A process for reducing the thiophene content in a synthesis gas mixture, comprises the steps of (i) passing a synthesis gas mixture comprising hydrogen and carbon oxides and containing thiophene over a copper-containing sorbent disposed in a sorbent vessel at an inlet temperature in the range 200-280° C., (ii) withdrawing a thiophene depleted synthesis gas containing methanol from the sorbent vessel, and (iii) adjusting the temperature of the methanol-containing thiophene-depleted synthesis gas mixture. The resulting gas mixture may be used for production of chemicals, e.g. methanol production or for the Fischer-Tropsch synthesis of liquid hydrocarbons, for hydrogen production by using water gas shift, or for the production of synthetic natural gas.