Dimethylcarbonate (DMC) production based on the oxy-carbonylation of methanol: chemical process simulation and life cycle assessment

Dimethyl carbonate (DMC) has been playing a significant role in the chemical sector, mainly due to its versatility as reagent and solvent, and to the apparent absence of toxic effects on human health and ecosystems. DMC can be a good substitute for some organic solvents or reagents (e.g. phosgene and dimethyl sulfoxide) whose use have been criticized because of the high environmental risks. In addition to the traditional method of synthesis based on phosgene, DMC can be synthesized from: 1) methyl nitrite and carbon monoxide, 2) carbon monoxide and methanol, 3) urea and methanol, 4) ethylene oxide and carbon dioxide, 5) oxy-carbonylation of methanol. Some synthesis routes have been already exploited on a commercial scale, while others are still implemented on a pilot plant scale. In particular, the technology based on methanol oxy-carbonylation is obtaining an increasing industrial interest due to its potential environmental benefits, which are the use of relatively less hazardous materials and the production of water as only by-product. In this study, a "cradle to gate" LCA analysis is carried out on the DMC production based on the oxy-carbonylation process. Consumption of resources, materials and energy were modeled and included in the analysis. The results can be used for the environmental impact assessment of processes which use DMC as innovative solvent or additive (e.g. fuel production from vegetal oils).