废弃煤矿巷道CO2"封存-利用"技术探索及转化效率研究OA

To address the urgent global demand for carbon dioxide(CO2)reduction,a new approach for utilizing the underground space of abandoned coal mines for CO2 sequestration and resource utilization is explored to enhance its environmental and resource benefits.A method for integrating capture,stor-age,conversion,and separation systems for CO2"sequestration-utilization"in abandoned coal mine tun-nels is proposed.Based on the geometric similarity theory and solid oxide electrolysis cell(SOEC)technology,a scale mapping relatonship between roadway reaction chambers and laboratory micro-reac-tion cavities is established,forming a parameter correspondence system for indoor experiments and un-derground applications.Through constant current co-electrolysis experiments and gas chromatography a-nalysis of gas composition,the influence of reaction temperature and CO2/H2O gas ratio on CO2 conver-sion efficiency is systematically revealed.The results show that under the condition of maintaining A/V constant,the size of the roadway reaction chamber is 2.4 m ×6 m ×3.6 m,corresponding to an effec-tive reaction area of 384 m2.The Faraday efficiency shows a characteristic of"first decreasing then in-creasing"with the increase of temperature,and decreases with the increase of the CO2/H2O gas ratio.The CO2 conversion rate significantly increases with the increase of temperature and decreases with the increase of the CO2/H2O gas ratio.Under the co-electrolysis condition of 850 ℃ and a gas ratio of CO2∶H2O=1∶1,the CO2 achieves the optimal conversion efficiency,with a conversion rate of 72.22％and a Faraday efficiency of 61.77％.The research provides a theoretical basis and technical support for the sequestration and high-value utilization of CO2 in abandoned coal mine tunnels.