Abstract:
The oil prices are constantly increasing which is motivating the researches to synthesize the alternative chemicals, which could have potential to be used as fuels. Moreover, the researchers are trying to blend certain chemical additives to fuels to reduce the use of current fuels-gasoline and diesel. The most challenging thing in synthesizing the fuel additive is to find the cheaper, easily available and environment friendly feedstock. One of such feedstock is CO2 that is economical, easily available as well as environment friendly and could be used for the synthesis of dimethyl carbonate (DMC) that can be used as an additive of the gasoline. The other cheaper feedstock is methanol. The reaction of CO2 with methanol is an equilibrium reaction. CO2 being thermodynamically very stable, it is very difficult to convert to DMC. Moreover, it is a challenge to device a separation scheme of reaction products: DMC and water from reaction mixture to favour the production of DMC from carbonylation of methanol.
To overcome the thermodynamic limitations of conversion of CO2, introduction of 2,2-dimethoxypropane (DMP) in the reaction mixture has studied using Aspen Plus process simulator which increased the DMC yield along with formation of Acetone as by-product. Moreover, direct carbonylation of DMP to DMC and acetone and regeneration of DMP has also successfully simulated using Aspen Plus process simulator. In this work four processes have studied: (1) Conversion of CO2 and methanol to DMC and water without any means to remove water. (2) Conversion of CO2 and methanol to DMC and water with use of 15% DMP. (3) Use of Equi-molar feed components-CO2, Methanol & DMP for conversion of CO2 and methanol to DMC along with separation of DMC from by-product acetone and unreacted methanol (4) Direct Carbonylation of DMP to synthesize DMC and regeneration of DMP. Based on the DMC yield criteria direct carbonylation of DMP to synthesize DMC and by-product acetone is the best method.
