水力空化场强化苯酚常温氧化制备苯醌

Oxidation of phenol into benzoquinone at room temperature reinforced byhydrodynamic cavitation field

基于文丘里型空化管的水力空化场强化,苯酚与过氧化氢在常温下进行氧化反应。采用气相色谱-质谱联用分析反应产物,考察反应条件对苯酚转化率的影响,并根据产物分布推测并验证了反应历程。在水力空化强化下,过氧化氢解离的羟基进攻苯酚形成对苯二酚,再由氢自由基的脱离形成半醌,最后成键形成苯醌。最佳反应条件:空化管入口压力0.4MPa,反应终温35.8℃,过氧化氢体积分数9%,溶剂水体积分数91%,初始苯酚加入量8g,反应时间10min。苯酚转化率和苯醌选择性分别为34.5%和80.5%。

The oxidation reaction between phenol and H 2O_(2) at room temperature was strengthened in the field of hydrodynamic cavitation on the basis of a Venturi tube. The products were analyzed by gas chromatography-mass spectrometry. The effect of reaction conditions on the phenol conversion efficiency was investigated, and the reaction process was also deduced and verified according to the products distribution. With the enhancement of hydrodynamic cavitation field, the hydroxide radical dissociated by H 2O_(2) could attack the phenol and thus transferred into hydroquinone. Hemiquinone was formed by the dissociation of hydrogen radicals, and finally bonded to form benzoquinone. The optimum reaction conditions were with 0.4 MPa venturi tube inlet pressure, 9% volume fraction of oxidant H 2O_(2), 91% volume fraction of solvent water, 8 g initial dosage of phenol, at 35.8 ℃ for 10 min, the conversion rate of phenol and the selectivity of benzoquinone are 34.5% and 80.5%.