A biomass-fired power plant produces electricity and heat by burning biomass in a boiler. Wood chips and residues, urban fibers (e.g. wood waste from recycling programs), and other types of biomass are used in the boilers, in the same way as coal, natural gas and oil in more traditional fossil-fuel power plants.
The power plant operations begin with trucks delivering woody biomass to power the facility. Incoming trucks are first weighed, then unloaded and re-weighed prior to exiting. Each driver has an electronic card that identifies the source of supply. The difference between gross and tare weight is the actual amount of biomass offloaded at the plant.
Fuel is continuously transferred to the power plant fuel handling conveyors from a reclaim hopper adjacent to the biomass storage pile which typically has 3-4 weeks of fuel supply at all times. The biomass chips are loaded into the reclaim hopper with a front-end loader. The biomass is typically at 50% moisture content and sized to a 2” minus size.
The fuel handling system takes a homogeneous mixture of material past a metal detector to the firebox fuel volume metering system. Ground materials will then be fed into the boiler in which the biomass is reduced to ash. As the primary output of the plant, the biomass is burned to produce high-pressure steam, which in turn, is directed to a steam turbine to produce electricity. A small percentage of the power (typically referred to as ‘parasitic’ loads) is used to operate all of the electrical loads at each facility.