| Biomass as an energy source is is material derived from recently living organisms – i.e. plants and to a lesser extent animal materials. This non-fossil energy can be used to supply heat, electricity and transportation fuels. It is a renewable alternative to coal, oil and natural gas. |
| Biomass includes all land and water-based vegetation such as dedicated energy crops and trees, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, animal wastes, municipal wastes, and other waste materials. |
| Biomass is the product, either directly or indirectly, of photosynthesis — the process by which plants use solar energy and atmospheric carbon dioxide to make carbohydrates including sugars, starches and cellulose. |
Energy crops are fast-growing plants, trees or other herbaceous biomass which are harvested specifically for energy production use. These crops can be grown, cut and replaced quickly.
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Herbaceous Energy Crops — These include grasses such as switchgrass, miscanthus (Elephant grass), bamboo, sweet sorghum, tall fescue, kochia, wheatgrass, and others. These crops are generally grown for fuel production. These energy crops are perennials. Perennials generally take two to three years to reach full productivity.
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Biomass is grown from several plants, including miscanthus, switchgrass, hemp, corn, and trees.
Industrial Crops — Industrial crops are being developed and grown to produce specific industrial chemicals or materials. Examples include kenaf and straws for fiber, and castor for ricinoleic acid.
Agricultural Crops — These feedstocks include the currently available commodity products such as cornstarch and corn oil; soybean oil and meal; wheat starch, other vegetable oils, and any newly developed component of future commodity crops.
Aquatic Crops — A wide variety of aquatic biomass resources exist such as algae, giant kelp, other seaweed, and marine microflora.
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Biomass Processing Residues. All processing of biomass yields byproducts and waste streams collectively called residues, which have significant energy potential. Not all residues can be used for electricity generation, some must be used to replenish the source with nutrients or elements. Still, residues are simple to use because they have already been collected.
• Pulp and paper operation residues. These residues are the byproducts of logging and processing operations such as sawdust, bark, branches and leaves/needles. In general, paper mills use their pulp residue to create energy for the paper mill.
• Forest residues. Forest residues include wood from forest thinning operations, materials not harvested or removed from logging sites in commercial hardwood and softwood stands and dead/dying trees.
• Agricultural or Crop Residues. These residues are the leftovers of crop harvesting. Agriculture crop residues include corn stalks and leaves, wheat straw, rice straw and nut hulls, to name a few.
- Animal waste, such as cattle, chicken and pig manure, can be converted to gas or burned directly for heat and power generation. These wastes can be used to make many products and generate electricity through methane recovery methods and anaerobic digestion
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Urban wood waste. Urban wood waste generally consists of lawn and tree trimmings, whole tree trunks, wood pallets and any other construction and demolition wastes made from lumber. This rejected material can easily be collected after a construction or demolition project and turned into mulch, or compost.
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Municipal Solid Waste. Waste paper, cardboard, wood waste and yard wastes are examples of biomass resources in municipal wastes.
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Landfill gas. The natural byproduct of bacterial digestion of organic garbage contains vast amounts of methane which can be captured, converted and used to create energy.
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Consider the benefits of biomass energy:
- A biomass fuel based power plant converts an existing waste stream to useful electrical energy.
- A biomass fuel based power plant uses a completely renewable fuel. Craven’s energy output displaces generation from non-renewable fossil fuels that have limited reserves and are being rapidly depleted.
- A biomass fuel based power plant provides a completely domestic energy supply, reducing our dependence on foreign oil. Craven’s annual production of 350,000 MWH is the equivalent of approximately one half million barrels of foreign oil.
- A biomass fuel based power plant utilizes a local fuel source, resulting in a boost to the local economy. Fossil fuels are not indigenous to North Carolina and result in a drain on the state’s economy.
- A biomass fuel based power plant is completely dispatchable, i.e. output can be varied and matched with customer demand. Unlike other sources of renewable energy that are instantaneously dependent on natural forces.
- A biomass fuel based power plant diverts material from landfills, prolonging the life of these landfills. North Carolina is rapidly running out of landfill capacity, and much of the material being land filled is wood waste.
- A biomass fuel based power plant has extremely low air emissions.
- Sulfur dioxide emissions are insignificant since there is virtually no sulfur in wood. Due to the moisture content, biomass combust at a cooler temperature than fossil fuels, resulting in inherently lower nitrous oxide emissions. Although all combustion processes release carbon dioxide, biomass combustion has a neutral "carbon balance," since trees convert carbon dioxide to oxygen. In addition, decomposing wood emits carbon dioxide, as well as methane – a greenhouse gas 22 times worse than carbon dioxide.
- A biomass fuel based power plant can recycle the fly ash produced. At CCWE, it is recycled as an agricultural liming agent, providing a benefit to local farmers.
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