Acid hydrolysis

A chemical reaction in which acid is used to convert starch or cellulose to sugar. It is often the first step in ethanol production.

ADM Hamburg AG

A division of ADM based in Germany that focuses on the production of biodiesel from rapeseed and grain.

Advanced biofuel

Also called second generation biofuels. Any biofuel produced from a sustainable feedstock that does not threaten the food supply.

AGE 85

Aviation fuel containing 85% ethanol and 15% biodiesel that can be used in piston engine aircraft. Abbreviation for Aviation Grade Ethanol 85


Any organic compound that contains an oxygen single-bonded to a hydrogen atom (OH group).


A group of diverse, generally autotrophic organisms that can be either single-cell or multi-cell. Various species of algae are used to produce ethanol and butanol.


A U.S. biofuel company that produces ethanol directly from algae without harvesting them.

Anaerobic digestion

Breakdown of organic matter in an environment where oxygen is NOT present, which produces methane and CO2.


Any hydrocarbon that contains a ring (usually six carbon atoms) in which the carbon atoms all share electrons equally, resulting in bonds with characteristics that are intermediate between single and double bonds. Bonds are considered to be unsaturated.

Australian Biofuels Research Institute (ABRI)

An organization funded by the federal government of Australia with the goal of developing biofuel research


Biodiesel that contains no petroleum products. It is 100% renewable, organic biodiesel. Requires extensive engine modifications. VW produces B100 compatible vehicles. Prone to low-temperature gelling.


A mixture of 2% biodiesel to 98% petrodiesel


A mixture of 20% biodiesel to 90% petrodiesel


A mixture of 5% biodiesel to 95% petrodiesel. A common blend in the UK.


The dry, fibrous remnants of sugarcane or sorghum once the sugar has been extracted. It contains mostly cellulose, hemicelluloses, and lignin. It can be burned directly to generate electricity or converted to ethanol.


Butanol produced from biomass. It can be used in unmodified gasoline engines.


Diesel fuel produced from biomass. Biodiesel cannot be used in standard engines without modification as it corrodes rubber seals and gaskets. It also has a lower gelling point than petrodiesel, making it unsuitable for use in colder climates. Biodiesel is often blended with petrodiesel.


The amount of variation in an ecosystem. Greater variation indicates a healthier ecosystem. Genetically modified organisms and large monocultures used in biofuel production can threaten biodiversity.


Any renewable energy made from biological sources. Fossil fuels are not counted because, even though they were once biological, they are long dead and have undergone extensive modification.


Any fuel derived from biological carbon fixation, including solid fuels, bioethanol and other bioalcohols, biodiesel, etc.


A mixture of methane and CO2 with water vapor created by the breakdown of organic matter in the presence of oxygen.


Hydrogen that is produced biologically (most often by bacteria and algae).


Any device that supports a biologically active environment. In the context of biofuels, a bioreactor is most often used to grow algae.

Black liquor

Used cooking liquor from the kraft process for producing paper. It contains lignin, hemicelluloses, and other wood extracts. It is considered a waste product and can be gasified to produce biofuel.

Blue Marble Biomatierals

A U.S. biofuel company that produces biofuel and biochemicals from various feedstock.

British Thermal Unit (BTU)

A measure of heat that is equivalent to the amount of energy required to raise the temperature of 1 pound of water by 1 degree Fahrenheit.

Brown liquor

Similar to black liquor, but it is derived from the sulfite process of paper production. Alternatively called red liquor, thick liquor, and sulfite liquor.

Butamax Advanced Biofuels

A joint venture between BP and DuPont to produce biobutanol from sugar and starch feedstock.


A six-carbon alcohol that is more similar to gasoline than ethanol. It can be used in gasoline engines without the need for modification and produces roughly that same amount of energy per mass as gasoline.


A genus of flowering plant related to flax. Some species produce seeds with large quantities of oil that can be converted to various biofuels (e.g. biodiesel). Camelina grows well in moderate climates.

Carbon dioxide

A molecule made of one carbon atom double bonded to two oxygen atoms (one of each side of the carbon). It is a colorless, odorless gas at standard temperature and pressure and is widely implicated as one of the major causal agents in greenhouse warming.

Carbon monoxide

A molecule made of one carbon atom bonded to a single oxygen atom via a triple bond. It is a product of inefficient combustion of hydrocarbon compounds. It is a pollutant and is toxic to humans at concentrations above 50 ppm during long term exposure or 667 ppm during short term exposure.

Carbon Negative

A product or process that, over its entire lifetime, causes a net decrease in atmospheric carbon levels.

