CEN/TS 14961:2005

SLOVENSKI STANDARD
01-maj-2005
Trdna biogoriva – Specifikacije goriv in razredi
Solid biofuels - Fuel specifications and classes
Feste Biobrennstoffe - Brennstoffspezifikationen und -klassen
Biocombustibles solides - Classes et spécifications des combustibles
Ta slovenski standard je istoveten z: CEN/TS 14961:2005
ICS:
75.160.10 Trda goriva Solid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 14961
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2005
ICS 75.160.10
English version
Solid biofuels - Fuel specifications and classes
Biocombustibles solides - Classes et spécifications des Feste Biobrennstoffe - Brennstoffspezifikationen und -
combustibles klassen
This Technical Specification (CEN/TS) was approved by CEN on 9 November 2004 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 14961:2005: E
worldwide for CEN national Members.

Contents
page
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Symbols and abbreviations .5
5 Principle.6
6 Classification of origin and sources of solid biofuels.7
6.1 General.7
6.2 Woody biomass .10
6.2.1 Forest and plantation wood.10
6.2.2 Wood processing industry by-products and residues .10
6.2.3 Used wood.10
6.2.4 Blends and mixtures .10
6.3 Herbaceous biomass.11
6.3.1 Agriculture and horticulture herb .11
6.3.2 Herb processing industry, by-products and residues.11
6.3.3 Blends and mixtures .11
6.4 Fruit biomass .11
6.4.1 Orchard and horticulture fruit .11
6.4.2 Fruit processing industry, by-products and residues .11
6.4.3 Blends and mixtures .11
6.5 Biomass blends and mixtures.11
7 Specification of solid biofuels based on traded forms and properties.11
7.1 Traded forms of solid biofuels .11
7.2 Specification of properties of solid biofuels.12
Annex A (informative) Examples of specifications for high quality classes of solid biofuels
recommended for household usage.25
Annex B (informative)  Illustrations of typical forms of wood fuels.27
B.1 Classification of wood fuels based on a typical particle size .27
B.2 Difference between wood chips (left) and hog fuel (right). Source: Swedish University of
Agricultural Sciences .27
Annex C (informative)  Typical values of solid biomass fuels.28
D.1 Examples of possible causes for deviant levels for different properties, woody biomass.38
D.2 Examples of consequences of handling and treatments for the properties of woody
biomass .39

