Recent advancements in integrating CO2 capture from flue gas and ambient air with thermal catalytic conversion for efficient CO2 utilization
Ruoyu Zhang, Zhenwei Xie, Qingfeng Ge, Xinli Zhu
Abstract
Capturing CO 2 and converting it into valuable chemicals and fuels have been regarded as a pivotal strategy in addressing the environmental challenges of ever-growing CO 2 emissions. Combining CO 2 capture and conversion through material or process integration can eliminate the energy-intensive steps such as separation, compression, and transportation across a wide range of space and temperatures. The flue gas at high temperatures > 300 °C can be handled with dual-function materials consisting of sorbents and catalysts. The dual-function materials combine CO 2 capture and conversion through material integration, converting CO 2 with reactions such as methanation, reverse water-gas shift, dry reforming of CH 4 , and oxidative dehydrogenation of propane. On the other hand, capturing CO 2 from air directly requires a long time to collect enough CO 2 for the subsequent conversion reaction. Consequently, direct air capture will likely combine with the conversion reactions in stepwise operations. The low latent heat in CO 2 from direct air capture makes it more suitable for reactions at a mild condition (< 250 °C), and stepwise operation allows the separate control of the capture and conversion conditions. Herein, we reviewed recent advancements in coupling CO 2 capture from flue gas and ambient air with thermal catalytic conversion. We discussed the requirements for materials, reactor configuration, and process operation for capturing and converting CO 2 from these sources and proposed that future research should focus on enhancing the efficiency, scalability, and sustainability of CO 2 capture and conversion technologies and optimizing the process design.