Biodiesel and oleo-chemical industries have been producing huge quantities of glycerol as a by-product. Value-added products can be synthesized from glycerol through different chemical and enzymatic reactions, such as oxidation, carbonylation, reforming, acetalyzation, etherification, dehydration, hydrogenolysis, hydrolysis, esterification, and transesterification. Glycerol is a low-cost polyol that can be converted into glycerol carbonate, which has potential applications in polymer and biobased non-isocyanate polyurethanes industries (Bio-NIPUs). The present contribution is the first of its kind to report on the synthesis of glycerol carbonate via catalyst and solvent-free transesterification of glycerol with dimethyl carbonate under conventional as well as microwave heating. Additionally, a comparative study of conventional and microwave-assisted transesterification was performed. Under conventional heating, 78% glycerol carbonate is obtained at 120oC in 36 hours, whereas, using microwaves, 92% of glycerol carbonate can be achieved in 30 minutes. Presently, biomass-based heterogeneous materials are used in catalysis due to their importance within the context of sustainability. In line with this, in this work, a series of green catalysts, namely, molecular sieves (MS, 4Å), Hβ- Zeolite, Montmorillonite K-10 clay, activated carbon prepared from the shell of groundnut (Arachis hypogaea), and biochar from sawdust pyrolysis were successfully employed. Glycerol carbonate was thoroughly characterized by 1H and 13C NMR, FT-IR and MS. The method described here is facile and green since the utilization of bioresource (glycerol) for the production of glycerol carbonate is performed under microwave.

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碳酸甘油酯可以在没有催化剂的情况下合成吗？

生物柴油和油脂化学工业一直在生产大量的甘油作为副产品。甘油可以通过不同的化学和酶促反应合成增值产品，例如氧化、羰基化、重整、乙酰化、醚化、脱水、氢解、水解、酯化和酯交换。甘油是一种低成本多元醇，可转化为碳酸甘油酯，在聚合物和生物基非异氰酸酯聚氨酯工业（Bio-NIPU）中具有潜在应用。本论文首次报道了在常规加热和微波加热下通过催化剂合成甘油碳酸酯以及甘油与碳酸二甲酯的无溶剂酯交换反应。此外，还对传统酯交换反应和微波辅助酯交换反应进行了比较研究。常规加热下，120℃下36小时可得到78%的碳酸甘油酯，而使用微波，30分钟内可得到92%的碳酸甘油酯。目前，基于生物质的异质材料由于其在可持续发展方面的重要性而被用于催化。与此相一致，在这项工作中，一系列绿色催化剂，即分子筛（MS，4Å）、Hβ-沸石、蒙脱石K-10粘土、花生壳制备的活性炭和生物炭木屑热解法已成功应用。通过 1H 和 13C NMR、FT-IR 和 MS 彻底表征了甘油碳酸酯。这里描述的方法简单且绿色，因为利用生物资源（甘油）来生产碳酸甘油酯是在微波下进行的。