Foreword
This document (CEN/TS 14961:2005) has been prepared by Technical Committee CEN/TC 335 “Solid
Biofuels”, the secretariat of which is held by SIS.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
Introduction
This is a Technical Specification of "Fuel Specifications and Classes" of the TC335 Solid Biofuels Working
group "Fuel Specifications, Classes and Quality Assurance".
The objective of this Technical Specification is to provide unambiguous and clear classification principles for
solid biofuels and to serve as a tool to enable efficient trading of biofuels and to enable good understanding
between seller and buyer as well as a tool for communication with equipment manufacturers. It will also
facilitate authority permission procedures and reporting.
This Technical Specification is made for all user groups.
Figure 1 describes the bioenergy utilisation chain from sources of biomass, to biofuel production to final use of
bioenergy. Although biomass can be used for energy generation it has many other primary uses (non-fuels) as
a raw material for construction, furniture, packaging, paper products etc. The classifications given in this
Technical Specification are provided with the objective of using biomass as a biofuel, and therefore do not
deal with all other uses.
Biofuel
Biomass
Bioenergy
Solid biofuel
CEN TC 335
Liquid and gaseous
biofuel
Non-fuels
Figure 1 — CEN TC 335 within the biomass – biofuel – bioenergy field
production
conversion
1 Scope
This Technical Specification determines the fuel quality classes and specifications for solid biofuels. According
to the mandate given for the standardisation work, the scope of the Technical Specification (TC335) only
includes solid biofuels originating from the following sources:
- products from agriculture and forestry;
- vegetable waste from agriculture and forestry;
- vegetable waste from the food processing industry;
- wood waste, with the exception of wood waste which may contain halogenated organic compounds or
heavy metals as a result of treatment with wood preservatives or coating, and which includes in particular
such wood waste originated from construction and demolition waste;
- fibrous vegetable waste from virgin pulp production and from production of paper from pulp, if it is co-
incinerated at the place of production and heat generated is recovered;
- cork waste.
NOTE For the avoidance of doubt, demolition wood is not included in the scope of this Technical Specification.
Demolition wood is “used wood arising from demolition of buildings or civil engineering installations” (CEN/TS 14588).
2 Normative references
Not applicable.
3 Terms and definitions
For the purposes of this Technical Specification, the terms and definitions given in CEN/TS 14588 and the
following apply.
3.1
chemical treatment
chemical treatment is in this Technical Specification defined as any treatment with chemicals other than air or
water (e.g. glue and paint). Examples of chemical treatment are listed in informative annex D.
4 Symbols and abbreviations
The symbols and abbreviations used in this Technical Specification comply with the SI system of units as far
as possible.
d dry (dry basis)
daf dry, ash-free, see informative annex C
ar as received
A Designation for ash content (w-%, dry basis) *
ρ Density [kg/m ]
BD Designation for bulk density *
DE Designation for particle density as received [kg/dm ]
D Designation for diameter *
DU Designation for mechanical durability *
E Energy density as received [MWh/m loose, solid or stacked volume (amount of energy/volume unit)
ar
E Designation for energy density as received [kWh/m or kWh/kg, unit is to be stated in brackets]*
F Designation for amount of fines (< 3,15 mm, w-%)
L Designation for length *
M Total moisture content as received [w-%] on wet basis
ar
M Designation for moisture content as received*
P Designation for particle size distribution*
q Gross calorific value [MJ/kg] at constant volume
V,gr
q Net calorific value [MJ/kg] at constant pressure
p,net
*Designation symbols are used in combination with a number to specify property levels in the Tables 4 to 13
and in informative annex A. For designation of chemical properties chemical symbols like S (sulphur),
Cl (chlorine), N (nitrogen) are used and the value is added at the end of the symbol.
5 Principle
Solid biofuels are specified by:
� origin and source, clause 6;
� major traded forms and properties, clause 7.
For specification of origin and source, see Table 1. For major traded forms, see Table 2.
For specification of properties see Tables 4 to 13. The major traded forms of solid biofuels are covered by
Tables 4 to 12. Table 13 is a general master table to be used for solid biofuels not covered by Tables 4 to 12.
Tables 4 to 13 list the normative properties, which have to be specified and informative properties, which are
voluntary. Normative properties vary depending on both origin and traded form.
Example of specification:
Origin:   Logging residues (1.1.3)
Traded form: Wood chips
Properties: Particle size distribution P45, Moisture M40, Ash A1.5
In the case of wood chips (Table 7) the properties of dimensions, moisture and ash are normative in the
specification. Other properties are informative.
Specifications for special high quality classes for solid biofuels recommended for household usage in each of
the traded forms of wood pellets, wood briquettes, wood chips and log woods, are given in annex A.
6 Classification of origin and sources of solid biofuels
6.1 General
The classification is based on the biofuel origin and source. In the hierarchical classification system (Table 1)
the main origin-based solid biofuel groups are:
• woody biomass;
• herbaceous biomass;
• fruit biomass; and
• blends and mixtures.
Woody biomass is biomass from trees, bushes and shrubs.
Herbaceous biomass is from plants that have a non-woody stem and which die back at the end of the growing
season.
Fruit biomass is the biomass from the parts of a plant which hold seeds.
The term “Blends and mixtures” in Table 1 refers to material of various origin within the given box in the
classification table and appears on four levels. Blends are intentionally mixed biofuels, whereas mixtures are
unintentionally mixed biofuels. The origin of the mixture or blend has to be described using Table 1. If solid
biofuel blend or mixture may contain chemically treated material it has to be stated. A blend or a mixture of e.g.
chemically treated wood and chemically untreated wood has to be classified as chemically treated wood.
The second level of classification in Table 1 describes fuels from different sources within the main groups,
primarily stating whether the biomass is a by-product or a residue from the industry or if it is virgin material.
Groups in Table 1 are further divided into third and fourth level sub-groups.
The purpose of Table 1 is to allow the possibility to differentiate and specify biofuel material based on origin
with as much detail as needed. With the help of typical values from informative annex C information on
physical and chemical properties can be deducted.
Example: Logging residues - 1.1.3.
Table 1 — Classification of origin and sources of solid biofuels
1. Woody 1.1 Forest and plantation 1.1.1 Whole trees 1.1.1.1 Deciduous
biomass    wood
1.1.1.2 Coniferous
1.1.1.3 Short rotation coppice
1.1.1.4 Bushes
1.1.1.5 Blends and mixtures
1.1.2 Stemwood 1.1.2.1 Deciduous
1.1.2.2 Coniferous
1.1.2.3 Blends and mixtures
