In our biochar FAQ you will find the most frequently asked questions about biochar and vegetable charcoal, which we will be happy to answer. If your question is not there, please ask us directly!

Biochar is a pure natural substance, which is produced by the thermal carbonization (pyrolysis) of biomass such as untreated wood, hedge or green cuttings as well as other residual biomass. Due to its porous structure and its huge inner surface, it can store water and nutrients and bind pollutants. In addition, around half of the carbon in the starting material remains bound. These properties make them a great all-around material that can play an important role in agriculture, industry, water and climate protection, in municipalities and in building construction.

Biochar is made through a process called “pyrolysis”. The biomass is thermally treated at high temperatures, usually between 400 and 750 °C, sometimes, up to 900 °C, and with extensive exclusion of atmospheric oxygen. This can be done on a large scale in large industrial plants, in which case the gases and heat generated can also be used. Biochar can also be produced by yourself or in the home garden in a pit or in a Kon-Tiki, a funnel-shaped metal container.

Biochar in itself is not a fertilizer or nutrient, but a carrier. If not activated in the ground, it would do more harm than good, at least in the beginning. The nutrients contained in the soil and the water would be absorbed by the biochar and bound in the coal. In order to be able to acquire its soil-improving properties, it must first be physically charged with nutrients, i.e. activated.

Biochar, which was previously used as a feed or additive for bedding, is automatically charged with animal manure. In addition, biochar can be incorporated in layers into the compost or for example, can be activated by adding liquid fertilizer (e.g. nettle liquid or Bokashi).


Crumble a cube of yeast and dissolve it together with 500 g sugar or molasses in 6 liters of lukewarm water. With this mixture you can achieve wonders in accelerating compost. If you mix this mixture with biochar, you have made a real long-term fertilizer for your plants.

Biochar as a supplement to feed is a tried and tested household remedy for digestive disorders. The intestinal flora (the natural microbiological balance in the intestine) is restored. This automatically increases the animal’s well-being, it becomes more balanced and vital. Feed is more productive and growth is accelerated. The improved digestion also reduces methane emissions. Studies by independent institutions also show that the need for drugs such as antibiotics is significantly reduced. Diarrhea in calves and piglets is noticeably reduced.

  • Improve digestion
  • Detoxifies and inhibits inflammation
  • Feed can be better utilized by the animal
  • Cost advantages due to higher feed efficiency and better growth
  • Strengthens the immune system

One liter of biochar in the bedding can absorb up to 5 liters of urine. Thanks to this property, the stable/pen or barn climate can be improved many times over in a very short time.
The spread of ammonia is prevented, which without biochar escapes from the urine within a few hours. Ammonia is not only harmful to smell, it is harmful to health: it attacks the mucous membranes and respiratory organs. On the ground, ammonia and water form the highly corrosive ammonia. It attacks toes, claws, balls of the feet and hooves.

  • Bedding areas in the stable dry off better
  • Urine is absorbed, inhibiting the formation of ammonia and reducing odors
  • Suppression of decay/rotting and reduces the presence of flies.
  • Reduces fungal and mold spores
  • Stress on the respiratory tract and irritation of the claws or hooves are significantly reduced


Mix around 10% biochar into the litter. If biochar is already used in feeding, the proportions can be reduced accordingly.

If biochar is introduced into the ground, it is stored there in a stable manner for several millennia, similar to crude oil or lignite. The proportion of carbon from the plant that was bound in the biochar is thus withdrawn from the carbon cycle, as it is neither converted to CO2 or methane by combustion nor by rotting. Over 80% of the carbon remains stable for more than 1000 years. This makes it possible to remove the CO2 originally absorbed by plants from the atmosphere in the long term, thereby slowing down climate change.

Smelly manure is a sign that the decaying and breakdown process is out of control. Thanks to the use of biochar, however, this material cycle can be closed again and the liquid manure becomes a highly efficient, sustainable and odorless fertilizer.

While some of the minerals contained in the liquid manure such as ammonium, nitrate, urea and phosphate are available to the plants as nutrients, in addition to the climate-damaging emissions, a significant part of the nutrients is washed out into ground and surface waters. Due to the outgassing of ammonia and the leaching of nitrates, fertilization with untreated manure also leads to soil acidification, which severely affects the fertility and biological activity of the soil and accelerates the degradation of humus.
Due to its high specific surface, biochar binds ammonium and ammonia as well as other odor-intensive, often toxic substances very efficiently. Thanks to the biochar, most of the manure nitrogen can be stored in a way that is available for plants. The leaching of the slurry nutrients in the soil is significantly slowed down, which not only protects the groundwater but also prevents acidification of the soil. The liquid manure treated with biochar promotes soil activity and the build-up of humus. Instead of leaching the soils with toxic manure, the soils are built up over the long term. Overall, the use of biochar almost doubles the fertilizing effect of the manure.

