55 Uses of Biochar

by Hans-Peter Schmidt

Initially only used in agriculture, the range of uses for biochar now covers a wide range of different fields, giving this plant-based raw material the chance to make the most of its positive properties. Wherever biochar is specifically used even for industrial purposes, the carbon taken from the atmosphere in the form of CO2 can be stored for long periods or at least used to replace fossil carbon sources.

The PDF-printversion of this article is to be found here

Biochar is much too valuable and expensive for any farmer to be able to afford to spread 10 tonnes or more per hectare on his fields. Whereas a hectare will normally provide an annual benefice of EUR 1000, the EUR 8000 needed to purchase and spread the biochar would need to be amortised over several decades. The CO2 certificates favoured by so many outside the trade would be of no much help either.

Does it really make sense to work biochar into fields?

These economic considerations are not so different from what the natives in the Amazon delta and Australia had to face when they used biochar to improve their soils, and where you will still find some places with over 100 tonnes of biochar buried into just one hectare of soil. Even if no money existed back in those days, it would have made no economic sense to cut down some 300 to 400 huge rain forest trees and then use ancient charcoal kilns to make some 100 tonnes of biochar from 2000 tonnes of wood – just to bury the biochar in the soil. And don’t forget: all this would have been done without any chainsaws or axes and no animals to pull the logs close to the field
The idea of applying dozens of tonnes of biochar to fields can only come from scholars who, on the basis of a right observation (50 t biochar per hectare) have arrived at a false conclusion completely without any practical relevance – i.e. the massive one-time application of biochar. And this is quite apart from the fact that no soil becomes Terra Preta just because tonnes of char have been ploughed in.

Example of Terra Preta Cultures

The char used back then was probably created in the typical hearths of the natives, in which not just ash but also relatively large amounts of charcoal were produced at relatively low heat (Smith 1999). This char, basically a waste product, was then apparently used as a way of preventing infectious diseases. This was done by regularly adding char to faeces and other waste in the large jungle settlements, thus sterilising them (see Terra Preta – Model of a Cultural Technique). Once the organic waste had been stabilised through composting or fermenting it with added char, it was then used as a fertiliser on the fields. These methods led to the char being loaded with nutrients and its surface achieving greater binding capability through oxidisation, with the consequence that, once worked into the soil, the char was able to fully unfold its function as a nutrient store and humus stabiliser (through the creation of char-clay-humus complexes).
According to investigations carried out by Bruno Glaser and colleagues (Birk et al 2007), the amount of phosphor in Terra Preta soils compared to natural soils in the immediate vicinity can be up to 500 times higher. Different to carbon and nitrogen, phosphor can not be accumulated in the soil through plant growth, but mainly through the manual addition of excrement, (fish-)bones and ash. A rough estimate shows that the char- stabilised organic waste of some 500 people must have been worked into every hectare of soil over a period of 1000 years to gain such Terra Preta nutrient contents. Terra Preta has been created over centuries through the secondary use of biochar for recycling organic wastes. In other words, it took centuries to bring the biochar content of the soil up to over 100 tonnes per hectare.

The many uses of biochar

Biochar is much too valuable for it to be just worked into the soil without having it used at least once for more beneficial purposes – whether as storage for volatile nutrients, as an adsorber in functional clothing, as insulation in the building industry, as energy storage in batteries, as a filter in a sewage plant, as a silage agent or as a feed supplement. Such uses can be followed by use in a farmer’s slurry pit or in a sewage plant, before being composted. It should only be worked into the soil at the end of this “cascade”, helping to create Terra Preta.
The following list of 55 possible uses of biochar is by no means complete. In fact it has only just been started. In the medium term biochar will (or must) replace oil as the main raw material of our industrial society, insofar as mankind is willing to maintain living conditions on the planet in the long term (see: Biochar – a key technology for the planet).
We will initially just comment shortly on each usage of the list, as we intend to devote in-depth articles to some of them, highlighting in particular the use of biochar in agriculture and cattle farming and supporting the articles with the latest research findings. Biochar is without doubt one of the decade’s most exciting fields of research, with findings and their practical implementation increasing exponentially from year to year. Nevertheless, however much we enthuse over our field of research and the importance of our findings, it’s the real world that decides about its success.

