This special issue in Aerosol and Air Quality Research features selected papers presented at the Symposium on CO2 Capture, Sequestration, Conversion and Utilization, during the 245th American Chemical Society (ACS) National Meeting & Exposition, which was held in New Orleans, Louisiana, USA, from April 7 to 11, 2013. The symposium was organized by Prof. Ying Li at the University of Wisconsin-Milwaukee and Prof. Fanxing Li at North Carolina State University. It was the largest symposium among the twenty symposia within the Division of Energy and Fuels at the 245th ACS National Meeting & Exposition. A total of 80 invited and contributed talks were presented at the symposium. Topics included fundamentals in CO2 activation and advanced processes and materials for CO2 capture, sequestration, conversion, and utilization.
Anthropogenic CO2 emission from fossil energy conversion is one of the major contributors to global climate change. With projected increase in global energy consumption, advanced carbon capture, sequestration, and utilization approaches need to be developed. As a first step for CO2 mitigation, carbon capture can potentially be achieved, in a cost-effective manner, through new technologies that reduce the energy consumptions for separating diluted CO2 from conventional power plant flue gas. Alternatively, smart combustion or gasification processes such as oxy-fuel or chemical-looping are capable of producing concentrated CO2 for easy capture. Successful development and deployment of these aforementioned technologies require breakthroughs in advanced materials as well as innovative reactor concepts and process schemes. Sequestration of captured CO2 into geological formations such as saline aquifers is the next important step to ensure long term storage of CO2. Besides sequestration, a number of emerging ideas have shown promise to recycle and utilize CO2 as a carbon source for clean energy carriers or chemicals, mainly through catalytic processes. While CO2 is thermodynamically stable, renewable energy sources like solar can accomplish the challenging task of CO2 conversion and utilization. For example, it has been demonstrated that nanostructured photocatalysts are capable of converting CO2 and water into C1 fuels like CO, methane or methanol under solar radiation. Extensive research efforts are underway to enhance the CO2 conversion efficiency using these novel photocatalytic processes.