ALBERT

Description: Carbon capture is the most critical stage for the implementation of a technically viable and economically feasible carbon capture and storage or utilization scheme. For that reason, carbon capture has been widely studied, with many published results on the technical performance, modelling and, on a smaller scale, the costing of carbon capture technologies. Our objective is to review a large set of published studies, which quantified and reported the CO2 capture costs. The findings are grouped, homogenised and standardised, and statistical models are developed for each one of the categories. These models allow the estimation of the capture costs, based on the amount of CO2 captured and the type of source/separation principle of the capture technology used.

Description: In this work, Rhodiasolv® PolarClean was employed as a more sustainable solvent for the preparation of poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) flat sheet membranes via phase inversion technique by coupling vapour induced phase separation (VIPS) and non-solvent induced phase separation (NIPS) processes. Preliminary calculations based on Hansen solubility parameters well predicted the solubilization of the polymer in the selected solvent. The effect of exposure time on humidity and the influence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP) and sulfonated polyether sulfone (S-PES) on membrane properties and performance, were evaluated. Three different coagulation bath compositions were also explored. The obtained membranes, prepared using a more sustainable approach, were compared with those produced with the traditional toxic solvent N-methyl-2-pyrrolidone (NMP) and characterised in terms of morphology, porosity, wettability, pore size, surface roughness and mechanical resistance. The potential influence of the new solvent on the crystallinity of PVDF-HFP-based membranes was also evaluated by infrared spectroscopy. The adjustment of the parameters investigated allowed tuning of the membrane pore size in the microfiltration (MF) and ultrafiltration (UF) range resulting in membranes with various morphologies. From the water permeability and rejection tests, performed with methylene blue dye, the prepared membranes showed their potentiality to be used in MF and UF applications.

Description: As renewable energy sources are spreading, the problems of energy usage, transport and storage arise more frequently. In order that the performance of energy producing units from renewable sources, which have a relatively low efficiency, should not be decreased further, and to promote sustainable energy consumption solutions, a living lab conception was elaborated in this project. At the pilot site, the produced energy (by PV panels, gas turbines/engines) is stored in numerous ways, including hydrogen production. The following uses of hydrogen are explored: (i) feeding it into the national natural gas network; (ii) selling it at a H-CNG (compressed natural gas) filling station; (iii) using it in fuel cells to produce electricity. This article introduces the overall implementation plan, which can serve as a model for the hybrid energy communities to be established in the future.

Description: Perennial rye grass is a widely used forage species in Ireland, on which the ruminant sector of agriculture is heavily dependent. While this species of grass is the primary source of fodder for cows, it is also abundant in plant protein, which could form a potential alternative ingredient in monogastric animal feed using a green biorefinery approach. In this study, perennial rye grass was processed using a novel biorefining process to extract value added products including protein as a potential replacement for soybean meal in monogastric feeds. Feed trials were conducted on a commercial farm with 55 weaner pigs for 31 days until slaughter. The diets comprised a control and a trial diet which integrated the green biorefinery protein concentrate. The effects of the new diet were determined by measuring the daily feed intake (DFI), average weight gain (AWG) and feed conversion ratio (FCR). Amino acid profiles of grass protein concentrate and soybean meal were comparable, with the latter having a slightly higher amount of total protein content, lysine and cysteine. The DFI and ADW indicated that the treatment diet was superior to the control. DFI for the treatment diet (1.512 kg/d) was 8% higher than the control diet (1.400 kg/d) by the end of the trial. Additionally, the ADW for the treatment diet was 6.44% higher than that achieved in the control sample. Meanwhile, FCR calculations indicated that the treatment diet is just as efficient as the conventional diet. Overall, the results of the study indicate positive potential for perennial ryegrass-derived green biorefinery protein concentrate as an alternative protein source for pig feed formulations in Ireland.

Description: In a context of accelerating deployment of distributed generation in power distribution grid, this work proposes an answer to an important and urgent need for better management tools in order to ‘intelligently’ operate these grids and maintain quality of service. To this aim, a model-based predictive control (MPC) strategy is proposed, allowing efficient re-routing of power flows using flexible assets, while respecting operational constraints as well as the voltage constraints prescribed by ENEDIS, the French distribution grid operator. The flexible assets used in the case study—a low-voltage power distribution grid in southern France—are a biogas plant and a water tower. Non-parametric machine-learning-based models, i.e., Gaussian process regression (GPR) models, are developed for intraday forecasting of global horizontal irradiance (GHI), grid load, and water demand, to better anticipate emerging constraints. The forecasts’ quality decreases as the forecast horizon grows longer, but quickly stabilizes around a constant error value. Then, the impact of forecasting errors on the performance of the control strategy is evaluated, revealing a resilient behaviour where little degradation is observed in terms of performance and computation cost. To enhance the strategy’s resilience and minimise voltage overflow, a worst-case scenario approach is proposed for the next time step and its contribution is examined. This is the main contribution of the paper. The purpose of the min–max problem added upstream of the main optimisation problem is to both anticipate and minimise the voltage overshooting resulting from forecasting errors. In this min–max problem, the feasible space defined by the confidence intervals of the forecasts is searched, in order to determine the worst-case scenario in terms of constraint violation, over the next time step. Then, such information is incorporated into the decision-making process of the main optimisation problem. Results show that these incidents are indeed reduced thanks to the min–max problem, both in terms of frequency of their occurrence and the total surface area of overshooting.