The cascaded use of biochar in animal farming

1. Silage agent, 2. Feed additive / supplement, 3. Litter additive, 4. Slurry treatment, 5. Manure composting, 6. Water treatment in fish farming

At present some 90% of the biochar used in Europe goes into animal farming. Different to its application to fields, a farmer will notice its effects within a few days. Whether used in feeding, litter or in slurry treatment, a farmer will quickly notice less smell. Used as a feed supplement, the incidence of diarrhoea rapidly decreases, feed intake is improved, allergies disappear, and the animals become calmer. For in-depth articles on the use of biochar in cattle and poultry farming, see: Treating liquid manure with biochar, Biochar in poultry farming, The use of biochar in cattle farming. Over 80 farmers in Germany, Austria and Switzerland are currently (as of January 2013) being surveyed with the aim of creating a statistic on the effects of biochar in the cowshed. The first results are expected in Mai 2013.

Use as a soil conditioner

7. Carbon fertiliser, 8. Compost, 9. Substitute for peat in potting soil, 10. Plant protection, 11. Compensatory fertiliser for trace elements

In certain very poor soils (mainly in the tropics), positive effects on soil fertility were seen when applying untreated biochar. These include the higher capacity of the soil to store water, aeration of the soil and the release of nutrients through raising the soil’s ph-value. In temperate climates, soils tend to have a humus content of over 1.5%, meaning that such effects only play a secondary role. Indeed the high adsorption of plant nutrients released in the soil can instead often have – at least in the short and medium term – a negative effect on plant growth. These are the reasons why in temperate climates biochar should only be used when first loaded with nutrients and when the char surfaces have been activated through microbial oxidation. The best method of loading nutrients is to co-compost the char. This involves adding 10 – 30% biochar to the biomass to be composted (see: Ways of Making Terra Preta: Biochar Activation). The co-composting of biochar results not only in a valuable soil conditioner. The compost can be used as a highly efficient substitute for peat in potting soil, greenhouses, nurseries and other special cultures.
When biochar is used as a carrier for plant nutrients, efficient mineral and organic long-term fertilisers can be produced. Such fertilisers prevent the leaching of nutrients, a negative aspect of conventional fertilisers. The nutrients are available as and when the plants need them. Through the stimulation of microbial symbiosis, the plant takes up the nutrients from the porous carbon structure. Through mixing biochar with such organic waste as wool, molasses, ash, slurry and pomace, organic carbon-based fertilisers can be produced. These are at least as efficient as conventional fertilizers, and have the advantage of not having the well-known adverse effects on the ecosystem.
The biochars contain all trace elements originally contained in the pyrolised biomass. During pyrolysis, the crucial trace elements (over 50 metals) become part of the carbon structure, thereby preventing them being leached out and making them available to plants via root exudates and microbial symbiosis. This feature can be used specifically when certain trace elements are missing in a certain regional soil or in soil-free intensive cultures such as “Dutch tomatoes”.
A range of by-products are produced during pyrolysis. These remain stuck to the pores and surfaces of the biochar and in many cases have the ability to mobilise plant’s internal immune systems, thereby increasing its resistance to pathogens (Elad et al. 2011). This potential use is however only just now being developed and still requires a lot of research effort.

Use in the building sector

12. Insulation, 13. Air decontamination, 14. Decontamination of earth foundations, 15. Humidity regulation, 16. Protection against electromagnetic radiation (“electrosmog”)

Two of biochar’s properties are its extremely low thermal conductivity and its ability to absorb water up to 6 times its weight. These properties mean that biochar is just the right material for insulating buildings and regulating humidity. In combination with clay, but also with lime and cement mortar, biochar can be added to sand at a ratio of up to 50%. This creates indoor plasters with excellent insulation and breathing properties, able to maintain humidity levels in a room at 45 – 70% in both summer and winter. This in turn prevents not just dry air, which can lead to respiratory disorders and allergies, but also dampness through air condensing on the outside walls, which can lead to mould developing (see (in German): Biochar as building material for an optimal indoor climate)
Such biochar-mud plaster adsorbs smells and toxins, a property not just benefiting smokers. Alongside their use in housing, biochar-mud plasters are particularly good for warehouses, factory and agricultural buildings as well as in schools and other rooms frequented by people.
Biochar is a very efficient adsorber of electromagnetic radiation, meaning that biochar-mud plaster is very good at preventing “electrosmog”.
Biochar can also be applied to the outside walls of a building by jet-spray technique mixing it with lime. Applied at thicknesses of up to 20 cm, it is a substitute for styrofoam. Houses insulated this way become carbon sinks, while at the same time having a more healthy indoor climate. Should such a house be demolished at a later date, the biochar-mud plaster can be recycled as a valuable compost additive.
Together with the German company Casadobe, the Delinat Institute is currently developing a range of biochar-mud plasters, expected to be available on the market in mid-2013.


