Rock ‘n’ use of CO2: carbon footprint of carbon capture and utilization by mineralization

A recent approach to reduce the carbon footprint of industries with process-inherent CO2 emissions is CO2 mineralization. Mineralization stores CO2 by converting it into a thermodynamically stable solid. Beyond storing CO2, the products of CO2 mineralization can potentially substitute conventional products in several industries. Substituting conventional production increases both the economic and the environmental potential of carbon capture and utilization (CCU) by mineralization. The promising potential of CO2 mineralization is, however, challenged by the high energy demand required to overcome the slow reaction kinetics. To provide a sound assessment of the climate impacts of CCU by mineralization, we determine the carbon footprint of CCU by mineralization based on life cycle assessment. For this purpose, we analyze 7 pathways proposed in literature: 5 direct and 2 indirect mineralization pathways, considering serpentine, olivine, and steel slag as feedstock. The mineralization products are employed to partially substitute cement in blended cement. Our results show that all considered CCU technologies for mineralization could reduce climate impacts over the entire life cycle based on the current state-of-the-art and today's energy mix. Reductions range from 0.44 to 1.17 ton CO2e per ton CO2 stored. To estimate an upper bound on the potential of CCU by mineralization, we consider an ideal-mineralization scenario that neglects all process inefficiencies and utilizes the entire product. For this ideal mineralization, mineralization of 1 ton CO2 could even avoid up to 3.2 times more greenhouse gas emissions than only storing CO2. For all mineralization pathways, the carbon footprint is mainly reduced due to the permanent storage of CO2 and the credit for substituting conventional products. Thus, developing suitable products is critical to realize the potential benefits in practice. Then, carbon capture and utilization by mineralization could provide a promising route for climate change mitigation.ISSN:2398-490

Rock 'n' use of CO2 : carbon footprint of carbon capture and utilization by mineralization

A recent approach to reduce the carbon footprint of industries with process-inherent CO2 emissions is CO2 mineralization. Mineralization stores CO2 by converting it into a thermodynamically stable solid. Beyond storing CO2, the products of CO2 mineralization can potentially substitute conventional products in several industries. Substituting conventional production increases both the economic and the environmental potential of carbon capture and utilization (CCU) by mineralization. The promising potential of CO2 mineralization is, however, challenged by the high energy demand required to overcome the slow reaction kinetics. To provide a sound assessment of the climate impacts of CCU by mineralization, we determine the carbon footprint of CCU by mineralization based on life cycle assessment. For this purpose, we analyze 7 pathways proposed in literature: 5 direct and 2 indirect mineralization pathways, considering serpentine, olivine, and steel slag as feedstock. The mineralization products are employed to partially substitute cement in blended cement. Our results show that all considered CCU technologies for mineralization could reduce climate impacts over the entire life cycle based on the current state-of-the-art and today's energy mix. Reductions range from 0.44 to 1.17 ton CO2e per ton CO2 stored. To estimate an upper bound on the potential of CCU by mineralization, we consider an ideal-mineralization scenario that neglects all process inefficiencies and utilizes the entire product. For this ideal mineralization, mineralization of 1 ton CO2 could even avoid up to 3.2 times more greenhouse gas emissions than only storing CO2. For all mineralization pathways, the carbon footprint is mainly reduced due to the permanent storage of CO2 and the credit for substituting conventional products. Thus, developing suitable products is critical to realize the potential benefits in practice. Then, carbon capture and utilization by mineralization could provide a promising route for climate change mitigation

From Unavoidable CO 2 Source to CO 2 Sink? A Cement Industry Based on CO 2 Mineralization

