New regulations tighten quality requirements for biomass fuels – how to effectively ensure the proper composition of your product

At the end of May 2025, new regulations governing quality requirements for biomass fuels intended for sale will come into force. The Regulation of the Minister of Climate and Environment was published in the form of a four-page document specifying quality standards for briquettes, class A2 pellets and class A1 pellets. 

The document indicates exact percentage ranges for parameters such as: moisture, ash content, density, admixture of external substances, nitrogen content, sulfur content, calorific value, etc. The entire document dated 9.05.25 can be found here - on the official website of the Sejm.

It is worth remembering, however, that the production of pellets or briquettes is not the domain exclusively of large companies or major sawmills. Biofuel production on a smaller scale is carried out by many farmers, owners of wood processing workshops or persons of other professions who have constant access to biomass. They will also be subject to the new law. 

So what can a small, independent producer do in order to legally sell the surplus of their production? 

It turns out that in a few simple ways we can improve the quality of our fuel.

1. Dry fuel is quality fuel

One of the most important parameters of biomass fuels is moisture content.

The latest regulations set its maximum permissible content at 12% for briquettes and 10% for pellets regardless of class.

The basis for producing low-moisture fuel is properly stored biomass.

It is worth avoiding direct contact of biomass with the ground, which may be a source of moisture. Wood waste and fragments of wood are best stored elevated, for example on pallets. For obvious reasons, it is also worth ensuring proper roofing. In the case of larger pieces of wood, it is important to stack them in such a way that constant air circulation is ensured between branches or beams.

Another way to quickly dry wood waste may be shredding the biomass.

For this purpose, a wood chipper will be useful — a device used for shredding wood-based waste. Wood processed by a chipper is easier to store and dries faster. Even very wet pieces of wood can be fed into the chipper. Chips evaporate water much faster than large pieces of wood, especially if they are evenly spread on a flat surface in a dry place.

When drying ground biomass, it is worth securing the ground with foil or another impermeable material - this will speed up drying.

Another, more professional solution in the field of raw material drying is the use of aerodynamic sawdust dryers. These are specialized machines intended rather for larger wood processing plants. They ensure the best quality of biomass storage,  however their purchase involves a greater investment.

2. Chemical additives in briquettes and pellets - better to avoid them

The latest regulations regarding the composition of biofuels also introduce restrictive rules concerning the content of “chemical additives”. The upper limit is 2%. 

The document itself lists the following substances: 

Additives supporting production, transport or combustion: pressing additives, slagging inhibitors or others, such as starch,
corn flour and potato flour, vegetable oil, lignin.

2.1. How to avoid chemicals in biofuel?

The presence of suspicious substances in self-produced fuel does not have to result from their intentional introduction.

Their presence in pellets or briquettes may be caused by the use of processed wood waste in production.

Lacquered, coated, glued or chemically dyed wood should not be introduced into the pellet mill or briquetting machine.

Another component that may reduce the quality of biomass fuel may be plywood or chipboard of questionable quality - they often contain chemical enhancers.

2.2. Natural binder - the domain of biomass fuels

Another group of substances sometimes added to pellets or briquettes are external binding agents. 

In the production of biomass fuels, a minimal or zero amount of external binder is needed.

Wood in the briquetting or pelletizing process releases natural lignin, which perfectly binds biomass particles. In many cases, this is sufficient for the fuel to maintain a uniform consistency.

3. Monitor pellet dimensions

The document published by the ministry contains precise guidelines regarding the size of a single pellet granule. A margin of error of 1 mm in each direction is allowed.

Diameter: 6 mm - 8 mm 

Length: 3.15 mm - 40 mm

The die has a direct impact on the size of the granules. It is a replaceable and relatively inexpensive part of the pellet press.

It is worth ensuring that the diameter of the holes in our die falls within the ministerial standard.

4. Briquette density – worth controlling

According to the current regulation, a briquette admitted to sale should achieve a density of at least 0.9 g/cm³ (in working condition). This parameter directly translates into calorific value and combustion efficiency – the higher the density, the slower the combustion and the higher the calorific value.

In practice, this means that the briquette must be well pressed and compacted – material that is too light may indicate low biomass compaction or excess air in the fuel structure. 

From a technical point of view, pressing quality depends both on proper preparation of the raw material (moisture, fraction) and on the technical condition of the briquetting press. 

Therefore, make sure that the biomass is properly shredded and dried before placing it in the briquetting machine. 

If, after meeting these conditions, the density of the briquette is still not appropriate, it means that the briquetting machine generates too low pressure.

What about biofuel produced before the change in regulations?

Transitional provisions apply until the end of 2025. This means that briquettes and pellets produced before June 1, 2025 may be legally sold until the end of the current year - provided that they meet the quality requirements resulting from previous regulations

In summary

Pellets and briquettes are fuels that are simple to produce - to “spoil” something in them one would rather have to try.

Maintaining high pellet quality therefore depends mainly on our decisions.

Importantly: quality standards apply only to fuels intended for sale.

For our own use, we may act at our own discretion and produce fuels of slightly lower quality, e.g. from agricultural waste, waste paper or straw. 

Ultimately - one does not exclude the other.