Abstract: A process for producing a substitute natural gas, the process comprising the steps of: (1) providing a synthesis gas comprising hydrogen and carbon monoxide; (2) forming a hydrogen-enriched synthesis gas; (3) subjecting the hydrogen-enriched synthesis gas to a methanation reaction to convert at least a portion of the gas into methane thereby forming a methane-enriched gas; and (4) recovering from the methane-enriched gas a methane-containing gas, wherein step (2) comprises providing a hydrogen gas and combining the hydrogen gas with the synthesis gas.

Abstract: A process for producing a substitute natural gas, the process comprising the steps of providing a synthesis gas comprising hydrogen and carbon monoxide; subjecting the synthesis gas to a water-gas-shift reaction to increase the ratio of hydrogen to carbon monoxide thereby forming a hydrogen-enriched synthesis gas; subjecting the hydrogen-enriched synthesis gas to a methanation reaction to convert at least a portion of the gas into methane thereby forming a methane-enriched gas; and recovering from the methane-enriched gas a methane-containing gas having a Wobbe number of from 43 to 57 MJ/m3.