N2O FORMATION DURING COAL COMBUSTION IN FLUIDIZED-BEDS - IS IT CONTROLLED BY HOMOGENEOUS OR HETEROGENEOUS REACTIONS

This paper discusses the results of the experimental work undertaken t o determine the N2O and NO emissions from fluidised bed combustion. Fi rst, studies were carried out to measure the amounts of both NO and N2 O formed during the combustion of bituminous coals and that chars prep ared from the same coals. Second, the combustion of the volatiles rele ased during the devolatilisation of coals was investigated and the N2O and NO emissions were measured. The analysis of HCN and NH3 in volati les was also undertaken. From our results, a better understanding of t he issue of homogeneous reactions versus those of heterogeneous for th e formation of N2O is achieved.