The cement industry emits 7% of the global anthropogenic greenhouse gas (GHG) emissions. Reducing the GHG emissions of the cement industry is challenging since cement production stoichiometrically generates CO2 during calcination of limestone. In this work, we propose a pathway towards a carbon-neutral cement industry using CO2 mineralization. CO2 mineralization converts CO2 into a thermodynamically stable solid and byproducts that can potentially substitute cement. Hence, CO2 mineralization could reduce the carbon footprint of the cement industry via two mechanisms: (1) capturing and storing CO2 from the flue gas of the cement plant, and (2) reducing clinker usage by substituting cement. However, CO2 mineralization also generates GHG emissions due to the energy required for overcoming the slow reaction kinetics. We, therefore, analyze the carbon footprint of the combined CO2 mineralization and cement production based on life cycle assessment. Our results show that combined CO2 mineralization and cement production using today’s energy mix could reduce the carbon footprint of the cement industry by 44% or even up to 85% considering the theoretical potential. Low-carbon energy or higher blending of mineralization products in cement could enable production of carbon-neutral blended cement. With direct air capture, the blended cement could even become carbon-negative. Thus, our results suggest that developing processes and products for combined CO2 mineralization and cement production could transform the cement industry from an unavoidable CO2 source to a CO2 sink

A climate-optimal supply chain for CO2 capture, utilization, and storage by mineralization

CO2 mineralization not only captures and stores CO2 permanently but also yields value-added products utilized in, for example, the cement industry. CO2 mineralization has been shown to potentially substantially reduce greenhouse gas (GHG) emissions. Realizing CO2 mineralization's potential on a large scale requires a) solid feedstock, b) CO2 sources, c) low-carbon energy, and d) markets for mineralization products. In general, these four requirements of CO2 mineralization are not satisfied at the same location. Thus, the assessment of CO2 mineralization's large-scale potential necessitates the full supply chain considering all requirements for CO2 mineralization simultaneously. At present, neither the potential of CO2 mineralization for GHG emissions reduction on a large scale nor the required supply chain to achieve the potential are fully understood. In our study, we design a climate-optimal supply chain for CO2 capture, utilization, and storage (CCUS) by CO2 mineralization to quantify the large-scale potential of CO2 mineralization in Europe. Our results show that a climate-optimal CCUS by CO2 mineralization could avoid up to 130 Mt CO2e/year of the industrial emissions in Europe even with the current energy supply system. By 2040, CCUS by CO2 mineralization could provide negative emissions of up to 136 Mt CO2e/year. The required energy and CO2 for the CCUS supply chain can be provided either by expanding the current infrastructure by about 5% or, even more climate efficiently, by building new infrastructure. The critical steps toward achieving the large potential of CO2 mineralization in Europe are 1) scaling up the CO2 mineralization technology to the industrial level and 2) exploiting large-scale mineral deposits.ISSN:0959-652

Towards a European supply chain for CO2 capture, utilization, and storage by mineralization: Insights from cost-optimal design

Carbon dioxide (CO2) capture, utilization, and storage (CCUS) by mineralization has been shown to reduce greenhouse gas (GHG) emissions not only in stand-alone plants but also in large-scale climate-optimal supply chains. Yet, implementing the large-scale supply chain for CCUS by mineralization requires a substantial financial investment and, thus, a deep understanding of its economics. The current literature estimates the economics of CO2 mineralization for stand-alone plants. While CO2 mineralization plants have their specific a) CO2 supply, b) solid feedstock supply, c) energy supply, and d) product market, the plant-level cost estimation does not account for a large and potentially shared supply chain. In our study, we assess the economics of mineralization by designing and analyzing cost-optimal supply chains for CCUS by mineralization in Europe. Our results show that the CO2e abatement costs of individual mineralization plants in a supply chain range from 110 to 312 €/ton CO2e avoided. The proposed supply chains for CCUS by mineralization can avoid 60 Mt CO2e/year in Europe at CO2e abatement costs comparable to CO2 capture and geological storage. Furthermore, we identify five locations that could offer a robust business case for CO2 mineralization. The analysis thus shows pathways on how to add CO2 mineralization to the GHG mitigation portfolio of Europe.ISSN:2212-9820ISSN:2212-983