The municipal solid waste industry has
four components: recycling, composting, land filling, and waste-to-energy via
incineration. Municipal solid waste is total waste excluding industrial
waste, agricultural waste, and sewage sludge. As defined by the U.S.
Environmental Protection Agency, it includes durable goods, non-durable goods,
containers and packaging, food wastes, yard wastes, and miscellaneous inorganic
wastes from residential, commercial, institutional, and industrial
sources. Examples from these categories include: appliances, newspapers,
clothing, food scrapes, boxes, disposable tableware, office and classroom paper,
wood pallets, rubber tires, and cafeteria wastes. Waste-to-energy
combustion and landfill gas are byproducts of municipal solid
waste.
Biomass energy is derived from three distinct energy sources: wood, waste, and alcohol fuels. Wood energy is derived both from direct use of harvested wood as a fuel and from wood waste streams. The largest source of energy from wood is pulping liquor or black liquor, a waste product from processes of the pulp, paper and paperboard industry. Waste energy is the second-largest source of biomass energy. The main contributors of waste energy are municipal solid waste (MSW), manufacturing waste, and landfill gas. Biomass alcohol fuel, or ethanol, is derived almost exclusively from corn. Its principal use is as an oxygenate in gasoline.
Wood/Wood WasteWood is a substantial renewable resource that can be used as a fuel to generate electric power and useful thermal output. Wood for use as fuel comes from a wide variety of sources. The Nations forestland (or timberland) is the primary, and in most cases original, resource base for fuel wood. Wood for fuel use is also derived from private land clearing and silvi-culture and from urban tree and landscape residues. A third major wood resource is waste wood, which includes manufacturing and wood processing wastes, as well as construction and demolition debris.
Landfill GasMunicipal solid waste contains significant portions of organic materials that produce a variety of gaseous products when dumped, compacted, and covered in landfills. Anaerobic bacteria thrives in the oxygen-free environment, resulting in the decomposition of the organic materials and the production of primarily carbon dioxide and methane. Carbon dioxide is likely to leach out of the landfill because it is soluble in water. Methane, on the other hand, which is less soluble in water and lighter than air, is likely to migrate out of the landfill. Landfill gas energy facilities capture the methane (the principal component of natural gas) and combust it for energy.