Process for the preparationn of hydrocarbons from oxygenates

Abstract

A process for the preparation of hydrocarbon products comprising the steps of a) providing a synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide; (b) reacting at least part of the synthesis gas to an oxygenate mixture comprising methanol and dimethyl ether in presence of one or more catalysts which together catalyse a reaction of hydrogen and carbon monoxide to oxygenates at a pressure of at least 3 MPa; (c) withdrawing from step (b) a reaction mixture comprising amounts of methanol, dimethyl ether, carbon dioxide and water together with unreacted synthesis gas and cooling the reaction mixture to obtain a liquid phase with the amounts of methanol, dimethyl ether and water and simultaneously dissolving carbon dioxide in the liquid phase; (d) separating the carbon dioxide containing liquid phase from a remaining gaseous phase comprising hydrogen and carbon monoxide; (e) evaporating and reacting the liquid phase being withdrawn from step (d) in presence of a catalyst being active in the conversion of oxygenates to higher hydrocarbons and a tail gas comprising carbon dioxide; (f) separating tail gas from a liquid phase with the higher hydrocarbons; and wherein pressure employed in step (c) to step (f) is substantially the same as employed in step (b).