1.1.3 Logging residues 1.1.3.1 Fresh/Green (including
leaves/needles)
1.1.3.2 Stored
1.1.3.3 Blends and mixtures
1.1.4 Stumps 1.1.4.1 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 (from forestry operations)*
1.1.6 Landscape management woody biomass
1.2 Wood processing 1.2.1 Chemically untreated 1.2.1.1 Without bark
industry, wood residues
1.2.1.2 With bark *
by-products and
1.2.1.3 Bark (from industry
residues
operations)*
1.2.1.4 Blends and mixtures
1.2.2 Chemically treated wood 1.2.2.1 Without bark
residues
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 1.2.3.1 Chemically untreated fibrous
pulp and paper industry waste
1.2.3.2 Chemically treated fibrous
waste
1.3 Used wood 1.3.1 Chemically untreated 1.3.1.1 Without bark
wood
1.3.1.2 Bark*
1.3.1.3 Blends and mixtures
1.3.2 Chemically treated wood 1.3.2.1 Without bark
1.3.2.2 Bark*
1.3.2.3 Blends and mixtures
1.4 Blends and mixtures
NOTE 1 Cork waste is included in bark sub-groups.
NOTE 2 For the avoidance of doubt, demolition wood is not included in the scope of this Technical Specification.
Demolition wood is “used wood arising from demolition of buildings or civil engineering installations” (see CEN/TS 14588).
Table 1 (continued)
2 Herbaceous 2.1 Agriculture and 2.1.1 Cereal crops 2.1.1.1 Whole plant
biomass    Horticulture herb
2.1.1.2 Straw parts
2.1.1.3 Grains or seeds
2.1.1.4 Husks or shells
2.1.1.5 Blends and mixtures
2.1.2 Grasses 2.1.2.1 Whole plant
2.1.2.2 Straw parts
2.1.2.3 Seeds
2.1.2.4 Shells
2.1.2.5 Blends and mixtures
2.1.3 Oil seed crops 2.1.3.1 Whole plant
2.1.3.2 Stalks and leaves
2.1.3.3 Seeds
2.1.3.4 Husks or shells
2.1.3.5 Blends and mixtures
2.1.4 Root crops 2.1.4.1 Whole plant
2.1.4.2 Stalks and leaves
2.1.4.3 Root
2.1.4.4 Blends and mixtures
2.1.5 Legume crops 2.1.5.1 Whole plant
2.1.5.2 Stalks and leaves
2.1.5.3 Fruit
2.1.5.4 Pods
2.1.5.5 Blends and mixtures
2.1.6 Flowers 2.1.6.1 Whole plant
2.1.6.2 Stalks and leaves
2.1.6.3 Seeds
2.1.6.4 Blends and mixtures
2.1.7 Landscape management herbaceous biomass
2.2 Herb processing 2.2.1 Chemically untreated herb 2.2.1.1 Cereal crops and grasses
industry,      residues
2.2.1.2 Oil seed crops
by-products and
2.2.1.3 Root crops
residues
2.2.1.4 Legume crops and flowers
2.2.1.5 Blends and mixtures
2.2.2 Chemically treated herb 2.2.2.1 Cereal crops and grasses
residues
2.2.2.2 Oil seed crops
2.2.2.3 Root crops
2.2.2.4 Legume crops and flowers
2.2.2.5 Blends and mixtures
2.3 Blends and mixtures
Table 1 (concluded)
3 Fruit 3.1 Orchard and  3.1.1 Berries 3.1.1.1 Whole berries
biomass    horticulture fruit
3.1.1.2 Flesh
3.1.1.3 Seeds
3.1.1.4 Blends and mixtures
3.1.2 Stone/kernel fruits 3.1.2.1 Whole fruit
3.1.2.2 Flesh
3.1.2.3 Stone/kernel
3.1.2.4 Blends and mixtures
3.1.3 Nuts and acorns 3.1.3.1 Whole nuts
3.1.3.2 Shells/husks
3.1.3.3 Kernels
3.1.3.4 Blends and mixtures
3.2 Fruit processing   3.2.1 Chemically untreated fruit 3.2.1.1 Berries
industry,      residues 3.2.1.2 Stone/kernel fruits
by-products and
3.2.1.3 Nuts and acorns
residues
3.2.1.4 Crude olive cake
3.2.1.5 Blends and mixtures
3.2.2 Chemically treated fruit 3.2.2.1 Berries
residue 3.2.2.2 Stone/kernel fruits
3.2.2.3 Nuts and acorns
3.2.2.4 Exhausted olive cake
3.2.2.5 Blends and mixtures
3.3 Blends and mixtures
4 Blends and 4.1 Blends
mixtures 4.2 Mixtures
6.2 Woody biomass
6.2.1 Forest and plantation wood
Forest wood and plantation wood in this category may only have been subjected to size reduction, debarking,
drying or wetting. Forest wood and plantation wood includes wood from forests, parks and plantations and
from short rotation forests.
6.2.2 Wood processing industry by-products and residues
Wood by-products and wood residues from industrial production are classified in this group. These biofuels
can be chemically untreated (for example residues from debarking, sawing or size reduction, shaping,
pressing) or chemically treated wood residues as long as they do not contain heavy metals or halogenated
organic compounds as a result of treatment with wood preservatives or coating.
6.2.3 Used wood
This group includes post consumer/post society wood waste. With respect to treatment the same criteria apply
as with respect to ‘’ wood processing industry by-products and residues”: i.e. the used wood shall not contain
heavy metals or halogenated organic compounds as a result of treatment with wood preservatives or coating.
6.2.4 Blends and mixtures
This refers to blends and mixtures of woody biomass in the categories 1.1 to 1.3 in Table 1. The mixing can
be either intentional (blends) or unintentional (mixtures).
6.3 Herbaceous biomass
6.3.1 Agriculture and horticulture herb
Material, which comes directly from the field, perhaps after a storage period, and may only have been subject
to size reduction and drying is included here. It covers herbaceous material from agricultural and horticultural
fields and from gardens and parks.
6.3.2 Herb processing industry, by-products and residues
This refers to an herbaceous biomass material that is left over after industrial handling and treatment.
Examples are residues from the production of sugar from sugar beets and barley malt residues from beer
production.
6.3.3 Blends and mixtures
This refers to blends and mixtures of herbaceous biomasses in the categories 2.1 to 2.2 in Table 1. The
mixing can be either intentional (blends) or unintentional (mixtures).
6.4 Fruit biomass
6.4.1 Orchard and horticulture fruit
Fruit from trees and bushes and also fruit from herbs (e.g. tomatoes) are classified in this class.
6.4.2 Fruit processing industry, by-products and residues
This refers to a fruit biomass material that is left over after industrial handling and treatment. Examples are
pressing residues from olive oil or apple juice production.
6.4.3 Blends and mixtures
This refers to blends and mixtures of fruit biomass in the categories 3.1 to 3.2 in Table 1. The mixing can be
either intentional (blends) or unintentional (mixtures).
6.5 Biomass blends and mixtures
These include blends and mixtures of different biomasses mentioned above under 6.2 to 6.4. The mixing can
be either intentionally (blends) or unintentionally (mixtures).
7 Specification of solid biofuels based on traded forms and properties
7.1 Traded forms of solid biofuels
Solid biofuels are traded in many different sizes and shapes. The size and shape influence the handling of the
fuel as well as its combustion properties. Biofuels may be delivered for example in the forms shown in Table 2.
Table 2 — Major traded forms of solid biofuels
Fuel name Typical particle size Common preparation method
Briquettes Ø > 25 mm Mechanical compression
Pellets Ø < 25 mm Mechanical compression
Fuel powder < 1 mm Milling
Sawdust 1 mm to 5 mm Cutting with sharp tools
Wood chips 5 mm to 100 mm Cutting with sharp tools
Hog fuel Varying Crushing with blunt tools
Logs 100 mm to 1000 mm Cutting with sharp tools
Whole wood > 500 mm Cutting with sharp tools
Small straw bales 0,1 m Compressed and bound to squares
Big straw bales 3,7 m Compressed and bound to squares
2,1 m
Round straw bales Compressed and bound to cylinders
Bundle Varying Lengthways oriented & bound
Bark Varying Debarking residue from trees
Can be shredded or unshredded
Chopped straw 10 mm to 200 mm Chopped during harvesting
Grain or seed Varying No preparation or drying
Shells and fruit stones 5 mm to 15 mm No preparation
Fibre cake Varying Prepared from fibrous waste by dewatering
NOTE Also other forms may be used.
