微通道反应器中高效催化合成丙烯酸十四酯

High-Efficiency Catalytic Synthesis of Tetradecyl Acrylate in Microchannel Reactor

为解决丙烯酸高碳酯常规工艺合成过程中出现的收率低、控温不准确、生产不连续、副反应多、后处理难等问题,以微通道反应器合成丙烯酸十四酯为主要研究对象,结合红外光谱、核磁共振、沸点、折光率及偏光显微镜等手段对成品酯进行分析表征,系统考察了醇/酸摩尔比、反应温度、进料流量、催化剂及阻聚剂添加量等对丙烯酸十四酯收率的影响。结果表明:随着醇/酸摩尔比的减小,油浴加热温度升高,进料流量、催化剂和阻聚剂添加量的增大,丙烯酸十四酯的收率基本上呈现先增加后减小的趋势;在进料醇/酸摩尔比为1∶1.2、高温循环器油浴加热温度为150℃、催化剂对甲苯磺酸与阻聚剂对苯二酚添加质量分数分别为0.8%和0.6%、甲苯与十四醇质量比为0.8、进料流量为0.3 L/min优化工艺条件下,采用微通道反应器进行催化合成丙烯酸十四酯的收率最大,达到92.4%,而常规间歇式反应器在相似工艺条件下,丙烯酸十四酯的收率仅为82.0%,且反应时间更长;丙烯酸十四酯与油品中蜡晶具有相似的结晶形态,有利于其相互融合,产生共晶,从而表现出降凝功效。

To solve the problems of low yield,inaccurate temperature control,discontinuous production,many side reactions and difficult post-treatments in the conventional synthesis process of higher alcohol acrylate esters(HAAEs),synthesis of tetradecyl acrylate(TA)in a microchannel reactor was investigated.Effects of molar ratio of alcohol to acid,reaction temperature,feed flowrate,amount of catalyst and inhibitor on TA yield were systematically investigated by means of Fourier transform infrared spectrometer,nuclear magnetic resonance,boiling point measurement,refractive index and polarized microscope.Experimental results show that,reducing molar ratio of alcohol to acid and increasing reaction temperature,feed flowrate,catalyst amount and polymerization inhibitor,TA yield increases in the beginning and then decreases.Under the optimal process conditions(i.e.,molar ratio of alcohol to acid 1∶1.2,reaction temperature 150℃,0.8%mass fraction of p-toluene sulfonic acid as catalyst,0.6%mass fraction of p-dihydroxybenzene as polymerization inhibitor,mass ratio of toluene to tetradecanol 0.8,and feed flowrate 0.3 mL/min),TA yield can be up to 92.4%.However,the TA yield in conventional batch reactor is only 82.0%and it needs much longer reaction time to reach.The synthesized TA has similar crystalline morphology with wax crystals in crude oils and thus can form eutectic with wax crystals.Therefore,TA demonstrates pour point depression effect.