A catalyst-free novel synthesis of diethyl carbonate from ethyl carbamate in supercritical ethanol

Diethyl carbonate has been synthesized via the alcoholysis of ethyl carbamate in supercritical ethanol under catalyst-free conditions. The influences of various parameters such as reaction temperature, reaction time, reaction pressure, ethanol/ethyl molar ratios and reaction loading volume on the yield of DEC were studied systematically. The experimental results indicated that the alcoholysis of ethyl carbamate was greatly improved in supercritical ethanol. The optimal reaction conditions were as follows: a reaction temperature of 573 K, a reaction time of 30 min, a reaction pressure of 13.2 MPa, an ethanol/ethyl carbamate molar ratio of 10 and a reactor loading volume of 285 μL respectively. The optimal yield of DEC was 22.9%.