Long reaction time, poor process safety and enormous amount of waste acids were the main problems in the sulfonation of naphthalene process. Naphthalene sulfonic acids were rapidly, safely, and continuously synthesized in integrated microstructured reactors. The reaction was carried out by first mixing naphthalene (dissolved in nonane) and sulfuric acid in the microreactor filled by 6 rings. Afterwards, the reaction mixture was flowed into a falling film micro-reactor (FFMR) for further sulfonation using SO3 gas as the sulfonating agent. In the stage of sulfuric acid as sulfonating agent, the effects of residence time, reaction temperature, and sulfuric acid to naphthalene molar ratio were investigated for the process of preparation of 1,3,6-naphthalene trisulfonic acid. Results showed that, 38.5% of 2-naphthalene sulfonic acid and 33.6% of 1,6-naphthalene disulfonic acid were obtained under conditions with sulfuric acid to naphthalene molar ratio of 3:1, reaction temperature of 160 ℃ ,and the residence time of 10 min, while the conversion of naphthalene was 99%. The above products then reacted in FFMR with SO3 at 90 ℃ for 8 min. The main product was 1,3,6-naphthalene trisulfonic acid with a yield of 71% , and naphthalene trisulfonic acid amount was over 99%.%针对萘的磺化过程中存在反应周期长、安全性差和产生的废酸多等问题,提出一种在微结构反应器内快速、安全、连续制备多种萘系磺酸的方法.先将溶解在壬烷中的萘与浓H2SO4输送到填有θ环的微结构反应器中,得到单萘磺酸和萘二磺酸；产物在微结构降膜反应器中与气体SO3磺化得到萘三磺酸.考察以H2SO4为磺化剂时,不同停留时间、H2SO4与萘摩尔比、反应温度对萘的转化率和产物分布的影响,并初步研究以气体SO3为磺化剂制备1,3,6-萘三磺酸的过程.结果表明:H2SO4与萘摩尔比为3∶1、反应温度为160℃、停留时间为10 min时,萘的转化率为99％,2-萘磺酸和1,6-萘二磺酸的质量分数分别为38.5％和33.6％.这2种产物与气体SO3在90℃下反应8 min后,得到的萘三磺酸总量大于99％,其中1,3,6-萘三磺酸的质量分数为71％.
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