Figures in the informative annex B describe the particle size differences between different wood fuels and also
the difference between wood chips and hog fuel.
7.2 Specification of properties of solid biofuels
Standards or Technical Specifications to be used for determination of properties to be specified are listed in
the Table 3. The annex A describes examples of the specifications for special high quality classes of solid
biofuels recommended for household usage. Wood pellets, wood briquettes, wood chips and log woods are
traded forms commonly used for household applications.
Properties to be specified are listed in Tables 4 to 12 for the following traded forms of solid biofuels:
Briquettes   Table 4
Pellets   Table 5
Exhausted olive cake Table 6
Wood chips  Table 7
Hog fuel   Table 8
Log woods  Table 9
Sawdust   Table 10
Bark   Table 11
Straw bales  Table 12
A general master table to be used for solid biofuels not covered by Tables 4 to 12 is given in Table 13.
For a specification of a solid biofuel, the denominations given in Tables 4 to 13 are normative (and voluntarily
informative) properties. In Tables 4 to 13 and the annex A solid biofuels are defined by property categories. A
biofuel entity (e.g. truckload, bag, shipload) fits to a specific property category when its average numerical
value is within the interval specified.
For an example in Table 7, the ash category A3.0 (≤ 3 %) means that the average ash content has to be from
0,0 to 3,0 % to belong to this category.
NOTE 1 Typical physical and chemical property values are listed for some biofuels in annex C. These can be used as an
indication of properties, when needed. The numerical values in tables of the annex C are examples for biofuels of different
types and origins. They cannot be used for the limitation of fuel parameters.
NOTE 2 The dry, ash free basis (daf) represent the combustible part of the fuel, without non-combustible moisture and
ash. For properties that are mainly related to the combustible part of the fuel (as e.g. calorific value), specific fuel
characteristic values are obtained on the dry, ash free basis as these values are not influenced by the varying amount of
moisture and ash in solid biofuels. Values stated on a dry basis (d) are influenced by the actual ash contents.
EXAMPLE Conversion of a value on a dry, ash free basis (daf) to a dry basis (d) is given by the formula (see also
Technical specification for the calculation of analyses to different basis).
100 − A
d
value = value × ( )
d daf
where
A is the ash on a dry basis, in a percentage by a weight (w-%).
d
NOTE 3 For Tables 4 to 13: only chemically treated biomass that are included in the scope, are to be considered, i.e.
wood waste which may contain halogenated organic compounds or heavy metals as a result of treatment with wood
preservatives or coating, are not included. Examples of chemical treatment are mentioned in the annex D.
Table 3 — List of standards or technical specifications to determine fuel properties
Property Standard/Technical Specification
Origin and source This Technical Specification (Table 1)
Traded forms This Technical Specification (Table 2)
Total moisture as received (Mar) Solid Biofuels - Methods for the determination of moisture
content – Oven dry method – Part 1: Total moisture –
Reference method (CEN/TS 14774-1)
Solid Biofuels - Methods for the determination of moisture
content – Oven dry method – Part 2: Total moisture –
Simplified method (CEN/TS 14774-2)
Solid Biofuels - Methods for the determination of moisture
content - Oven dry method – Part 3: Moisture in general
analysis sample (CEN/TS 14774-3)
Ash content (A)
Solid Biofuels - Method for the determination of ash
content (CEN/TS 14775)
Net calorific value (q ) Solid Biofuels - Methods for the determination of calorific
p,net,d
value (CEN/TS 14918)
Particle size distribution (P) Solid Biofuels - Methods for the determination of particle
size distribution. Part 1: Oscillating screen method using
sieve apertures of 3,15 mm and above (CEN/TS 15149-1)
Solid Biofuels - Methods for the determination of particle
size distribution. Part 2: Vibrating screen method using
sieve apertures of 3,15 mm and below (CEN/TS 15149-2)
Amount of fines (F) Solid Biofuels - Methods for the determination of particle
size distribution. Part 2: Vibrating screen method using
sieve apertures of 3,15 mm and below (CEN/TS 15149-2)
Table 3 (concluded)
Particle density (DE) Solid Biofuels - Methods for the determination of particle
density (CEN/TS 15150) to be published
Bulk density (BD) Solid Biofuels - Methods for the determination of bulk
density (prCEN/TS 15103), to be published
Mechanical durability of pellets and briquettes (DU) Solid Biofuels - Methods for the determination of
mechanical durability of pellets and briquettes, to be
published (CEN/TS 15210)
Calculation of analyses to different bases Solid Biofuels - Calculation of analyses to different bases,
to be published
Carbon (C), hydrogen (H) and nitrogen (N) content Methods for the determination of carbon , hydrogen and
nitrogen - instrumental methods, (CEN/TS 15104) to be
published
Water soluble chloride (Cl) content, sodium (Na) and potassium Solid Biofuels: Methods for determination of the water
(K), soluble content of chloride, sodium and potassium, to be
published
Sulphur (S) and chlorine (Cl) content Methods for the determination of sulfur (S) and chlorine
(Cl) content. to be published
Major elements (Al, Si, K, Na, Ca, Mg, Fe, P and Ti) Methods for the determination of the content of major
elements (Al, Si, K, Na, Ca, Mg, Fe, P and Ti), to be
published
Minor elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Methods for the determination of minor elements (As, Ba,
Se, Te, V and Zn) Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Se, Te, V and
Zn),to be published
NOTE Other properties of interest are the Bridging and Ash melting behaviour. Technical Specifications on test
methods for these properties are on the list of Work Items in TC335/WG4 Solid Biofuels Physical and Mechanical Test
Methods.
Table 4 — Specification of properties for briquettes
Master table
Origin: Woody biomass (1)
According to 6.1 and Table 1 Herbaceous biomass (2)
Blends and mixtures (4)
Traded Form (see Table 2) Briquette
Dimensions (mm) Diameter (D) or equivalent (diagonal or cross cut), mm
D40
25 ≤ D ≤ 40
D50 ≤ 50
D
D60
≤ 60
D80 ≤ 80
D100
≤ 100
L
D125 ≤ 125
D125+
≥ 125 actual value to be stated
Length (L)
L50 ≤ 50
L100
≤ 100
L200 ≤ 200
L300
≤ 300
L400 ≤ 400
L400+
≥ 400 actual value to be stated
Examples of briquettes
Moisture (w-% as received)
M10 ≤ 10 %
M15
≤ 15 %
M20 ≤ 20 %
Ash (w-% of dry basis)
A0.7 ≤ 0,7 %
A1.5
≤ 1,5 %
A3.0 ≤ 3,0 %
A6.0
≤ 6,0 %
A10.0 ≤10,0 %
Sulphur (w-% of dry basis)
S0.05 Sulphur is normative only for chemically treated biomass
≤ 0,05 %
or if sulphur containing additives have been used
S0.08 ≤ 0,08 %
S0.10
≤ 0,10 %
S0.20 ≤ 0,20 %
S0.20+ > 0,20 % (actual value to be stated)
Particle density (kg/dm )
DE0.8 0,80 to 0,99
DE1.0 1,00 to 1,09
DE1.1 1,10 to 1,19
DE1.2
≥ 1,20
Additives (w-% of pressing mass)
Type and content of pressing aids, slagging inhibitors or any other additives have to be stated
Nitrogen, N (w-% of dry basis)
N0.3 ≤ 0,3 %
Nitrogen is normative only for chemically treated biomass
N0.5
≤ 0,5 %
N1.0 ≤ 1,0 %
N3.0
≤ 3,0 %
N3.0+ >3,0 % (actual value to be stated)
Net calorific value, q (MJ/kg as received) or
Recommended to be stated at the retail level
p,net,ar
energy density, E (kWh/m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis

Chlorine, Cl (w-% of dry basis, %) Recommended categories
Cl 0.03, Cl 0.07, Cl 0.10 and Cl 0.10+ (if Cl > 0,10 % the
actual value to be stated)
Informative Normative
Table 5 —Specification of properties for pellets
Master table
Origin: Woody biomass (1),
According to 6.1 and Table 1 Herbaceous biomass (2),
Fruit biomass (3),
Blends and mixtures (4)
Traded Form (see Table 2) Pellets
Dimensions (mm)
D
L
a
Diameter (D) and Length (L)
D06
≤ 6 mm ± 0,5 mm and L ≤ 5 x Diameter
D08
≤ 8 mm ± 0,5 mm, and L ≤ 4 x Diameter
D10 ≤ 10 mm ± 0,5 mm, and L ≤ 4 x Diameter
D12
≤ 12 mm ± 1,0 mm, and L ≤ 4 x Diameter
D25 ≤ 25 mm ± 1,0 mm, and L ≤ 4 x Diameter
Moisture (w-% as received)
M10
≤ 10 %
M15
≤ 15 %
M20
≤ 20 %
Ash(w-% of dry basis)
A0.7
≤ 0,7%
A1.5
≤ 1,5 %
A3.0
≤ 3,0 %
A6.0
≤ 6,0 %
A6.0+ > 6,0 % (actual value to be stated)
Sulphur (w-% of dry basis)
S0.05 Sulphur is normative only for chemically treated biomass
≤ 0,05 %
and if sulphur containing additives have been used
S0.08 ≤ 0,08 %
S0.10
≤ 0,10 %
S0.20+ > 0,20 % (actual value to be stated)
a
Mechanical durability (w-% of pellets after testing )
DU97.5 ≥ 97,5 %
DU95.0
≥ 95,0 %
DU90.0 ≥ 90,0 %
Amount of fines (w-%, < 3,15 mm) after production at factory gate
a
F1.0 At the last possible place in the production site
≤ 1,0 %
F2.0
≤ 2,0 %
F2.0+ > 2,0 % (actual value to be stated)
Additives (w-% of pressing mass)
Type and content of pressing aids, slagging inhibitors or any other additives have to be stated
Nitrogen, N (w-% of dry basis)

