Dry biomass fuels

The most straightforward way to recover energy from dry biomass fuels is by combustion to provide heating or hot water.  These types of applications range in size from simple log fires and stoves, to sophisticated wood or straw fueled boiler systems, usually with automatic fuel handling and control systems.

Combined Heat and Power (CHP), otherwise expressed as Cogeneration, is becoming an increasingly attractive option for biomass plants, offering a reliable low-cost heat source for industrial or commercial uses (such as a district heating system for a small community), together with electricity that can be sold to the local grid.  Forest residues, industrial wood wastes and a range of agricultural wastes are often readily available as fuel for CHP plants.  However, energy crops, such as wood coppice (willow or poplar in cooler climates, wattle and eucalyptus in warmer climates), or perennial grasses such as miscanthus, are becoming increasingly important.  These may be grown specifically for use as a fuel and can provide long-term secure resources.  Biomass fuels are increasingly being used with advanced conversion technologies, such as gasification systems, which may offer superior efficiencies compared with conventional power generation.  Gasification is a thermochemical process in which biomass is heated with little or no oxygen present to produce a low-energy gas.  The composition of the gas will depend on the nature of the gasification process used.  The gas can then be used to fuel a gas turbine or a combustion engine to generate electricity.