Separation process for one-step production of dimethyl ether from synthesis gas

An improvement to the process for separating dimethyl ether (DME) from byproducts in a one-step catalytic conversion of synthesis gas (syngas), the improvement comprising using a scrubbing solvent comprising a mixture of dimethyl ether and methanol for the separation of dimethyl ether and carbon dioxide from the unconverted synthesis gas in a scrubbing column. Additional improvements include recycling of the scrubbing solution, multi-step processing of the liquid effluent from the scrubber, and methods of processing the methanol-water effluent of the flash column that is interposed between the DME reactor and the scrubber.