高酸值废弃油脂制备生物柴油的预酯化

摘要

为了有效解决现有酯化体系中存在反应慢、时间长、产能低等问题，提出了一种高温下甲醇连续酯化反应的新技术，并采用该技术以对甲苯磺酸为催化剂催化高酸值废弃油脂预酯化试验研究。系统讨论了不同酯化方法对反应的影响，并着重研究了工艺条件对预酯化效果的影响。实验结果表明：高温下甲醇连续酯化的新技术可显著提高酯化反应效率，在反应温度120℃、甲醇流量4.0mL/min、催化剂加入量0.8%的条件下，酯化率达98.8%以上，可将油脂的酸值降至1.0mgKOH/g以下，满足下一步酯交换制备生物柴油的要求；并基于实验研究的基础上将该技术工艺对不同酸值的废弃油脂进行了放大试验研究，皆取得了较好的酯化效果，为产业化、规模化的应用提供理论依据和参数指导。%In order to effectively solve problems in current esterification system,such as low reaction rate,long reaction time and low yield,this paper proposes a new continuous esterification technology at high temperature. The pre-esterification of high acid value waste oil catalyzed by solid acid was carried out based on the technology. The effects of process conditions on esterification were studied, and the influence of different esterification method for reaction was discussed. The optimal reaction condition for pre-esterification was obtained as follow:the flow velocity of methanol is 4.0mL/min,the temperature of reaction kettle was 120℃,catalyst dosage was 0.8% of raw materials. Under this condition,the esterification rate was above 98.5%,and the acid value of waste oil could be reduced to 1.0mgKOH/g,which satisfied the transesterification requirement on acid value. The scale-up experiment was conducted to investigate this technology using waste oils with different acid values. The results showed that a good esterification efficiency was obtained,would provide the theoretical basis and parameter guidance for the industrial application of this technology.