Carbon Neutral

A product or process that, over its entire lifetime, causes no net increase or decrease in atmospheric carbon levels.

Carbon Positive

A product or process that, over its entire lifetime, causes a net increase in atmospheric carbon levels.

Carbon sink

Any reservoir that can accumulate or store carbon-containing compounds for a prolonged or indefinite period. This is particularly relevant to carbon dioxide, which could be stored to reduce its environmental impact.


A woody, tropical shrub well known for being the source of tapioca extract. It is used in southeast Asai for the production of biodiesel and ethanol.


An organic polysaccharide of the general formula (C6H10O5)n that is the structural component of the cell wall of most green plants. It is used in several biofuel production processes. Biofuel produced primarily from cellulose is sometimes called cellulosic biofuel.

Cellulosic ethanol

Ethanol produced from the inedible, cellulose-rich parts of plants. Studies are conflicting on its benefits, but he U.S. Department of Energy has suggested it can reduce green house gas emissions by as much as eighty-five percent over reformulated gasoline.

Cetane Rating

A number used to rate the quality of diesel fuel or any fuel combusted via compression ignition. Petro diesel ranges from cetane 40-55 in most cases while biodiesel ranges from 46-52 if plant-based and 56-60 if animal based


The protective casings of seeds of many grains, cereals, and straw. Some livestock can consume it, but it is generally considered to be a waste product.


A residue consisting of amorphous carbon that is obtained by pyrolysis or burning of wood or other organic compounds. It is used in the production of syngas.                   


A company based in Stockholm, Sweden that specializes in the conversion of black and brown liquors to syngas

Chinese National Petroleum Corporation

The largest stated-owned oil and gas company in China. CNPC has recently branched into ethanol production to meet the expanding demands of the Chinese economy for fuel.

Cloud Point

The temperature at which solids dissolved in al liquid are no longer completely soluble and begin to precipitate. Biodiesel often reaches a cloud point at higher temperatures than petrodiesel, making it less suitable for cold environments. This is one measure of the quality of diesel fuel or aviation fuel.


The production of electric energy along with a second for of energy (often heat).

Combined Heat and Power

See Cogeneration


Commonly referred to as burning. This is the process by which a fuel and an oxidant react to product heat (energy) and other compounds (CO2 and H2O in ideal hydrocarbon combustion)

Combustion Gases

The gases released during a combustion process. Similar to emissions.

Compression-ignition engine

An internal combustion engine in which the fuel is ignited by heat generated from compressing the gas to high pressures rather than from a spark. Most diesel engines work this way.


Also called maize, corn is a domesticated grain grown widely throughout the world. Corn is the largest source of ethanol feedstock in the world. Forty percent of the 332 million metric tons of corn grown in the U.S. is used to make ethanol.

Cunninghamella japonica

A type of tropical fungus recently found to produce hydrocarbons from organic matter. The hydrocarbons indistinguishable from those found in fossil fuels.


See Dried Distillers Grains


See Dried Distillers Grains with Solubles

Denatured ethanol

Ethanol that has additives to make it undrinkable. It is commonly used as a fuel and in chemical applications.

Diesel fuel

Any liquid fuel used in a diesel engine.


The French term for biodiesel. It is a contraction of the words diesel and ester.

Diester Industrie

A subsidiary of the French petroleum company Diester Industrie International that specializes in the production of biodiesel


A heterocyclic compound that can be used as a biofuel. It is easier to produce than butanol and has an energy content 40% greater than ethanol.

Direct Land Use Changes

Refers to changes in the way humans impact a given area of the earth and how that change affects greenhouse gas emissions. Attention is given to water diversion, biodiversity, and limited energy investment costs.

Distiller’s Wet Grains (DWG)

Grains containing more than 12% water and often up to 70% water.

Dried Distillers Grains

Unfermented grain residues that have been dried so as to extend the shelf life.

Dried Distillers Grains with Solubles

Unfermented grain residues that have been dried to 10-12% moisture so as to extend shelf life. Commonly used in ethanol production

Dry milling

Mechanical grinding of a feedstock that does not use water.


Apparatus that removes water from distiller’s wet grains to produce distiller’s dried grains.

DuPont Danisco

A joint venture between DuPont and Danisco foods to produce cellulosic ethanol using sugarcane, corn, and switchgrass.


A blend of 10% ethanol and 90% gasoline. The standard fuel in the United States


100% fuel ethanol. Used mainly in Brazil.


A blend of 2% ethanol and 98% gasoline.


A blend of 85% ethanol and 15% gasoline, which is the common blend implied by the term flex fuel vehicle (FFV). Generally seen only in the Brazil and the Midwestern United States.


