(762g) Triflic Acid Catalyzed Continuous Alkylation of Isobutane and Butene with Ionic Liquids As a Promoter

Haifang Li^ab, Guoying Zhao^a*, Huiting Liu^a, Fangfang Liu^b,Suojiang Zhang^a

^a State Key Laboratory of Multiphase Complex System, Beijing Key Laboratory of Ionic Liquid Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China

^b College of Chemical and Pharmacetical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China

*Corresponding author:   gyzhao@home.ipe.ac.cn

Abstract

The alkylation of isobutane with C₃-C₅ olefin is an important refinery process, which form a highly branched C₈ paraffins mixture with high research octane number (RON) and free of sulphur and aromatics. An improved process for the continuous alkylation of isobutene and butene in the presence of the acidic ionic liquid catalysts which could be effectively tuned physical-chemical properties of the catalytic systems containing the acidity, solubility, density, viscosity, interfacial properties and so on were reported in this study. The acidic ionic liquids catalysts have been prepared from the quaternary ammonium-based ionic liquids with varied anion (such as BF₄^-, PF₆^- SbF₆^- or NTf₂^-) and triflic acid. In addition, several additives, including metal triflates, trifluoroethanol, PPh₃ and so on, were used further to improve the catalytic performances. High-quality alkylate with up to 90% C₈selectivity and 98 RON value were achieved with the optimized catalyst and operation condition. ICP-Mass, refractometer and UV spectroscopy were used to study the changing trends of the catalytic composition and catalytic performance as well as alkylate quality in the continuous process.

References:

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Acknowledgements

We would like to thank the financial support from the Beijing Municipal Natural Science Foundation (grand No. 2122052) and Key Program of National Natural Science Foundation of China (grant No. 21036007).