 |
Energy derived from resources that are regenerative or for all practical purposes can not be depleted. Types of renewable energy resources include moving water (hydro, tidal and wave power), thermal gradients in ocean water, biomass, geothermal energy, solar energy, and wind energy. Municipal solid waste (MSW) is also considered to be a renewable energy resource.
Back to Top
Biomass is any sort of vegetation - trees, grasses, plant parts such as leaves, stems and twigs, and ocean plants. From it, we can extract a wealth of stored energy. During photosynthesis, plants combine carbon dioxide from the air and water from the ground to form carbohydrates, which form the building blocks of biomass. The solar energy that drives photosynthesis is stored in the chemical bonds of the structural components of biomass. While the actual ratio of components varies among species, biomass averages 75% carbohydrates or sugars and 25% lignin.
If we burn biomass efficiently (which extracts the energy stored in the chemical bonds), then oxygen from the atmosphere combines with the carbon in plants to produce carbon dioxide and water. Biomass can produce electricity, heat, liquid fuels, gaseous fuels, and a variety of useful chemicals, including those currently manufactured from fossil fuels. Industry and agriculture need superior energy crops and cost-effective conversion technologies to expand the use of renewable biomass. Biomass is available from various industries - including agriculture, forest products, transportation, and construction - that dispose of large quantities of wood and plant products. Whether cultivated or growing wild, biomass represents a huge renewable energy source.
Back to Top
Energy crops are crops that are grown for the specific purpose of producing energy (electricity or liquid fuels) from all or part of the resulting plant. Switchgrass, alfalfa, willow, poplar and eucalyptus are examples of plants that can be grown as energy crops.
Back to Top
Virtually every part of the world has a biomass resource that can be tapped to create power.
Back to Top
Worldwide, biomass is the fourth largest energy resource after coal, oil, and natural gas. It is used for heating (such as wood stoves in homes and for process heat and steam in industries such as pulp and paper), cooking (especially in many parts of the developing world), transportation (fuels such as ethanol and biodiesel) and for electric power generation. It is estimated that there are about 278 Quadrillion Btu of installed biomass capacity worldwide, with about 2.7 Quadrillion Btu of biomass generated in the United States. Most of this capacity is in the pulp and paper industry using combined heat and power systems (IEA Key World Energy Statistics (PDF 745 KB) (Download Acrobat Reader)).
Back to Top
In practice, we tend to use these three different terms for three different end uses - transportation, electric power or heat, and products such as chemicals and materials. "Biofuel" is short for "biomass fuel." We use the term "biofuels" for liquid fuels for transportation, such as ethanol and biodiesel that can be purely from biomass such as B100 or, in part, such as E10 (the number after the letter represents the percentage of biodiesel or ethanol in the fuel). We tend to use "BioPower" for "biomass power" systems that generate electricity or industrial process heat and steam, such as from combined heat and power (CHP) systems. The term "bioproduct" is short for biomass products, and can be used to describe a chemical, material, or other product derived from renewable biomass resources.
Back to Top
Ethanol is the most widely used biofuel today. In 2003, more than 2.8 billion gallons were added to gasoline in the United States to improve vehicle performance and reduce air pollution. Ethanol is an alcohol, and most is made using a process similar to brewing beer where starch crops are converted into sugars, the sugars are fermented into ethanol, and then the ethanol is distilled into its final form. Ethanol made from cellulosic biomass materials instead of traditional feedstocks (starch crops) is called bioethanol.
Ethanol is used to increase octane and improve the emissions quality of gasoline. The Clean Air Act Amendments of 1990 mandated the sale of oxygenated fuels in areas of the country with unhealthy levels of carbon monoxide. Since that time, there has been strong demand for ethanol as an oxygenate blended with gasoline. In some areas of the United States today, ethanol is blended with gasoline to form an E10 blend (10% ethanol and 90% gasoline), but it can be used in higher concentrations such as E85 or in its pure form. All automobile manufacturers that do business in the United States approve the use of certain ethanol/gasoline blends. Fuel ethanol blends are successfully used in all types of vehicles and engines that require gasoline. Approval of ethanol blends is found in the owners' manuals under references to refueling or gasoline.