 A blend of 90% ethanol and 10% gasoline.


The gaseous or particulate components expelled during a combustion reaction. The term commonly refers to the mix of gases and particulate that exit the exhaust of an internal combustion engine.

Energy Balance

In regard to biofuel, this term refers to the amount of energy required to produce the fuel versus the amount of energy derived from the fuel.

Energy Content

Also referred to as heating value, energy content is a measure of the number of British Thermal Units obtained by burning a set volume of fuel. Because it relies on volume, energy content can change with temperature and pressure.

Energy Crop

A low-cost, low maintenance plant gown exclusively for use as fuel.

Energy Density

Generally, the amount of energy stored in a given region of space per unit volume. Specifically, the amount of energy obtained from a specified mass of biofuel. Useful for comparing various types of biofuels in a standardized manner.

Energy Efficiency Ratio

A comparison of the energy stored in a fuel and the energy needed to produce, transport, and distribute the fuel.


A biological molecule that performs chemical interconversions. I.E., a molecule from a living organism that converts one chemical into another.


An alcohol composed of two carbons. The formula is C2H4O


A class of organic compounds that contains an ether group defined as R-O-R’ where R is any hydrocarbon chain and R’ is another hydrocarbon chain. Ethers are under consideration as biofuels and are used as additives in current fossil fuel blends

Ethyl Alcohol

See ethanol

Ethyl Tertiary Buytl Ether (ETBE)

Ether commonly used to oxygenate gasoline. Ether provides for cleaner combustion and decreased emissions.

FAME biodiesel

Fatty Acid Methyl Ester biodiesel


The raw material from which a biofuel is produced. Feedstock is generally a plant itself, but in the case of algae, the feedstock is any source of carbon (often carbon dioxide)


A normal metabolic process in which oxygen is NOT the final electron acceptor. Fermentation is the process through which alcohols are made.


See Flexible Fuel Vehicle.

First generation biofuel

Any biofuel derived from sugar, starch, or vegetable oil. In general, these fuels are considered a threat to food supply chains.

Fischer-Tropsch Biodiesel

Biodiesel made using the Fischer-Tropsch process

Fischer-Tropsch Process

A series of chemical reactions that convert carbon monoxide and hydrogen into liquid hydrocarbons. It is used in the production of synthetic lubricants and low-sulfur diesel fuel.


The lowest temperature at which a flammable liquid produces enough vapor to ignite. For most flammable liquids like gasoline, it is the vapor and not the liquid itself that is combustable.

Flexible Fuel Vehicle

A vehicle with an internal combustion engine that can run on more than one fuel. Usually the vehicle is designed to run on pure gasoline or a defined blend of gasoline/ethanol or gasonline/methanol. In some cases the vehicle can run on pure ethanol.

Fossil fuel

A fuel formed by the anaerobic decomposition, over thousands or millions of years, of dead biomass. Petroleum, coal, and natural gas are major categories of fossil fuels.


One of the kingdoms of living organisms. Fungi are eukaryotic organisms that are similar to plants in many ways, but which are not able to perform photosynthesis. Yeast, mold, and mushrooms are all fungi.

Gas to liquid

A refinery process that takes gaseous hydrocarbons like natural gas and converts them into longer hydrocarbons that are liquids. Methane and syngas are commonly converted to liquid fuels.


The conversion of carbonaceous solids into carbon monoxide, hydrogen, and carbon dioxide gases. This usually takes place at high temperatures and in the presence of steam.


Blends that are between E5 and E25 are commonly referred to as gasohol in the United States. The E10 blend is most commonly called gasohol throughout the rest of the world.

Gel point

The temperature at which an infinite polymer network is formed. Sometimes this term is used interchangeably with cloud point, but the two do not mean the same thing. At cloud point, solute precipitates (comes out of) from the solution where as at gel point, the components of the substance form polymer chains long enough to make the substance solid rather than liquid. Gel point is also defined as the point that a liquid fuel takes on the consistency of petroleum jelly.

Genetically modified organism (GMO)

A living thing that has had its genetic material (either DNA or RNA) manipulated by humans using recombinant techniques. The direct modification of DNA through an artificial process.


A U.S. company that creates “renewable chemicals” and isobutanol using genetically modified microorganisms.

Gliocladium roseum

A fungus from Patagonia that produces diesel fuel from cellulose.               


The sugar most commonly produced by living organisms.


See Glycerol


A simple compound mad of three carbons and three OH (hydroxyl) groups. It is a component of fatty acids and, as a result, a byproduct of biodiesel production via transesterification.

