三乙胺为催化剂正丁醇乙氧基化过程模拟与分析

Simulation and Analysis of Ethoxylation of n-butanol over Triethylamine Catalyst

研究了以三乙胺为催化剂,正丁醇乙氧基化反应合成乙二醇单丁醚(EGMBE)的可行性和反应动力学行为。依据建立的催化反应动力学模型,模拟考察了体积为10 L、带冷凝回流的连续搅拌釜式反应器中的反应行为,取得优化的操作参数,并将模拟结果和实验结果进行比较。在优化条件下环氧乙烷的转化率达到99.2%,EGMBE选择性为68.2%,约有2.6%的环氧乙烷被Hoffman消去副反应及N,N-二乙基乙醇胺乙氧基化副反应消耗。研究表明,与传统的正丁醇钠催化剂比较,由于存在Hoffman消去副反应,三乙胺为催化剂条件下环氧乙烷的反应速率和乙二醇单丁醚的选择性均更低,工艺经济可行性的关键是回收更多有价值的副产物。

The feasibility and reaction kinetics of ethylene glycol monobutylether (EGMBE) from ethoxylation of n-butanol with triethylamine (TEA) as catalyst were studied. Based on the established kinetic model of catalytic reaction,the reaction behavior of the continuous stirred tank reactor with a volume of 10 liters and a reflux condenser was investigated. The optimized operating parameters were obtained and the simulation results were compared with the experimental results. Under the optimized conditions,the conversion of EO reached about 99.2% and the selectivity of EGMBE was about 68.2%. Approximately 2.6% of EO was consumed by the Hoffman elimination and ethoxylation of N,N-diethylethanolamine side reactions. Studies have shown that the reactive rate of EO and the selectivity of EGMBE were lower in the presence of TEA compared with the conventional n-butanol sodium catalyst due to the existence of Hoffman elimination side reaction. The key to the economic feasibility of the process was the recovery of more valuable by-products.