1. ISO 17225-pellets standards
New international standards for residential and industrial pellets November 2013
Principal scientist Eija Alakangas, VTT
Convenor of WG2 for CEN/TC 335 and ISO/TC 238

2. European and international framework for solid biofuel standardisation
Legislation
Standardisation
WTO
No barriers to trade
ISO/TC 238
Solid biofuels
Vienna agreement*
European
Commission
Mandate
CEN/TC 335
Solid biofuels
Standards
Results
Supporting
EU-funded
projects
Information to market actors of solid biofuels 2
* ISO standards will be published as EN ISO standards in Europe

3. European (EN) pellet standards published
EN General requirements
Include all biomass raw materials
Flexible classification, each property selected separatetely
Include classification of raw material, which is needed for the product standards
Product standard EN Wood pellets for non-industrial use
Properties are bound together to class A1, A2 and B
ENplus certification system is based on this standard with some exceptions
Product standard EN Non-woody pellet for non-industrial use
EN and 6 standards are targeted for non-industrial use in small-scale appliances, such as, households, small commercial and public sector buildings.

4. Solid biofuels standardisation progress during 2000 - 2013
ISO
International standards
(≈60 under preparation)
European standards will be superseded by ISO standards other countries make their own national decisions EN
CEN/TS
weighed votes 3 years in force
Prepared during
European standards
EN (36 published)
National standards withdrawn
1 vote each country
2 years preparation time
3 years in force
Prepared
Technical specifications
(27 published)
National standards in force
weighed votes 5 years in force
Prepared
2000
2004
2006
2008
2010
2012
2014

5. International pellet standards (ISO) – 1
EN ISO General requirements (FDIS)
Include all biomass raw materials and also aquatic biomass
Flexible classification, each property selected separatetely
Include classification of raw material, which is needed for product standards
Includes also special property classes for thermally treated biomass pellets (e.g. torrefied pellets)
EN ISO Graded pellets (FDIS)
Table 1 for non-industrial use
Table 2 for industrial use

6. International pellet standards (ISO) – 2
Graded non-woody pellets – EN ISO (FDIS)
Table 1 for agrobiomass blends and mixtures (classes A and B)
Table2 for straw, miscanthus and reed canary grass pellets
EN ISO , 2 and 6 (FDIS stage)
Values has been agreed
standards have been sent for final approval in May (voting)
Standards will be published in beginning of year 2014
ISO will supersede EN standards and will be published as EN ISO standards in Europe
Graded thermally treated densified biomass (proposal stage)
Proposal for work item (WI) has been discussed in March in ISO/TC 238 meeting and there is support to also prepare this standard
Voting for new WI will done soon and if accepted standard will be prepared within 2 years.
SECTOR project is supporting planning and also AEBIOM torrefaction group.

7. Specification and classes (EN ISO 17225-1)
Classification is based on origin and source, major traded forms and properties
Hierarchical classification system in table format:
1 Woody biomass
2 Herbaceous biomass
3 Fruit biomass
4 Aquatic biomass
5 Biomass blends and mixtures
blends = intentional (composition known)
mixtures = unintentional
Chemical treatment defined as any treatment with chemicals other than air, heat or water (e.g. glued, painted, coated, lacqued or otherwise treated wood
Chemically treated material shall not include halogenated organic compounds or heavy metals at levels higher than those in typical virgin material values or higher than typical values of the country of origin.

8. Solid biofuel utilisation chain
Tables with property grades
in EN ISO to 7
Origin/Source
Traded form
(e.g. pellet)
Fuel
production
Solid biofuel
Bioenergy
use
Biomass
Conversion
Documentation of origin
(Table 1 in EN ISO
Product declaration
EN series (in Europe)
Fuel Quality Assurance
EN series (in Europe)

9. Wood pellets for households and commercial applications
Wood pellets for households and commercial applications* (EN ISO , Table 1)
* Facility that utilise solid biofuel burning appliances or equipment that have similar fuel requirements as residential appliances.

10. Specification of industrial wood pellets (EN ISO 17225-2 (1)
Property
Standard A1 A2 B
Origin and source
EN ISO
1.1.3 Stemwood
1.2.1 Chemically untreated wood*
1.1.1 Whole trees
1.1.3 Stem wood
1.1.4 Logging residues
1.1 Forest plantation and other virgin wood
1.2 By-products and residues
1.3.1 Chemically untreated used wood
Diameter and length (D and L, mm)
ISO 17829
D06, 6 ± 1;
3,15 < L < 40
D08, 8 ± 1;
3,15 < L <40
(1 % longer, <45mm)
*Negligible levels of glue, grease and other timber production additives used in sawmills during production of timber and timber product from virgin wood are acceptable if all chemical parameters of the pellets are clearly within the limits and concentrations are too small to be concerned with.