Grain Alcohol

See Ethanol

Green diesel

See Renewable Diesel

Greenhouse Effect

The warming of the Earth as a result of heat that is trapped by certain gases.

Greenhouse Gas

Any gas that traps heat in the Earth’s atmosphere and thus leads to increased temperatures. Water vapor, carbon dioxide, methane, ozone, chlorofluorocarbons, and nitrous oxide are all greenhouse gases.

Gushan Environemental Energy

A Chinese biodiesel and glycerol producer that uses vegetable oil and used cooking oil for feedstock.


A compound that consists solely of hydrogen and carbon atoms. Most fossil fuels are hydrocarbons.

Hydrogen sulfide

A poisonous, foul-smelling (rotten eggs) gas mde up of two hydrogen atoms and one sulfur atom. It is often found along with petroleum deposits and is considered a contaminant in fossil fuels.

Indirect Land Use Changes

Changes to land as a result of growing biofuel feedstock that are not a direct result of human intervention. This can include loss of biodiversity, subsequent changes to the ecosystem that have broader impact, and more. Essentially, this refers to the unintended consequences of releasing more CO2 by using land for biofuel feedstock growth. Abbreviated ILUC.

International Energy Agency (IEA) Bioenergy

A subdivision of the IEA working to achieve global integration of substantial bioenergy use.

Jatro BioJet Fuel

A German company focusing on the production of Jet Fuel from Jatropha. The company produces certified Jet A-1 fuel, which has been using in several test flights and is set to be purchased by several major airlines in the coming years.


A genus of flowering plants that grown in tropic regions, on marginal land. Oil from Jatropha seeds can be used to produce biodiesel.

Jilin Fuel Ethanol

A Chinese bioethanol company that operates the largest bioethanol plant in the world.


A measure of energy or work defined as the energy expended by applying a force of one newton over a distance of one meter.

Joule Unlimited

A U.S. biofuel company that focuses on the production of ethanol and biodiesel using genetically modified algae.

Jugian Zhongde Energy Co

A Chinese Energy company that produces ethanol.


A pinging sound that occurs in internal combustion engines when fuel is burned at the incorrect time. This often occurs because the fuel either burns too quickly, too slowly, or too early in the cycle. Fuels with a low octane rating are more prone to detonate early or burn too long.

Landfill Gas

Biogas (methane, CO2, and water vapor) produced from the breakdown of organic material in landfills.

Lifecycle analysis

Determining the environmental impact of all stages of an activity starting with raw material extraction through production, use, and disposal.


A complex chemical found mostly in woody plants and some algae


A group of substances that make up the plant walls of woody plants and which consist of a mixture of cellulose and lignin.

LS9 Inc.                 

A U.S. company that produce biofuels from genetically modified organisms, primarily algae


A measure of how well a lubricant reduces friction. Also referred to as a lubricant’s “anti-wear property.”


A mixture of 85% methanol and 15% gasoline. It is relatively uncommon given the low energy density and high toxicity of methanol.


A mixture of grain and water that is used as the base for fermenting ethanol.


1,000,000 joules. A common measure of energy in fuels.


Also called wood alcohol. Methanol is composed of a single carbon, one oxygen, and four hydrogen molecules. It is highly toxic and has a relatively low energy density.

Methyl Ester

The primary component of biodiesel, created by adding methanol to a fatty acid to produce three methyl esters and a glycerol molecule.

Methyl Tertiary Butyl Ether (MTBE)

A common gasoline additive used to raise octane and thus reduce knock. It is used to oxygenate gasoline.


A technology that is able to produce fuel or energy from more than one type of feedstock.

National Fuel Alcohol Program

Also called the Programma Nactional do Alcool in Brazil, this was the national policy of the country of Brazil that set standards for the inclusion of ethanol in fuel. As a result of this program, Brazil became the global leader in ethanol-based fuels.

National Renewable Energy Laboratory (NREL)

The scientific arm of the U.S. government tasked with research and development of alternative energy technology.

Neat Fuel    

Any fuel that is pure or unmixed. For example, neat ethanol is 100% ethanol.


Nitrogen is the name of both an element and a molecule. Molecular nitrogen is a colorless, odorless gas made up of two nitrogen atoms covalently bonded to one another. Under the high temperatures and pressures of combustion, nitrogen can combine with other compounds to form nitrogen oxides, which are considered pollutants.

Nitrogen oxides

A group of compounds containing oxygen and nitrogen in varying ratios. NO and NO2, generically referred to as NOx, are produced during high temperature combustion and contribute to the production of acid rain and ozone.


