficient of 0.999 was found to be the best for fitting the CO2 adsorption isotherm data. The kinetic study also indicated that the Elovich model fits the experimental kinetic data well. The negative values of Gibbs free energy change (ΔG°) and enthalpy change (ΔH°) show that the reaction is spontaneous in nature and exothermic. The negative value of entropy change (ΔS°) shows a reduction in the irregularity of the adsorption process. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The impact of long‐term CO2‐brine‐rock interactions on the frictional properties of faults is one of the main concerns when ensuring safe geological CO2 storage. Mineralogical changes may alter the frictional strength and seismogenic potential of pre‐existing faults bounding a storage complex. However, most of these reactions are too slow to be reproduced on laboratory timescales and can only be assessed using geochemical modeling. We combined modeling of CO2‐charged formation water and fault gouges (1–1000 years residence time, i.e. 10–106 pore volume flushes) with friction experiments on simulated fault gouges (T = 22–150°C; σneff = 50 MPa; Pf = 25 MPa; V = 0.2‐100 μm/s), having mineralogical compositions as predicted by the models. As an analogue for clay‐rich caprocks overlying potential CO2 storage sites in Europe, we used the Opalinus claystone. Our experiments showed that, although significant mineralogical changes occurred, they did not significantly change the frictional behavior of faults. Instead, initial fault‐gouge mineralogy imposed a stronger control on clay‐rich fault behavior than the extent of CO2‐brine‐rock interactions, even under chemical conditions allowing for significant reaction. We demonstrated that the impact of mineralogical changes due to CO2‐brine‐rock interactions on the frictional behavior and seismogenic potential of faults could be assessed using our combination of geochemical modeling and friction experiments. Note that a complete understanding requires evaluation of additional effects, such as that of shear velocity, effective normal stress, and other fault characteristics (maturity, shear strain). © 2018 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In this study, different concentrations of urea (0, 12.1, 30, 45, 61 and 80 mmol·L−1) were added separately, as external carbon sources, to a two‐stage vertical subsurface‐flow constructed wetland (VSSF CW) where Cyperus alternifolius L. was planted, with the aim of understanding methane (CH4) emissions driven by urea. Results indicate that the average CH4 emissions from a two‐stage VSSF CW were 6.88, 7.11, 6.22, 7.45, 5.06 and 2.80 mol·m−2·day−1, corresponding to urea concentrations of 0, 12.1, 30, 45, 61 and 80 mmol·L−1 added in the VSSF CW, respectively. Urea as a carbon source had an average of 31.57% of influent total organic carbon (TOC). It was transformed into CH4‐C, of which CH4‐C/TOCinfluent may be be considered as an important component when anthropogenic methanogenesis from treatment wetlands was driven by carbon sources or carbon loading. Methane emissions were at their lowest when the C/N ratio was 5.89, at a urea concentration of 80 mmol·L−1. Principal component analysis (PCA) indicates that CH4 correlated positively with temperature and redox conditions (Eh). Methane emissions driven by urea in the two‐stage VSSF CW were found to be in accordance with the second‐rate dynamics kinetic model (kinetic constant = 22.94 mg CH4·h−1, R2 = 0.99), which can be considered as a high level of CH4 emissions. It indicates that external carbon sources can influence CH4 emissions from two‐stage VSSF CW significantly. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract It sometimes feels that because The United Nations Framework Convention on Climate Change (UNFCCC) Conference of Parties is held just before the year end, there is sense of pressure for the meeting to finish in jubilant mood. Certainly the 24th Conference of Parties (COP 24) was launched with an air of expectation. But one of the stand out features of the meeting was the continued and serious debate on carbon capture utilisation and storage (CCUS). In this feature article, GHGS&T's Muriel Cozier rounds up a few of the main points on a climate technology that might just be about to come of age. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract An understanding of CO2 sources, sinks, and their optimal matching relationships is helpful when making an initial assessment or making decisions regarding CO2 sequestration. One of the most populous and developed provinces in China, Jiangsu, is facing tremendous pressure to reduce CO2 emissions. This study assessed CO2 emissions from large, stationary CO2 sources and the CO2 geological storage capacity for the Jiangsu province, and studied their optimal geographical matching relationships. The results of the study show that major, large, stationary sources have a total of 730.75 Mt/year CO2 emissions, and the majority of them are located in southern Jiangsu. The Subei‐Southern South Yellow Sea basin, with a total storage capacity of 5.21 × 104 Mt, can be subdivided into 28 storage blocks based on the faults. Source‐sink geographical matching shows that the locations of the sources and the matched sinks are approximately translational. When the entire Subei‐Southern South Yellow basin was chosen as an option for CO2 sinks, the sinks that matched to the northern Jiangsu CO2 sources were mainly located in the onshore northern Subei basin. The northern sources tended to match the north sinks of the northern Subei basin. The CO2 from the southern Jiangsu should be stored in the southern Subei basin and the offshore Southern South Yellow basin. When only the offshore storage blocks are optional CO2 sinks, the CO2 sources in the northern and central Jiangsu mainly match the sinks in the northwestern Southern South Yellow basin. The CO2 sources from southern Jiangsu mainly match the sinks in the southern and eastern Southern South Yellow basin. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Sites where anthropogenic CO2 captured from industrial sources is stored in deep geological formations for climate change mitigation are required to show secure retention of the injected CO2. Monitoring, reporting, and verification (MRV) plans are needed to indicate that no CO2 release has occurred. We explored the degree to which direct comparison between a surface anomaly and reservoir geochemistry using various geochemical parameters can be used for attribution. We used data collected on light hydrocarbons and noble gases throughout the sedimentary column at three CO2 enhanced oil recovery (EOR) sites to understand the processes that may cause fluid evolution. Light hydrocarbon and noble gases were sampled from reservoirs, gas‐bearing intervals above reservoirs, and groundwater. Vertical profiles indicated that lighter components are relatively enriched during migration (i.e. chromatographic separation). Static and numerical models were designed to simulate episodic gas migration and geochemical alteration of these geochemical parameters from solubility and sorption. The effects of hydrocarbon solubility were minimal (Bernard ratio changes within 5.2%) although field data were within the range of expected alterations from sorption. Forward models of CO2 migration and noble gas interactions showed that CO2 stripping causes an enrichment of crustal noble gases. In areas where natural fluxes of CO2 from depth are non‐existent, the occurrence of crustal noble gas signature may distinguish fugitive CO2 from the reservoir from natural near‐surface sources, and could be considered to explain apparent fluid anomalies. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Mixed matrix membranes (MMMs) comprised of organic selective polymers and inorganic nano‐particles under the name of fillers have attracted much attention in the field of gas separation. In this study, poly (amide‐6‐b‐ethylene oxide) [PEBA]/Fe2O3 mixed matrix membranes were prepared using the dry phase separation technique with ethanol / water (70/30 wt%) as solvent. Various amount of Fe2O3 nanoparticles were chosen to disperse within the polymer matrix (0, 0.5, 1, 1.5 and 2 wt% of polymer). To prepare this type of novel membrane, a magnetic field of 0.3 T was used to align the position of NPs. The structural properties and surface morphology of prepared membranes were characterized by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Field emission scanning electron microscopy analysis was also used to study the physical bonding. Phase identification and crystallinity, effective area, and distribution of pore size were investigated by X‐ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) analysis. Carbon dioxide permeability through these membranes increased with pressure in the range of 2 to 14 bar. Magnetic membrane loaded with 1.5 wt% of Fe2O3 gave the best performance: CO2 permeability, CO2/CH4, and CO2/N2 selectivity were enhanced by 30, 42 and 81%, compared to a pure membrane, respectively. The results indicated that the magnetic MMMs gave better separation performance than pure membranes. Molecular simulation has also been used to investigate the structural and transport properties of fabricated membranes. Structural characterizations like radial distribution function (RDF), fractional free volume (FFV), and X‐ray diffraction were applied to the simulated membrane cells. Grand canonical Monte Carlo (GCMC) and molecular dynamic (MD) simulations, were used to calculate the selectivity and diffusivity of membranes. Results from experimental tests and simulation runs revealed that the selectivity and permeability of fabricated and simulated membranes are consistent. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The carbon dioxide post‐combustion capture process using amine solutions is considered the most appropriate method for CO2 capture from flue gas in power plants. This paper focuses on the CO2 capture performance of six common organic amines. Two amines, piperazine (PZ) and diethylenetriamine (DETA), which showed better performance, were then filtered out to form amine blends to improve performance further. The absorption heat from the CO2 absorbing process was measured directly using an advanced C80 micro calorimeter for more accurate calculation of regenerative energy consumption. Experimental results confirmed the optimal amine blend to be 10% PZ plus 20% DETA, with a 42% increase in absorption capacity and a 9% increase in initial absorption rate compared to traditional 30% monoethanolamine (MEA). The regeneration energy consumption of this chosen PZ‐DETA blend was calculated to be 3.979 GJ/ton CO2, a decrease of 9% compared with MEA. Moreover, it led to an improvement of about 55% in stable cyclic absorption capacity in comparison with 30% MEA. It was confirmed that this PZ‐DETA blend can bring practical economic benefits to industrial applications when replacing the current 30% MEA solution. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon dioxide (CO2) extraction from deep reservoirs is currently important in CO2 enhanced oil recovery (EOR) and may become more important in the future if interim CO2 storage becomes common. In late 2014, we were involved in a production test of liquid CO2 from the Middle Duperow dolostone at Kevin Dome, Montana. The test resulted in lowering the temperature at the well bottom to ∼2 °C, and showed that the well and reservoir had very low CO2 productivity. We have used the CO2 modeling capabilities of the TOUGH codes to simulate the test and to show that liquid CO2 in the reservoir changes to gas phase as the pressure is lowered in the well during production testing. The associated phase change and decompression combine to drastically lower the bottom‐hole temperature, creating the potential for water ice or CO2 hydrate to form. By hypothesizing a relatively high‐permeability damage zone near the well surrounded by lower permeability reservoir rock, we can match the observed pressure, temperature, and production rate. Moving from the Kevin Dome test to the question of CO2 extraction from deep reservoirs in general, we carried out a parametric study to investigate the effects of reservoir depth and transmissivity on CO2 production rate for a prototypical reservoir. Simulations show that depth and high transmissivity favor productivity. Complex phase changes within the ranges of P‐T encountered in typical CO2 production wells affect production rates. The results of our parametric study may be useful for the preliminary feasibility assessment of CO2 extraction from deep reservoirs. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Global climate change resulting from substantial CO2 emissions is increasingly attracting attention, and coal‐fired power plants are a major source of CO2 emission, so it is necessary to control and reduce CO2 emissions from power plants. Using alkali‐based solutions for CO2 capture is thought to be an effective method to achieve this but poor CO2 sorption/desorption kinetics inhibit its development. The use of nanofluids, prepared by adding nanoparticles to an alkali‐based solution, is a promising way to improve CO2 sorption/desorption reactivity because the addition of nanoparticles not only improves the gas‐liquid mass/heat transfer but also enhances the reaction kinetics. In this paper, a nanostructured Cu/TiO(OH)2 was prepared and used to accelerate the CO2 sorption/desorption performance of a potassium‐based solution. The CO2 sorption/desorption reaction rates increased with the thermal conductivity of the nanofluid but the inclusion of more nanoparticles resulted in particle sedimentation. The potassium‐based solution containing 0.014 vol% of the nanostructured Cu/TiO(OH)2 was therefore the targeted nanofluid that gave the best CO2 sorption/desorption performance and cyclic stability. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon dioxide (CO2) can be at risk of leakage during its storage in deep saline aquifers due to stress field changes in the reservoir. The aim of this study was to investigate the effects of CO2 injection pressure on dynamic strain response of the reservoir and the CO2 migration process. A series of core flooding experiments was performed with the‐state‐of‐art fiber Bragg grating sensors. The results show that the surface strain response was linearly correlated with CO2 injection pressure. Carbon dioxide migration velocity can be estimated from the strain response time differences among three gratings. The migration velocity of supercritical CO2 is higher than that of liquid CO2 but lower than gaseous CO2. Finally, numerical simulation was applied to model the CO2 migration process and the simulated values were compatible with those of experiments. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 1, Page 1-2, February 2019.

Description: Abstract Salt caverns have been identified as one of the best options for the underground storage of gases due to salt rock's excellent sealing capabilities and interesting mechanical properties, such as self‐healing when damaged or cracked. It is feasible to build salt caverns in the Brazilian pre‐salt ultra‐deep water environment for gas storage. However, the peculiar geology of the Brazilian province considered here is characterized by the stratification of thick layers of halite with intercalations of carnallite and tachyhydrite salt rock, whose creep strain rate is almost two orders of magnitude higher than halite's creep strain rate under the same conditions of temperature and pressure. Computational mechanics is being used for the design of offshore salt caverns opened by dissolution mining for the storage of natural gas. The challenge presented in this paper requires the storage of natural gas with high CO2 content offshore in ultra‐deep water (2140 m) in salt caverns. If the economics proves feasible, this offshore gas storage station will be the first of its kind in the world. A technical feasibility rock mechanics study of giant salt caverns, 450 m high by 150 m in diameter, has shown that one cavern can store 4 billion Sm3 or 7.2 million tons of CO2. The salt dome studied can accommodate the construction of 15 caverns, thus providing the confinement of approximately 108 million tons of gas. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The study of the frosting behavior of CO2 in the binary CH4‐CO2 is very important for energy minimization and for the smooth operation of the cryogenic purification process for natural gas due to its extensive cooling requirements. The present study focuses on the solid region of the phase envelope and the development of a predictive model using the artificial neural network (ANN) technique. It validates the model using available experimental data. The model points out the outlying data points. The ANN prediction method developed in this work can be successfully used for the vapor‐solid (V‐S) and vapor‐liquid‐solid (V‐L‐S) equilibrium of a CH4‐CO2 binary mixture for CO2 concentration of 1 to 54.2% and a temperature range of −50°C to −200°C. The use of the model for the liquid‐solid (L‐S) region in its current form is not recommended because the model was not validated due to lack of experimental data in this region. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Oxy‐fuel combustion in coal‐fired plants has become one of the most promising technologies for carbon capture and storage (CCS). Because of the obvious difference between the oxy‐fuel combustion medium (O2/CO2) and air in the atmosphere (O2/N2), the characteristics of combustion, heat transfer, etc., under oxy‐fuel combustion have changed greatly from those under air combustion. In this paper, computational fluid dynamics (CFD) simulation was used to investigate pulverized coal combustion in a 200 MWe tangentially fired oxy‐fuel combustion boiler. Improved models for the gas radiative properties and chemical reaction mechanisms were incorporated into the CFD code. Both conventional air‐fired and oxy‐fuel combustion were operated. Different flue gas recycling patterns (dry recycling and wet recycling) were also investigated. The temperature distribution in the furnace, the temperature field, and the CO concentration field in each scheme were analyzed, this being relevant to the design of oxy‐fuel combustion boilers. It was found that combustion could form a good tangential circle and stable temperature field in the furnace either under air‐fired or oxy‐fule combustion conditions. The temperature under oxy‐fuel combustion was lower than with air combustion. The burnout rate under the air condition was lower than that with the oxy‐fuel combustion condition. With oxy‐fuel combustion, it is necessary to pay special attention to the slagging tendency of the primary combustion zone in the furnace. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract This paper deals with greenhouse gas (GHG) emissions originating from changes in the waste sector in developing and transitional economies. Using a Serbian case study, the effects of different waste disposal techniques on GHG emissions were analyzed in three scenarios: the current one, the worst one, and the best one. According to the Serbian national‐waste management strategy, a large number of dumpsites and unsanitary landfills should be merged into several regional sanitary landfills. Results obtained from the SWM‐GHG Calculator have shown potentially higher emissions from modern regional landfills than from dumpsites. Related environmental policy should therefore be analyzed in detail and applied. Environmental policy options are analyzed using the SWOT technique. The policy option to be implemented depends on country‐specific circumstances, such as the adequate functioning of institutions, the effectiveness of the judicial system, the established legal framework, and the general level of competence in the waste management sector. If all of these conditions are in place, the ‘polluter pays’ option is the superior one. However, if the level of knowledge and capacity in waste sector is low, and if there are no adequate institutions, or if the judicial system is inefficient, the first option appears to be the right one. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon capture, utilization and storage (CCUS) technology includes three sub‐systems of CO2 capture: transportation, utilization, and storage. Pipeline transportation is the middle link of CCUS, and its optimization is closely connected with the other two sub‐systems. However, technical and economic parameter uncertainties strongly affect the optimal pipeline cost, which creates a need for flexibility in pipeline design. To solve the flexible optimization design problem in CO2 pipeline transportation, this paper proposes an interval number optimization algorithm. Average levelized cost and system robustness are given as the optimization objectives. A two‐objective, two‐level, two‐step optimization problem is established and solved using a quantum genetic algorithm (QGA). The proposed interval number optimization algorithm makes the optimization process with good decision space, the decision makers can flexibly make decisions based on experimental analysis and subjective preference, and the designed pipeline transportation is flexible and can be combined with the optimization of the other sub‐systems. It can also attain the goal of coordination and unification of CCUS optimization. Numerical studies show that the proposed method can solve the flexible optimization problem effectively in the presence of uncertainties. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Aqueous ammonia‐based post‐combustion carbon capture (PCC) is a well recognized and leading technology for the reduction of CO2 emissions from coal‐fired power stations. Despite its many techno‐economic advantages over its counterparts, there are still a few major challenges that could prevent its large‐scale adoption. This model‐based study addresses the most common problems of solid precipitation at the stripper overhead and ammonia slipping with the product CO2. We propose using a direct contact condenser (DCC) to replace the conventional gas / liquid heat exchanger (HX) at the stripper overhead. Three scenarios were proposed and assessed for DCC configuration: open, closed, and combined DCC circuits. It was found that combined‐circuit DCC could better enhance the CO2 product's purity, bringing its temperature to the nominal target, and producing less condensate, which is diluted and easier for downstream integration. Most important, this configuration can effectively eliminate ammonia slipping in the product line and solid precipitation at the stripper overhead. Validating these improvements at our current pilot plant would bring tremendous benefits for the commercialization of this technology. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Ethanolamine (MEA) solution is the most commonly used commercial chemical absorbent in conventional CO2 postcombustion processes; however the high heat duty and reaction temperature (e.g. 125°C) for solvent regeneration leads to high energy requirements (approximately 70–80% of the total running cost). This paper reports a catalytic solvent regeneration of a CO2‐loaded MEA solution using industrial calcined rough metatitanic acid (TiO(OH)2) as the catalyst to improve the CO2 desorption rate and reduce the regeneration temperature to 95°C. The catalytic reaction parameters were systematically investigated with an improvement in the CO2 desorption rate of 28.9% in comparison with the non‐catalytic process. The results of characterization, such as the thermogravimetry analysis, X‐ray diffraction, N2 adsorption‐desorption, pyridine‐infrared spectroscopy (Py‐IR), showed that the Lewis acid of the industrial metatitanic acid played a major role in the decomposition of carbamate and in enhancing the regeneration rate of MEA solvent in a CO2‐rich MEA solution. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Mineral carbonation is an important technical option for the effective reduction of CO2 emissions. Natural magnesium‐containing minerals, such as serpentine and blast furnace slag (BFS), have recently been used for CO2 storage with an indirect carbonation route using ammonium sulfate. In this study, the effects of the feeding mode and process parameters on the magnesium conversion, product phase, and morphology during the aqueous carbonation of MgSO4 with ammonium carbonate solution were investigated in detail. The results showed that the carbonation ratio with a parallel feed was higher than the forward and reverse feed by about 3–5% with a limited reaction time, and the product size was more uniform. The phase and morphology of the products were affected significantly by the temperature. The highest carbonation ratio appeared at 40°C because only 75% of magnesium was carbonated if hydromagnesite was produced. When the mole ratio of (NH4)2CO3 to MgSO4 was 2:1 and the concentration of magnesium sulfate was higher than 0.4 mol·L−1, the carbonated products contain ammonium magnesium carbonate, and the ammonia should be recovered by selective thermal decomposition. When the mole ratio decreased to 1.5:1, only nesquehonite appears with high crystallinity and uniform size. The optimized conditions were therefore selected as 40°C, a mole ratio of 1.5:1, and magnesium sulfate concentration of 0.7 mol·L−1. Under these conditions the carbonation ratio reached 88%. Additionally, the optimal initial pH of MgSO4 solution was 9.5 (the product was nesquehonite at low pH) while the hydromagnesite will be produced at higher pH (pH more than 10). © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon dioxide emissions to the atmosphere lead to global warming and unpredictable climate change via the greenhouse effect. Carbon dioxide from industrial sources can be captured by the membrane separation technique to mitigate the greenhouse effect. In this research, a polymer solution was prepared by blending a cellulose triacetate (CTA) polymer with a tri‐n‐butyl phosphate (TBP) additive. The polymer solution was coated on an alumina (α‐Al2O3) tube, which acted as a support material, to prepare a composite membrane for the CO2 separation. The composite membrane that was prepared was characterized by Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermo‐gravimetric analysis (TGA), and differential scanning calorimetry (DSC) analyses. The CO2 permeance and the selectivity for the prepared composite membrane were evaluated using a constant pressure‐variable volume method. The influence of the concentration of CTA and TBP, polymer solution preparation time, number of sequential dip coating, and the feed gas pressure on the CO2, N2, and CH4 gas separation performances was examined. The highest CO2 permeance of 129 GPU and the selectivity of 19.9 versus N2 and 10.6 against CH4 were obtained for the pure gases, and a CO2 permeance of 116 GPU and selectivity of 17.1 against N2 were obtained for a mixture of gases (15% CO2/85% N2). © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Saline aquifers are the largest potential continental geologic CO2 sequestration resource. Understanding of potential geochemically induced changes to the porosity and permeability of host CO2 storage and sealing formation rock will improve our ability to predict CO2 plume dynamics, storage capacity, and long‐term reservoir behavior. Experiments exploring geochemical interactions of CO2/brine/rock on saline formations under CO2 sequestration conditions were conducted in a static system. Chemical interactions in core samples from the Lower Tuscaloosa formation from Jackson County, Mississippi, with exposure to CO2‐saturated brine under sequestration conditions were studied through six months of batch exposure. The experimental conditions to which the core samples of Lower Tuscaloosa sandstone and Selma chalk were exposed to a temperature of 85°C, CO2 pressure of 23.8 MPa (3500 psig), while immersed in a model brine representative of Tuscaloosa Basin. Computed tomography (CT), X‐Ray diffraction (XRD), Scanning Electron Microscopy (SEM), brine chemistry, and petrography analyses were performed before and after the exposure. Permeability measurements from the sandstone core sample before and after exposure showed a permeability reduction. No significant change of the permeability measurements was noticed for the core sample obtained from Selma chalk after it was exposed to CO2/brine for six months. These results have implications for performance of the storage interval, and the integrity of the seal in a CO2 storage setting. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Description: Abstract Carbon dioxide mineralization for the disposition of blast‐furnace slag is an important method for reducing CO2 emissions and simultaneously dealing with solid waste from the steel industry. However, due to the stable structures and properties of blast‐furnace slag, low mineralization reaction efficiency is a key issue in this process and hinders industrial applications. This work presents a method for enhancing the CO2 mineralization reaction by the addition of salt solutions (e.g., NaCl 1 mol · L−1) in the slurry of the blast‐furnace slag (〈75 μm). The results showed that CO2 mineralization efficiency could be greatly improved with a high CO2 storage amount of ∼280 kg CO 2 · tBFS−1 at a liquid‐solid ratio (L/S ratio) of 10, a temperature of 150°C and CO2 pressure of 3 MPa. The mineralization process was systematically characterized to identify the mechanism for mineralization enhancement by saline solution. The results indicated that saline solution could accelerate the dissolution of Ca2+ in blast‐furnace slag, reduce the activity of water, and lead to high acidity in the solution, and thus facilitate mineralization and improve the reaction rate. The NaCl solution was not consumed and could be recycled in the process, suggesting that this approach could use the brine and saline water as the medium for solid waste treatment and CO2 emission reduction in high energy‐consuming industries such as mineral processing, power plants, and the steel industry. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Rational prediction of the extension limit of a horizontal well under the condition of supercritical carbon dioxide drilling can ensure drilling security for developing unconventional oil and gas resources. Based on the physical property of supercritical carbon dioxide and the mechanics theory on the rock surrounding the wellbore, the extension limit model of a horizontal well under the condition of supercritical carbon dioxide drilling has been established, which can analyze the flow distribution in the horizontal well and the influence of the azimuth angle, the bedding dip angle, drilling parameters, and so on. The result shows that when the supercritical carbon dioxide is flowing in the borehole, the pressure at the horizontal section at 3320 m is 2.21 MPa lower than the pore pressure, which is in the safe pressure range of underbalanced drilling (∼0–3 MPa), and the wellbore is stable. The extension limit changes periodically as the azimuth angle increases. Under actual working conditions, reducing the inlet mass flow rate or wellhead back pressure within a safe range helps to increase the extension limit. The maximum extension limit of a horizontal well with supercritical carbon dioxide drilling is 8081 m in the paper, which is longer than that of clear water drilling under the same condition due to low pressure loss. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Identifying the impact factors of CO2 emissions is the basis of economic‐related CO2 emission analysis. In this study, we used the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model to investigate the extent of influence of each impact factor on the CO2 emissions of Ordos Basin, a typical heavy industrial region and the largest coal production area of China. A new parameter, exhaust gas treatment costs ratio (R), was introduced into the STIRPAT model to examine the relationship between abatement investment and CO2 emissions. The impact factors that were positively associated with the CO2 emissions of Ordos Basin (and the corresponding coefficient values, from the largest to the smallest) were the population count (1.0449), property of secondary industry (0.8366), energy intensity (0.7672), GDP per capita (0.7598), property of tertiary industry (0.6978), and urbanization level (0.4641). The only negatively associated parameter was the exhaust gas treatment costs ratio, which had a coefficient value of −0.1339. In addition, the technological factors (i.e., energy intensity and exhaust gas treatment costs ratio) could be used as indicators of CO2 emission control. This study systematically investigated and discussed the impact factors of CO2 emissions in coal‐producing areas, to gain insight into the emissions’ characteristics and to lay a foundation for CO2 reduction in such regions. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon dioxide (CO2) injection into geological formations is pointed out as one of the most effective alternatives to reduce anthropogenic CO2 emissions to the atmosphere. To promote long‐term CO2 storage, wellbore integrity is a critical issue to be considered. Portland cement is commonly used for cementing wells, and considered chemically unstable in CO2‐rich media. In this context, this study investigated the CO2 chemical resistance of class G Portland cement modified with novel additives (epoxy resins, epoxy–clay composites, and clay minerals) at 1 and 2.5 wt% contents. Reaction times of 7 and 30 days of exposure to CO2 in supercritical conditions were evaluated. Samples were characterized by mechanical compression tests and phenolphthalein indicator as well as field emission scanning electron microscopy in order to determine the depth of carbonation in cement. Our results indicate that although there is slight reduction in the initial compressive strength, the addition of tested additives to cement paste offers improvements in terms of chemical resistance. The optimum content of different additives was 1 wt% in order to maintain compressive strength properties and improve chemical resistance to CO2. The best result was achieved with an epoxy resin blend as an additive, decreasing carbonation by up to 60% (7 days of exposure to CO2) and 52% (30 days of exposure to CO2). Addition of montmorillonite to the epoxy blend tends to improve chemical resistance of cement paste when compared to the neat epoxy blend. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In this study, a feasibility analysis of a solar‐assisted transcritical Rankine cycle working with carbon dioxide (CO2) is performed for Isparta, Turkey, in comparison with Kyoto, Japan, conditions. For the analyses, the characteristics of the system are adapted from the actual experimental research conducted at Doshisha University, Kyoto, Japan. In order to evaluate the performance of the CO2‐based integrated system, a mathematical model is established for the evacuated solar collectors. Energy and exergy analyses are carried out using the solar energy data of both cities. According to the simulation results, the average turbine power capacities are determined as 0.415 and 0.396 kW, while the average heat recovery capacities are calculated as 2.10 and 1.89 kW for Isparta and Kyoto, respectively. The yearly electricity generation for Isparta conditions is found to be about 40% higher than the Kyoto conditions with 1138.09 kWh. The results of second law analyses are showed that the highest exergy destruction rate occurs in August for Isparta conditions with 8.18 kW due to the higher solar radiation rates. From the results, it appears that the CO2‐based next‐generation solar‐assisted power and heat generation system can be established and utilized in Isparta more effectively. The future research should, therefore, concentrate on moving the actual experimental setup to Isparta for field test experiments. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 6, Page 1081-1083, December 2019.

Description: The cover image is based on the Review Utilization of mineral carbonation products: current state and potential by Caleb M. Woodall et al., https://doi.org/10.1002/ghg.1940. Cover image © Caleb M. Woodall, Noah McQueen, Hélène Pilorgé and Jennifer Wilcox Images.