11. Specification of residential wood pellets (ISO 17225-2) (2)
Property
Standard A1 A2 B
Moisture (M, w-%)
ISO 18134
M10 < 10
Ash (A), % d
ISO 18122
A0.7 < 0,7
A1.2 < 1,2
A2.0 < 2,0
Bulk density (BD, kg/m3)
ISO 17828
BD600 > 600
Fines (F, w-%) EN
F1.0 < 1.0
Durability (DU, w-%
ISO
DU97.5 > 97.5
DU96.5 > 96.5
Net calorific value, Q (as received, MJ/kg, kWh/kg)
ISO 18125
Q16.5 > 16,5
Q4.6 > 4.6
Cl (w-% dry)
ISO 16994
Cl0.02 < 0,02
Cl0.03 < 0,03
N (w-% dry)
ISO 16948
N0.3 < 0,3
N0.5 < 0,5
N1.0 < 1,0
S (w-% dry)
S0.04 < 0,04
S0.05 < 0,05

12. Specification of residential wood pellets (ISO 17225-2) (3)
Property
Standard A1 A2 I3
As (mg/kg d)
ISO 16968
< 1
Cd (mg/kg d)
< 0.5
Cr (mg/kg d)
< 10
Cu (mg/kg d)
Pb (mg/kg d)
Hg (mg/kg d)
< 0.1
Ni (mg/kg d)
Zn (mg/kg d)
< 100
Ash melting behaviour*
CEN/TS
Informative, should be stated
* all temperatures SST, DT, HT and FT in oxidating conditions at 550oC.
Pre-ashing temperature other than 550 oC should be stated.
ENplus certification has 815oC.

13. Wood pellets for industrial use (EN ISO 17225-2, Table 2)

14. Specification of industrial wood pellets (ISO 17225-2 (1)
Property
Standard I1 I2 I3
Origin and source
ISO
1.1.3 Stemwood
1.2.1 Chemically untreated wood*
1.1 Forest plantation and other virgin wood
1.2 By-products and residues
1.3.1 Chemically untreated used wood
Diameter and length (D and L, mm)
ISO 17829
D06, 6 ± 1;
3,15 < L < 40
D08, 8 ± 1;
3,15 < L <40
(1 % longer, <45mm)
D10, 10 ± 1;
D12, 12 ± 1;
*Negligible levels of glue, grease and other timber production additives used in sawmills during production of timber and timber product from virgin wood are acceptable if all chemical parameters of the pellets are clearly within the limits and concentrations are too small to be concerned with.

15. Specification of industrial wood pellets (ISO 17225-2) (2)
Property
Standard I1 I2 I3
Moisture (M, w-%)
ISO 18134
M10 < 10
Ash (A), % d
ISO 18122
A1.0 < 1,0
A1.5 < 1,5
A3.0 < 3,0
Bulk density (BD, kg/m3)
ISO 17828
BD600 > 600
Max. 750
Fines (F, w-%) EN
F4.0 < 4.0
F5.0 < 5.0
F6.0 < 6.0
Durability (DU, w-%
ISO
97.5<DU <99.0
97.0 <DU<99.0
96.5 < DU <99.0
Net calorific value, Q (as received, MJ/kg)
ISO 18125
Q16.5 > 16,5
Cl (w-% dry)
ISO 16994
Cl0.03 < 0,03
Cl0.05 < 0,05
Cl0.06 < 0,06
N (w-% dry)
ISO 16948
N0.3 < 0,3
N0.6 < 0,6
S (w-% dry)
S0.05 < 0,05

16. Specification of industrial wood pellets (ISO 17225-2) (3)
Property
Standard I1 I2 I3
As (mg/kg d)
ISO 16968
< 2
Cd (mg/kg d)
< 1
Cr (mg/kg d)
< 15
Cu (mg/kg d)
< 20
Pb (mg/kg d)
Hg (mg/kg d)
< 0.1
Zn (mg/kg d)
< 200
P (%)
ISO 17830
>99% (<3.15 mm)
>95% (<2.0 mm)
>60% (<0.1 mm)
>90% (<2.0 mm)
>50% (<0.1 mm)
>97% (<3.15 mm)
>85% (<2.0 mm)
>40% (<0.1 mm)
Ash melting behaviour*
CEN/TS
Informative, should be stated
* all temperatures SST, DT, HT and FT in oxidating conditions (550oC).

17. Additional information
CEN and ISO Fuel specification standards: Eija Alakangas, VTT, tel
Training material of wood pellets and non-woody pellets SolidStandards project (
This presentation is supported by PellCert project: