Tian Jiazhuang, Mao Qiuyun, You Zihan, Zhong Qifan
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Department of Educational Science, Hunan First Normal University, Changsha 410205, China.
ACS Omega. 2023 May 10;8(20):18140-18150. doi: 10.1021/acsomega.3c01446. eCollection 2023 May 23.
The removal of environmentally harmful S/N is crucial for utilization of high-S petroleum coke (petcoke) as fuels. Gasification of petcoke enables enhanced desulfurization and denitrification efficiency. Herein, petcoke gasification with the mixture of two effective gasifiers (CO and HO) was simulated via reactive force field molecular dynamics (ReaxFF MD). The synergistic effect of the mixed agents on gas production was revealed by altering the CO/HO ratio. It was determined that the rise in HO content could boost gas yield and accelerate desulfurization. Gas productivity reached 65.6% when the CO/HO ratio was 3:7. During the gasification, pyrolysis occurred first to facilitate the decomposition of petcoke particles and S/N removal. Desulfurization with the CO/HO gas mixture could be expressed as thiophene-S → S → COS → CHOS, thiophene-S → S → HS → HS. The N-containing components experienced complicated mutual reactions before being transferred into CON, HN, HCN, and NO. Simulating the gasification process on a molecular level is helpful in capturing the detailed S/N conversion path and reaction mechanism.
去除对环境有害的硫/氮对于将高硫石油焦（petcoke）用作燃料至关重要。石油焦气化可提高脱硫和脱硝效率。在此，通过反应力场分子动力学（ReaxFF MD）模拟了石油焦与两种有效气化剂（CO和H₂O）混合物的气化过程。通过改变CO/H₂O比例揭示了混合剂对产气的协同作用。确定H₂O含量的增加可提高气体产率并加速脱硫。当CO/H₂O比例为3:7时，气体生产率达到65.6%。在气化过程中，首先发生热解以促进石油焦颗粒的分解和硫/氮的去除。用CO/H₂O气体混合物脱硫可表示为噻吩-S → S → COS → CH₃OS，噻吩-S → S → H₂S → HS⁻。含氮成分在转化为CO₂、H₂N、HCN和NO之前经历了复杂的相互反应。在分子水平上模拟气化过程有助于捕捉详细的硫/氮转化路径和反应机理。
