SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 33 ›› Issue (5): 139-146.DOI: 10.1016/j.cjche.2020.06.011

• Catalysis, Kinetics and Reaction Engineering • Previous Articles     Next Articles

Formation kinetics of polyoxymethylene dimethyl ethers from methylal and trioxane with little water

Xiaofei Qin1, Sen Lei2, Xubin Zhang1, Chen Cao1, Feng Xin1, Honglin Chen2, Xiaoming Zhang2, Yachen Yin1, Guilian Wu1   

  1. 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2 Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
  • Received:2020-04-09 Revised:2020-05-12 Online:2021-08-19 Published:2021-05-28
  • Contact: Xubin Zhang, Feng Xin
  • Supported by:
    This research was supported by the National Key R&D Program of China (2018YFB0604900).

Formation kinetics of polyoxymethylene dimethyl ethers from methylal and trioxane with little water

Xiaofei Qin1, Sen Lei2, Xubin Zhang1, Chen Cao1, Feng Xin1, Honglin Chen2, Xiaoming Zhang2, Yachen Yin1, Guilian Wu1   

  1. 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China;
    2 Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
  • 通讯作者: Xubin Zhang, Feng Xin
  • 基金资助:
    This research was supported by the National Key R&D Program of China (2018YFB0604900).

Abstract: Polyoxymethylene dimethyl ethers (CH3-O-(CH2O)n-CH3, PODEn, n>1) can be added to diesel to reduce air pollution caused by incomplete combustion. Driven by this need, a cost-effective and efficient synthetic route is presented and investigated by this work for the production of PODEn, which are formed from methylal and trioxane with low water content (b10 %(mass)) over HZSM-5 catalyst in a batch slurry autoclave at the temperature from 353.15 K to 393.15 K. The reaction rate laws including the PODEn and byproducts of polyoxymethylene hemiformals (HFn), polyoxymethylene glycols (MG), methanol (MeOH) and methyl formate (MF) are developed. The rate constants of propagation step (k6) and depolymerization step (k-6) are assumed independent on polymerization degree of PODEn. The rate of reaction is proportional to the content of the catalyst (Wcat) for the catalytic reaction within the scope of the study. All kinetic parameters were estimated by combining genetic algorithm and least square regression to fit experimental data well. This work is valuable for process optimization and reactor design.

Key words: Fuel additive, Polyoxymethylene dimethyl ethers, Kinetics, HZSM-5

摘要: Polyoxymethylene dimethyl ethers (CH3-O-(CH2O)n-CH3, PODEn, n>1) can be added to diesel to reduce air pollution caused by incomplete combustion. Driven by this need, a cost-effective and efficient synthetic route is presented and investigated by this work for the production of PODEn, which are formed from methylal and trioxane with low water content (b10 %(mass)) over HZSM-5 catalyst in a batch slurry autoclave at the temperature from 353.15 K to 393.15 K. The reaction rate laws including the PODEn and byproducts of polyoxymethylene hemiformals (HFn), polyoxymethylene glycols (MG), methanol (MeOH) and methyl formate (MF) are developed. The rate constants of propagation step (k6) and depolymerization step (k-6) are assumed independent on polymerization degree of PODEn. The rate of reaction is proportional to the content of the catalyst (Wcat) for the catalytic reaction within the scope of the study. All kinetic parameters were estimated by combining genetic algorithm and least square regression to fit experimental data well. This work is valuable for process optimization and reactor design.

关键词: Fuel additive, Polyoxymethylene dimethyl ethers, Kinetics, HZSM-5