Back to Top
Renewable diesel fuels are fuels that are used in diesel engines in place of or blended with petroleum diesel, but are made from renewable resources such as vegetable oils, animal fats, or other types of biomass such as grasses and trees. Biodiesel is an example of a renewable diesel fuel that is used all across America today. Biodiesel is manufactured from vegetable oils, animal fats, and recycled restaurant greases, which are all renewable. E-diesel may be the next new renewable diesel fuel. E-diesel is a blend of ethanol and diesel fuel with other chemicals to improve the performance of the blend. The ethanol portion of E-diesel is renewable because it is made from grains like corn. Another new renewable diesel fuel is Fischer-Tropsch diesel fuel. Fischer-Tropsch diesel is made from coal and natural gas today, but in the future we could make it out of grasses, trees, or anything organic. All these renewable diesel fuels can be used instead of petroleum diesel fuel to help reduce our petroleum imports, reduce our air pollution, and improve our nation's economy.
Biodiesel is a renewable diesel fuel consisting of fatty-acid alkyl esters. Fatty-acid alkyl esters are actually long chains of carbon molecules (12 to 22 carbons long) with an alcohol molecule attached to one end of the chain. Biodiesel is made by a process called transesterification. Organically derived oils are combined with alcohol (usually methanol) and chemically altered to form fatty esters such as methyl ester. The biomass-derived esters can be blended with conventional diesel fuel or used as a neat fuel (100% biodiesel).
Back to Top
Biomass power is the use of biomass feedstocks instead of conventional fossil fuels (natural gas or coal) to generate electricity or industrial process heat and steam. Biomass is one of the oldest fuels known to humanity. Although basic, the primitive campfire illustrates the nature of using biomass for power. When the biomass is burned, it produces heat. In a power plant, this heat is used to turn water into steam. The steam is then used to turn turbines, which are connected to electric generators. Gasifiers heat the biomass to convert it into a gas that can be used in highly efficient power systems, such as combustion turbines or fuel cells.
Back to Top
Renewable bioproducts are products created from plant- or crop-based resources such as agricultural crops and crop residues, forestry, pastures, and rangelands. Many of the products that could be made from renewable bioproducts are now made from petroleum.
Back to Top
In 2003, production of ethanol from biomass reached 2.81 billion gallons and was made primarily from corn (Renewable Fuels Association, Ethanol Industry Outlook 2004. In 2003, ethanol and biodiesel represented only about 1% of transportation fuels consumed in the United States (EIA 2004 Monthly Energy Review). Nearly all gasoline oxygenated to reduce carbon monoxide during winter months contains ethanol, although this is a relatively small market. A modest but growing portion of reformulated gasoline for reducing ground-level ozone (smog) also contains ethanol. This market is growing because of groundwater pollution concerns with and bans on methyl tertiary butyl ether (MTBE), the alternative oxygenate. About half of current ethanol use, however is as an octane booster in regular gasoline. For this market, ethanol competes with petroleum-derived additives such as aromatics and alkylates, as well as MTBE. States using the most ethanol for octane boosting seem to be a function of blender preferences, political support for ethanol, and past as well as current subsidies for ethanol use, rather than straight price competition.
As of December 2003 approximately 177 E-85 fueling stations exist in various states for flexible fuels vehicles FFV. The Alternative Fuels Data Center Alternative Fuel Station Locator or Alternative Fuels Hotline (800-423-1363) can help you locate these stations and other alternative fuels stations in your area. Ethanol is more widely used in Brazil, where it is made from sugar cane, than in the United States.
Ethanol is not yet being commercially produced from cellulose and hemicellulose, the fibrous sugar polymers that make up the bulk of plant material. However, several companies are moving toward commercial production.
