Intensification and performance assessment of ethanol production process by hydrogenation of methyl acetate

Fuel ethanol has attracted wide attention due to its advantages of environmental friendliness, high octane number, and excellent explosion resistance. In this paper, the design and intensification for the ethanol production process by hydrogenation of methyl acetate is developed. The conventional process containing reaction units and separation units is established. The separation units are optimized upon minimum the total annual cost (TAC). Subsequently, the dividing wall column (DWC) and extractive dividing wall column (EDWC) techniques are applied to obtain the DWC-EDWC intensified process. The results show that the TAC, CO2 emissions, and total energy consumption (TEC) of the DWC-EDWC intensified process are reduced by 9.4%, 14.9%, and 28.7%, respectively. To further improve thermodynamic efficiency, the DWC-EDWC with intermediate reboiler (DWC-IR-EDWC) intensified process is proposed. It is indicated that the DWC-IR-EDWC intensified process has more advantages in the economy. Finally, pinch technology is carried out to make full use of the heat of process streams. Compared with the conventional process, the TAC, CO2 emissions, and TEC of the modified process with heat exchange networks (HENs) are reduced by 23.7%, 29.3%, 65.4%, respectively, and the thermodynamic efficiency is increased by 9.1%.