Design and Economic Evaluation for the Production of Ethyl Lactate via Reactive Distillation Combined with Various Separation Configurations

Two commercial scale ethyl lactate (L1E) production processes are studied in the work. The L1E processes can be divided into the reaction part and the separation section. For the reaction part, instead of the three-column design presented by Miller et al.,(1) the proposed configuration only contains two reactive distillation (RD) columns, where the L1E product is taken from the first RD column as a sidedraw. This novel improvement can reduce 22.26% of energy consumption in the reaction part. Additionally, disparate separation approaches such as extractive distillation (ED) and the pervaporation (PV) are then implemented to deal with the ethanol/water azeotrope. Economics for alternative configurations are analyzed to find the most competitive and cost-effective process. As a result, the RD with PV design can save at least 31.46% of total annual cost compared to the RD with ED configuration.