研究了在酸性体系中,用电场强化铁粉还原对苯醌制对苯二酚的方法,该法考察了铁粉用量、硫酸用量、硫酸加入方式、电解电压和反应时间对铁粉利用率与对苯二酚收率的影响,并在此基础上探讨了还原机理。结果表明:电场强化了还原反应过程中电子的定向迁移,活化了反应物。此时,在95℃下,当硫酸与铁粉的摩尔比n(硫酸)∶n(铁粉)=1∶3,采用逐步加入硫酸的方式,电解电压为3.0V,反应时间为2h时,铁粉利用率由28.57%提高到75.19%,对苯二酚收率达95%。与现有工艺相比,电场强化法的铁粉利用率高、还原过程无副产物,并且该法易于控制,反应周期短。
Preparation of hydroquinone fromp-benzoquinone intensified by reduction with iron powder was studied under electric field in the acidic system. The effects of dosage of iron powder,dosage of H2SO4,means of adding H2SO4,voltage and reaction time on the utilization ratio of iron powder and the yield of hydroquinone were investigated and the mechanism of the reaction process was studied. Electric field strengthened the electronic directional migration and activated iron powder in the reduction process.Optimal parameters were obtained with molar ratio of H2SO4/Fe 1:3 at 3.0V for 2h,and H2SO4 was added gradually. The utilization ratio of iron powder was increased from 28.57% to 75.19% and the yield of hydroquinone was up to 95%. Compared with the present industrial process, there was higher iron powder utilization and there was no reduction byproduct. Furthermore,the method was easy to control and could greatly shorten the reaction period.