  • Significantly less stench
  • No “sink and swim” layers
  • the nitrate pollution in groundwater and soil is significantly reduced
  • Decreased soil acidification
  • Climate-damaging gases are reduced
  • Quick humus build-up and good soil structure
  • Nutrients and water are optimally stored for plants to use
  • Save approx. 50% fertilizer in the long term due to the low losses
  • improved plant growth
  • plant bio-diversity is promoted
  • chemical-free fertilization helps save the environment and the ecosystem

Biochar is not itself a fertilizer, but a carrier material: it is used together with other things: fertilizer, cattle manure or compost introduced into the soil and stores these substances. There, the coal particles provide a habitat for many useful microorganisms, fungi and bacteria, from which the cultivated plants benefit. The biochar is therefore an excellent store of nutrients and water.

Vorteile für den Boden:

  • Higher water storage capacity of the soil (up to 5 times its own weight)
  • Soil bacteria thrive and improve the nutrient supply for the plants
  • Mycorrhizae (fungus and root) increase and improve the absorption of water and nutrients, protect against pests
  • Toxins and heavy metals are absorbed; the quality of the products and the groundwater increases
  • Better soil aeration and reduction of methane and nitrous oxide emissions
  • Nutrient dynamics: Plants grow better, nutrients stay bound in the soil longer
  • Plants are generally more resilient and more productive

Excess energy is created in the production of biochar. We assume that biochar will be used more and more in future – especially large, production plants, for example to provide District or Process heat. This creates an additional benefit, the production plant becomes more economical, and the coal can be offered more cheaply.

The coal should have the highest possible carbon content, based on the total mass. Biochar sometimes contains a lot of water, and high carbon content, which is related to the dry matter. However, if the dry matter is only 70% and 85% of this is carbon, then that is significantly less carbon than with 95% dry matter and 80% carbon, based on the total mass. Apart from that, the heavy metal content in particular should be taken into account. Incidentally, a certificate alone is by no means a guarantee that the coal is of high quality.

As a rule, biochar can be prepared and processed in the same way as fossil coal. However, not all coal is the same. Just as Colombian anthracite coal differs significantly from Central European hard coal, biochar made from hardwood, for example, also differs from coal made from grain husks.

As an animal feed additive, the coal should be ground as finely as possible. But then the coal becomes very dusty, it spreads through the slightest movement of air and settles everywhere. In this case it is advantageous to moisten the coal or to add it to the animals’ drinking water.

When processing large quantities of powdered biochar, the same safety precautions must be taken as when processing conventional coal dust, including explosion protection.

The production of biochar in your own garden is not recommended. The small quantities and short process cycles result in high emissions and low efficiency. Biochar should only be produced in large plants designed for this purpose with appropriate process management and flue gas cleaning.

In principle, biochar can be produced from any biogenic residue, for example from grain husks, waste wood or green cuttings. The dry pyrolysis processes needs dry raw material, these processes have already proven themselves. For the charring of sewage sludge and organic waste, which are usually rather wet, the HTC process is to be used in the future, but this is still in the development phase.

The highly volatile components, such as hydrogen and nitrogen, heavy metals with a low melting and evaporation temperature, are expelled with the pyrolysis gas and burned. Heavy metals with a high melting point remain in the ashes as pollutants. That is why it is not allowed, for example, to use treated waste wood for the production of animal feed charcoal.

That depends on what raw material(s) you are using. If the starting material is very moist and already partly fermented, such as B. the fermentation residues from a biogas plant, then the process will in the best case be energy self-sufficient. In the case of natural logs without high moisture, the pyrolysis gas even creates an energy surplus.

When plants grow, they remove CO₂ from the atmosphere. Depending on the application of the biochar, this CO₂ is either released again (barbecue charcoal) or bound in the long term (industrial products with a long service life). Apart from the energy required for harvesting, transporting and producing the biochar, the use of biochar is consequently CO₂-neutral or, ideally, even CO₂-negative. In contrast, fossil coal is carbon that has been gradually stored in the ground over millions of years. Thanks to the industrial revolution and technical developments, mankind has succeeded in releasing a large part of this enormous amount of pollution within a very short time, thereby significantly increasing the CO₂ content in the atmosphere and the temperature of the earth. This process must be stopped. The use of biochar instead of fossil coal can make a significant contribution to this.

We cannot answer this question, we can only state our personal opinion here. We are convinced that there is not enough biomass to fuel all coal-fired power plants with biochar in the future, especially when you consider that biochar should also be used in agriculture and in numerous industrial processes. Other, environmentally neutral forms of energy generation must certainly be further developed and established here. What is certain, however, is that biochar is obtained from a CO₂-neutral, constantly renewable raw material that is available in large quantities in many places, even if it is used sustainably. Biochar can replace fossil coal in a number of areas, e.g. B. in the pharmaceutical industry and medicine and in environmental technology. And it offers numerous advantages in the field of agriculture and animal husbandry. Which applications will ultimately prevail remains exciting.

This mainly depends on the water content of the input material supplied. With a water content of 45%, about three times the amount of the final biochar.

When CO₂ is withdrawn from the environment and does not get back into the atmosphere, we speak of negative emissions. The technical term for this is sequestration. As long as the biochar is not used again to generate energy, but is used in agriculture or the construction industry, a carbon sink is created.

Yes, however, these are far more complex and costly than the process of biochar production.