环氧乙烷与CO_2合成碳酸乙烯酯动力学研究

环氧乙烷与CO2合成法是一种具有工业应用价值的碳酸乙烯酯生产方法,有必要对其反应机理和动力学加以研究。文中假设CO2与环氧乙烷合成碳酸乙烯酯的反应按照亲核加成反应机理分3步进行,其中催化剂溴化四乙铵作为亲核试剂。在一定温度和一定的压力下,碳酸乙烯酯的合成反应速率正比于催化剂和环氧乙烷浓度。提出了动力学方程,通过实验对假设机理进行了验证,并回归得到动力学方程参数。所得合成碳酸乙烯酯的反应动力学方程对大规模工业化生产具有一定参考价值。

Study on the reaction kinetics of ethylene carbonate synthesized by ethylene oxide and carbon dioxide

Addition method of ethylene oxide(EO) and carbon dioxide(CO2) is a valuable process for commercial production of ethylene carbonate(EC).It is necessary to study the mechanism and kinetics of the reaction.The reaction of EC synthesized by EO and CO2 with tetraethyl ammonium bromide(TEAB) as catalyst was a nucleophilic addition reaction in three steps,the nucleophilic reagent was TEAB and the mechanism was SN2.It shows that the reaction rate is in direct proportion to the molar concentrations of catalyst and EO in certain pressure and temperature based on the experimental results.The kinetic equation was proposed.The experimental data verified the reasonability of the mechanism and the parameters were correlated by means of regressing the experimental results.The kinetic equation could be as a reference for designing commercial production of EC in larger scale.