Experimental Investigations of Dimethyl Ether Production from Syngas in a Slurry Reactor

The conversion of syngas, which consists of carbon monoxide (CO) and hydrogen (H₂), into value-added products and chemicals has gained significant attention due to its potential to mitigate greenhouse gas emissions and provide alternative energy sources. Dimethyl Ether (DME) is one such promising clean-burning fuel that can be synthesized from CO and H₂ using various catalytic processes. While fixed-bed reactor configurations are widely pursued, slurry reactors have been comparatively less explored. This work focuses on the experimental optimization of direct DME production and separation from syngas by using a slurry reactor equipped with a gas-entrainment impeller. It employs a thermochemical route and a bifunctional catalyst (Cu/Zn/Al + γ-Al₂O₃) with n-hexadecane as an inert medium at the lab scale. N-hexadecane is selected as the carrier liquid for its stability, inertness under the reaction conditions, and excellent mass transfer characteristics. The influence of key operating parameters, including temperature, pressure, H₂/CO ratio, space velocity, and impeller speed, on syngas conversion and DME yield was systematically investigated. Results indicate that an increase in temperature, pressure, H₂/CO ratio, and impeller speed leads to an increase in CO conversion and DME yield. Additionally, the optimum results obtained a CO conversion of 63% and a DME yield of 62.3% at a temperature and pressure of 270 °C and 65 bar, respectively. The insights underscore the potential of slurry reactors in the efficient synthesis of DME.