Standards Specification and Quality

Typically we have been working to the Austrian and German Institute's standards -

ONORM M7 133 and DIN 66 - 165 (respectively)

 Predominately we have offered woodchip size classification

  • G50 (particle size 6 - 32 mm) 
  • W35 (moisture content by weight of 30 - 35%)

 

We are now working to the European standard

BS EN 14961 - Part 4 : 2011

We offer woodchip

  • Particle size - P31.5
  • Class - A2
  • Moisture content - M35 (30> P <35%)

Background Information

Potentially, there is a broad spectrum of biomass that can be used for heat energy.  Naturally, there are also major performance differences within this range of wood fuel.  These variations are due to the varying calorific values of different tree species, differing moisture content and even the type of chipper used.  (All Fuel Chips Ltd.  wood fuel is sourced from virgin timber.)

As a rule, biomass equipment (boilers and fuel chip delivery systems,) are designed to operate most effectively with a specific type or form of biomass fuel.

Fuel Standards provide an accurate description of the wood chip fuel's physical parameters and performance characteristics. The physical description covers the maximum size; absence of slivers / spears or fines (sawdust;) and maximum moisture content.  Also described are the levels of contaminants and ash, along with reassurance of the bio fuels origin / source (whether it is sustainable).

The descriptions (specifications) ensure the correct wood fuel can be matched to any type and size of biomass boiler and be appropriate to a boilers geographical location (with respect to air pollution).  These specifications ensure the wood chip delivery systems from the 'point of use fuel store' to the biomass boiler operate reliably.

In describing accurately the nature and performance of the different biomass fuels available, the fuel standards / specifications are vital to give energy user's confidence in the wood chip fuel they purchase.  This reassures the end user that the biomass fuel is consistent, efficient, and that their equipment will operate problem free.

European Standards

The European Standards Organisation is called CEN (Comite' de Normalisation) CEN Technical Committee 335 - Solid bio-fuels was established around 10 years ago with a mandate to produce standards for solid bio-fuel including wood chip.

CEN has now published a suite of standards (Euro Norms) that have replaced all other individual European country standards and in the UK these standards have been adopted by British Standards (BS EN).  The standards describe a fuel that is provided and what it's agreed properties are.  The properties specified for each individual fuel are divided into:

Normative properties, which must be provided - materials origin, particle size, moisture level and ash content.

 Informative properties, which are voluntary - net energy content, bulk density, chlorine and nitrogen content.

The Forestry Commission's Biomass Energy Centre also provides a useful glossary of the terms and abbreviations used in the biomass sector

 

Other European Standards - prior to the CEN universal standards being published, other European countries had developed biomass fuel standards of their own. 

Historically both Austrian and German boilers are the prevailing manufactured units to have been installed in the UK and their standards are;

 

The Austrian Standards Institute, typically boilers installed specify ONORM M7 133

The German Standard Institute (Deutshes Institutfur Normung), again typically DIN 66 165 

 

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