Description: Abstract The words ‘high level’ and ‘carbon capture and storage’ (CCS) are beginning to crop up in the same sentence more frequently. CCS has indeed made its way into the high‐level discussions on which tools need to be deployed to mitigate climate change. In this article GHGS&T's Muriel Cozier reviews the European High Level Conference on Carbon Capture and Storage and looks to see if CCS has, at last, come of age. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Past reservoir simulations of carbon dioxide (CO2) storage in saline aquifers have shown that the injection procedure can influence CO2 storage efficiency and injectivity. To investigate the influence of injection rate and timing on reservoir dynamics and storage performance, scenarios of continuous and intermittent injections were devised for storing 1 million tonnes of CO2 per year for 30 years and were assessed through numerical simulations on saline aquifers constructed with real field data. Our results show that almost all the intermittent injections need higher injection pressure than the constant injection for the same targeted amount of CO2. Only one intermittent injection showed the potential to have a lower injection pressure than the constant injection. The injectivity for the constant injection consistently declines over the years, while the intermittent injections result in an injectivity above a reference value for some years, with the number of years that maintain the injectivity linearly increasing with the length of the injection break. The injectivity for an intermittent injection peaks a few years later after the injection starts. Intermittent injections improve the residual and solubility trapping by up to 15% only in the first few years of injection, but the differences in trapping efficiencies among all the injections are within a few percent in the long term. Therefore, the intermittent injections would be useful for a CO2 storage project to make the best use of a reservoir in 5–10 years under the injection pressure restrictions. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Monoethanolamine (MEA) solution has been used widely in the post‐combustion CO2 capture process; however, the high heat duty and reaction temperature (e.g. 125°C) for MEA regeneration leads to a high energy requirement (nearly 70–80% of the total running cost). We report the use of solid particles (H‐Zeolite Socony Mobile‐5 (HZSM‐5), quartz, and activated carbon) to facilitate the mass transfer of CO2 bubble nucleation and enhance the CO2 desorption rate. The results show that the mass transfer of CO2 from liquid phase to gas phase is the rate‐determining step, rather than the chemical reaction. The addition of HZSM‐5 particles in the solution significantly enhanced CO2 bubble nucleation by providing nucleation sites and gas cavities, leading to an average CO2 desorption rate enhancement of 43.2%, and an energy consumption reduction of 23.3%. This process also operated at ∼95°C, which is a much lower temperature than that used in the commercial process and is feasible for industrial applications. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract CO2 flooding is essential for significantly enhancing oil recoveries and long‐term CO2 storage. We performed CO2 flooding experiments on target tight cores obtained from Honghe oilfield to investigate the water–rock interaction during CO2 flooding. In addition, we investigate the impact of mineralization and CO2 injection patterns on the sweep efficiency and CO2 long‐term storage using numerical simulations. Results show target core samples are composed of calcite, quartz, Na‐feldspar, and K‐feldspar. In particular, the main water–rock interactions during CO2 flooding are calcite and Na‐feldspar dissolution. The impact of water–rock interactions on the reformation of the matrix is not significant. However, such water–rock interactions will decrease the permeability of the natural fracture system near injection wells, which will lead to the enhancement of CO2 flooding efficiency in fractured formations. In addition, results show that water alternating gas injection will enhance oil recovery and CO2 primary storage. After CO2 flooding, mineral‐trapped CO2 is only 0.53wt.% of the total CO2 storage. As the flooding time increases, the mineral‐trapped CO2 increases. Results show that mineral‐trapped CO2 is 31.08% of the total CO2 storage at the simulation time of 500 years. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract In this paper, a novel comprehensive permeation model for mixed matrix membranes (MMMs) is introduced. This model shows the importance of understanding and developing a more reliable model for the permeation behavior of MMMs containing porous filler nanoparticles. A new method is established to provide a more precise/large‐scale three‐dimensional MMMs geometry. The required number of spherical porous fillers in random/nonuniform positions in the polymer matrix is calculated. Interfacial equilibrium constant (K) at the polymer/filler interfaces was adjusted as the concentration ratio of the diffusing penetrants (C2 and C1) at the interface, respectively. In this case, the K values are changed by varying the intended gaseous concentration due to their permeation through the MMM. Hence, its effect on penetrants effective diffusion coefficient was examined. Then, the obtained results were evaluated with similar experimental data, which showed much consistency. Therefore, the accurate calculation method for MMMs permeability was governed for the entire range of the operating pressures in MMMs. The results showed that the permeability of MMMs increases with increasing filler particle size. On the other hand, variations that occur in the MMM permeability at various particle size were much more distinct at higher loadings. Moreover, some well‐known analytical permeation models were used to compare and validate the model's permeability results. It can be concluded that this model provides a method for more precise and realistic design of MMMs as well as to better construe the large number of related experimental data. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The microbial‐induced calcite precipitation (MICP) process for ground improvement uses microorganisms to hydrolyze urea, producing carbonate ions to induce in situ calcium carbonate (CaCO3) precipitation in soil to improve its strength. This paper proposes using the hydroxide‐based absorption of CO2 instead to provide the carbonate ion source. This study utilizes direct air capture (DAC) to absorb atmospheric CO2 using potassium hydroxide (KOH) in a semi‐batch bubble absorption column. Potassium carbonate (K2CO3) was then injected into sand with calcium hydroxide (Ca(OH)2 as a calcium source to precipitate CaCO3 and regenerate KOH. Batch and continuous flow precipitation methods produced a poor distribution of CaCO3, with more CaCO3 precipitated on top, resulting in unconfined compressive strength (UCS) of 6.9 to 19.6 kPa. Sand pre‐mixed with Ca(OH)2 gave well distributed CaCO3, precipitated throughout the sample with 7.56 wt% and 6.87 wt% CaCO3 content and UCS of 39.2 and 35.3 kPa before failing for batch and continuous flow precipitation respectively. This differs from MICP strength improvement of 1000 kPa with 5.3 wt% CaCO3 due to poor binding of sand with the precipitated CaCO3 crystals. However, this application provides a stable sequestration source for atmospheric CO2 in soil. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract It is important for researchers to look at alternative fuels to reduce dependence on fossil fuels as a primary source of energy, to protect the environment, and to reduce greenhouse‐gas emissions. An alternative fuel has to be environment friendly and economically viable, both in terms of production and suitability for the modern world. Fuel derived from biomass has long been viewed as a potential replacement. First‐generation biomass‐derived fuels such as bioethanol and biodiesel have already been competing with conventional fuels, assisted by legislation. This review paper assesses the feasibility of adapting and incorporating second‐generation advanced biofuel production technology for the thermochemical conversion of biomass to produce alternative fuels. The conversion technologies considered here are pyrolysis and gasification, and their potential has been examined using techno‐economic assessment (TEA). A brief overview of different business models that can be incorporated during TEA has also been discussed. Techno‐economic assessment data help in determining costs of technologies if they are employed on a commercial scale, especially in terms of per unit cost of product. The review has compiled the technical and economic data available for assessing the types and combination of processes that can assist competitiveness in the existing market. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Hydration of the spent calcium‐based sorbent from calcium‐looping can improve its inadequate pore characteristics. The hydrated sorbent can be used for desulfurization before calcium‐based looping, which decreases the SO2 concentration in the flue gas entering the calcium‐based looping and also decreases the cost of CO2 capture. The effects of hydration time, hydration temperature, and liquid‐solid ratio on the reactivation performance of a hydrated spent calcium‐based sorbent were studied using spent calcium magnesium acetate (CMA) in this study. Fractal analysis based on the pore structure data of the hydrated sorbents was also conducted, and the relationship between the fractal dimension and the desulfurization performance of the hydrated spent sorbents was also investigated. The results showed that the sulfation conversion rate of the hydrated spent CMA decreased slowly at first, and then increased with hydration time. The conversion rate also increased with the hydration temperature but it decreased with the liquid‐solid ratio. The maximum sulfation conversion of the hydrated spent CMA under the optimized conditions was 68.0%, which approached that of fresh CMA. Compared to that of spent CMA, the sulfation conversion increased by 53.3%. The spent CMA consisted mainly of mesopores and macropores. After hydration, the volumes of both types of pores increased. However, the mesopore percentage decreased, while the macropore percentage increased. The hydrated spent CMA had obvious fractal characteristics. There was an optimum range for the fractal dimension of the samples, 2.31 〈 D 〈 2.35, at which the sulfation conversion was maximized. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 3, Page 447-449, June 2019.

