Abstract: A process for producing a high-purity dimethyl carbonate, which includes: (I) cooling a commercial grade dimethyl carbonate containing 1 ppm or more of chlorine to a temperature from +6° C. to ?5° C. at a rate from 0.5-2° C./hour, to obtain a first solid dimethyl carbonate; (II) heating the first solid dimethyl carbonate to a temperature from ?5° C. to +6° C. at a rate of 1-5° C./hour, to obtain a mixture comprising a second solid dimethyl carbonate and a predetermined amount of a first liquid dimethyl carbonate; (III) separating the first liquid dimethyl carbonate from the mixture, to obtain the second solid dimethyl carbonate; (IV) heating the second solid dimethyl carbonate to a temperature from 20° C. to 40° C., to obtain a second liquid dimethyl carbonate, wherein the second liquid dimethyl carbonate has a purity degree higher than 99.99% and a chlorine content lower than or equal to 1 ppm.

Abstract: A process for producing a high-purity dimethyl carbonate, which includes: (I) cooling a commercial grade dimethyl carbonate containing 1 ppm or more of chlorine to a temperature from +6° C. to ?5° C. at a rate from 0.5-2° C./hour, to obtain a first solid dimethyl carbonate; (II) heating the first solid dimethyl carbonate to a temperature from ?5° C. to +6° C. at a rate of 1-5° C./hour, to obtain a mixture comprising a second solid dimethyl carbonate and a predetermined amount of a first liquid dimethyl carbonate; (III) separating the first liquid dimethyl carbonate from the mixture, to obtain the second solid dimethyl carbonate; (IV) heating the second solid dimethyl carbonate to a temperature from 20° C. to 40° C., to obtain a second liquid dimethyl carbonate, wherein the second liquid dimethyl carbonate has a purity degree higher than 99.99% and a chlorine content lower than or equal to 1 ppm.

Abstract: Process for the preparation of dimethylcarbonate which consists in feeding oxygen and a mixture of methanol and carbon monoxide to the reactor, with a molar ratio methanol/carbon monoxide of between 1 and 2, this mixture coming directly from the non catalytic direct oxidation of methane with oxygen characterized in that the above molar ratio between methanol and carbon monoxide, with fixed temperature and pressure values, is obtained by maintaining the ratio between methane and oxygen between 1 and 100, by injections of fresh oxygen into a tubular reactor, during the above oxidation reaction.