PROCESS FOR PRODUCING A GASEOUS PRODUCT FROM METHANOL WHICH CONTAINS CARBON OXIDE AND HYDROGEN

摘要

The methanol vapor is mixed with a gas mixture which consists mainly of carbon dioxide and hydrogen and a high-methanol mixed feedstock is thus obtained. The mixed feedstock is fed to a first catalytic breakdown zone at an entrance temperature from 300 DEG to 400 DEG C., which contains a zinc-containing catalyst, which is indirectly heated. An intermediate having a methanol content not in excess of 1% by volume is withdrawn at a temperature in the range from 350 DEG to 600 DEG C. from the first breakdown zone and is cooled. Condensed water is removed at least in part from the intermediate, which is subsequently heated to a temperature in the range from 320 DEG to 420 DEG C. At least one-half of the heated intermediate product is supplied to a second catalytic breakdown zone, which also contains a zinc-containing catalyst, which is indirectly heated. A precursor product is withdrawn from the second breakdown zone at temperature from 350 DEG to 600 DEG C. and is cooled and aqueous condensate is withdrawn from the precursor. The product, which is subsequently supplied at an entrance temperature from 20 DEG to 80 DEG to and is passed through a separating zone, which contains a multiplicity of selectively permeable membranes. First and second gas streams are withdrawn from the separating zones. The first gas stream contains at least 90% by volume CO2 and H2. The second gas stream contains at least 30% by volume CO. The first gas stream is enriched with CO2 to provide a gas mixture, which is mixed with the methanol vapor.