ISO 17225 Solid Biofuels - Fuel Properties and Classes

The “ISO 17225 Solid biofuels - Fuel properties and classes” standard published by the International Standards Organization (ISO) consists of a number of subsections published under the same title. Namely,

• The standard “ISO 17225-1 Part 1: General requirements” describes fuel quality classes and specifications for solid biofuels from raw and processed materials originating from forestry and arboriculture, agriculture and horticulture and aquaculture. Chemically processed material shall not contain halogenated organic compounds or heavy metals at levels higher than typical values ​​for virgin material or typical values ​​for the country of origin. Raw and processed material includes woody, herbaceous, fruity, aquatic biomass and biodegradable wastes originating from the sectors listed.
• The standard “ISO 17225-2 Part 2: Graduated wood pellets” describes the fuel quality classes and properties of graded wood pellets for industrial and non-industrial uses. This standard covers only wood pellets produced from the following raw materials:
  • Forest, plantation and other virgin wood
  • By-products and residues from the wood processing industry
  • Used wood that has not been chemically treated

Heat-treated biomass pellets (e.g. torrefied pellets) are not included in the scope of this standard.

• The standard “ISO 17225-3 Part 3: Graded wood briquettes” describes the fuel quality classes and properties of graded wood briquettes. This standard covers only wood briquettes produced from the following raw materials:
  • Forest, plantation and other virgin wood
  • By-products and residues from the wood processing industry
  • Used wood that has not been chemically treated

Heat-treated biomass briquettes (e.g. torrefied briquettes) are not included in the scope of this standard.

• The standard “ISO 17225-4 Part 4: Graded woodchips” describes the fuel quality classes and properties of graded woodchips. This standard covers only woodchips produced from the following raw materials:
  • Forest, plantation and other virgin wood
  • By-products and residues from the wood processing industry
  • Used wood that has not been chemically treated

This standard covers only wood chips produced by sharp tools and does not cover hog fuel produced by dull tools. (Hog fuel is an unrefined mixture of coarse bark and wood fiber chips. Hog fuel is any wood by-product or waste that can be burned for fuel but is not categorized as chips, sawdust, bark or sawdust).

• The standard “ISO 17225-5 Part 5: Graded fuelwood” describes the fuel quality classes and properties of graded fuelwood. This standard covers only fuelwood produced from the following raw materials:
  • All trees without roots
  • Trunk wood
  • Log debris (thick branches, tops, etc.)
  • Chemically untreated by-products and residues from the wood processing industry
• The standard “ISO 17225-6 Part 6: Graded non-woody pellets” describes the fuel quality classes and properties of graded non-woody pellets. This standard covers only non-woody pellets produced from the following raw materials: — 2
  • Herbaceous biomass
  • Fruit biomass
  • Water biomass
  • Biomass mixtures and blends

Herbaceous biomass originates from plants that have a non-woody stem and die at the end of the growing season. It includes grain or seed crops and their by-products, such as cereals, from the food production or processing industry.

Blends include mixtures and blends from the major origin-based solid biofuel groups woody biomass, herbaceous biomass, fruit biomass, and aquatic biomass.

• The standard “ISO 17225-7 Part 7: Graded non-woody briquettes” describes the fuel quality classes and properties of graded non-woody briquettes. This standard covers only non-woody briquettes produced from the following raw materials:
  • Herbaceous biomass
  • Fruit biomass
  • Water biomass
  • Biomass mixtures and blends

Herbaceous biomass originates from plants that have a non-woody stem and die at the end of the growing season. It includes grain or seed crops and their byproducts, such as cereals, from the food production or processing industry.

Blends include mixtures and blends from the major origin-based solid biofuel groups woody biomass, herbaceous biomass, fruit biomass, and aquatic biomass.

• The standard “ISO 17225-8 Part 8: Graded thermally treated and condensed biomass fuels for commercial and industrial use” describes the fuel quality classes and properties of graded condensed solid biofuels produced from thermally treated biomass for commercial applications and industrial use. This standard covers pellets and briquettes produced from the following raw materials:
  • Woody biomass
  • Herbaceous biomass
  • Fruit biomass
  • Aquatic biomass
  • Mixtures

Subcategories of these feedstocks are included. This standard does not consider products marketed as coal or coal products. ISO 17225-1 and ISO 17225-8 standards apply to these products. Health, safety and environmental issues for solid biofuels are important and require special attention but are outside the scope of this standard.

• The standard “ISO 17225-9 Part 9: Hog fuel and wood chips graded for industrial use” describes the fuel quality classes and properties of hog fuel and wood chips graded for industrial use. This standard covers only hog fuel and wood chips produced from the following raw materials:
  • Forest, plantation and other virgin wood
  • By-products and residues of the wood processing industry
  • With the mixture

This standard covers hog fuel, which is produced by crushing with blunt tools such as a roller, hammer or flail, into pieces of varying sizes and shapes, and wood chips, which are defined as sub-rectangular and fragmented woody biomass, typically 5 mm to 50 mm long, produced by mechanical processing, typically with sharp tools such as knives.

ISO 17225-1 applies to by-products and residues from the wood processing industry, including chemically treated material (e.g. glued, painted, laminated). It is not allowed to contain halogenated organic compounds or heavy metals at levels higher than typical raw material values ​​or typical values ​​for the country of origin.

If the mixtures contain chemically treated used wood, they can only be used in facilities where their use is permitted.

Our organization, which has been trying to support businesses from every sector with its wide range of testing, measurement, analysis and evaluation studies for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "ISO 17225 Solid biofuels - Fuel properties and classes" standard are also provided to businesses.