中文摘要：

硝化反应大多为快速强放热反应,要求硝化反应器应同时具备优良的混合和传热性能。采用新型螺旋盘管反应器并以混酸硝化苯作为工作体系进行了硝化工艺研究,考察了循环流量、混酸流量、混酸组成、反应温度等因素对苯转化率和硝化反应选择性的影响规律,并与螺旋盘管直径和长度相同的直管硝化工艺进行了对比研究。结果表明,在实验考察范围内,反应温度或物料循环流量提高时,硝基苯的选择性提高,但苯的转化率有所降低。增大混酸流量或混酸中硫酸摩尔比时,可提高苯的转化率,但由于增大了酸局部过量的几率,副产物亦随之增加。与直径和长度相同的直管相比,螺旋盘管反应器硝化过程中苯的转化率和硝基苯的选择性均有所提高。

英文摘要：

The majority of nitration reactions belong to fast and strong exothermic reaction.Therefore,nitration reactors are demanded to have good mixing and heat-transfer performance simultaneously.In this paper,a novel helical tube reactor was used as nitration reactor,and benzene nitration with mixed acid was employed as working system.Effects of circulating volume flowrate,mixed acid volume flowrate,reaction temperature and molar ratio of sulfuric acid to nitric acid on the conversion of benzene and reaction selectivity were studied.Comparison of nitration process in helical tube and in straight tube was also conducted.Experimental results show that the selectivity of nitrobenzene increases,and the conversion of benzene decreases with the increase of circulating volume flowrate of benzene or reaction temperature.The increase of mixed acid volume flowrate or the molar ratio of sulfuric acid to nitric acid results in the increase of conversion of benzene and the decrease of selectivity of nitrobenzene,and the reason is that the high probability of local excess of acid leads to the increase of by-products.By comparison,the conversion of benzene and selectivity of nitrobenzene in the helical tube are higher than that in the straight tube with similar diameter and length.