Biofuels

SIEC section 5. One of the ten top-level sections of the Standard International Energy Product Classification (SIEC); see that page for the classification’s scope rules, coding system and full Table 3.1 code list. Biofuels split into three divisions: solid, liquid, and biogases.

5 Biofuels

Fuels derived directly or indirectly from biomass [IRES, Ch. III, SIEC 5, PDF p. 49, 2018].

Remark: Fuels produced from animal fats, by-products and residues obtain their calorific value indirectly from the plants eaten by the animals [IRES, Ch. III, SIEC 5, PDF p. 49, 2018].

51 Solid biofuels

Solid fuels derived from biomass [IRES, Ch. III, SIEC 51, PDF p. 49, 2018].

511 Fuelwood, wood residues and by-products

Fuelwood or firewood (in log, brushwood, pellet or chip form) obtained from natural or managed forests or isolated trees, plus wood residues used as fuel in which the original composition of wood is retained [IRES, Ch. III, SIEC 511, PDF p. 49, 2018].

Remark: Charcoal and black liquor are excluded [IRES, Ch. III, SIEC 511, PDF p. 49, 2018].

5111 Wood pellets

A cylindrical product agglomerated from wood residues by compression, with or without a small quantity of binder. Diameter not exceeding 25 mm, length not exceeding 45 mm [IRES, Ch. III, SIEC 5111, PDF p. 49, 2018].

5119 Other fuelwood, wood residues and by-products

Fuelwood, wood residues and by-products except in the form of wood pellets [IRES, Ch. III, SIEC 5119, PDF p. 49, 2018].

512 / 5120 Bagasse

The fuel obtained from the fibre that remains after juice extraction in sugar cane processing [IRES, Ch. III, SIEC 5120, PDF p. 49, 2018].

513 / 5130 Animal waste

Excreta of animals, meat and fish residues that, when dry, are used directly as a fuel [IRES, Ch. III, SIEC 5130, PDF p. 49, 2018].

Remark: Excludes waste used in anaerobic fermentation plants; fuel gases from those plants are classified under biogases (division 53, below) [IRES, Ch. III, SIEC 5130, PDF p. 49, 2018].

514 / 5140 Black liquor

The alkaline-spent liquor obtained from the digesters during the production of sulphate or soda pulp required for paper manufacture [IRES, Ch. III, SIEC 5140, PDF p. 50, 2018].

Remark: The lignin in the liquor burns to release heat when the concentrated liquor is sprayed into a recovery furnace and heated with hot gases at 900°C. Used as a fuel in the pulping process [IRES, Ch. III, SIEC 5140, PDF p. 50, 2018].

515 / 5150 Other vegetal material and residues

Solid primary biofuels not specified elsewhere, including straw, vegetable husks, ground nut shells, pruning brushwood, olive pomace and other wastes arising from the maintenance, cropping and processing of plants [IRES, Ch. III, SIEC 5150, PDF p. 50, 2018].

516 / 5160 Charcoal

The solid residue from the carbonization of wood or other vegetal matter through slow pyrolysis [IRES, Ch. III, SIEC 5160, PDF p. 50, 2018].

52 Liquid biofuels

Liquids derived from biomass and used as fuels [IRES, Ch. III, SIEC 52, PDF p. 50, 2018].

Remark: Comprises biogasoline, biodiesels, bio jet kerosene and other liquid biofuels; used for transport, electricity generation and stationary engines [IRES, Ch. III, SIEC 52, PDF p. 50, 2018].

521 / 5210 Biogasoline

Liquid fuels derived from biomass and used in spark-ignition internal combustion engines [IRES, Ch. III, SIEC 5210, PDF p. 50, 2018].

Remark: Common examples: bioethanol (hydrous and anhydrous), biomethanol, biobutanol, bio ETBE (ethyl-tertio-butyl-ether) and bio MTBE (methyl-tertio-butyl-ether). May be blended with petroleum gasoline or used directly in engines; blending may take place in refineries or at or near the point of sale [IRES, Ch. III, SIEC 5210, PDF p. 50, 2018].

522 / 5220 Biodiesels

Liquid biofuels derived from biomass and used in diesel engines [IRES, Ch. III, SIEC 5220, PDF p. 50, 2018].

Remark: Biodiesels obtained by chemical modification are a linear alkyl ester made by transesterification of vegetable oils or animal fats with methanol — transesterification distinguishes biodiesel from straight vegetable and waste oils. Biodiesel has a flash point of around 150°C and a density of about 0.88 kg/litre. Biological sources include, but are not limited to, vegetable oils from canola (rapeseed), soybeans, corn, oil palm, peanut or sunflower. Some liquid biofuels (straight vegetable oils) may be used without chemical modification, usually requiring engine modification. A further category of diesel fuels can be produced by thermal processes (e.g. gasification followed by Fischer-Tropsch synthesis, pyrolysis followed by hydrogenation, or conversion of sugar to hydrocarbons using microorganisms such as yeast), drawing on a wide range of biomass feedstocks including cellulosic materials and algal biomass. Biodiesels may be blended with petroleum diesel or used directly in diesel engines [IRES, Ch. III, SIEC 5220, PDF p. 50, 2018].

