Patent ID: 7652176

Claim:
Process for the preparation of dimethyl ether product by catalytic conversion of synthesis gas to dimethyl ether comprising contacting a stream of synthesis gas comprising carbon dioxide in a dimethyl ether synthesis step in one or more reactors and with one or more catalysts active in the formation of methanol and the dehydration of methanol to dimethyl ether, to form a product mixture comprising the components dimethyl ether, methanol, carbon dioxide and unconverted synthesis gas washing the product mixture comprising carbon dioxide and unconverted synthesis gas in a scrubbing zone with a liquid solvent being rich in potassium carbonate or amine and thereby selectively absorbing carbon dioxide in the liquid solvent, subjecting the thus treated product mixture to a distillation step to separate methanol and water from dimethyl ether and unconverted synthesis gas stream with reduced carbon dioxide content and separating the unconverted synthesis gas from the dimethyl ether product.