Wisconsin State Energy Office

A Renewable Energy & Bioeconomy Dictionary

What is biomass?
Biomass is organic matter (plant material, vegetation, agriculture waste, forestry waste) used as a fuel or source of energy. Use of biomass as an energy source results in little net production of carbon dioxide because the CO2 generated during combustion of plant material equals the CO2 consumed during the lifecycle of the plant.

What is a feedstock?
Feedstocks are any material which is converted to another form or product. It is the raw material required for an industrial purpose. Biomass feedstocks can include everything from soybeans and corn to prairie grasses and trees.

What are biofuels?
Biofuels are liquid, solid, or gaseous fuels produced by the conversion of biomass. Examples include bio-ethanol from corn or sugarcane; bio-gas from anaerobic (in the absence of air) decomposition of wastes; and biodiesel from materials such as soybean oil.

What are energy crops?
Energy crops are crops grown specifically for their value as a fuel. Examples of energy crops include corn, sugarcane, poplar trees and switchgrass.

What is Ethanol?
Ethanol is a liquid fuel that is produced by the fermentation of plant sugars. Currently, one bushel of field corn will yield approximately 2.7 gallons of fuel ethanol.

What is Biodiesel?
Biodiesel is an alternative to petroleum diesel that is made from vegetable oils and animal fats through a process called transesterification. Biodiesel can be used as a pure fuel or blended with petroleum and can be used in any diesel engine with little or no engine modifications.

What is Cellulosic Ethanol?
New technological advancements are leading to the production of cellulosic ethanol. Even though it is chemically identical to the ethanol made from corn or soybeans, cellulosic ethanol has a net energy content nearly three times higher, a lower net level of greenhouse gases and can be made from many different kinds of cellulosic biomass feedstocks such as corn stover, switchgrass, prairie grasses and wood materials.

What is a Biorefinery?
A biorefinery would work like a petrochemical refinery, producing transportation fuels and high-value chemicals, but would use plant matter as the raw material instead of petroleum. The plant matter would be any number of things, including corn, wheat, barley, switchgrass, crop residues or waste wood.

Biorefineries offer Wisconsin an avenue for expanding its existing ethanol-production facilities to produce more high-value products from a wider variety of crops.

The basic molecules in petrochemicals are hydrocarbons (compounds of carbon and hydrogen). In plants, the basic molecules are carbohydrates, proteins and vegetable oils (compounds of carbon, hydrogen, and oxygen). Molecules from either source can be processed to create building blocks for manufacturing a wide variety of goods, including plastics, solvents, paints, adhesives and drugs. One scenario for Wisconsin could be the whole-plant biorefinery, which would process both corn grain and corn stover (the stalks and husks).

Current ethanol plants take the grain and break down its starch, which is a string of glucose molecules. That would continue. Cellulose, the fibrous material in the cornstalk, also is made up of a strain of glucose molecules, but their bonds are more difficult to break down. A retrofitted ethanol plant would use advanced enzymes to treat the cellulose. Such a plant would produce not only ehtanol but a product called lignin, which would be converted into synthetic gasoline and heat for plant operations.

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