Single-step synthesis of dimethyl ether in a slurry reactor

Abstract

Dimethyl ether (DME) is an important intermediate in several alternative fuels processes which ultimately convert synthesis gas to liquid products. Our work details a novel slurry-based process which yields DME and variable amounts of co-product methanol (MeOH) from synthesis gas in a single step. The water-gas shift, MeOH synthesis, and MeOH dehydration reactions proceed concurrently in a three-phase reactor. Operation with a back-mixed slurry reactor exploits the synergy of the three reactions, and moderates the reaction exotherm to permit high per-pass conversions. Feed gases with CO concentrations ranging from 20% to 60%, and H 2/CO ratios varying from 0.01 to 2.9 have been tested with several multi-functional catalyst systems. The process offers the potential for both lower capital and operating costs compared to processes using independent shift, MeOH, and DME reactors.