Nitrogen-borne (1000: 1000 ppm) NO-CH4 model mixtures, 0.45 m(3)/h, were reduced over a 5-mm active coke, contact times 3, 6, 9 or 12 s, at 300-600degreesC. At <300degreesC. no reduction occurred. At 600degreesC, the degree of reduction of NO was highest, 0.7-0.88 (over 3-12 s); CH4 reacted in 26% (max. rise over 500-600degreesC). At 400-500degreesC, contact time 12 s, C and CH4 were reducers in 80-85% and 15-20% and, at 600degreesC, in 0-10 and 90-100%, resp. Accordingly, two NO removal mechanisms were suggested. Since the AKP self-ignited at 435degreesC, O-2-free conditions were required, which made the method useless for exhaust gases, unless a coke-based modified catalyst is developed to reduce NOx with hydrocarbons.