Process for the preparation of dimethyl ether

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 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 a reduced content of carbon dioxide and separating the unconverted synthesis gas from the dimethyl ether product.