Process for producing a purified and converted synthesis gas containing hydrogen (H 2) and carbon monoxide, comprising the following process steps: a) providing a carbon-containing gasification or reforming input stream and introducing said stream into a synthesis gas generation stage, b) reacting the carbon-containing gasification or reforming input stream in the synthesis gas generation stage under synthesis gas generation conditions to afford a raw synthesis gas product stream which contains not only the primary constituents H 2 and CO but also carbon dioxide (CO 2) and hydrogen sulfide (H 2 S) as acidic synthesis gas constituents as well as secondary and trace components such as carbonyl sulfide, ammonia (NH 3), hydrogen cyanide, mercaptans, metal carbonyls, discharging the raw synthesis gas product stream from the synthesis gas generation stage, c) introducing the raw synthesis gas product stream into a CO conversion zone, converting the raw synthesis gas product stream in the CO conversion zone under CO conversion conditions into an H 2 -enriched and CO-depleted CO conversion product stream, discharging the CO conversion product stream from the CO conversion zone, d) introducing the CO conversion product stream into a gas scrubbing zone operating according to a physical gas scrubbing process with methanol as the absorption medium in which the methanol is recirculated and is continuously regenerated, discharging a pure synthesis gas product stream depleted of acidic gas constituents such as CO 2 and H 2 S from the gas scrubbing zone, discharging one or more material streams enriched in acidic gas constituents such as CO 2 and H 2 S from the gas scrubbing zone, discharging a liquid methanol purge stream laden with trace impurities from the gas scrubbing zone, wherein the methanol purge stream is at least partially recycled into the CO conversion zone and added to the raw synthesis gas product stream before introduction into the CO conversion zone. a) providing a carbon-containing gasification or reforming input stream and introducing said stream into a synthesis gas generation stage, b) reacting the carbon-containing gasification or reforming input stream in the synthesis gas generation stage under synthesis gas generation conditions to afford a raw synthesis gas product stream which contains not only the primary constituents H 2 and CO but also carbon dioxide (CO 2) and hydrogen sulfide (H 2 S) as acidic synthesis gas constituents as well as secondary and trace components such as carbonyl sulfide, ammonia (NH 3), hydrogen cyanide, mercaptans, metal carbonyls, discharging the raw synthesis gas product stream from the synthesis gas generation stage, c) introducing the raw synthesis gas product stream into a CO conversion zone, converting the raw synthesis gas product stream in the CO conversion zone under CO conversion conditions into an H 2 -enriched and CO-depleted CO conversion product stream, discharging the CO conversion product stream from the CO conversion zone, d) introducing the CO conversion product stream into a gas scrubbing zone operating according to a physical gas scrubbing process with methanol as the absorption medium in which the methanol is recirculated and is continuously regenerated, discharging a pure synthesis gas product stream depleted of acidic gas constituents such as CO 2 and H 2 S from the gas scrubbing zone, discharging one or more material streams enriched in acidic gas constituents such as CO 2 and H 2 S from the gas scrubbing zone, discharging a liquid methanol purge stream laden with trace impurities from the gas scrubbing zone,