Combustion of bagasse and woodwaste in boilers for integration into a cogeneration steam cycle

Highly rated bagasse-fired boilers utilised in the cane sugar industry have to be designed to burn other biomass fuels outside of the crush. While fibrous fuels have similar combustion characteristics on a dry ash free basis, the design has to be capable of accommodating large variations in ash, moisture and size grading. A furnace cycling phenomenon observed on some highly rated boilers is described. A combustion model is developed which provides an explanation of the cycling phenomenon. This leads to a qualitative approach for assessing the use of fuels for operation at high boiler ratings on cogeneration plants_ A steam cycle for use in biomass cogeneration facilities is described. The effect of bleed steam from the steam turbine for feedheating and for heating the combustion air is described.