微反应器中乙炔法合成N-乙烯基吡咯烷酮的过程研究

搭建了以商用微反应器为核心的气液微反应系统，成功实现了加压乙炔法合成N-乙烯基吡咯烷酮（NVP）的产品过程，采用液相循环方式完成反应物2-吡咯烷酮的高效转化，全面考察了反应温度、KOH含量、内构件数量和原料乙炔纯化对液相反应的影响。结果表明，反应温度和KOH含量对选择性有显著影响，高温和高含量催化剂会严重降低产物NVP的选择性，综合调控反应温度和KOH含量，可保证产物选择性在95%以上；微反应器中内构件的存在有利于促进气液传质过程；反应体系水分的脱除有助于循环反应中转化率和选择性的提高；与高压釜相比，产物NVP收率提高了28.7%（无助剂），反应时间有适当缩短。

Synthesis of N-vinyl pyrrolidone by acetylene process in a microreactor

Vinylation reaction of 2-pyrrolidone with acetylene to synthesize N-vinyl pyrrolidone was successfully implemented in a microreactor, which had the advantages of the intrinsic safety of acetylene and intensified gas-liquid mass transfer. To realize the efficient transformation of the reactants, the liquid phase was recycled to obtain the sufficient gas-liquid contact time. The effects of reaction temperature, KOH content, internals in the microreactor and acetylene purifier on vinylation reaction with the recycled liquid phase were investigated in detail. The results showed that both reaction temperature and KOH content had significant effects on the selectivity to N-vinyl pyrrolidone. The higher reaction temperature and higher catalyst content caused the reduction of the selectivity seriously, among which a better result of >95% selectivity to NVP can be achieved by comprehensive control of these two operation conditions. The application of internals improved the mixing efficiency and promoted the gas-liquid mass transfer rate evidently. As a comparison, the yield of NVP was increased by 28.7% (without promoters) against the semi-continuous process in autoclaves, and the reaction time was shortened as well.