Biomass co-firing for coal-fired boilers

In this study ground biomass and pulverized coal were used for co-firing test. The tests of co-firing of coal and biomass were carried out in a bench-scale bubbling fluidized bed combustor. Biomass is an attractive and sustainable renewable fuel to supplement coal combustion in utility boilers. Coal co-firing was successful with up to a 20% biomass mix boilers. Coal and biomass fuels are quite different in composition. Ash composition for the biomass is fundamentally different from ash composition for the coal. Chlorine in the biomass may affect operation by corrosion. Ash deposits reduce heat transfer and may also result in severe corrosion at high temperatures. Biomass and coal blend combustion is a promising combustion technology; however, significant development work is required before large-scale implementation can be realized. Issues related to successful implementation of coal biomass blend combustion are identified. Co-firing of coal and biomass is an effective method of control NOx. Formation of NOx decreases with the increase of biomass fraction.