Acid Catalyst

An acid used to accelerate the process of a chemical reaction (to catalyze). The catalyst itself is not consumed by the reaction. Used in the pretreatment of oils or fats for biodiesel production in an esterification process to remove fatty acids. (This definition may need work) (sources: (source:Wikipedia, EPA Technology Matrix)

aerobic process

Organic material decomposing with oxygenSU (This definition may need work)

aerobic technologies

advanced biofuels

a term used by organizations advocating “sustainable” or “green” biofuels; “biofuels that are greenhouse gas-reducing, water conserving and wildlife-friendly.”


agrichar is also called biochar, which is a type of charcoal produced from biomass. In some cases, the term is used to distinguish biomass charcoal produced via pyrolysis.

agricultural inputs

All substances or materials used in the production or handling of agricultural products.

agrifuel (also “agri-fuel” or “agrofuel”)

Fuel derived from agricultural products

alcohol / alcohol fuel

See ethanol.

algae reactor

Also known as algae bioreactors. A technology that uses algae to remove CO2 from power plant emissions. The algae can then be converted into various kinds of biofuel using gasification, extraction and transesterification, fermentation, anaerobic digestion or drying to produce biomass. (Source: Green Fuel Technology)

algal biodiesel

Biodiesel produced from algae. (


all-lands approach

An integrated approach to land use management expounded in 2009 by U.S. Department of Agriculture Secretary Tom Vilsack, to include Federal- and state-managed, as well as privately owned forest lands.[1]

alternative fuel

The definition of alternative fuels will vary based on the context the term is used in. It usually means an alternative to petroleum fuels and not necessarily a renewable one.

alternative fuel vehicle (AFV)

Any dedicated, flexible-fueled, or dual-fueled vehicle designed to operate on at least one alternative fuel. (Source: National Energy Policy Act USA)

anaerobic activated sludge process

The anaerobic activated sludge process consists of a bioreactor and clarifier in series. When influent waste is pumped into the bioreactor, bacteria are allowed to digest the waste, and biogas is created. The gas is then collected at the top of the bioreactor in a variety of ways. The effluent waste, often called mixed liquor, is sent to a clarifier where the larger solids are allowed to settle out of solution. A portion of these sediments are returned to the bioreactor in order to maintain an adequate level of biomass in the reactor. The liquid effluent from the clarifier is then ready for disposal. (source: RPI) (This definition may need work)

anaerobic clarigester

The anaerobic clarigester is a form of anaerobic digester. It is regarded as being the ancestor of the UASB anaerobic digester . A clarigester treats dilute biodegradable feedstocks and separates out solid and hydraulic (liquid) retention times. (source:Wikipedia) (This definition may need work)

anaerobic contact process

The anaerobic contact process is a type of anaerobic digester. Here a set of reactors are created in series, often with recycling. This recycled material is pumped up into the bottom of the first reactor, an upflow reactor, which allows the waste to flow up from the bottom and separates the waste into 3 zones. At the very top is the biogas zone where the gas is collected. (source:Wikipedia)

anaerobic digester

An anaerobic digester is an industrial system that harnesses the naturally occurring process of anaerobic decomposition to treat waste, produce biogas that can be used to power electricity generators, provide heat and produce soil improving material. (Source: Wikipedia)

anaerobic digestion

Decomposition of biological wastes by micro-organisms, usually under wet conditions, in the absence of air (oxygen), to produce a gas comprising mostly methane and carbon dioxide. (Source: BFIN)

anaerobic expanded-bed reactor

an expanded bed reactor that is operated anaerobically. An expanded bed reactor is a wastewater treatment process where the wastewater flows upward through a bad of sand or activated carbon.

anaerobic filter

An anaerobic filter (AF) is a form of anaerobic digester, commonly employed in the treatment of waste waters.. The digestion tank contains a filter medium which anaerobic bacterial populations can establish upon. They are used to produce biogas(source:Wikipedia) (This definition may need work)

anaerobic fluidized bed

a system for the treatment of moderate and high strength industrial waste

anaerobic lagoon

A type of anaerobic digester used to treat animal waste and produce biogas. Animal waste is flushed into a pool of water where organisms naturally present in manure and the environment decompose the waste and a cover captures the released biogas. (source:Wikipedia) (This definition may need work)

anaerobic migrating blanket reactor AMBR

A kind of anaerobic digester. It is a continuously fed, compartmentalized reactor that reverses its flow in a horizontal manner. This system is developed without the requirement of elaborate gas-solids-separator and feed-distribution systems. Effluent recycling is not required, but mixing is necessary to obtain a sufficient biomass/substrate contact. (source:freepatentsonline)

anhydrous ethanol

Ethanol that has less than 1 percent volume water content. Most commonly used in the United States for blending with gasoline (e.g., E10, E85); in Brazil, many vehicles are set up to run on hydrated ethanol

aquatic biofuels

Aquatic organisms and wastes that can be used to produce biofuels. (See Aquatic Biofuels (PDF file), paper by T. Piccolo.)

ASTM D6751

A U.S. standard for biodiesel that establishes fuel quality requirements such as purity and lubricity characteristics. See CEN 14214 for European specifications

auto-thermal reforming (ATR)

A method for extracting hydrogen from hydrocarbons. ATR breaks down hydrocarbon molecules into separate hydrogen and carbon atoms using a catalyst, steam, and oxygen