Biodiesel, made from soybean oil or recycled restaurant grease, is used mostly by fleet operators, but as of January 2004, was already offered by retail service stations in about two-thirds of the states in the United States. The Alternative Fuels Data Center and National Biodiesel Board (NBB), Web sites can help you locate these stations and the NBB, a trade association for biodiesel producers can help you locate biodiesel producers and distributors that market to fleets in your area. Biodiesel is more widely used in Europe, where it is made from canola oil, than it is in the United States.
Back to Top
Although ethanol production from corn can still expand greatly, its primary use is for animal feed and food products such as beverage sweeteners, and it may not always be in surplus. Advanced biotechnology cellulosic ethanol will supplement rather than replace corn ethanol, but it will also provide diversity, possible cost savings, and a vastly greater choice of potential feedstocks. Starches, such as that in corn kernels, and sugars are only a very small portion of available biomass materials; cellulose and hemicellulose form the bulk of most plant materials. Making ethanol from cellulose and hemicellulose dramatically expands the types and amount of available feedstock. This includes many materials now regarded as wastes requiring disposal, as well as biomass residues such as corn stalks and wood chips or "energy crops" of fast-growing trees and grasses.
Back to Top
In short, the costs associated with being a new technology. Although cellulosic feedstocks such as agricultural and forestry residues and waste materials would be far cheaper than corn grain-the main cost in current ethanol production-the added cost of capital equipment and processing needed to breakdown and then ferment the cellulose and hemicellulose is currently more than the savings. Reducing those costs is the principal focus of the Biomass Program, however, and we anticipate substantial cost reductions. The other main hurdle for the first advanced bioethanol technology producers is just that they would be first with a new technology. Investors are reluctant to commit to unproven technologies—and much of the cost of advanced bioethanol technology is for the capital equipment—so financing construction is a major challenge for the "pioneer" cellulosic ethanol plants.
Back to Top
If you have an inexpensive starch or sugar supply to use as a feedstock, the technology is relatively simple; similar to making alcoholic beverages. Just be sure to check with the Bureau of Alcohol, Tobacco, and Firearms to avoid being arrested as a moonshiner. Around 1980/1981, the USDA, DOE, and others actively promoted on-farm production of fuel ethanol. We do not know how much production was stimulated by that or how much of it continues today (would like to hear, if someone knows), but a Fuel from Farms (PDF 9.17 KB) guide produced at the time contains useful information for small-scale ethanol production. On a larger scale, you would want to hire an engineering or consulting firm. Check the membership list of the Renewable Fuels Association. Advanced bioethanol technology for cellulosic feedstocks is considerably more sophisticated, so you will definitely need to hire an ethanol industry engineering or consulting firm. The U.S. Environmental Protection Agency currently limits ethanol fuel use to blends of 5.7%-10% or 70%-85% with gasoline. The higher blends should only be used in flexible-fuel vehicles with corrosion-resistant fuel systems.
Biodiesel can be produced quite easily on a small scale from an appropriate vegetable oil or animal fat source, but it is critical to rigorously meet prescribed fuel specifications to avoid the possibility of engine damage. 2004 Biodiesel Handling and Use Guidelines (PDF 1.6 MB, see Table 4) is a good initial information source. The actual prescribed standards may be purchased from the American Society for Testing and Materials. The National Biodiesel Board is a good source for consultants and current producers.
Back to Top
Biomass gasifiers are reactors that heat biomass in a low-oxygen environment to produce a fuel gas that contains from one fifth to one half (depending on the process conditions) the heat content of natural gas. The gas produced from a gasifier can drive highly efficient devices such as turbines and fuel cells to generate electricity.