N0.3
≤ 0,3 % Nitrogen is normative only for chemically treated
N0.5 ≤ 0,5 %
biomass
N1.0
≤ 1,0 %
N3.0
≤ 3,0 %
N3.0+ > 3,0 % (actual value to be stated)
Net calorific value, q (MJ/kg as received) or Recommended to be informed by retailer.
p,net,ar
energy density, E (kWh/ m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis
Chlorine, Cl (weight of dry basis, w-%) Recommended to be stated as a category
Cl 0.03, Cl 0.07, Cl 0.10 and Cl 0.10+ (if Cl > 0,10 % the
actual value to be stated)
a
Maximum 20 w-% of the pellets may have a length of 7,5 x Diameter.

Informative Normative
Table 6 — Specification of properties for exhausted olive cake
Master table
a
Origin: Fruit biomass (3.2.2.4)
According to 6.1 and Table 1
Traded Form (see Table 2) Packed grains, briquettes, pellets
Dimensions (mm) Diameter (D) and Length (L)
Briquettes D
D
L
D145 D ≤ 145 mm and D ≤ 65 mm, L ≤ 70 mm
1 2
Pellets
D06
D ≤ 6 mm ± 0,5 mm, L ≤ 10 mm to 15 mm
D08 D ≤ 8 mm ± 0,5 mm, L ≤ 10 mm to 15 mm

