水力空化场苯-甲醇低温烷基化制备二甲苯

基于文丘里型空化管的水力空化场强化，苯与甲醇在低温下进行烷基化反应；采用气相色谱 质谱联用分析反应产物，考察反应条件对反应效果的影响，并根据产物分布，推测并验证了反应历程。结果表明：在水力空化条件下，苯与甲醇在低温下发生了烷基化反应，其主要反应产物为甲苯、二甲苯和乙苯。最佳反应条件为：空化管入口压力0.4 MPa，反应终温40 ℃，苯摩尔分数20%，时间40 min。该反应历程为：在水力空化场强化下，苯与甲醇解离生成·C₆H₅、·H、·CH₃和·OH，继而·C₆H₅与·CH₃和·H发生自由基串联反应，依次生成烷基苯和烷基环烷烃，·OH与·C₆H₅或·H发生自由基反应，分别生成苯酚或水。

Low Temperature Alkylation of Benzene and Methanol in Hydrocavitation Field

The alkylation of benzene and methanol was strengthened in the field of hydrodynamic cavitation based on a Venturi tube at low temperature. Reaction products were analyzed by gas chromatography-mass spectrometry, and the influence of reaction conditions on the reaction was investigated. Subsequently, the reaction process was proposed according to the products distribution. Results show that the main products of alkylation reaction between benzene and methanol are toluene, xylene and ethylbenzene. The optimum reaction conditions are Venturi tube inlet pressure of 0.4 MPa， final temperature of 40 ℃， benzene molar fraction of 20%， and time of 40 min. With the enhancement of hydrodynamic cavitation field, benzene and methanol are dissociated to generate ·C₆H₅, ·H, ·CH₃ and ·OH, respectively. Afterwards, ·C₆H₅ and ·CH₃ form alkyl benzene, alkyl benzene and ·H generate alkyl cycloalkane, whereas ·OH reacts with ·C₆H₅ or ·H to form phenol or water.