In this article, dimethyl ether (DME) synthesis from syngas and catalysts for related reactions were reviewed. DME are generally synthesized in a two-step process via methanol so called as indirect methods as state of the art technology, and in order to decrease the cost and increase the conversion, the new studies focused on single step process from syngas by eliminating thermodynamic limitations which comes from syngas-to-methanol equilibrium, called as direct synthesis. In direct DME synthesis, syngas is converted into methanol over a metallic copper-based catalyst, and simultaneously methanol is dehydrated to DME over solid acid catalysts (such as γ-alumina and zeolites), so methanol synthesis and methanol dehydration reactions occur in a single reactor in the presence of bifunctional/hybrid catalysts resulting in an increase in the syngas conversion to DME. In this paper, the effect of bifunctional/ hybrid catalysts and reaction parameters used for direct DME synthesis on syngas conversion, DME yield and selectivity are also summarized.
Keywords: Syngas; Dimethyl ether (DME); Methanol; Bifunctional/Hybrid Catalysts; Syngas to DME
