Effect of fuel moisture content on biomass-IGCC performance

The moisture level in biomass fuels potentially impacts efficiency in conversion to power. This paper examines the efficiency and net power output of a fluidized bed gasifier-combined cycle with flue gas drying for a range of as-received raw biomass moisture contents and levels of pregasification drying. Due to the lack of empirical data available, a modeling approach is used to simulate the effect of varying moisture content in the gasifier feed biomass. For a specified as-received biomass moisture content, drying prior to gasification increases overall efficiency but the gains in efficiency decrease with increasing levels of drying. For a specified post-dryer gasifier feed moisture content, cycle efficiency and power output increase with decreasing as-received biomass moisture down to 30 percent, below which the change in cycle performance is negligible.