Today, there huge stronger demand by customers, communities and various regulators placed upon electric utilities to provide ever increasing amounts of renewable energy. Biomass fueled steam and electric power plants are significant contributors of renewable energy production in the United States the high price of natural gas is also causing many owners to look at the feasibility of changing to biomass. The Energy Policy Act of 2005 provides for additional incentives for the use of biomass fuels. During this presentation will discuss biomass applications, boiler technologies, fuel sources, fuel quality and some of the challenges of ensuring a reliable fuel supply.
BENEFITS OF USING BIOMASS
Burning biomass has three major beneficial effects on the economy and environment. First, using biomass as a fuel significantly reduces the amount of waste that must otherwise be placed in landfills. Instead of land filling waste sawdust, bark, chips and municipal trash, using these materials as a fuel can decrease the volume of waste from one hundred percent to about three percent, depending on the type of material converted to a fuel. Second, the use of wood as a fuel decreases the amount of sulfur dioxide emitted when producing electricity. As a comparison, about 250 tons of Wyoming coal with 8,750 BTU/lb and 0.2% sulfur will produce one ton of sulfur dioxide. To produce that same ton of sulfur dioxide, it takes about 1,700 tons of wood with 5,000 BTU/lb and 0.03 % sulfur. When compared on a BTU basis, wood-fired generation produces about one-fourth of the sulfur dioxide of the Wyoming coal. Third, by converting waste streams to a fuel, a plant operator can help lower a biomass fuel supplier's cost of operations and allow them to be more competitive. This helps stimulate the economy of a region.
The term "biomass" encompasses diverse fuels derived from timber, agriculture and food processing wastes or from fuel crops that are specifically grown or reserved for electricity generation. Biomass fuel can also include sewage sludge and animal manure. Some Biomass fuels are derived from trees. Given the capacity of trees to regenerate, these fuels are considered renewable. Burning crop residues, sewage or manure - all wastes that are continually generated by society -- to generate electricity may offer environmental benefits in the form of preserving precious landfill space OR may be grown and harvested in ways that cause environmental harm.
At present, most biomass power plants burn lumber, agricultural or construction/demolition wood wastes. Direct Combustion power plants burn the biomass fuel directly in boilers that supply steam for the same kind of steam-electric generators used to burn fossil fuels. With biomass gasification, biomass is converted into a gas - methane - that can then fuel steam generators, combustion turbines, combined cycle technologies or fuel cells. The primary benefit of biomass gasification, compared to direct combustion, is that extracted gasses can be used in a variety of power plant configurations
for more see http://www.ue-corp.com/news/wp_biomass.pdf