Description: For years, concentrated solar power (CSP) has been considered an emerging technology that could disrupt the energy production sector . The possibility to store the electricity generated during the sunny operating hours in the form of heat enhances energy dispatchability and gives CSP a unique value proposition that conventional renewable energies cannot provide cost-efficiently since it requires the integration of costly large-scale battery systems. CSP is a cleaner technology compared to photovoltaics, but photovoltaics currently has lower overall capital costs, making it more attractive to investors and stakeholders who want to spend less money upfront, . This is one of the main reasons why CSP has never really led either the electricity market or the heating one, even if its combined generation capability (heat and electricity) is globally recognized as a great advantage for a renewable technology. In this study, we analyze the reasons why CSP is not as widespread as it could be; at the same time, we look at the opportunities and the enablers for a further deployment of this technology, focusing on the European region.

Description: Due to low system inertia in microgrids, frequencies may vary rapidly from the nominal value, leading to the complete blackout of the system unless there is an adequate spinning reserve available for balancing the supply with the demand load. This issue of instability in microgrids under islanded operation has attracted particular attention recently. A diesel generator is considered to be an ideal spinning reserve to provide back-up power to the load along with the renewable energy source in islanded system. However, the high maintenance cost and CO2 emissions of diesel generator are detrimental factors which have inspired searches for more cost effective and cleaner technologies. The integration of an energy storage system (ESS) in islanded system along with generator not only reduces generator maintenance costs but also reduces the CO2 emissions by limiting its operating hours. This paper proposes an islanded PV hybrid microgrid system (PVHMS) utilizing flywheel energy storage systems (FESS) as an alternative to battery technology to support the PV system and meet the peak demand of a small residential town with 100 dwellings. The diesel generator is used in the islanded system as a spinning reserve to maintain the stability of the islanded system when the PV system and flywheel storage cannot meet the load demand. Results of analysis of such a system demonstrate that flywheel energy storage technology of appropriate size offers a viable solution to support the operation of the standalone PV system. Furthermore, the reduction in CO2 emissions and fuel consumption has been quantified as compared with the case with flywheel energy storage systems which means the diesel generator but always be operating.

Description: This article aims to study the interest of spent coffee grounds (SCG) valorization through caffeine recovery. In an original way, this study takes into account all the parameters such as (i) the brewing coffee methods (household, coffee shops, etc.); (ii) the storage conditions, in particular the drying step; (iii) the solid/liquid extraction parameters such as the nature of solvent, the temperature, the extraction time and the solid/liquid ratio; and (iv) the liquid/liquid purification parameters such as the nature, the volume and the pH of extraction medium. Results have shown that spent coffee grounds from coffee-shops obtained by percolation contain a higher amount of caffeine than spent coffee grounds from households obtained from spent pods or filters. A drying treatment is not required when extraction is performed under one week after the spent coffee grounds collection with 96.4% of not degraded caffeine. Solid/liquid extraction performed with 25 mL.g−1 SCG of hydroalcoholic solvent (water/EtOH, v/v 60/40) at 60 °C during 15 min have given a caffeine yield up to 4.67 mg.g−1 SCG. When using ethyl acetate, 93.4% of the caffeine has been selectively recovered by liquid/liquid extraction. Finally, the extraction of caffeine for the valorization of spent coffee grounds is a promising and easy way, which fits with an already important and well established market.

Description: This paper presents a comparative study of a clean technology based on a DSF (double skin facade) used in winter conditions in the occupied buildings comfort improvement, namely the thermal comfort and air quality. The performance of a solar DSF system, the building’s thermal response, the internal thermal comfort and the internal air quality are evaluated. In this study, a DSF system, an air transport system and a HVAC (heating, ventilating and air conditioning) system based on mixing ventilation are used. The study considers a virtual chamber occupied by eight persons and equipped, in the outside environment, by three DSFs. A new horary pre-programming control methodology is developed and applied when the airflow rate is constant and the number of DSFs to operate is variable, when the airflow rate is variable and the number of DSFs to operate is constant and when the airflow rate is variable and the number of DSFs to operate is variable. This work uses a numerical model that simulates the integral building thermal behavior and an integral human thermal response. The internal air, provided by a mixing ventilating system, is warmed using the DSF system. The air temperature inside the DSF system and the virtual chamber, the thermal comfort level using the PMV index, the internal air quality using the carbon dioxide concentration and the uncomfortable hours are calculated for winter conditions. The results obtained show that the energy produced in the DSF, using solar radiation, guarantees acceptable thermal comfort conditions in the morning and in the afternoon. The indoor air quality obtained at the breathing level is acceptable. It is found that the airflow rate to be used is more decisive than the DSF operating methodology. However, when a solution is chosen that combines a ventilation rate with the number of DSF to operate, both variables throughout the day can obtain simultaneously better results for indoor air quality and thermal comfort according to the standards.

Description: Small-scale wind turbines simulations are not as accurate when it comes to costs as compared to the large-scale wind turbines, where costs are more or less standard. In this paper, an analysis was done on a decision for a wind turbine investment in Bellingham, Whatcom County, Washington. It was revealed that a decision taken based only on a software tool could be destructive for the sustainability of a project, since not taking into account specific taxation, net metering, installation, maintenance costs, etc., beyond the optimization that the tool offers, can hide the truth.