Description: Abstract The extreme amount of greenhouse gases (GHGs) being released into the atmosphere has proved to be a globally challenging phenomenon that leads to changes in the climate and global warming. The amount of GHGs in the atmosphere has escalated immensely, with a substantial growth of 5.8% in 2010; a similar increase was observed in Pakistan as well. In Pakistan, carbon dioxide (CO2) emissions stand at 54% of total GHG emissions whereas methane, nitrous oxide, carbon monoxide and volatile organic carbon contribute to emissions at 36%, 9%, 0.75% and 0.3%, respectively. One of the key reasons for climatic changes is GHG emission generation from human interventions and activities related to transportation, urban development, industrialization, energy sources, farming and agriculture, waste's improper management, land use and forestry. In 2011, Pakistan's entire GHG emissions were a whopping 347 Mt of CO2‐eq, and by 2050, they are estimated to reach 4621 Mt CO2‐eq. This review evaluates and assesses GHG emissions generating from various sectors in Pakistan, in a socio‐scientific prospect that is caused by human activities and interventions in different economic sectors in Pakistan, endangering the environment across the country. Additionally, the review examines the current level of GHG emissions while accounting for China–Pakistan Economic Corridor–based emissions, abatement strategies including development of a state‐of‐the‐art technique for carbon capture and storage/utilization technologies in Pakistan. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract The complexity of water–rock–CO2 interactions associated with CO2 geological storage requires more comprehensive understanding with regard to the geochemical characteristics of reservoirs. In this paper, five groups of batch reactions and coupled simulations were conducted, in which rocks of different cementation types were reacted with purified water and CO2 at 180°C and 18 Mpa for 15 days, to reveal the possible geochemical effects of cement mineral variations on water–rock–CO2 interactions. With water chemistry and mineral alteration being monitored, the thermodynamics and kinetic characteristics of each CO2–water–rock system were fully analyzed in PHREEQC by the method of mineral saturation index, mineral phases diagram, and kinetics modeling to reveal the possible reaction paths and to compare their geochemical differences, which are caused by cement mineral variations. The experiment identified quite different dissolution characteristics and rates for cement minerals, and as a result, favored a diverse water chemistry and precipitation of different secondary minerals. Generally, the sensitive orders of cement mineral variations due to water–rock–CO2 interactions are carbonates, argillaceous, and siliceous minerals. The modeling showed good consistency with experiment results especially in cation evolution but underestimated the dissolution rate of alkali feldspar and carbonate mineral solubility. In addition, the modeling also predicted the carbonate reprecipitation of dolomite and calcite as cement minerals themselves, as well as dolomite precipitation at the expense of chlorite and calcite dissolution, which we failed to observe in the experiment. Thus, special attention should be paid to cement mineral variations when conducting CO2 injection in sandstone reservoirs. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 3, Page 445-446, June 2019.

Description: Abstract As an important evaluation transformation index, exploring green total factor productivity (GTFP) trend and related key factors is significant for China's economy entering into high‐quality development and green transformation. In this study, stochastic frontier analysis (SFA) and kernel density function are used to evaluate GTFP growth trend for 36 China's industrial sectors during 2000–2016, and system generalized method of moment is used to explore their key driving factors. The results are as follows: First, SFA supplies efficient estimation for GTFP growth information. The 36 industrial sectors are classified into three emission types, that is, high‐, moderate‐, and low emission. Second, GTFP growth differs significantly in three types of sectors. With kernel density results for 36 sectors, the curve of GTFP growth has shifted upward and toward the left since 2010. For high‐emission type sectors, their kernel curve has also moved upward and toward the left. The curve of moderate‐emission type sectors significantly shifted toward the left, whereas the curve of low‐emission type moved upward. Third, based on regression estimation results, environmental regulatory policy, resource input structure, foreign direct investment, and energy‐type structure significantly influence GTFP growth. Technology innovation makes insignificant impact on GTFP for industrial sectors. In conclusion, sectorial heterogeneity should be paid more focus in order to improve their growth, especially for high‐emission type sectors. Green technology innovation is the most potential factor in the future to stimulate GTFP growth in China. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Predicting CO2 plume migration is an important aspect for the geological sequestration of CO2. In the absence of experimental data, the storage performance of CO2 geo‐storage can be assessed through the dynamic modelling of the fluid flow and transport properties of the rock‐fluid system using empirical formulations. Using the van Genuchten empirical model, this study documents a Darcy flow modelling approach to investigate different aspects of CO2 drainage in a sandstone formation with interbedded argillaceous (i.e. mudstone) units. The numerical simulation is based on the Sleipner gas field storage unit where several thin argillite layers occur within the sandstone of the Utsira Formation. With respect to forward modelling simulations that have used Sleipner Formation as a case study, it is noted that previous attempts to numerically calibrate the CO2 plume migration to time‐lapse seismic dataset using software governed by Darcy flow physics achieved poor results. In this study, CO2‐brine buoyant displacement pattern is simulated using the ECLIPSE ‘black oil’ simulator within a two‐dimensional axisymmetric geometry and a three‐dimensional Cartesian coordinate system. This investigation focussed on two key parameters affecting CO2 migration mobility, namely relative permeability and capillary forces. Examination of these parameters indicate that for the gravity current of CO2 transiting through a heterogeneous siliciclastic formation, the local capillary forces in geologic units, such as mudstone and sandstones, and the relative permeability to the invading fluid control the mass of CO2 that breaches and percolates through each unit, respectively. In numerical analysis, these processes influence the evaluation of structural and residual trapping mechanisms. Consequently, the inclusion of heterogeneities in capillary pressure and relative permeability functions, where and when applicable, advances a Darcy modelling approach to history matching and forecasting of reservoir performance. Results indicate that there is a scope for a revision of the basic premise for modelling flow properties in the interbedded mudstones and the top sand wedge at the Sleipner Field when using Darcy flow simulators. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Carbon capture utilisation and storage (CCUS) continues its rise on the global agenda. Once consigned to the realm of researchers, scientists and those who saw the potential and need for technology to help in climate change mitigation, CCUS is getting increasing ministerial level backing. In this article, GHGS&T's Muriel Cozier reviews the two G20 meetings held in Japan, which put CCUS on the ministerial table. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Greenhouse Gases: Science and Technology, Volume 9, Issue 5, Page 849-851, October 2019.

