Methanol production

Claim 1

In a process for producing methanol from a gaseous aliphatic hydrocarbon feedstock of empirical formula CH x where x is between 2 and 4 which comprises steam reforming the feedstock to give a synthesis gas containing hydrogen and at least one carbon oxide selected from the group consisting of carbon monoxide and carbon dioxide, the amount of hydrogen in the resulting synthesis gas being in excess of the stoichiometric amount necessary to form methanol, and reacting the synthesis gas in a catalytic synthesis stage using a copper catalyst to obtain methanol, the improvement which comprises reacting the synthesis gas incompletely in said catalytic synthesis stage to give a reaction product of methanol and unreacted hydrogen and carbon oxide, separating methanol from the remaining gas in said reaction product, recycling the remaining gas comprising unreacted hydrogen and carbon oxide to said synthesis stage for further reaction to form more methanol, and controlling the amount of hydrogen thereby recycled to said synthesis stage to prevent undesired build-up of hydrogen in said synthesis stage by withdrawing a part of said remaining gas before it is recycled to said synthesis stage, separating the carbon oxide from the hydrogen in this withdrawn part and recycling only the separated carbon oxide from said withdrawn part to said synthesis stage for reaction with hydrogen to form further methanol.