Study On Synthesis Diethyl Oxalate Through CO Coupling Reaction

Synthesis of diethyl oxalate through CO coupling reaction is an environment friendly and atomic economy technology, it will replace the conventional method to synthesis of diethyl oxalate. Study on the catalyst and reaction mechanism can provide the theory basis for industrial production, so it is in dire need currently.In the thesis, Palladium catalyst withα-Al2O3 as support was studied on the catalytic activity. Through analysis of the specific area and pore structure, it was found that pore size distribution was an important factor affecting the catalytic activity, which is identified with previous researches. The paper also presents the influence of reactor diameter and catalyst volume to the catalytic activity, it was found that as diameter reducing and catalyst volume magnifying, the STY increased and the selectivity decreased.Thiele modulus and internal diffusion effectiveness factor of catalysts were important factors which indicated the internal diffusion, so they were calculated in the paper. Thiele modulus of catalysts were tiny, and in the experiment it was testified that there was little internal diffusion. Experiment was carried out at different gas velocity with 5g and 2.5g catalyst, CO conversion was testified close, it was indicated that the condition of experiment was out of external diffusion.The kinetic experiment was carried out on Pd catalyst at the optimum CO coupling reaction conditions as described: temperature 100℃~120℃, residence time 1~2.5s, mole concentration of ethyl nitrite between 10%~15%, and CO mole concentration 25%~30%. Simplex method was used to optimize these data and the kinetics of CO coupling reaction was simulated using power function type as follow:Because the activation energy in major reaction equation was larger, heightening temperature will accelerate the reaction. In the kinetic equation, the power of ethyl nitrite is larger than the power of CO, so more content of EN would be better to DEO yield.