17. Soil additive for soil remediation [for use in particular on former mine-works, military bases and landfill sites.]

18. Soil substrates [highly adsorbing, plantable soil substrates for use in cleaning waste water; in particular urban waste water contaminated by heavy metals]

19. A barrier preventing pesticides getting into surface water [Sides of field and ponds can be equipped with 30-50 cm deep barriers made of biochar for filtering out pesticides.]

20. Treating pond and lake water [Biochar is good for adsorbing pesticides and fertilisers, as well as for improving water aeration.]


Biogas production

21. Biomass additive, 22. Biogas slurry treatment

First tests show that, through adding biochar to a fermenter’s biomass (especially heterogeneous biomasses), the methane and hydrogen yield is increased, while at the same time decreasing CO2 and ammonia emissions (Inthapanya et al. 2012; Kumar et al. 1987).
Through treating biogas slurry with lacto-ferments and biochar, nutrients are better stored and emissions prevented (see (in German): The sustainable production of biogas through climate farming)


The treatment of waste water

23. Active carbon filter, 24. Pre-rinsing additive, 25. Soil substrate for organic plant beds, 26. Composting toilets,


The treatment of drinking water

27. Micro-filters, 28. Macro-filters in developing countries


Divers other uses

Exhaust filters (29. Controlling emissions, 30. Room air filters)

Industrial materials (31. carbon fibres, 32. plastics)

Electronics (33. semiconductors, 34. batteries)

Metallurgy (35. metal reduction)

Cosmetics (36. soaps, 37. skin-cream, 38. therapeutic bath additives)

Paints and colouring (39. food colorants, 40. industrial paints)

Energy production (41. pellets, 42. substitute for lignite)

Medicines (43. detoxification, 44. carrier for active pharmaceutical ingredients)



45. Fabric additive for functional underwear, 46. Thermal insulation for functional clothing, 47. Deodorant for shoe soles

In Japan and China bamboo-based biochars are already being woven into textiles (Lin et al. 2008) to gain better thermal and breathing properties and to reduce the development of odours through sweat. The same aim is pursued through the inclusion of biochar in inlay soles and socks.


48. Filling for mattresses, 49. filling for pillows

Biochar adsorbs perspiration and odours, shields against electromagnetic radiation (electrosmog), and removes negative ions from the skin. Moreover, it acts as a thermal insulator reflecting heat, thereby enabling comfortable sleep without any heat build-up in summer. In Japan, pillows have been filled with biochar for a long time. This is supposed to prevent insomnia and neck tension.

50. Shield against electromagnetic radiation

Biochar can be used in microwave ovens, television sets, power supplies, computers, power sockets, etc. to shield against electromagnetic radiation. This property can also be used in functional clothing as protection for parts of the body particularly sensitive to radiation.

All of the proposed biochar uses except nos. 35, 41, 42 are carbon sinks. After its initial or cascading use, the biochar can be recycled as a soil conditioner. Fully depreciated when finally returned to the soil, the black carbon will slowly build up in the soil – and over a few generations the soil’s biochar content could easily reach 50 to 100 t per ha.

We have listed 50 possible uses of biochar. But the title refers to 55 uses …. This is to be seen as an indication of our intention to keep on adding to the list over the coming weeks and years, as experience builds up. We can also be sure that the author has missed out a number of uses already available today (the first version of this article only contained 44 possible uses)

The PDF-printversion of this article is to be found here



Birk J, Grosch H, Neves E, Teixeira W, Glaser B (2007): Rekonstruktion von Besiedlungsmuster und –intensität einer Terra Preta anhand der kleinräumigen Nährstoffverteilung, Mitteilungen der Deutschen Bodenkundlichen Gesellschaft 110:643-644
Elad, Y., D. R. David, Y. M. Harel, M. Borenshtein, H. B. Kalifa, A. Silber, und E. R. Graber. 2010. „Induction of systemic resistance in plants by biochar, a soil-applied carbon sequestering agent“. Phytopathology 100 (9): 913–921.
Inthapanya, Sangkhom, Preston T R, und Leng R A. 2012. „Biochar increases biogas production in a batch digester charged with cattle manure“. http://www.lrrd.org/lrrd24/12/sang24212.htm.
Kumar, S., M. C. Jain, und P. K. Chhonkar. 1987. „A note on stimulation of biogas production from cattle dung by addition of charcoal“. Biological wastes 20 (3): 209–215.
Lin, C. M., und C. W. Chang. 2008. „Production of thermal insulation composites containing bamboo charcoal“. Textile Research Journal 78 (7): 555–560. Smith NJH (1980) Anthrosols and human carrying capacity in Amazonia. Ann Assoc Am Geogr 70:553–566
Smith NJH (1999) The Amazon River forest: a natural history of plants, animals, and people. Oxford University Press, New York

