Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol under Supercritical CO_2 Condition

The new route of synthesis of dimethyl carbonate by the reaction of methanol with carbon dioxide in the presence of K_2CO_3 and CH_3I near the critical point of CO_2 was studied. The reactions were carried out in a stainless steel autoclave with inner volume of 500 mL provided with a magnetic stirrer and an electric heater. The products were analyzed by means of GC with a thermal conductivity detector. The influences of reaction temperature and pressure on the production of DMC were investigated, respectively. From the viewpoint of the unique characteristic of supercritical CO_2, the reaction mechanism was discussed.