A biotech company headquartered in Denmark that produces enzymes and microorganisms for various industries, including biofuels.


A collection of hydrocarbons of the formula C8H12 that are components of gasoline. Pure isooctane, one of the structural isomers of octane, is used as the reference for rating the anti-knock qualities of gasoline.

Octane Rating

A way of rating the performance of motor and aviation fuels. Higher octane numbers indicate the ability of a fuel to withstand greater compression without detonation (burning). Higher compression generally means higher engine performance.


Oil Producing & Exporting Countries

Organization for Economic Cooperation and Development (OECD)

An international association of 34 countries that work to improve the economic situation of all people on the planet. Part of their focus includes holding down the costs of energy and so they have a lot of input regarding biofuel policy.

Palm oil

An edible vegetable oil derived from oil palm trees. Palm oil is used to produce biodiesel.


A small quantity of solid or liquid that is dispersed within a gaseous (or liquid) emission. Dust, smoke, soot, aerosols, and sprays are all particulates.


A plant that lives more than two years.


A semi-public petroleum corporation headquartered in Brazil. Petrobras is partially controlled by the state and so makes decisions regarding the Brazilian Ethanol Program.


A device that supports a biologically active environment that incorporates a light source to provide energy. Often used in the growth of algae.


The process by which living organisms like plants and algae convert light energy into chemical energy.

Programma Nactional do Álcool

See National Fuel Alcohol Program


In reference to ethanol, a proof is equivalent to 0.5% by volume. For example, a 30 proof alcoholic beverage would be 15% alcohol by volume.


A flowering member of the mustard/cabbage family that grows in temperate climates.

Reformulated gasoline (RFG)

Gasoline blended to burn more cleanly and to reduce smog and other toxins from entering the air. Reformulated gasoline contains MTBE, ETBE, or an alcohol to add oxygen for improved combustion.

Renewable Diesel

Any diesel fuel that is produced from a renewable source. Renewable diesel does not have to be environmentally friendly or reduce GHG emissions.

Renewable Fuels Standard (RFS)

The U.S. policy governing the minimum amount of renewable fuel in transportation fuel.

Sapphire Energy

A U.S. biofuel company that produces crude oil from algae. The oil can be refined to generate gasoline, jet fuel, and diesel fuel.

Second generation biofuel

Also called advanced biofuels. Any biofuel produced from a sustainable feedstock that does not threaten the food supply.

SG Biofuels

A U.S. biofuel company that focuses on molecular breeding and biotechnology to produce hybrid varieties of Jatropha.


A U.S. biofuel company that produces algal fuel for use in ground and air application. The company also produces personal care and nutritional products derived  from algae.

Solid Biofuel

Any solid biomass including wood, sawdust, grass trimmings, charcoal, agricultural waste, and dried manure.

Solix Biofuels

A U.S. company that focuses on the production of modular growth solutions for algae used in biofuel production.


A type of legume native to Asia that is used primarily as a food, but which also has limited application in biofuel production.


A polymer of glucose molecules that is made by plants. Starch must be converted to sugar (individual glucose molecules) before it can be fermented to produce alcohol.


The dried stalks and leaves of a crop after the edible parts have been harvested.


Any of 37 species of perennial grass rich in sugar and native to warm tropical regions. Sugarcane is the primary source of ethanol in Brazil, yielding roughly 800 gallons of ethanol per acre of planting.


Chemical element number 16. This abundant element is a common contaminant in fossil fuels which, when burned, produce sulfur dioxides that eventually become acid rain.


A perennial grass native to North America that is considered as a potential fuel for the production electricity via direct combustion.


A mixture of carbon monoxide and hydrogen that can be used to produce synthetic petroleum via the Fischer-Tropsch process.

Thermal Conversion

The transformation of complex organic material into light crude oil using pressure and heat.


The process of exchanging the organic group of an ester with the organic group of an alcohol. The process is used to produce biodiesel from triglyceride.


Organic compounds composed of three fatty acid chains connected to a glycerol molecule.

Vegetable Oil

A triglyceride extracted from a plant.


A measure of the resistance of a fluid to deformation by shear stress or tensile stress. Viscosity is an important component of lubricating oils.


A measure how easily a liquid is converted to a gas. The lower the temperature at which a liquid evaporates, the more volatile it is considered to be.

Waste Vegetable Oil (WVO)

Vegetable oil that is no longer fit for use in food.

Wet milling

A process in which feedstock is steeped in water to soften it before it is ground.

Wood Alcohol

See Metahnol.

Zero Carbon Contribution

See Carbon Neutral