NOVELTY - Apparatus (A1) comprises: compressor and/or cooler; means for sending feed gas to compressor and/or cooler; means for recovering water; purification unit; means for sending compressed and/or cooled feed gas to purification unit; means for sending compressed and/or cooled and dried feed gas to purification unit; means for outputting carbon dioxide-enriched fluid; means for sending regeneration gas (11); means for outputting water enriched regeneration gas (13); and means for mixing water condensed during compression and/or cooling with regeneration gas enriched in water to form wet gas flow.    USE - The apparatus is useful for compressing and/or cooling, and purifying a feed gas rich in carbon dioxide and containing water and impurities and at least one of hydrogen, carbon monoxide, methane and nitrogen and for producing synthesis gas (all claimed).    ADVANTAGE - The apparatus avoids the use of condensing pumps that are of significant cost and evaporator.    DETAILED DESCRIPTION - Apparatus (A1) comprises: compressor and/or cooler; means for sending feed gas to the compressor and/or cooler; means for recovering water present in the condensed feed gas during compression and/or cooling; a purification unit for adsorption containing adsorbent beds; means for sending compressed and/or cooled feed gas to purification unit to produce a feed gas compressed and dried, where the purification unit is at sub-ambient temperature; means for sending compressed and/or cooled and dried feed gas to a purification unit; means for outputting a carbon dioxide-enriched fluid (10) of the purification unit; means for sending a regeneration gas (11) to the purification unit; means for outputting the water enriched regeneration gas (13) of an adsorption bed of the purification unit; and means for mixing at least a portion of water condensed during compression and/or cooling with the regeneration gas enriched in water to form a wet gas flow. INDEPENDENT CLAIMS are also included for:    (1) an apparatus (A2) for producing a synthesis gas (1) and a carbon dioxide-enriched gas comprising a generation unit of synthesis gas, an enrichment unit of carbon dioxide in synthesis gas to produce a gas power, a compression device for cooling and purification, means for sending feed gas to compression and purification unit to be compressed and purified, and means for sending at least a portion of the wet gas flow to the syngas generation unit;    (2) compressing and/or cooling and purification of a feed gas rich in carbon dioxide and containing water and impurities and at least one of hydrogen, carbon monoxide, methane and nitrogen comprising recovering compressed and/or cooled feed gas from condensed water, sending compressed and/or cooled gas to a purification unit for drying, feeding dried feed gas to purification unit, cooling dried gas at sub ambient temperature and purifying to form a fluid enriched in carbon dioxide and a carbon dioxide-depleted fluid, sending a regeneration gas, optionally comprising at least part of the carbon dioxide-depleted fluid to the purification unit as regeneration gas, and mixing regeneration gas with a portion of the condensed water during the compression and/or cooling to form a wet gas flow; and    (3) producing a synthesis gas and a gas enriched in carbon dioxide comprising generating a synthesis gas in a synthesis gas generation unit, where the synthesis gas is enriched with carbon dioxide, producing feed gas, compressed and/or cooling, purifying feed gas, and sending at least a portion of the wet gas flow to synthesis gas generation unit.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the apparatus.    Synthesis gas (1)    Carbon dioxide-enriched fluid (10)    Regeneration gas (11)    Water enriched regeneration gas (13)    Flow (21)