Wood Fuels Standards
Key words - Bioenergy, wood fuel, biomass, heat standards, heat technology
Quality of fuel is of paramount importance for the efficient and trouble free operation of wood fired heating systems. Poor quality fuels with low calorific value can increase running costs beyond expectations, result in jammed feeding mechanisms, cause scaling and result in high levels of ash. In extreme cases, contaminants in the fuel can cause physical damage to the boiler or stove.
CEN Technical Committee CN/TC355 have issued a number of standards relating to the quality of solid bio-fuels as listed below.
CEN/TS 14588:2003 Solid biofuels - Terminology, definitions and descriptions
CEN/TS 14774-1:2004 Solid biofuels - Methods for determination of moisture content - Oven dry method - Part 1: Total moisture - Reference method
CEN/TS 14774-2:2004 Solid biofuels - Methods for the determination of moisture content - Oven dry method - Part 2: Total moisture - Simplified method
CEN/TS 14774-3:2004 Solid biofuels - Methods for the determination of moisture content - Oven dry method - Part 3: Moisture in general analysis sample
CEN/TS 14775:2004 Solid biofuels - Method for the determination of ash content
CEN/TS 14778-1:2005 Solid biofuels - Sampling - Part 1: Methods for sampling
CEN/TS 14778-2:2005 Solid biofuels - Sampling - Part 2: Methods for sampling particulate material transported in lorries
CEN/TS 14779:2005 Solid biofuels - Sampling - Methods for preparing sampling plans and sampling certificates
CEN/TS 14780:2005 Solid biofuels - Methods for sample preparation
CEN/TS 14918:2005 Solid Biofuels - Method for the determination of calorific value
CEN/TS 14961:2005 Solid biofuels - Fuel specifications and classes
CEN/TS 15103:2005 Solid biofuels - Methods for the determination of bulk density
CEN/TS 15104:2005 Solid biofuels - Determination of total content of carbon, hydrogen and nitrogen - Instrumental methods
CEN/TS 15105:2005 Solid biofuels - Methods for determination of the water soluble content of chloride, sodium and potassium
CEN/TS 15148:2005 Solid biofuels - Method for the determination of the content of volatile matter
CEN/TS 15149-1:2006 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 15149-2:2006 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 15149-3:2006 Solid biofuels - Methods for the determination of particle size distribution - Part 3: Rotary screen method
CEN/TS 15150:2005 Solid biofuels - Methods for the determination of particle density
CEN/TS 15210-1:2005 Solid biofuels - Methods for the determination of mechanical durability of pellets and briquettes - Part 1: Pellets
CEN/TS 15210-2:2005 Solid biofuels - Methods for the determination of mechanical durability of pellets and briquettes - Part 2: Briquettes
CEN/TS 15234:2006 Solid biofuels - Fuel quality assurance
CEN/TS 15289:2006 Solid Biofuels - Determination of total content of sulphur and chlorine
CEN/TS 15290:2006 Solid Biofuels - Determination of major elements
CEN/TS 15296:2006 Solid Biofuels - Calculation of analyses to different bases
CEN/TS 15297:2006 Solid Biofuels - Determination of minor elements
CEN/TS 15370-1:2006 Solid biofuels - Method for the determination of ash melting behaviour - Part 1: Characteristic temperatures method
Ireland has adopted TC335 standards. Although it is not a legal obligation for fuel suppliers to apply this standard, it is strongly recommended that fuels meeting informative recommendations provided in this standard are requested when purchasing. In practice, it is a good idea to check that fuel quality standards meet those defined by the boiler or stove manufacturer.
The standards are available from www.standards.ie.
Many of the above standards relate to the laboratory testing of the fuels. Of particular interest to suppliers and end users is CEN/TS 14961 "Solid Biofuels - Fuels specifications and classes" as highlighted in red above. Although it is not possible to reproduce the standard here for copyright reasons a brief summary of the contents is provided:
- Solid biofuels are classified by origin and source, i.e. woody biomass, herbaceous biomass, fruit biomass or blends and mixtures.
- Each classification is then subdivided into a number of sub-classifications on 3 sub-levels. For woody biomass there are approximately 34 lower level classifications.
- The standard then goes on to specify traded forms of solid biofuels including briquettes, pellets, chips, logs, bark and whole wood.
- For the main forms of traded solid biomass tables are provided specifying characteristics.
- From the characteristics table it is possible to define the quality of the solid biofuel according to the EN standard.
By using the standard it is possible to communicate the quality of the wood fuel using commonly recognised terminology.
Wood pellets are often imported to Ireland. Other equivalent standards may therefore have been applied to these products and are equally valid. Common European standards include:
- ONORM M17135 (Austria)
- SS 187120 & SS 187121 (Sweden)
- DIN 51731 (Germany)
In the US and Canada the equivalent standard is "Premium Grade".
For manufacturers of wood fuels and those looking to test wood fuel products, COFORD / SEAI have compiled a voluntary list of organisations offering testing facilities - see below.
Voluntary List of Wood Fuel Testing Organisations in Ireland
Modern Wood Fuel Procurement - The Finnish Experience and European quality standards for wood fuels - Eija Alakangas, VTT Processes
Report on work experience in a wood fuel testing centre in Denmark - COFORD
Quality Requirements and Certification for EU Pellet Markets - Philipp Koskarti - Austrian Research Institute for Chemistry & Technology- Presentation for the EUBionet Workshop at Bioenergy 2007
A Practical Guide to CEN Standards in Forest Chip Production - Geraldine O'Sullivan- SWS Forestry Services- Presentation for the EUBionet Workshop at Bioenergy 2007
CEN Standard for Fuel Specification, Classes and Quality Assurance - Jouni Valtanen - Finnish Forest Industries Federation - Presentation for the EUBionet Workshop at Bioenergy 2007