Grains
D03
D ≤ 3 mm, 1 mm to 3 mm diameter of grains
(35 % 1,1 mm to 2,8 mm; 25 % > 2,8 mm and 40 % < 1,1 mm)
Moisture (w-% as received)
M10 ≤ 10 %
M20
≤ 20 %
Ash(w-% of dry basis)
A1.5 ≤ 1,5 %
A3.0
≤ 3,0 %
A6.0 ≤ 6,0 %
Nitrogen, N (w-% of dry basis)
N0.5
≤ 0,5 %
N1.0 ≤ 1,0 %
N3.0
≤ 3,0 %
Net calorific value, q (MJ/kg as received) Recommended to be stated at the retail level
p,net,ar
≥ 13,5 MJ/kg for industrial use
≥ 15,0 MJ/kg for domestic use
a
The exhausted olive cake is left after the extraction of the remaining oil in the already treated crude olive cake. The extraction of
this oil is made by using a solvent (hexane). The used solvent does not contain halogenated organic compounds or heavy metal.

Informative Normative
Table 7 —Specification of properties for wood chips
Master table
Origin: Woody biomass (1)
According to 6.1 and Table 1.
Traded Form Wood chips
a
Dimensions (mm)
Main fraction Fine fraction < 5 % Coarse fraction
> 80 % of weight max. length of particle,
a
P16 < 1 mm max 1 % > 45 mm, all < 85 mm
3,15 mm ≤ P ≤ 16 mm
a
P45 3,15 mm ≤ P ≤ 45 mm < 1 mm max 1 % > 63 mm
a
P63 < 1 mm max 1 % > 100 mm
3,15 mm ≤ P ≤ 63 mm
a
P100 < 1 mm max 1 % > 200 mm
3,15 mm ≤ P ≤ 100 mm
Moisture (w-% as received)
M20 Dried
≤ 20 %
M30 ≤ 30 % Suitable for storage
M40 Limited for storage
≤ 40 %
M55 ≤ 55 %
M65
≤ 65 %
Ash (w-% of dry basis)
A0.7 ≤ 0,7 %
A1.5
≤ 1,5 %
A3.0 ≤ 3,0 %
A6.0
≤ 6,0 %
A10.0 ≤ 10,0 %
Nitrogen, N (w-% of dry basis)
N0.5 ≤ 0,5 % Nitrogen is normative only for chemically treated biomass
N1.0
≤ 1,0 %
N3.0 ≤ 3,0 %
N3.0+ > 3,0 % (actual value to be stated)

Net calorific value q (MJ/kg as received) or Recommended to be specified when retailed.
p,net,ar
energy density, E (kWh/m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis in
categories (BD200, BD300, BD450)

Chlorine, Cl (weight of dry basis, w-%) Recommended to be stated as a category
Cl 0.03, Cl 0.07, Cl 0.10 and Cl 0.10+ (if Cl > 0,1 % the actual
value to be stated)
a
The numerical values for dimension refer to the particle sizes passing through the mentioned round hole sieve size (3,15 mm, 16 mm,
45 mm, 63 mm and 100 mm). Dimensions of actual particles may differ from those values especially the length of the particle.

Informative Normative
Table 8 —Specification of properties for hog fuel
Master table
Origin: Woody biomass (1)
According to 6.1 and Table 1.
Traded Form Hog fuel
a
Dimensions (mm)
Main fraction Fine fraction < 5 % of Coarse fraction,
> 80% of weight weight max. length of a particle, mm
< 1 % of weight
P45 < 1 mm > 63 mm
3,15 mm ≤ P ≤ 45 mm
P63 < 1 mm > 100 mm
3,15 mm ≤ P ≤ 63 mm
P100 < 1 mm > 200 mm
3,15 mm ≤ P ≤ 100 mm
P300 < 1 mm > 400 mm
3,15 mm ≤ P ≤ 300 mm
Moisture (w-% as received)
M20 Dried
≤ 20 %
M30 ≤ 30 % Suitable for storage
M40 Limited for storage
≤ 40 %
M55
≤ 55 %
M65
≤ 65 %
Ash (w-% of dry basis)
A0.7 ≤ 0,7 %
A1.5
≤ 1,5 %
A3.0 ≤ 3,0 %
A6.0
≤ 6,0 %
A10.0
≤ 10,0 %
Nitrogen, N (w-% of dry basis)

N0.5 Nitrogen is normative only for chemically treated biomass
≤ 0,5 %
N1.0 ≤ 1,0 %
N3.0
≤ 3,0 %
N3.0+ > 3,0 % (actual value to be
stated)
Net calorific value q (MJ/kg as received) Recommended to be specified when retailed.
p,net,ar
or energy density, E (kWh/m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis in
categories (BD250, BD350, BD450)

Chlorine, Cl (weight of dry basis, w-%) Recommended to be states as a category Cl 0.03, Cl 0.07, Cl
0.10 and Cl 0.10+ (if Cl > 0,10 % the actual value to be stated)
a
The numerical values for dimension refer to the particle sizes passing through the mentioned round hole sieve size (3,15 mm, 16
mm, 45 mm, 63 mm and 100 mm). Dimensions of actual particles may differ from those values especially the length of the particle.

Informative Normative
Table 9 — Specification of properties for log woods
Master table
Origin: Woody biomass (1.1)
According to and Table 1.
Traded Form Log woods
Dimensions (mm)
D
D
L
L
D
L
Length (L) and thickness (D) (maximum diameter of a single chop)
L < 200 mm and D < 20 ignition wood
P200-
L = 200 mm ± 20 mm and 40 mm ≤ D ≤ 150 mm
P200
P250 L = 250 mm ± 20 mm and 40 mm ≤ D ≤ 150 mm
P330 L = 330 mm ± 20 mm and 40 mm ≤ D ≤ 160 mm
P500 L = 500 mm ± 40 mm and 60 mm ≤ D ≤ 250 mm
P1000 L = 1 000 mm ± 50 mm and 60 mm ≤ D ≤ 350 mm
L > 1 000 mm actual value has to be stated and D has to be stated
P1000+
Moisture content (w-% as received)
M20 ≤ 20 % Oven-ready log
M30 Seasoned in the storage
≤ 30 %
M40 ≤ 40 % Seasoned in the forest
M65 Fresh, after cut in the forest
≤ 65 %
Wood
To be stated if coniferous or deciduous wood or mixture of these is used.

