Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene  

作　　者：Ji Liu Shuang-Wei Yang Wei Zhao Yu-Long Wu Bin Hu Si-Han Hu Shan-Wei Ma Qiang Lu 

机构地区：[1]National Engineering Research Center of New Energy Power Generation,North China Electric Power University,Beijing 102206,China [2]Suzhou Institute of North China Electric Power University,Suzhou 215000,China [3]Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China [4]School of Chemistry and Chemical Engineering,Xinjiang University,Urumqi City 830046,China

出　　处：《Frontiers of Chemical Science and Engineering》2023年第3期334-346,共13页化学科学与工程前沿（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.52006069,51922040,51821004);Fundamental Research Funds for the Central Universities(Grant No.2020MS020);Hunan Science and Technology Planning Project(Grant No.2020RC5008)for financial support.

摘　　要：The release and control of sulfur species in the pyrolysis of fossil fuels and solid wastes have attracted attention worldwide.Particularly,thiophene derivatives are important intermediates for the sulfur gas release from organic sulfur,but the underlying migration mechanisms remain unclear.Herein,the mechanism of sulfur migration during the release of sulfur-containing radicals in benzothiophene pyrolysis was explored through quantum chemistry modeling.The C_(1)-to-C_(2)H-transfer has the lowest energy barrier of 269.9 kJ·mol-1 and the highest rate constant at low temperatures,while the elevated temperature is beneficial for C−S bond homolysis.2-Ethynylbenzenethiol is the key intermediate for the formation of S and SH radicals with the overall energy barriers of 408.0 and 498.7 kJ·mol-1 in favorable pathways.The generation of CS radicals is relatively difficult because of the high energy barrier(551.8 kJ·mol-1).However,it can be significantly promoted by high temperatures,where the rate constant exceeds that for S radical generation above 930°C.Consequently,the strong competitiveness of S and SH radicals results in abundant H2 S during benzothiophene pyrolysis,and the high temperature is more beneficial for CS2 generation from CS radicals.This study lays a foundation for elucidating sulfur migration mechanisms and furthering the development of pyrolysis techniques.

关 键 词：BENZOTHIOPHENE sulfur migration PYROLYSIS density functional theory 

分 类 号：O177[理学—数学]