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15 Responses to “55 Uses of Biochar””

  1. Kelpie Wilson
    Title: Ms.

    Wunderbar! Thank you so much for this list. This is the most sensible approach to Biochar deployment. I would like to add one use … Food preservation. I put a mesh bag filled with Biochar pieces in the refrigerator to absorb odors and ethylene gas that fruits and vegetables emit. Ethylene gas will make produce ripen and rot faster so sorbing it keeps the veggies fresh. There is great potential to use this commercially as food spoilage and waste is a huge issue. It is a natural benefit of using Biochar in soil as root crops like carrots and beets are often stored best unwashed. Biochar in soil that adheres to these veggies will help keep them fresh.

    Vielen Dank,

  2. hps

    Thanks Kelpie, that’s a great use of biochar and I will add it to the list with your explanation. We use biochar since long in the fridge against odours and never thought even about this principle that works behind keeping the food longer fresh. I will try it in the bread box too. And I am just thinking of storing apples, carrots and even tomatoes in a bed of biochar. Will try it. Thanks again and also for your great work on biochar and your website: http://www.greenyourhead.com.

  3. Dolph Cooke
    Title: Charmaster

    Hello Folks

    This is a good run-down. My only issue is that charcoal used for any application outside of agriculture should not be referred to as biochar. The English language already had words for carbonised material, so using the word biochar for non-agricultural applications confuses the fact that biochar is a charcoal specifically intended for agriculture, not industry. The word biochar should not be used as a catch-all word for any carbonised biomass.

    Charcoal = The catch all word for carbonised biomass. Covers a very wide range of qualities. May used as a fuel, for making activated carbon, as biochar (when prepared properly), or any one of 8000 different uses.

    Biochar = A form of charcoal specially prepared to be “fed” to plants or animals. You should not feed just any grade of charcoal to plants and animals .. if you do not want to make them sick. My personal test of a fresh biochar (with the exception of those made from manures) is that I should be able to put it in my mouth and chew on it. If I can’t do that then it is probably not suitable for plants or animals without additional processing.

    Activated carbon = Carbonised material, which might be from biomass, coal or petrochemcials, which has been prepared with a high surface area (typically more than 400 m2/gram). Sometimes acgivated carbon is used in agriculture, but most of the time it is used in industrial and household applications as an adsorbent. Some biochars have properties similar to a low grade activated carbon, however they should not be called biochar when used for industrial applications.

    Keep up the Great work : ) and than kyou Kelpie for more great ideas : )

    Charmaster Dolph Cooke
    Channeling Biochar Experts since 2009

  4. hps

    Hi Dolph,
    You are quite right to insist on the meaning of biochar. The problem arises as the article is a translation from German where we use the term “Pflanzenkohle” which means vegetal carbon. In German this is clearly distinguished to Holzkohle (charcoal). For the most of the 55 uses the same quality exigencies that you described for agronomic uses apply (chewing on it with no harm or the EBC-certificat). The whole thing about the 55 uses is that on their dead end they finish charged and enhanced in the soil. The end of fate of all this uses is a soil amendment which is for free as it was paid by all the preceding uses in the biochar cascade.
    Thanks Dolph, as an admirer of your work, I am happy to have you commenting in Ithaka

  5. Dolph Cooke

    Awesome Hans, thank you for that it makes it crystal clear now : )
    I did not even think about translation problems.

    Your entire site is really well done.

