固定床反应器中超临界酯交换反应连续制备生物柴油

Continuous production of biodiesel by supercritical transesterification in fixed bed reactors

反应器是生物柴油制备过程中的核心设备,优化反应器结构有利于降低制备成本,有效提高生物柴油转化率。为强化超临界连续化酯交换反应,文中对固定床反应器填料结构进行研究,以玻璃珠、玻璃弹簧以及θ环作为填料,分别考察温度、压力、流量、醇油物质的量比以及填料种类对超临界酯交换反应的影响。结果表明在温度为350℃、压力为22 MPa、醇油物质的量比42∶1、停留时间为717 s时,θ环作为填料时效果最佳,产率高达90.27%。对甲醇和豆油混合物进行热力学计算,得到混合物临界温度和临界压力,与实验现象相匹配,为温度、压力对酯交换反应的影响提供理论依据。

A reactor is the core equipment for biodiesel production,and well-designed reactor can reduce the production cost and increase the yield of biodiesel effectively. The packings＇ structures of the fixed bed reactors was investigated in order to strengthen the continuous supercritical transesterification. The effect of temperature,pressure,the molar ratio of methanol to oil,flow rate and the shape of the packings on the supercritical transesterification were researched and the highest yield 90.27% was obtained by filling the Dixon rings as packings under the condition of 350°C,pressure 22 MPa,the molar ratio of methanol to oil 42∶1 and the residence time 717 s. The critical temperature and pressure of the mixture of soybean oil and methanol were calculated by thermodynamic research,which matched well with the experimental data,providing a theoretical basis for the experiment.