The production of glycerol carbonate (GC) from industrial grade crude glycerol was catalyzed by calcium oxide (CaO) via microwave assisted transesterification (MAT). Influencing process parameters including reaction temperature, time and molar ratio of dimethyl carbonate/glycerol (DMC/Gly) were examined and optimized by applying Box Behnken Design (BBD). The reaction was modelled into a reduced cubic model with good predictive accuracy. A high GC yield of 99.5% was achieved with 1 wt% CaO at optimized conditions such as reaction temperature of 65 °C, reaction time of 3 min and DMC/Gly molar ratio of 2.5. The study performed on the reaction kinetics suggests that the reaction follows an irreversible second order rate equation. A relatively low activation energy of 4.53 kJ mol⁻¹ was determined for the microwave assisted transesterification of crude glycerol for the production of GC. The values of rate constants between 45 °C to 65 °C were in the range of 0.023–0.026 L mol⁻¹ min⁻¹, which are of one magnitude order higher than that of the conventional heating.

中文翻译：

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微波辅助粗甘油甘油酯交换制备碳酸甘油酯的工艺和动力学

由工业级粗甘油生产碳酸甘油酯（GC）是通过微波辅助酯交换反应（MAT）由氧化钙（CaO）催化的。应用Box Behnken Design（BBD）检查并优化了影响工艺参数，包括反应温度，时间和碳酸二甲酯/甘油（DMC / Gly）的摩尔比。将反应建模为具有良好预测精度的简化立方模型。在优化的条件下，例如65℃的反应温度，3分钟的反应时间和2.5的DMC / Gly摩尔比，在1％的CaO下可达到99.5％的高GC收率。对反应动力学的研究表明，该反应遵循不可逆的二级速率方程。4.53 kJ mol ^-1的较低活化能测定用于粗甘油的微波辅助酯交换以生产GC。45°C至65°C之间的速率常数的值在0.023–0.026 L mol ^-1 min ^-1的范围内，比常规加热的速率常数高一个数量级。