关键词: CO₂捕集-转化一体化, 生命周期评价, 碳足迹, 甲烷化

Abstract:

Carbon capture, utilization, and storage (CCUS) technology stands as a pivotal approach to mitigating carbon emissions stemming from fossil energy utilization. However, conventional CCUS technologies grapple with the drawbacks of high energy consumption and costs. The integrated CO₂ capture and conversion technology addresses these challenges by seamlessly integrating CO₂ adsorption with catalytic conversion processes. In recent years, researchers have explored the feasibility of integrating carbon capture with diverse CO₂ conversion pathways, with methanation garnering substantial attention. As an emerging technology for emission reduction, assessing its low-carbon attributes is vital for enhancing its technical competitiveness. Based on previous experimental work conducted by our research group, this study employs Aspen Plus to simulate the integrated CO₂ capture and methanation technology (ICCC-CH₄). Furthermore, leveraging the life cycle assessment framework, we establish a methodological model for carbon footprint accounting of this process, enabling the calculation and analysis of the technology’s carbon emissions. The study finds that under current grid conditions, the ICCC-CH₄ technology emits 0.22kg CO₂/MJ. However, when powered by wind, hydro, and nuclear energy, the technology can even achieve negative carbon emissions. With future improvements in alkaline water electrolysis efficiency, under photovoltaic power generation, the technology is expected to achieve near-zero carbon emissions by 2030. By enhancing hydrogen utilization efficiency, the carbon emissions of the technology can be reduced to 0.207kg CO₂/MJ, marking a 6% decrease compared to current levels. Conversely, enhancements in dual-functional material performance exert a negligible impact on carbon emissions.

Key words: integrated CO₂ capture and conversion, life cycle assessment, carbon footprint, methanation