This report deals with the reduction of NO/sub x/ with char in a hot fluid bed. The fluidized bed combustor with its high heat transfer rates is one possibility for improving the potential for coal use. As in all coal-fired systems, control of nitric oxide emissions is a major environmental concern because of its harm to vegetation and human health and its participation in photochemical smog. Previous research has shown that some of the nitric oxide generated by combustion is later destroyed by coal char. Nitric oxide reacts with carbon significantly at temperatures characteristic of a fluidized bed combustor. The reaction is NO C = products (CO, CO/sub 2/, N/sub 2/). The relative amount of each carbon oxide is dependent upon the reaction temperature. A 15-cm diameter fluidized bed was used to study this reaction using freshly pyrolyzed Utah subbituminous coal char in a bed of sand fluidized by a mixture of nitric oxide and nitrogen. Data were collected in the form of nitric oxide concentration versus reactor bed height for a range of temperatures and char weights with all other variables held constant. The temperature range studied was 650 to 860/sup 0/C and the char weight range was 0.3 to 1.0 wt % of the total bed weight. The nitric oxide concentration in and above the reaction zone (zone of fluidized solids) of the fluidized bed reactor decreased with the increase of either temperature or char weight in the bed, and the overa-1 nitric oxide conversion was shown to be a linear function of the char weight.