| Shrnutí: | Though numerous efforts have been made to mitigate the impact of global warming, deep decarbonization of the world's largest sources of CO₂ emissions is proving increasingly necessary. Progress in many sectors is proceeding quickly, but we have so far failed to address all sources of industrial emissions. Aviation, long-distance shipping, load-following electricity, and steel, iron, and cement production together account for 27% of emissions and are considered hard-to-decarbonize sectors. We demonstrate and analyze several approaches using electrochemistry in an attempt to address two of these hard-to-decarbonize sectors: cement production and load-following electricity.
For cement production, a novel approach to drive the decarbonation of calcium carbonate using neutral water electrolysis is proposed. This approach also generates concentrated gas streams of H₂ and O₂/CO₂. The fine powder Ca(OH)₂ that is generated in the reactor is then used to synthesize the majority cementitious phase in cement. Approaches to use the concentrated gas streams from this process may be used synergistically with other processes under development for a decarbonized energy economy, suggesting a pathway to cost-competitive emissionless cement manufacturing wherein all energy is supplied by renewable electricity.
For load-following electricity, an evaluation of metal-air batteries is first performed that provides a roadmap of the scale of cost reductions that might be accessible by 2050. We find that because metal-air batteries for grid energy storage are based on low-cost materials, system-level energy costs are low. However, we also find metal-air batteries currently suffer from performance and cost characteristics that prevent wide-scale deployment. Should these be addressed, we find that the cost of ownership for long-duration metal-air batteries is projected to become lower than $100/kWh.
Drawing on the need for low-cost energy storage, a novel battery architecture that uses abundant chemicals separated by two immiscible phases is demonstrated. This self-assembling Zn-Cl₂ battery takes advantage of the immiscible nature of aqueous solutions and non-polar solvents. This system shows an inverse relationship between temperature and energy density that allows for low chemical cost while simultaneously exhibiting high energy density, reaching roughly $2/kWh and 700 Wh/L.
|
|---|