Conversion of synthesis gas to hydrocarbon mixtures

Claim 1

In a process for producing a hydrocarbon product effluent by contacting a syngas mixture of hydrogen and carbon monoxide with a catalyst mixture comprising a CO reducing component in combination with a special crystalline zeolite providing a silica to alumina ratio of at least 12 and a constraint index within the range of 1 to 12, the improvement which comprises, converting syngas initially comprising hydrogen and CO in a ratio up to about 2 to 1 to primarily gasoline boiling range hydrocarbons with limited methane production by contacting a catalyst mixture comprising from about 0.2 up to about 5 weight percent of ruthenium in combination with said special crystalline zeolite, maintaining the temperature during contact within the range of about 470° F. to about 650° F. and a pressure within the range of 400 to 1500 psig, selecting a temperature in the range of about 530° to about 650° F. for aromatic gasoline production and in the range of about 470° to about 530° F. for predominantly olefinic gasoline production, separating light gases containing excess carbon monoxide from the reactor product effluent and providing a portion of the separated gases for admixture with fresh syngas feed as required and passed to the syngas conversion step.