Several materials such as waste and residues from typically the food, agricultural and wood industry could be defined and used as biomass fuels. However, the definition and classification of these materials differ depending on which country you are situated.

At the same time international utilisation and thereby international trade with biomass is increasing. Due to the different ways of defining and analysing biomass in different countries international trade with biomass fuel can be confusing and a hinder.

Such hinders can be overcome if you clearly specify the biomass fuel after the new technical specifications developed by the European Committee for Standardisation (CEN ), within the technical committee CEN/TC 335 “Solid biofuels” This technical specification is currently being tested and can after three years evaluation become a European standard that will form the basis for future standard quality control of traded biomass fuels in Europe.

In the CEN/TS 14961 solid biomass fuels are described according to:

  • Fuel type and origin
  • Traded form of the fuel
  • Fuel properties

The basic idea is that by specifying the biomass fuel type and origin a lot of properties of the fuel will be known and thereby save analysis costs. The specification is done according to CEN/TS 14961.

The origin of the sample is defined in four main groups:

1. Woody
2. Herbaceous
3. Fruits and nuts
4. Blends and mixtures.

These main groups are subsequently divided into subgroups resulting in a full specification consist of four digits. An example of a complete classification could be 1.1.1.2 , which specifies pure coniferous wood from the forest without any bark. An extract of the CEN/TS 14961 is shown in Figure 1 below. Due to copyright issues, only a part of the table can be shown here. The complete CEN/TS 14961 can be bought at Danish Standards, www.en.ds.dk

The form of the solid biomass fuel, described in the technical specification, could be chips, briquettes, pellets, etc. The analytical methods that should be used to determine the properties of the fuel are also declared in the technical specification.
Figure 1: CEN classification table for the main group of woody biomass

1. Woody biomass1.1 Forest and plantation wood1.1.1 Whole trees1.1.1.1 Deciduous
1.1.1.2 Coniferous
1.1.1.3 Short rotation coppice
1.1.1.4 Bushes
1.1.1.5 Blend and mixtures
1.1.2 Stemwood1.1.2.1 Deciduous
1.1.2.2 Coniferous
1.1.2.3 Blend and mixtures
1.1.3 Logging residues1.1.3.1 Fresh/Green (including leaves/needles)
1.1.3.2 Stored
1.1.3.3 Blend and mixtures
1.1.4 Stumps1.1.4.1 Deciduous
1.1.4.2 Coniferous
1.1.4.3 Short rotation coppice
1.1.4.4 Bushes
1.1.4.5 Blends and mixtures
1.1.5 Bark
1.1.6 Landscape management woody biomass
1.2 Wood processing industry, by products and residues1.2.1 Chemically untreated wood residues1.2.1.1 Without bark
1.2.1.2 With bark
1.2.1.3 Bark (from industry operations)
1.2.1.4 Blends and mixtures
1.2.2. Chemically treated wood residues1.2.2.1 Without bark
1.2.2.2 With bark
1.2.2.3 Bark (from industry operations)
1.2.2.4 Blends and mixtures
1.2.3 Fibrous waste from the pulp and paper industry1.2.3.1 Chemically untreated fibrous waste
1.2.3.2 Chemically treated fibrous waste
1.3 Used wood1.3.1 Chemically untreated wood residues1.3.1.1 Without bark
1.3.1.2 With bark
1.3.1.3 Blends and mixtures
1.3.2 Chemically treated wood residues1.3.2.1 Without bark
1.3.2.2 With bark
1.3.2.3 Blends and mixtures
1.4 Blends and mixtures