Energy density, E (kWh/m loose or Recommended to be specified when retailed.
ar
stacked)
Volume, m solid, stacked or loose as To be stated which volume is used when retailed
3 3 3
received (m solid, m stacked or m loose)

Proportion of split volume No split (=mainly round wood)
Split: more than 85 % of volume is split
Mixture: split and round wood as a mixture

a
The cut-off surface To be stated if the cut-off surface of log woods are even and
a
smooth or ends of log woods are uneven

Mould and decay If significant amount (more than 10 % of weight) of mould and decay
exists it should be stated.
In case of doubt particle density or net calorific value could be used as
indicator.
a
Use of chainsaw is considered to be smooth and even.

Informative Normative
Table 10 —Specification of properties for sawdust
Master table
Origin: Woody biomass (1)
According to 6.1 and Table 1.
Traded Form Sawdust
Moisture (w-% as received)
M20 ≤ 20 % Dried
M30 Suitable for storage
≤ 30 %
M35 ≤ 35 % Limited for storage
M55
≤ 55 %
M65
≤ 65 %
Ash (w-% of dry basis)
A0.7
≤ 0,7 %
A1.5 ≤ 1,5 %
A3.0
≤ 3,0 %
A6.0 ≤ 6,0 %
Nitrogen, N (w-% of dry basis)
N0.5
≤ 0,5 % Nitrogen is normative only for chemically treated
N1.0 ≤ 1,0 %
biomass
N3.0
≤ 3,0 %
N3.0+ > 3,0 % (actual value to be stated)

Net calorific value q (MJ/kg as received or energy Recommended to be specified.
p,net,ar
density, E (kWh/m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis
in categories (BD200, BD300, BD350)

Chlorine, Cl (weight of dry basis, w-%) Recommended to be stated as a category
Cl 0.03, Cl 0.07, Cl 0.10 and Cl 0.10+ (if Cl > 0,10 %
the actual value to be stated)

NOTE Particle size for sawdust is considered to be homogenous. Particle size distribution could be specified if
requested.
Informative Normative
a
Table 11 —Specification of properties for bark
Master table
Origin: Woody biomass
According to 6.1 and Table 1. (1.1.5, 1.2.1.2, 1.2.2.2, 1.3.1.2, 1.3.2.2)
Traded Form: Bark
Moisture (w-% as received)
M40 ≤ 40 %
M50
≤ 50 %
M60 ≤ 60 %
M70
≤ 70 %
Ash (w-% of dry basis)
A0.7 ≤ 0,7 %
A1.5
≤ 1,5 %
A3.0 ≤ 3,0 %
A6.0
≤ 6,0 %
A12.0 ≤ 12,0 %
Nitrogen, N (w-% of dry basis)

N0.5 Nitrogen is normative only for chemically treated biomass
≤ 0,5 %
N1.0
≤ 1,0 %
N3.0
≤ 3,0 %
N3.0+ > 3,0 % (actual value to be stated)
Shredding
To be stated if bark is shredded into pieces or unshredded

Net calorific value, q (MJ/kg as received) or Recommended to be specified.
p,net,ar
energy density, E (kWh/m loose)
ar
Bulk density as received (kg/m loose) Recommended to be stated if traded by volume basis in
categories (BD250, BD350, BD450)

Chlorine, Cl (w-% of dry basis) Recommended to be stated as a category
Cl 0.03, Cl 0.07, Cl 0.10 and Cl 0.10+ (if Cl > 0,10 % the
actual value to be stated)
a
Also cork is included.
Informative Normative
Table 12 — Specification of properties for straw bales
Master table
Origin: 2.1.1.2 Cereal crop straw
According to 6.1 and Table 1.
2.1.2.2 Grass straw
2.1.3.2 Oil seed crops stalks and leaves
Traded Form Big Bale
Dimensions (mm), height (L ), width (L ) and length (L )
1 2 3
L
L
L
Height (L )
1 Width (L) Length (L )
2 3
P1 1 300 1 200 2 200
P2 1 300 1 200 2 400
P3 600 to 900 1 200 2 400
1 200
P4 1 300 1 100 to 2 750
Bale density (kg/m )
≤ 135
BD130
BD150 ≤ 150
BD165 ≤ 165
BD165+ > 165
Moisture (w-% as received)
No part over 23 %
M16 ≤ 16 %
Parts over 23 % acceptable
M16+ ≤ 16 %
no part over 30 %
M23 ≤ 23 %
one or more parts over 30 %
M23+ ≤ 23 %
no part over 35 %
M30 ≤ 30 %
one or more parts over 35 %
M30+ ≤ 30 %
Ash (w-% of dry basis)
A05
≤ 5 %
A10 ≤ 10 %
A10+ > 10 %
Species of biomass
Has to be stated
Net calorific value, q (MJ/kg as received Recommended to be specified.
p,net,ar
or energy density, E (kW
...