Abstract: This invention relates to a process for producing methanol from a synthesis gas produced by partial oxidation of natural gas with an oxidant stream having a high nitrogen content, such as an oxygen enriched air stream. This invention utilizes a high pressure non-permeate gas stream of low BTU content obtained from a partial expansion of a very high pressure tail gas of the process down to a high pressure together with a high pressure non-permeate gas stream of low oxygen content to achieve an energy efficient process by passing these non-permeate, high pressure streams in combination into contact with an oxidizing catalyst, so to significantly increase the temperature of these combine high pressure gas streams, for increased working energy recovery therefrom, as by their expansion through a hot gas expander.