Intensification of isobutane alkylation with C4 olefin catalyzed by ionic liquid/sulfuric acid—interfacial features

CAO Piao1 ZHENG Weizhong1 SUN Weizhen1 ZHAO Ling

(1.State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, China 200237)
【Knowledge Link】alkylation

【Abstract】The intensification of the Brønsted acidic ionic liquids (BILs) with different alkyl chain lengths with or without the sulfonic acid groups on the interfacial behaviors of H2SO4/C4 carbons were studied by molecular dynamics (MD) simulation. The results indicated that the introduction of BILs into the H2SO4 could contribute to a better dissolution and diffusion of C4 hydrocarbons at the interface compared to pure H2SO4, which is helpful to the quality of alkylate. The stronger density enrichment at interface can be found for the cations with longer alkyl chains with their alkyl chains protruding more deeply into the C4 hydrocarbons phase, which is beneficial to the enhancement of the interfacial properties. The longer alkyl chains can facilitate the dissolution of C4 hydrocarbons, but increase the survival probability at the interface and limits their interfacial diffusion. Compared to the non-sulfonic-acid-functionalized ILs (non-SFILs), SFILs can facilitate a higher dissolution of isobutane but inhibit its diffusion at the interface. In this work, the intensification on the interfacial behaviors of C4 alkylation provides deeper understanding of the C4 alkylation process. The related results are expected to help the alkylation process strengthening and optimization and design of new catalysts.

【Keywords】 MD simulations; Brønsted ionic liquids; liquid/liquid interface; alkylation; SFILs;

【DOI】

【Funds】 National Natural Science Foundation of China (91434108)

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This Article

ISSN:0438-1157

CN: 11-1946/TQ

Vol 69, No. 11, Pages 4832-4839+4490

November 2018

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Abstract

  • Introduction
  • 1 Simulation method
  • 2 Results and discussion
  • 3 Conclusions
  • Symbol description
  • References