Description: Abstract The requirement to pre‐treat flue gas prior to the CO2 capture step is an economic challenge when using aqueous amine absorbents for capturing CO2 from coal‐fired power station flue gases. A potentially lower cost alternative is to combine the capture of both CO2 and SO2 from the flue gas into a single process, removing the requirement for the desulfurization pre‐treatment step. The CSIRO's CS‐Cap process uses a single aqueous amine absorbent to capture both of these acid gases from flue gas streams. This paper covers the initial simulation of this process applied to both brown and black coal flue gases. Removal of absorbed SO2 is achieved via reactive crystallization. This is simulated here using a ‘black box’ process, resulting in a K2SO4 product. Different operating conditions have been evaluated that increase the sulfate concentration of the absorbent in the SO2 capture section of the process, which is expected to increase the efficiency of the reactive crystallization step. This paper provides information on the absorption of SO2 into the amine solution, and heat and mass balances for the wider process. This information will be required for further detailed simulation of the reactive crystallization step, and economic evaluation of the CS‐Cap process. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Mineral carbonation (MC) is a form of carbon capture and storage that reacts CO2 with alkaline feedstock to securely store CO2 as solid carbonate minerals. To improve process economics and accelerate commercial deployment, research has increased around product utilization, where markets exist primarily in the construction industry. This review assesses the potential for advancing MC product utilization to decrease CO2 emissions toward neutral, or even negative, values. First, the literature surrounding the current state and challenges for indirect MC processes is reviewed, indicating that process intensification and scale‐up are important areas for further research. Alkalinity sources available for MC are examined, differentiating between those sourced from industrial processes and mining operations. Investigation of possible end uses of carbonate products reveals that further CO2 avoidance can be achieved by replacing conventional carbon‐intensive products. Companies that are currently commercializing MC processes are categorized based on the feed used and materials produced. An analysis of company process types indicates that up to 3 GtCO2 year–1 could be avoided globally. It is suggested that upcoming commercial efforts should focus on the carbonation of industrial wastes located near CO2 sources to produce precast concrete blocks. Carbonation of conventional concrete shows the highest potential for CO2 avoidance, but may face some market resistance. Carbonation of Mg silicates lacks sufficient market demand and requires the development of new high‐value products to overcome the expense of mining and feed preparation. It is suggested that research focus on enhanced understanding of magnesia cement chemistry and the development of flame‐retardant mineral fillers. © 2019 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Previous studies on the Deccan basalt–water–CO2 interaction were focused on numerical simulations and experimental validation that revealed carbonate formation, but restricted to low temperatures and for a shorter period. However, during prolonged interactions, silicates restricted carbonates from forming, and thus necessitated for comparative mass‐balance calculations of parent basalt, neo‐formed mineral and dissolution products to understand apposite parameters that control the reaction extent and optimal geochemical conditions. To examine these interactions, mass‐balance calculations have been attempted. A gradual increase in HCO3− concentration and basalt dissolution is concomitant with the increase in experimental run time; thus, the pH of the solution is affected. X‐ray diffraction and scanning electron microscope–energy dispersive X‐ray spectrometer analyses revealed the presence of carbonates in the post‐experiment residue (run for a shorter period). Owing to gradual carbonate decrease in the residue, Ca2+, Fe2+ and Mg2+ released from basalt gradually increased in the leachate at 100°C. But with the progression of time at 200°C, more secondary silicates were formed and incorporated Mg2+ and Si4+, which led to a decrease in Mg2+ and Si4+ concentrations in the leachate. Mass‐balance calculations revealed that the maximum amount of CO2 is mineralized (22.88 mol%) from the ions derived from the parent basalt at 100°C under 5 bar CO2 and 70 h of experiment running time. But, for longer periods of experiments, the rate of ionic interactions as well as CO2 mineralization is almost ceased. Thus, the rate of dissolution is affected by temperature, but the amount of CO2 mineralization is directly a function of the basalt–water–CO2 interaction time. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Description: Abstract Biodiesel is among the solutions to substitute petroleum‐based fuel. However, the autoxidation ability of biodiesel, which results in degradation of the existing oxygen, has delayed its use on a global level. A potential solution to this problem is the addition of antioxidant additives. Palm oil methyl ester (POME) is the most popular biodiesel in Malaysia. Diesel 80% + POME 20% (B20) was added with two types of monophenolic antioxidant additives, which were butylated hydroxytoluene and butylated hydroxyanisole, at 1000 ppm and 1500 ppm concentrations, respectively, to examine their effects on combustion characteristics, engine performances and exhaust emissions. Hielscher UP400S ultrasonic emulsifier was used to prepare the fuel blends at 20% of the maximum stirring speed. Yanmar TF120M single‐cylinder diesel engine was employed at a constant speed of 1800 rpm with various engine loads. The results showed that B20 and antioxidant‐treated B20 produced a mean increase in brake specific fuel consumption of 8.33%–23.27% and reduced brake thermal efficiency by a mean that was 8.40%–24.95% greater than that of diesel fuel. Both antioxidants reduced nitrogen oxide emission by a mean of 12.92%–30.54%, compared to B20. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.