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在较低压力(1.0—2.0mPa)下,研究了杂多酸对丙烯和醋酸的气-液加成酯化反应的催化作用。实验表明杂多酸具有很高的活性和选择性,其活性大小次序为:12-钨磷酸≈12-钨硅酸>10-钼磷酸≈12-钼磷酸,在以最佳反应温度(T_(opt))为界的两个温度段,温度的影响不同,即:TT_(opt)时随反应温度升高醋酸转化率降低,在液相中含水量低于1.0％时,醋酸转化率随含水量增加急剧增高;含水量在1.0～2.0％时达极大值;含水量进一步增加时,醋酸转化率减少,伴生的异丙醇量增加,还考察了反应压力和时间等因素的影响,提出了由丙烯与醋酸生成醋酸异丙酯和伴生异丙醇的反应机理。
At lower pressure (1.0-2.0mPa), the catalytic effect of heteropolyacid on gas-liquid addition esterification of propylene and acetic acid was studied. Experiments show that heteropolyacid has high activity and selectivity, the order of its activity size is: 12-tungstophosphoric acid ≈12-tungstosilicic acid> 10-molybdophosphoric acid ≈12-molybdophosphoric acid, at the optimum reaction temperature (T_ ( opt), the effects of temperature are different, that is, the conversion of acetic acid increases with the increase of reaction temperature at T T_ (opt) , When the water content is less than 1.0%, the conversion of acetic acid increases sharply with the increase of water content; when the water content reaches 1.0-2.0%, the conversion reaches the maximum; when the water content further increases, the conversion of acetic acid decreases The amount of isopropanol was also increased. The effects of reaction pressure and time were also investigated. The reaction mechanism of isopropyl acetate and isopropanol with propylene and acetic acid was proposed.