SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 58 ›› Issue (6): 291-305.DOI: 10.1016/j.cjche.2022.12.004

• Full Length Article • 上一篇    下一篇

Microscopic mechanism study and process optimization of dimethyl carbonate production coupled biomass chemical looping gasification system

Wende Tian, Jiawei Zhang, Zhe Cui, Haoran Zhang, Bin Liu   

  1. College of Chemical Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
  • 收稿日期:2022-01-26 修回日期:2022-12-03 出版日期:2023-06-28 发布日期:2023-08-31
  • 通讯作者: Zhe Cui,E-mail:cuiz@qust.edu.cn
  • 基金资助:
    The authors gratefully acknowledge that this work is supported by the National Natural Science Foundation of China (22178189), the Natural Science Foundation of Shandong Province (ZR2021MB113), and the Postdoctoral Science Foundation of China (2022M711746).

Microscopic mechanism study and process optimization of dimethyl carbonate production coupled biomass chemical looping gasification system

Wende Tian, Jiawei Zhang, Zhe Cui, Haoran Zhang, Bin Liu   

  1. College of Chemical Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
  • Received:2022-01-26 Revised:2022-12-03 Online:2023-06-28 Published:2023-08-31
  • Contact: Zhe Cui,E-mail:cuiz@qust.edu.cn
  • Supported by:
    The authors gratefully acknowledge that this work is supported by the National Natural Science Foundation of China (22178189), the Natural Science Foundation of Shandong Province (ZR2021MB113), and the Postdoctoral Science Foundation of China (2022M711746).

摘要: Biomass chemical looping gasification technology is one of the essential ways to utilize abundant biomass resources. At the same time, dimethyl carbonate can replace phosgene as an environment-friendly organic material for the synthesis of polycarbonate. In this paper, a novel system coupling biomass chemical looping gasification with dimethyl carbonate synthesis with methanol as an intermediate is designed through microscopic mechanism analysis and process optimization. Firstly, reactive force field molecular dynamics simulation is performed to explore the reaction mechanism of biomass chemical looping gasification to determine the optimal gasification temperature range. Secondly, steady-state simulations of the process based on molecular dynamics simulation results are carried out to investigate the effects of temperature, steam to biomass ratio, and oxygen carrier to biomass ratio on the syngas yield and compositions. In addition, the main energy indicators of biomass chemical looping gasification process including lower heating value and cold gas efficiency are analyzed based on the above optimum parameters. Then, two synthesis stages are simulated and optimized with the following results obtained: the optimal temperature and pressure of methanol synthesis stage are 150 ℃ and 4 MPa; the optimal temperature and pressure of dimethyl carbonate synthesis stage are 140 ℃ and 0.3 MPa. Finally, the pre-separation-extraction-decantation process separates the mixture of dimethyl carbonate and methanol generated in the synthesis stage with 99.11% purity of dimethyl carbonate. Above results verify the feasibility of producing dimethyl carbonate from the perspective of multi-scale simulation and realize the multi-level utilization of biomass resources.

关键词: Biomass chemical looping gasification, Reactive force field molecular dynamics simulation, Separation, Multi-scale simulation

Abstract: Biomass chemical looping gasification technology is one of the essential ways to utilize abundant biomass resources. At the same time, dimethyl carbonate can replace phosgene as an environment-friendly organic material for the synthesis of polycarbonate. In this paper, a novel system coupling biomass chemical looping gasification with dimethyl carbonate synthesis with methanol as an intermediate is designed through microscopic mechanism analysis and process optimization. Firstly, reactive force field molecular dynamics simulation is performed to explore the reaction mechanism of biomass chemical looping gasification to determine the optimal gasification temperature range. Secondly, steady-state simulations of the process based on molecular dynamics simulation results are carried out to investigate the effects of temperature, steam to biomass ratio, and oxygen carrier to biomass ratio on the syngas yield and compositions. In addition, the main energy indicators of biomass chemical looping gasification process including lower heating value and cold gas efficiency are analyzed based on the above optimum parameters. Then, two synthesis stages are simulated and optimized with the following results obtained: the optimal temperature and pressure of methanol synthesis stage are 150 ℃ and 4 MPa; the optimal temperature and pressure of dimethyl carbonate synthesis stage are 140 ℃ and 0.3 MPa. Finally, the pre-separation-extraction-decantation process separates the mixture of dimethyl carbonate and methanol generated in the synthesis stage with 99.11% purity of dimethyl carbonate. Above results verify the feasibility of producing dimethyl carbonate from the perspective of multi-scale simulation and realize the multi-level utilization of biomass resources.

Key words: Biomass chemical looping gasification, Reactive force field molecular dynamics simulation, Separation, Multi-scale simulation