ABSTRACT
Biomass is widely known to be an alternative to fossil fuel combustion and can be used for many energy applications, such as heat and electricity generation. Choice of the method of utilization depends on the purpose of the combustion system. There are three basic concepts of biomass combustion: direct, indirect and parallel co-combustion (Brown et al. 2005). Of these, indirect co-combustion seems the most promising solution for using biomass of variable properties, but it is also more expensive than direct co-combustion. One of the chief disadvantages of biomass is the variation in properties, especially moisture content and elemental composition. This may require the adaptation of combustion installations for defined kinds of biomass. In indirect co-combustion systems this problem may be easily solved. Combustible syngas created in the gasification process is mainly composed of H2, CO, CO2, CH4 and higher hydrocarbons, and may be further combusted in the power boiler, avoiding risks to burner and boiler operation associated with direct combustion. Use of syngas can reduce fossil fuel consumption, and since it contains hydrocarbons and other combustible species, it may be used as a reburning fuel to reduce NOx emissions.