523 / 5230 Bio jet kerosene

Liquid biofuels derived from biomass and blended with or replacing jet kerosene [IRES, Ch. III, SIEC 5230, PDF p. 50, 2018].

Remark: Can be produced by thermal processes including gasification followed by Fischer-Tropsch synthesis, pyrolysis followed by hydrogenation, or conversion of sugar to hydrocarbons using microorganisms (e.g. yeast), drawing on a wide range of biomass feedstocks including cellulosic materials and algal biomass [IRES, Ch. III, SIEC 5230, PDF pp. 50–51, 2018].

529 / 5290 Other liquid biofuels

Liquid biofuels not elsewhere specified [IRES, Ch. III, SIEC 5290, PDF p. 51, 2018].

53 Biogases

Gases arising from the anaerobic fermentation of biomass and the gasification of solid biomass (including biomass in wastes) [IRES, Ch. III, SIEC 53, PDF p. 51, 2018].

Remark: Biogases from anaerobic fermentation are composed principally of methane and carbon dioxide, comprising landfill gas, sewage sludge gas and other biogases from anaerobic fermentation. Biogases can also be produced from thermal processes (gasification or pyrolysis) of biomass, yielding mixtures containing hydrogen and carbon monoxide (usually known as syngas) along with other components; these gases may be further processed to modify their composition and can be further processed to produce substitute natural gas. The gases divide into two groups by production route: biogases from anaerobic fermentation, and biogases from thermal processes. They are used mainly as a fuel but can also serve as a chemical feedstock [IRES, Ch. III, SIEC 53, PDF p. 51, 2018].

531 Biogases from anaerobic fermentation

Composed principally of methane and carbon dioxide; comprises landfill gas, sewage sludge gas and other biogases from anaerobic fermentation [IRES, Ch. III, SIEC 531, PDF p. 51, 2018].

Explanation: Includes gas produced from a range of wastes and other biomass materials, including energy crops in anaerobic digesters (including sewage sludge gas and landfill gas). The gases may be processed to remove carbon dioxide and other constituents to produce a methane fuel [IRES, Ch. III, SIEC 531, PDF p. 51, 2018].

5311 Landfill gas

Biogas from the anaerobic fermentation of organic matter in landfills [IRES, Ch. III, SIEC 5311, PDF p. 51, 2018].

Landfill gas is classified separately from natural gas even though both consist mainly of methane, because they differ in source and production method — see Natural Gas and SIEC Classification System [IRES, Ch. III, para. 3.14, PDF p. 36, 2018].

5312 Sewage sludge gas

Biogas from the anaerobic fermentation of waste matter in sewage plants [IRES, Ch. III, SIEC 5312, PDF p. 51, 2018].

5319 Other biogases from anaerobic fermentation

Other biogases from anaerobic fermentation not elsewhere specified [IRES, Ch. III, SIEC 5319, PDF p. 51, 2018].

Remark: Two of the largest sources are fermentation of energy crops and fermentation of manure on farms [IRES, Ch. III, SIEC 5319, PDF p. 51, 2018].

532 / 5320 Biogases from thermal processes

Biogases from thermal processes (gasification or pyrolysis) of biomass [IRES, Ch. III, SIEC 5320, PDF p. 51, 2018].

Remark: A mixture containing hydrogen and carbon monoxide (usually known as syngas) along with other components; may be further processed to modify composition and can be further processed to produce substitute natural gas [IRES, Ch. III, SIEC 5320, PDF pp. 51–52, 2018].

Chapter VI’s reference list of data items defines liquid biofuel plant capacity — disaggregated into biogasoline, biodiesel and other liquid biofuel plant capacity — as a production-capacity data item (item 6.6 and its sub-items) — see Production, Storage and Transmission Capacity [IRES, Ch. VI, para. 6.68, PDF p. 95, 2018].

Related

• SIEC Classification System — SIEC’s scope rules, coding system and full Table 3.1 code list, of which this section is one entry; also covers the landfill-gas/natural-gas classification example
• Energy Products — the general energy-product definition and SIEC scope-precision rules this classification operationalizes
• Oil — the preceding SIEC fuel section
• Waste — the next SIEC section; the renewable fraction of combusted waste is classified according to the biofuel it best matches
• Production, Storage and Transmission Capacity — the liquid biofuel plant-capacity data items