Verfahren zum Erzeugen von Methanol aus Erdgas

摘要

Production of methanol from natural gas comprises: (a) catalytically reacting the natural gas with water vapour and oxygen in an autothermic reactor (1) containing a burner (3) injected with natural gas and oxygen and a granular catalyst charge (2) positioned below the burner; (b) removing the crude synthesis gas at 800-1200 degrees C from the reactor, cooling, condensing out the water vapour, and removing the condensate formed; (c) mixing the crude synthesis gas with H2-rich gas and circulating gas, the synthesis gas having a stoichiometric number of 1.3-1.9 calculated from the molar concentrations of H2, CO and CO2, to form a synthesis gas mixture; (d) feeding the mixture to a methanol synthesis reactor (22) containing a Cu catalyst and operating at 10-150 bar at 180-350 degrees C; (e) withdrawing a gas mixture containing methanol vapour and cooling to condense out the methanol; (f) withdrawing a cooled residual gas from the methanol and dividing into recirculating gas and a second partial stream (purge gas) containing 30-80 (vol.%) H2, 7-35 CO2 and 3-25 CO; and (g) removing a H2-rich gas from the purge gas in a separating device (15) and mixing it with crude synthesis gas.