EMISSIONS FROM A CONICAL FLUIDIZED BED COMBUSTOR FIRING VARIOUS BIOMASS FUELS

抄録

This paper presents the results of an experimental study of biomass combustion in a conical fluidized bed combustor (conical FBC) using silica sand as the inert bed material. Three biomass fuels (sawdust, rice husk and pre-dried sugar cane bagasse) were fired with the aim of determining combustion efficiency. Effects of operating variables (load and excess air) on axial temperature and gas (CO and NO) concentration profiles as well as on CO and NO emissions from the conical FBC were also the focus of study. Both CO and NO axial profiles were found to have a maximum whose location divides conventionally the combustor volume into formation (lower) and reduction (upper) regions for these pollutants. The excess air values of 50-60% ensure minimized CO and NO emissions from the conical FBC fired with these biomass fuels. The combustion efficiencies greater than 99% for firing sawdust and bagasse, and of about 86% for firing rice husk, were achieved in the experimental tests on this combustor.