化工学报 ›› 2018, Vol. 69 ›› Issue (11): 4832-4839.DOI: 10.11949/j.issn.0438-1157.20180659

• 表面与界面工程 • 上一篇    下一篇

离子液体/硫酸催化C4烷基化反应过程强化——表界面特性研究

曹飘, 郑伟中, 孙伟振, 赵玲   

  1. 化学工程联合国家重点实验室, 华东理工大学, 上海 200237
  • 收稿日期:2018-06-14 修回日期:2018-08-27 出版日期:2018-11-05 发布日期:2018-11-05
  • 通讯作者: 孙伟振
  • 基金资助:

    国家自然科学基金项目(91434108)。

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

CAO Piao, ZHENG Weizhong, SUN Weizhen, ZHAO Ling   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2018-06-14 Revised:2018-08-27 Online:2018-11-05 Published:2018-11-05
  • Supported by:

    supported by the National Natural Science Foundation of China (91434108).

摘要:

利用分子动力学(MD)模拟研究了不同支链长度以及官能团的Brønsted酸性离子液体(BILs)对H2SO4/C4烷烯界面特性的调控。结果表明,BILs的加入可以明显增强C4烷烯在两相界面处的溶解和扩散,有利于烷基化油品的提升。烷基链较长的阳离子表现出较强的界面密度富集现象,并且其支链倾向于伸入C4烷烯相,有利于界面性质的增强。阳离子支链的增长能够促进C4烷烯的溶解,同时增大了C4烷烯的界面存留率,不利于其界面扩散。另外,相比于非磺酸功能化离子液体(non-SFILs),磺酸功能化离子液体(SFILs)促进了C4烷烯的溶解,但抑制了C4烷烯的扩散。本文在C4烷基化界面性质方面的研究有利于深入理解C4烷基化过程,相关结果有望为烷基化过程强化和新型催化剂的优化和设计提供帮助。

关键词: MD模拟, Brønsted离子液体, 液液界面, 烷基化, SFILs

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 hydrocarbons were studied by molecular dynamic (MD) simulation. The results indicated that the introduction of BILs into the H2SO4 can contribute to a better dissolution and diffusion of C4 hydrocarbons at the interface compared to the 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-SFILs, the sulfonic-acid-functionalized ILs (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 provide 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.

Key words: MD simulations, Brønsted ionic liquids, liquid/liquid interface, alkylation, SFILs

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