Guest Seminar - Non-thermal Plasma Catalysis for Turning SO2 in Flue Gas to Elemental Sulfur
Sulfur dioxide (SO2) is a toxic pollutant emitted in various manufacturing processes in energy and fuels production, transportation and utilization from various stationary and mobile systems. Flue gas desulfurization (FGD) is used in commercial processes due to increasingly more stringent environmental regulations for electric power generation, refining, chemical industry, iron and steel as well as cement manufacturing). There is a large global market for flue gas desulfurization (FGD) systems (valued at ~$19.3 Billion USD in 2021; anticipated to grow to ~$24.9 Billion USD in 2026), where an alkaline sorbent such as limestone (CaCO3) or magnesium hydroxide (Mg(OH)2) is used in wet slurry or dry form to capture and convert SO2 gas into calcium sulfite (CaSO3) or magnesium sulfite (MgSO3) followed by solid disposal. We present a new design approach which consists of two key steps: (1) selective adsorption separation of SO2 in flue gas streams using regenerable solid “molecular basket” sorbent (MBS-S), followed by (2) non-thermal plasma-enhanced catalysis for SO2 reduction, in one-step, to elemental sulfur (SO2 to S) over transition metal catalysts. Both the MBS-S and the catalysts were prepared in our laboratory. We have developed SO2-selective solid molecular basket sorbent that is regenerable for adsorptive separation of SO2 from gas mixture. For low-temperature SO2 reduction to elemental sulfur in a flow reactor, coupling non-thermal plasma with supported transition metal sulfide catalysts can significantly promote low-temperature reduction of SO2 by 148–200%, with over 98% selectivity to elemental sulfur. Strong synergistic effects are attained, as the sulfur yield is about 47–82% higher than the sum of the yield when using plasma alone or catalyst alone. The new approach presented may be an alternative to conventional flue gas desulfurization technology.
Dr. Chunshan Song is Dean of the Faculty of Science and Wei Lun Professor of Chemistry at the Chinese University of Hong Kong, and Distinguished Professor Emeritus of Fuel Science and Chemical Engineering at the Pennsylvania State University in the US since July 2020. Before joining CUHK, he was Director of EMS Energy Institute, Distinguished Professor of Fuel Science, and Professor of Chemical Engineering at Penn State. He was the founding Director of the University Coalition for Fossil Energy Research consisting of 15 major research universities funded by the US Department of Energy during 2015-2020. He received his PhD in Applied Chemistry in 1989 and his MS in Applied Chemistry in 1986 from Osaka University, Japan, and his BS in Chemical Engineering in 1982 from Dalian University of Technology, China. He held a visiting or guest professorship at Imperial College London, University of Paris VI (now Sorbonne University), Tsinghua University, Dalian University of Technology, and as an honorary professor at Tianjin University. His research focuses on the catalysis and chemistry of energy and fuels including adsorptive CO2 separation and CO2 conversion to chemicals and fuels; adsorptive, oxidative and catalytic processing of fuels; shape-selective catalysis; synthesis and application of nano-porous materials. He has over 470 refereed journal articles (with 42,500 citations and H-index of 97 in Google Scholar, Mar 2023), 8 patents, 33 book chapters and 15 edited books.
His original and innovative research contributions to hydrocarbon chemistry, fuel processing, catalysis and CO2 research have been recognized through many awards and honours, including Fellow of American Chemical Society (ACS), George A. Olah Award in Hydrocarbon or Petroleum Chemistry, Henry H. Storch Award in Fuel Science; Fulbright Distinguished Scholar; ACS Energy & Fuels Division’s Distinguished Researcher Award; Outstanding Achievement Award from the Chinese American Chemical Society; Herman Pines Award from Catalysis Club of Chicago; Catalysis Club of Philadelphia Award; Chang Jiang Scholar Award from Ministry of Education of China; Global Alumni Fellow of Osaka University; Alumni Achievement Award from Dalian University of Technology; and within Penn State, the Faculty Scholar Medal, Distinguished University Professor, Faculty Mentoring Award and Wilson Award for Excellence in Research. He was the Chair of the International Conference on Carbon Dioxide Utilization in 2013, Co-chair of the North American Catalysis Society Biennial Meeting in 2015, Editor in Chief for Advances in Catalysis (Elsevier) during 2015-2020 and is currently serving as Associate Editor in Chief for Frontiers of Chemical Science and Engineering (Springer), Advisory Editor for Journal of CO2 Utilization (Elsevier), and Advisory Board member for 12 research journals in catalysis, energy and fuels, chemistry and chemical engineering.