草酸二甲酯加氢合成乙二醇反应的研究

在微型管式反应器中,采用Cu/SiO2催化剂,在温度190～210℃、压力1～3MPa、草酸二甲酯(DMO)与氢气的摩尔比(氢酯比)40～120、DMO空速6.0～25.0mmol/(g.h)的条件下,对DMO加氢制乙二醇的反应进行了研究。实验结果表明,高温、高压、高氢酯比和低DMO空速都能提高DMO的转化率和乙二醇的收率,但同时也增加了副产物的选择性。较适合的反应条件为:压力2MPa,温度205～210℃,氢酯比80～100,DMO空速10.0mmol/(g.h)。动力学研究表明,DMO加氢反应符合Langmuir-Hinshelwood吸附反应动力学模型,表面反应为速率控制步骤,氢气不解离吸附,由此得到了相应的动力学方程及参数。统计检验结果表明,该模型对DMO加氢反应高度适定。

Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

Hydrogenation of dimethyl oxalate(DMO) to ethylene glycol(EG) was investigated in a tubular microreactor on Cu/SiO2 catalyst.Effects of temperature,pressure,mole ratio of H2 to DMO and DMO space velocity on reaction were studied in ranges of 190-210 ℃,1-3 MPa,40-120 and 6.0-25.0 mmol/(g·h),respectively.Both DMO conversion and EG yield increased at higher temperature,higher pressure,larger mole ratio of H2 to DMO and lower DMO space velocity,but selectivity to byproduct also increased.The optimized reaction conditions were: pressure 2 MPa,temperature 205-210 ℃,mole ratio of H2 to DMO 80-100 and DMO space velocity 10.0 mmol/(g·h).Langmuir-Hinshelwood mechanism model with nondissociative hydrogen adsorption is remarkably suitable to DMO hydrogenation.Surface reaction is the velocity controlling step.The kinetic equation was checked by statistic test.