Pilot-scale azeotrope purification of dimethyl carbonate by cost-efficient pervaporation-assisted distillation

Abstract

The production processes of dimethyl carbonate (DMC) typically involve an excess amount of methanol, and therefore, the separation of DMC from methanol is essential in the chemical industry. While pressure swing distillation is commonly used for this separation, it is an energy-intensive process. Pervaporation, on the other hand, has been found to be a more energy-efficient method, especially when a suitable inorganic or ceramic membrane is used. The use of polymeric membranes is not recommended due to the high operating temperatures required. Hybrid silica membranes, such as HybSi®, have emerged as a promising option for this purpose. In this study, we conducted both laboratory and pilot-scale pervaporation experiments along with pilot-scale pervaporation-assisted distillation experiments, and carried out process simulations to evaluate the potential cost savings in DMC purification using a HybSi® membrane. The cost of purification was calculated per ton of DMC produced, and results demonstrated cost savings compared to the base case using pressure swing distillation. These savings were attributed to reduced operating and capital expenditures resulting from lower energy consumption and a more compact design. Our results indicate that the use of HybSi® membranes has the potential to revolutionize the DMC production process and provide a more sustainable and cost-effective solution.