Definitions

We will be adding definitions as the need arises (and when we have a little free time). Comments and suggestions are certainly welcome. Also see the Renewable Fuel Standard defintions.

A

Artificial photosynthesis. The process of converting carbon dioxide gas into useful carbon-based chemicals, most notably fuel or other compounds usually derived from petroleum, as an alternative to extracting them from biomass.

B

Bagasse. The fibrous matter that remains after sugarcane or sorghum stalks are crushed to extract their juice. It is currently used as a biofuel and in the manufacture of pulp and paper products and building materials. A waste product, it is also used as a locally-grown source for manufacturing cellulosic ethanol.Agave bagasse is a similar material that consists of the tissue of the blue agave after extraction of the sap.

Biochar. A charcoal-type material created by heating biomass in a low-oxygen environment, also known as pyrolysis. In addition to biochar, pyrolysis also releases volatile gases that can be converted into liquid fuels or used to generate power or heat. Biochar can increase soil fertility, raise agricultural productivity and reduce pressure on forests. Biochar is a stable solid, rich in carbon and can endure in soil for thousands of years. Biochar is under investigation as an approach to carbon sequestration via bio-energy with carbon capture and storage.

Biogas. A gas produced by the biological decomposition of organic waste in an oxygen deprived environment, such as anaerobic digestion or the methane released from decomposing food waste in a landfill. It is usually composed of carbon dioxide and methane. It can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields. Also see the Renewable Fuel Standard definition for biogas.

C

Combined Heat and Power (CHP), Also known as cogeneration, CHP utilizes a single fuel source to generate both electricity and thermal energy. The waste heat is usually captured in the form of steam or hot water. A CHP system is typically designed to meet the heating and electrical base loads of a given facility, thereby increasing operational efficiency and decreasing energy costs.CHP is one of the most efficient ways to use fuel. Other potential benefits to CHP include reduced fuel costs, reduced greenhouse gas emissions; increased power reliability, reduced peak demand charges, avoided distribution losses, and reduced grid congestion.

P

Pyrolysis. A thermochemical decomposition of material at elevated temperatures in a low-oxygen environment to produce gases, liquids (tar), and char (solid residue). Pyrolysis involves the simultaneous change of chemical composition and physical phase, and is irreversible. The resulting products can be used as fuels, with or without prior upgrading, or they can be utilized as feedstock for the chemical or material industries. The types of materials which are candidates for pyrolysis processing include coal, plant biomass, animal and human waste, food scraps, paper, cardboard, plastics, and rubber.

S

Solid Recovered Fuel (SRF). 1) Solid recovered fuel / specified recovered fuel (SRF) or refuse-derived fuel (RDF) is a fuel produced by shredding and dehydrating or otherwise processing municipal solid waste (MSW) with a waste converter technology. SRF or RDF consists largely of combustible components of MSW such as plastics and biodegradable waste. 2) Per the mandate given by the European Commission, a “solid fuel prepared from non-hazardous waste to be utilised for energy recovery in incineration or co-incineration plants, and meeting the classification and the specification requirements laid down in prCEN15359 (European Standard in preparation).

Syngas. Synthesis gas or synthetic gas, a gas composed of carbon monoxide, hydrogen, and other hydrocarbons and has less than half the energy density of natural gas. Examples of production methods include gasification (a thermo-chemical process) of coal or biomass, and steam reforming of natural gas or liquid hydrocarbons to produce hydrogen. The name comes from its use as an intermediate in creating synthetic natural gas (SNG), and for producing ammonia or methanol.

T

Torrefaction. A thermo chemical treatment of biomass at temperatures typically ranging between 200-320 °C. During torrefaction the biomass properties are changed to obtain a much better fuel quality for combustion and gasification applications. Torrefaction combined with densification leads to a very energy dense fuel carrier of 20-25 gigajoules per tonne. The  process creates a uniform, hydrophobic, dense, and highly efficient fuel similar to coal in combustion properties, but lacking most of the contaminants.