Carbon capture and utilization (CCU) is receiving worldwide attention due to its potential to mitigate CO2 emissions that contribute to climate changes, and the ability to produce high-value chemicals (e.g: methanol, gasoline, olefin) and fuels that lessen the burden on conventional resources. Carbon capture and utilization for energy products (CCU4E) offers several potential benefits in climate change mitigation, energy security, and sustainability. Although advances in fundamental research have shown a high potential for CCU4E framework implementation, the realistic strategies to demonstrate CCU4E in global and local applications are still unclear. For example, which pathway from CO2 capture to what mix of products through what types of conversion technologies makes CO2-based fuels economically and/or environmentally viable. Accordingly, to quicken the implementation of a competitive, practical CCU4E framework, the research team developed a system-level methodology for synthesis and evaluation of a wide range of CCU4E pathways. In this work, 72 CO2-to-fuel pathways were assessed using Process Systems Engineering (PSE)-centric techniques such as process simulation, techno-economic evaluation, environmental impact analysis, and optimization. Based on the 72 CO2-to-fuel pathways examined, the team discussed the trade-off between economic output (via unit production cost of fuels) and environmental impact (via net CO2 equivalent emissions). In addition, an optimization model was used to identify the optimal pathway and judge the decision to use conventional (black) or renewable (green) hydrogen in different scenarios. An extended sensitivity analysis was performed to understand the important role of H2 in the mitigation of CO2eq and its economic potential, globally and locally, as well as the prospect of future CO2-based fuels. This study provides practical decision-making strategies to major carbon-emitting countries to make decisions on using domestic resources to balance economy and environmental protection in the CCU4E framework. The green hydrogen price is revealed to be the key factor in future CCU4E by allowing a huge reduction in CO2eq emissions at a more stable and lower price.

*Paper Title:  A CO2 utilization framework for liquid fuels and chemical production: techno-economic and environmental analysis