Modeling and assessment of novel configurations to enhance methanol production in industrial mega-methanol synthesis plant

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2019-11, Vol.104, p.40-53
• Main Authors: Mirvakili, A., Chahibakhsh, S., Ebrahimzadehsarvestani, M., Soroush, E., Rahimpour, M.R.
• Format: Article
• Language: English
• Subjects: Mega methanol plants; Methanol synthesis; Parallel reactors; Recycled gas; Simulation
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2019.09.018

•Lower mass flowrates passes through the catalyst packed bed of novel configurations.•All proposed configurations had higher methanol production than conventional system.•All proposed configurations had lower CO2 emission than conventional system.•Methanol molar flowrate in optimal system was 12 times greater than original plant.•CO2 emission in optimal system was 20% lower than conventional configuration. In the current study, the utilization of parallel reactors instead of series configurations in the mega methanol plants is investigated. In the conventional reactor (CR), two parallel fixed bed water-cooled reactors are in series with a gas-cooled reactor. In this study, three novel configurations are proposed in which the gas-cooled is in parallel with two water-cooled reactors and the feed is divided in different manners between the reactors. There is almost 31% fresh feed included in the feed and the rest is composed of recycled stream. In the first configuration, named “Equal Parallel (EP)”, the feed is divided equally between the reactors. In the second configuration, named “Recycled gas to the gas-cooled (RG)”, the total recycled gas is sent the gas-cooled reactor and the fresh synthesis gas is sent to the water-cooled reactors. The last configuration, named “Recycled gas to the water-cooled (RW)”, is in contrast to the RG. These systems are simulated to find the superior configuration. The simulation results showed that the produced methanol in RG system was about 21.7% more than the CR configuration, and 7.4% and 10.6% more than EP and RW configurations, respectively. Moreover, CO2 emission in RG system was 18.9% less than CR configuration.