Back to Top
Gasoline blended with 10% ethanol is exempt from 5.3 cents of the 18.3-cent per gallon federal excise tax on gasoline. This provides an effective subsidy of 53 cents per gallon of ethanol produced, generally making it cost competitive with MTBE. Alternatively, or for E85 (70% ethanol in winter, 83% ethanol in summer), ethanol producers may file for an income tax credit of 53 cents per gallon (effective rate somewhat less than that) for production not covered by excise tax exemption. The excise tax exemption was initially enacted at a rate of 5.4 cents by the Energy Security Act of 1979 and has been extended several times, most recently through 2007 by the 1998 Federal Highway bill with the exemption dropping to 5.3 cents in 2003 and 5.2 cents in 2005. Small (less than 30 million gallons per year capacity) producers are also eligible for an additional subsidy, but the mechanics of how the small producers credit is offered has limited its use thus far. As of January 2004, according to a California Energy Commission study (PDF 770 KB), a total of 36 states provide some sort of incentive for ethanol production (22) or use (32)—many have both. (Biofuels for Your State" (PDF 319 KB, p.3) explains these incentives. Because of interstate sales, the trend in state incentives is away from state excise tax exemptions that promote use, toward producer credits that promote production.
Air quality regulations based on the Clean Air Act Amendments of 1990 requiring oxygenated fuels for carbon monoxide reduction and oxygenated reformulated gasoline for ground-level ozone (smog) reduction strongly support ethanol use in specific geographic markets. State actions to limit MTBE use (19 as of May 2004) also encourage ethanol use. Also, the alternative-fuel-vehicle requirements of the Energy Policy Act of 1992 support purchase of flexible-fuel vehicles capable of using E85 by federal and state fleets, though they stop short of requiring its use in those vehicles.
As of early 2004, Congressional proposals for a renewable fuel standard mandating that a gradually increasing percentage of automotive fuel be ethanol or other renewable fuel have been included in major energy bills several times over the past couple years, but none have passed both houses yet. Enactment of a program along these lines could be expected to be a great boost to ethanol production. Any sort of "carbon tax" or other promotion of renewable energy generally would likely also help ethanol.
A U.S. Department of Agriculture program, (Farm Service Agency/Commodity Credit Corporation Bioenergy Program) supports increased biofuels production from commodity purchases strongly supporting new production capacity of biofuels. The $150 million per year maximum program makes cash payments to compensate for a portion of increased biomass feedstock purchases to bioethanol and biodiesel producers based on their increased production. Payments in the first three quarters of FY 2003 were credited with increasing ethanol production by 414 million gallons and biodiesel by 12 million gallons. General agriculture programs that promote crop production also support biofuels production from those crops or their residues.
New with the 2002 Farm Bill (Agriculture Risk Protection Act of 2000 as amended by the Farm Security and Rural Investment Act of 2002) is a U.S. Department of Agriculture Value-Added Development Grant program that provides grants to independent producers, agricultural producer groups, farmer or rancher cooperatives, or majority-controlled producer-based business ventures that are developing new businesses—including producing renewable energy such as biofuels—that process or otherwise expand the market for and produce greater revenue from agricultural products. Nearly 200 biofuels projects received funding under the program in 2003 and $13 million for grants of up to $500,000 each are available for 2004.
Because financing capital construction is a key hurdle for biofuels production facilities—particularly for advanced bioethanol production from cellulosic materials—any rural or industrial development programs can be of great help, as well.
Back to Top
As a government laboratory, we cannot really recommend any particular companies to help with biofuels projects. A good place to start, however, is with the members of the industry trade associations. For ethanol, look at the associate members of the membership/links list of the Renewable Fuels Association or the Ethanol Consultants/Ethanol Plant Builders pages of the American Coalition for Ethanol. Also, BBI International publishes an Ethanol Plant Development Handbook, which, in addition to discussing considerations for building an ethanol plant, includes a listing of providers for the ethanol industry. Kansas State University's Department of Agricultural Economics has set up a Web-based "Ethanol Pre-feasibility Calculator" which may help you assess prospects for an ethanol project. You can also check our Theoretical Ethanol Yield Calculator for the potential ethanol production from various starch and cellulosic feedstocks. For cellulosic ethanol, you might get some ideas from descriptions of our industry partners involved in related projects which are listed in our Multi-Year Technical Plan (PDF 62 MB). For Biodiesel, check the "related links" page of the National Biodiesel Board. The Renewable Energy Power Project has an extensive list of companies working with biomass gasification/power production.
Back to Top
See also related FAQs section of the State Energy Alternatives Web Site.
|
){kind=small}
