Ionic Liquid Catalyst Used in Deep Desulfuration of the Coking Benzene for Producing Sulfurless Benzene

• Published in: Chinese journal of chemistry 2008-04, Vol.26 (4), p.607-610
• Main Authors: ZHOU, Xia-Ping, WANG, Yan-Liang, MENG, Fan-Wei, FAN, Xing-Ming, QIN, Song-Bo
• Format: Article
• Language: English
• Subjects: acid ionic liquid; coking benzene; de-thiophene; ionic liquid; sulfurless benzene
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.200890114

For the widening need of benzene used in organic synthesis, ionic liquid catalyst was prepared to study the process of deep desulfuration in the coking benzene. The result shows that the effect of de‐thiophene by the ionic liquid catalyst (N‐methyl imidazolium hydrogen sulfate [Hmim][HSO4]) is related to its acid function value. Hammett indicator was used to determine the acid function value H0 of the ionic liquid. It can be concluded that while the acid function value is in the range from −4 to −12, the ionic liquid catalyst can make the concentration of thiophene in the coking benzene be under 0.5 mg·L−1. Similarly to the catalytic mechanism of solid acid, with a certain acid quantity and strength, the ionic liquid catalyst helps to form alkyl thiophene through Friedel‐Crafts reaction, which differs from the character of benzene and it is absolutely necessary for the separation and refinement of benzene. But overabundant quantity and higher acid value of [Hmim][HSO4] are more suitable for the side copolymerization of benzene, thiophene and alkene, thereby affecting repeated use of the ionic liquid catalyst([Hmim][HSO4]). In our research, thiophene derivant produced by desulfurization in the coking benzene was used as the polymer to provide the passing channel of the charges. The ionic liquid composition in poor performance after repeated use was made to prepare conductive material (resisting to static electricity) as an "electron‐receiving" and "electron‐giving" doping agent. The result shows that thiophene derivant after desulfuration in the coking benzene can be used to prepare doping conductive materials.