At present, an essential part of the used energy resources, especially for electricity generation and transportation, came from fossil fuels, most of which are consumed by combustion. World population growth and demand for higher living standards require energy resources consumed at a hasty rate. Based on the simulation, the direct DME synthesis process is superior over the indirect process in terms of DME and methanol productions, SPCs, and system energy efficiencies. Specific power consumption (SPC) was used as a tested parameter for the effectiveness of recycling unreacted gas. Compressor is required to increase the unreacted gas pressure to the desired pressure in the methanol reactor or dual methanol-DME reactor in both processes. Simulation results show that the DME production was enhanced by around 49.6% and 65.1% for indirect and direct processes, respectively, at a recycling rate of 7 MMSCFD.
Simulation was validated by several studies conducted by many researchers and giving satisfactory results especially in terms of productivity, conversion, and selectivity as a function of reactor temperatures in the indirect and the direct DME synthesis processes. Simulation was developed in Unisim R390.1 using Peng–Robinson–Stryjek–Vera (PRSV) as a fluid package. This study proposed the simulation process to utilize CO 2 released from the acid gas removal unit in one of gas processing plants in Indonesia to enhance the production of dimethyl ether (DME) through unreacted gas recycle that can be beneficial in reducing CO 2 emission to the atmosphere. Increase in the world energy demand also increases the concentration of CO 2 in the atmosphere, which contributes to global warming and ocean acidification.