Optimal design of an industrial scale dual-type reactor for direct dimethyl ether (DME) production from syngas

Since in foreseeable future DME as a clean-burning fuel with versatile applications will play a significant role in the transportation sector, the least improvement in its production process which can increase the production capacity is economically favorable. In this study, an industrial dual-type reactor is designed and optimized by DE algorithm for increasing DME production and also overcoming the reaction equilibrium limitations of the direct DME synthesis. The proposed reactor configuration is composed of two fixed bed reactors: (1) the water-cooled reactor and (2) the gas-cooled reactor. The syngas feed is preheated with the hot exit product from the first reactor (water-cooled), and is entered into the first reactor. The reactors are simulated by means of a one-dimensional steady-state heterogeneous model. The simulation results indicate that the best flow pattern for the proposed configuration is the counter-current mode. Maximizing the outlet mole fraction of DME from the second reactor is the objective of the optimizer. Seven operating and geometrical parameters of the system are considered as the decision variables. The results show that the proposed configuration can enhance DME production capacity about 60 ton/day in comparison to conventional industrial DME reactor which operates based on the indirect DME synthesis process.

► Optimal design of a novel reactor configuration to produce direct DME from syngas is proposed.
► The equilibrium of DME synthesis reaction is shifted in the proposed reactor.
► Counter-current mode was found as the best flow pattern in the gas-cooled reactor.
► DME production is increased up to 60 ton/day compared to TOPSOE conventional process.