ALBERT

Description: PURPOSE: To investigate the long-term effects of total body irradiation (TBI) on the incidence and time course of ocular complications. MATERIALS AND METHODS: Rhesus monkeys treated with TBI photon doses up to 8.5 Gy and proton doses up to 7.5 Gy were studied at intervals up to 25 years post-irradiation. They were compared with control groups with a similar age distribution. Cataract formation and ocular fundus lesions were scored according to a standardized protocol. Fluorescein angiography and histopathology was performed in selected animals. RESULTS: Cataract formation occurred after a latent period of 3-5 years. Significant cataract induction was observed for photon-doses of 8 and 8.5 Gy and beyond 20 years after proton irradiation. The severity of the lesions represents significant impairment of vision and would require cataract surgery if similar results occurred in human bone marrow transplant patients. Fluorescein angiography demonstrated a normal pattern of retinal vessels in 13 out of 14 animals (93%) from the irradiated group and in eight out of nine animals (89%) from the control group. No additional lesions apart from age-related degenerative changes could be demonstrated. Histological evaluation revealed no radiation-associated vasculopathy. CONCLUSIONS: Radiation alone for doses up to 8.5 Gy of photons does not carry a potential risk for fundus pathology, whereas clinically important cataract induction should be anticipated within 5 years after photon doses of 8.0 and 8.5 Gy and proton doses in excess of 2.5 Gy.

Description: Natural gas based hydrogen production with carbon capture and storage is referred to as blue hydrogen. If substantial amounts of CO2 from natural gas reforming are captured and permanently stored, such hydrogen could be a low-carbon energy carrier. However, recent research raises questions about the effective climate impacts of blue hydrogen from a life cycle perspective. Our analysis sheds light on the relevant issues and provides a balanced perspective on the impacts on climate change associated with blue hydrogen. We show that such impacts may indeed vary over large ranges and depend on only a few key parameters: the methane emission rate of the natural gas supply chain, the CO2 removal rate at the hydrogen production plant, and the global warming metric applied. State-of-the-art reforming with high CO2 capture rates combined with natural gas supply featuring low methane emissions does indeed allow for substantial reduction of greenhouse gas emissions compared to both conventional natural gas reforming and direct combustion of natural gas. Under such conditions, blue hydrogen is compatible with low-carbon economies and exhibits climate change impacts at the upper end of the range of those caused by hydrogen production from renewable-based electricity. However, neither current blue nor green hydrogen production pathways render fully “net-zero” hydrogen without additional CO2 removal.

Description: The cement industry which is characterised by the highest carbon intensity per unit of revenue among all major industries needs to rapidly reduce their CO2 equivalent (CO2e) emissions to reach carbon neutrality. To do so economically optimal strategies for emission reductions need to be formulated that lead the cement industry to reach net-zero-CO2e by mid-century. While all suggested strategies might have their advantages and disadvantages (e.g.,some can be expected to lead to the produced cement qualities to change, while for others like carbon capture and storage the produced cement types will remain the same) and will come with different costs, a holistic comparison of all strategies from an economic perspective is currently lacking. To tackle these knowledge gaps, we here present a spatio-economic model for estimated cost burden associated with different CO2e emission reduction strategies. As a case study we present preliminary estimates on the cost burdens for the United Kingdom and Germany in form of marginal abatement cost curves for emission reduction in these countries’ cement industries.

Description: This paper presents the development of an open-source toolkit aimed to help industrial clusters design (economically and environmentally) optimal pathways towards net-zero greenhouse gas (GHG) emissions, critical to reaching the Paris and Glasgow climate ambitions. The decarbonization of industrial processes bares many challenges; high energy intensity and non-energy-related emissions, cost-optimized workstreams with limited margins, but also non-technical aspects such as job security and social equality within and among regions. Strategic planning is essential to achieve sustainable industries promptly. Moving as a cluster of industrial sites, rather than each site on its own, can leverage synergies and further accelerate the transition. However, such a level of integration requires further planning and an understanding of all incorporated industrial processes. The here presented toolkit fills this void, by enabling a user to investigate net-zero pathways for any cluster of industrial sites. The toolkit builds on an optimization framework which solves the necessary technological interventions and transport infrastructure (e.g., CO2 pipelines) to reach a defined emission target. The problem is a mixed-integer linear programming (MILP) implementation, following a Resource Technology Network (RTN) formulation. The toolkit allows the user to solve for optimal, instantaneous configurations as a snapshot and then explore time-phased transformation pathways which reach that snapshot. The pathways follow a backcasting approach bounded by user-defined state gates. This publication explains the methodology of the toolkit, which is currently being developed as part of the work within the UK Industrial Decarbonisation Research and Innovation Centre (IDRIC). The functionality of the toolkit has been tested on a small example of a hypothetical cluster, which consisted of a refinery, a steel mill, a power plant, and a cement plant. The outcome was a pathway for the installation of carbon capture technologies, direct air carbon capture plants, CO2 pipelines, and CO2 injection wells. The pathway provided information on the cluster setup over three investment rounds, which ultimately reached net-zero CO2 emissions.

Description: The cement industry, an industry characterised by low margins, is responsible for approximately 7% of anthropogenic CO2 equivalent (CO2e) emissions and holds the highest carbon intensity of any industry per unit of revenue. To encourage complete decarbonisation of the cement industry, strategies must be found in which CO2e emission reductions are incentivised. Here we show through integrated techno-economic modelling that CO2 mineralisation of silicate minerals, aiming to store CO2 in solid form, results in CO2e emission reductions of 8–33% while generating additional profit of up to €32 per tonne of cement. To create positive CO2 mineralisation business cases two conditions are paramount: the resulting products must be used as a supplementary material in cement blends in the construction industry (e.g., for bridges or buildings) and the storage of CO2 in minerals must be eligible for emission certificates or similar. Additionally, mineral transport and composition of the product are decisive.

Description: The pathways toward net-zero greenhouse gas emissions by 2050 should be designed based on solid scientific evidence. Ex ante system analysis tools, such as techno-economic assessments (TEAs), are key instruments to guide decision-makers. As ex ante TEAs of CO2 mitigation technologies embody a high level of uncertainty, the informed use of uncertainty analysis becomes crucial for meaningful interpretation and communication of TEA outputs. To foster enhanced appreciation and the use of uncertainty analysis, we compare multiple uncertainty analysis methods for ex ante TEAs, using a case study on CO2 mineralization in the cement industry. We show that local sensitivity analysis tools such as one-way analysis, which are most often used by TEA practitioners, may not suffice for deriving reliable conclusions and provide guidance on how to apply global sensitivity analysis methods, such as variance-based indicators for TEAs in this field.

Description: Employing mineral carbonation products as a cementitious substitute could reduce the cement industry’s greenhouse gas (GHG) emissions. However, a transition toward low-emission cement requires financially competitive cement production at standardized product specifications. Aiming to tackle this challenge, we modeled and optimized a direct mineral carbonation process. In detail, we embedded a mechanistic tubular reactor model in a mineral carbonation process and imposed product specifications based on the European cement standard in the optimal design formulation. In the next step, we considered the business case of blended cement consisting of ordinary Portland cement and the mineral carbonation product that could be categorized as CEM II in the European cement standard. We computed the minimum production cost and GHG emissions of the produced blended cement by using Bayesian optimization to find Pareto optimal operating conditions of the mineral carbonation process. Our results showed that the cost of mineral carbonation in the cement industry can be competitive while cutting the GHG emissions by up to 54%.