Skip to main content

Optimise energy efficiency and plant availability

Wood is a biogenic solid fuel, i.e. a fuel with a biological-organic origin. The renewable raw material brings with it many advantages. It is a climate-neutral energy source and can be easily stored and used after drying, crushing - and in the case of wood pellets, pressing.

From forest wood to residual wood from wood processing to waste wood, they accumulate in many different forms. The good thing about an ENDRESS wood combustion system: Due to their robust industrial quality, they can use a wide range of fuels for energy. We have compiled a list of these for you on this page.


Legal classifications of fuels for wood combustion systems

The use of waste wood and residual wood for energy purposes is regulated by law. The basis is essentially the Ordinance on Small and Medium-Sized Combustion Plants not Requiring a Permit (Section 1 of the 1st BImSchV) and the Waste Wood Ordinance (AltholzV).


Common fuels in practice

Depending on the industry, one or even several wood fuels can be considered for heat generation with an ENDRESS wood combustion system.

Panel materials

During the production of panel materials such as OSB boards, chipboards and MDF fibreboards, bark, dust and wood residues from production accumulate. Burning the wood, which in many cases is varnished, glued or coated, in a private fireplace is of course strictly forbidden due to the pollutant emissions. In an ENDRESS combustion plant with a nominal heat output of 30 kilowatts and more (pursuant to Section 1 of the 1st BImSchV), however, companies active in the wood and furniture industry and wood glue construction may use them without hesitation.



Everywhere in the woodworking industry and in the carpentry trade, systems are used to extract dust, chips and sawdust produced during planing, sawing or milling. Chip extraction systems are a must, not only to protect people and machines. They also collect the valuable fuel for thermal recycling in an ENDRESS wood combustion system. We design and plan your new combustion system complete using storage tanks and conveyor technology.


Wood briquettes

Many carpenters press their waste wood from wood processing into briquettes. The lignin contained in the wood and liquefied by pressing acts as a binding agent. Briquettes require much less storage space than chips, storage is subject to less stringent regulations, for example in terms of explosion protection, and you do not have to build a silo. Of course, you can use wood pellets in any ENDRESS wood combustion system.


Wood chips

For the production of wood chips, also known as wood shavings or wood chips, forest residues, sawn wood from landscape conservation or residual wood from the sawmill industry are first dried and then crushed. This regional, climate-neutral and inexpensive fuel can be used in all ENDRESS wood combustion systems as the sole or supplementary fuel. Another advantage is that it can be easily stored and automatically fed into the wood combustion system via screw conveyors.


Wood pellets

Do you operate a wood combustion system but don’t use your own waste wood for this purpose? Then you should think about using industrial pellets as a fuel. Due to their composition and the simplified manufacturing process, they are cheaper than pellets for small domestic combustion plants. When used in an ENDRESS wood combustion system, you can rely on clean combustion with high efficiency.


One-way pallets

Pallets are made from untreated wood and can therefore be used without hesitation as fuel in an ENDRESS wood combustion system at the end of their product life. But a wood combustion systemis also a worthwhile investment, especially for companies in the packaging industry, because in addition to the damaged pallets, residual wood from production also falls off.


Packing wood

Wood is an indispensable raw material for the production of transport packaging and especially export packaging. Wooden boxes and cover plates can be custom-made quickly and inexpensively. As the boards are generally untreated, they can be used for energy recovery in an ENDRESS wood combustion system without hesitation.


Fuel classes according to Section 3 paragraph 1 of the 1st BImSchV

Section 3 paragraph 1 of the 1st BImSchV describes in detail in clauses 4 to 7 the fuels that may be used in combustion plants according to Section 1, i.e. also in an ENDRESS underfeed combustion system.

  • 4Natural lumpy wood including adhering bark, especially in the form of logs and wood chips, as well as brushwood and cones.
  • 5Natural, non-lumpy wood, especially in the form of sawdust, shavings and sanding dust, as well as bark.
  • 5a Pressed pellets of untreated wood in the form of wood briquettes in accordance with DIN 51731, October 1996 edition, or in the form of wood pellets in accordance with the fuel technology requirements of the DINplus certification programme "Wood pellets for use in small fireplaces in accordance with DIN 51731-HP 5", August 2007 edition, as well as other wood briquettes or wood pellets of untreated wood of equivalent quality.
  • 6Painted, lacquered or coated wood and residues thereof, provided that no wood preservatives have been applied or are present as a result of treatment and coatings do not contain any organohalogen compounds or heavy metals
  • 7Plywood, chipboard, fibreboard or otherwise glued wood and any residues thereof, provided no wood preservatives have been applied or are present as a result of treatment and coatings do not contain any organohalogen compounds or heavy metals.

Fuel classes 6-7

The fuels listed in fuel classes 4 and 5 of Section 3 paragraph 1 of the 1st BImSchV, such as untreated lumpy wood, untreated non-lumpy wood and pressed wood from untreated wood, are largely uncritical from a health point of view, as long as the wood combustion system is equipped with an appropriate particulate matter filter. The situation is different with fuels in fuel group 6-7. The glues, resins, binding agents and hydrophobing agents contained in the wood residues pose a risk of increased nitrogen oxide emissions or carbon monoxide emissions in the event of improper combustion and defective flue gas filters.


Waste wood categories A I and A II according to the Waste Wood Ordinance (AltholzV)

Waste wood is divided up into 5 different categories depending on the pollution load. The waste wood categories A I and A II essentially correspond to fuel classes 4 to 7 of the 1st BImSchV. Waste wood may be recycled either materially (e.g. for the production of new chipboard) or thermally, e.g. for heat generation in an ENDRESS wood combustion system. From A III, waste wood must be disposed of properly and may not be burned in a wood combustion system for heat generation.

Waste wood category A I:

Natural or only mechanically processed waste wood that has not been more than insignificantly contaminated with non-wood substances during its use

Waste wood category A II:

Glued, painted, coated, lacquered or otherwise treated waste wood without organohalogen compounds, in particular polyvinyl chloride (PVC) in the coating, and without wood preservatives


Your FUEL was not listed? Talk to us.

ENDRESS adapts your new combustion system individually to your fuel and quantity of waste wood as well as the space conditions on your site.

Cookies verwalten