A method is provided for performing catalytic or non-catalytic processes which uses oxygen supplied from the permeate side of a mixed oxygen ion and electron conducting membrane by means of a sweep gas at an elevated temperature. The sweep gas is formed by burning fuel in a sweep gas preheater. The sweep gas containing oxygen picked up from the membrane is reacted with a hydrocarbon fuel in a catalytic reactor to form a syngas containing nitrogen and hydrogen. The nitrogen and hydrogen containing syngas is worked up into ammonia; the ammonia is burned in an ammonia burner to produce a nitrogen oxides containing gas, and the nitrogen oxides containing gas is used in the production of nitric acid. The process is able to directly transfer the oxygen containing sweep gas to the catalytic reactor, without any intermediate cooling; recompression and reheating.