TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The methanogenic archaea comprises Methanobacterium alcaliphilum, Methanobacterium bryantii, Methanobacterium congolense, Methanobacterium defluvii, Methanobacterium espanolae, Methanobacterium formicicum, Methanobacterium ivanovii, Methanobacterium palustre, Methanobacterium thermaggregans, Methanobacterium uliginosum, Methanobrevibacter acididurans, Methanobrevibacter arboriphilicus, Methanobrevibacter gottschalkii, Methanobrevibacter olleyae, Methanobrevibacter ruminantium, Methanobrevibacter smithii, Methanobrevibacter woesei, Methanobrevibacter wolinii, Methanothermobacter marburgensis, Methanothermobacter thermautotrophicum, Methanothermobacter thermoflexus, Methanothermobacter thermophilus, Methanothermobacter wolfeii, Methanothermus sociabilis, Methanocorpusculum bavaricum, Methanocorpusculum parvum, Met hanoculleus chikuoensis, Methanoculleus submarinus, Methanogenium frigidum, Methanogenium liminatans, Methanogenium marinum, Methanosarcina acetivorans, Methanosarcina barkeri (preferred), Methanosarcina mazei, Methanosarcina thermophila, Methanomicrobium mobile, Methanocaldococcus jannaschii, Methanococcus aeolicus, Methanococcus maripaludis (preferred), Methanococcus vannielii, Methanococcus voltaei, Methanothermococcus thermolithotrophicus, and/or Methanopyrus kandleri. Preferred Method: The conversion is carried out at 35-37 degrees C; involves agitation of the bacterial culture, maintaining a redox potential of less than or equal to 100 mV, supplying hydrogen gas, removing methane gas from bioreactor, where removed methane gas comprising less than 450 (preferably less than 150) ppm hydrogen sulfide.    TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Process: The industrial process is ethanol production by biomass fermentation.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The industrial output gas comprises air ( less than or equal to 32, preferably 4 vol.%), carbon monoxide (less than 40, preferably 8 vol.%). EXAMPLE - A bench bioreactor containing Methanococcus maripaludis was prepared and culture was exposed to a mixture of air (4 vol.%) and hydrogen (76 vol.%) at a flow rate of 100 cc/mm and carbon dioxide (CO2) at 25 cc/mm for 2.3 hours. The percentage of air was then increased to 8%, providing a mixture of air (8 vol.%) and hydrogen (72 vol.%) at a flow rate of 100 cc/mm and CO2 at 25 cc/mm for 1.7 hours. The percentage of air was then increased to 16 vol. %. Finally, the percentage of air was then increased to 32 vol.%. Methane production continues even in the presence of air provided that hydrogen is present to maintain the oxidation-reduction potential of the culture at productive levels. Up to air (4 vol.%) was tolerated without a persistent reduction in methane production. The efficiency of conversion of the input hydrogen to methane remains unaffected at 22-23% under the conditions of the experiment until the air concentration rises from 8% to 16% of the total gas mixture.