    Charmaster Dolph Cooke

  6. Richard S. Levine

    The ultimate value of biochar is in the realization of a complex network of causes and effects in the development and management of sustainable city-regions. This has been the subject of our research for more than thirty years. (For more on this see: “The City as Fulcrum of Global Sustainability,” Ernest J. Yanarella & Richard S. Levine, Anthem Press (UK),2011.) The sustainable city will be powered by renewables – principally solar energy and wind, however these are intermittent sources and it is difficult to store the energy they produce. Pyrolysis of biological materials has two fractions: the gases driven off in the heating process – principally carbon monoxide and hydrogen, and the char, which is left behind. the process may be driven in two different ways: the gases – also called producer gas, which can be stored and which can be substituted for natural gas, may be burned to produce the bio-char, or the biochar can be used as the fuel to pyrolyze the producer gas, or the same process can be used to produce a combination of producer gas and char. At the moment the emphasis is mostly on the production of bio-char using the producer gas fraction to do so. In the current economic situation this doesn’t appear to be very attractive although when long term considerations are taken into account, particulerly the alieviation of global warming through carbon sequestration, the economics couldn’t be better.

    To see how attractive a pyrolysis based local economy will be try this thought experiment: Imagine a small town-region where both agriculture and forestry and value-added industries derived from them are being practiced all centered around a small, but dense urban core. The buildings in this community are all built to the Passivhaus standard greatly reducing their use energy. Production from the land produces a good deal of cellulostic residue and along with human and animal wastes becomes fuel for a pyrolysis process. Wind and photovoltaic collectors provide the great majority of the electricity needed in the town, but as these renewable sources of energy are intermittent (no sun at night and on cloudy days) another source of renewable, but storable energy is required. The pyrolysis process is used to build up a store of producer gas which is used to power a standing engine coupled to a generator to produce all the required electricity when wind energy or solar energy (nights and cloudy days) is not available. When a sufficient store of producer gas has been produced, the pyrolysis process reverses its output to produce bio-char for all its many uses. The waste heat from the pyrolysis process is used to power any industries that are able to use it as well as a district heating system to provide most of the heat necessary to heat the (now reduced energy requirements through the use of the passivhaus standard) homes, factories and other buildings in the town. The town -region is a zero energy, zero unemployment economic ecology as the energy-employment couple becomes self adjusting to accommodate ongoing conditions. The town-region system satisfies the requirements of sustainability as it has the capacity of being the sort of no-growth, balance-seeking, self-provisioning (on a net basis) system that both Ecological Economists and Sustainable City theorists advocate. It also describes a system which is designed for continuous improvement (increasing the bio-char quotient of the soil for one thing), and toward the enrichment of an empowering participatory negotiation process as surpluses continue to accumulate. This is a short sketch of the ultimate value and use of bio-char/pyrolysis processes (for more detail, including the Sustainable Area Budget, see the book or http://www.centerforsustinablecities.com).

  7. Elise Hancock

    This compendium is really excellent. Thanks for all the thought and work. I will refer people to it.

    I have a question that may be important, based on a report I can no longer find on your site about the results—bad—when you gave urban “hobby gardeners” some char to use. As I remember it, you were puzzled, because the avid urban gardeners who had sought you out in previous years, agitating for char, had in general had EXCELLENT results. You were expecting the same from the hobby gardeners, but even after you supplied them with good live compost (in case that was the problem), their results were ragged. A few had a good increase in yield, but most? many? actually got worse.

    So I wonder… could the hobby gardeners have been using city water, full of chlorine? Most people do, after all, and think nothing of it. It’s what everyone does—water with the water you have. Of course. And if you’re using NPK fertilizers, all might seem to be well. Avid long-time gardeners, on the other hand, would probably have rain barrels, having had an experience like mine described on my website (below), when I finally figured out that city water kills microbes, all right, not only the ones that might make me sick, but the ones that my plants might need.


    This idea makes sense to me because it also makes sense of the works-in-the-tropics factor: those tropical fields are not urban, and the water isn’t treated.

    If this is true, harvesting enough rainwater to fill cities with backyard forest gardens won’t be easy, but at least we’ll know our struggle is not the fault of the char.

  8. hps

    The article you were looking for is here: http://www.ithaka-journal.net/pflanzenkohle-in-kleingarten-resultate-2011?lang=en. Results of biochar have been not too bad with an average increase of more than 10%. However, you are right that chlorine treated water is not beneficial for soil microbes.

  9. Karl Ennemoser
    Title: Landwirt

    Ich möchte Pflanzenkohle im Stall testen und würde mir gemeinsam mit E- M Wertvolleren Dünger und somit eine Verbesserung unserer übernützten Böden erwarten.Woh kann ich ca. 2000 kg Planzenkohle zu leistbaren Bedingungen erhalten. Ich wohne im Bregenzerwald, in Vorarlberg.

  10. Karl Ennemoser
    Title: Landwirt

    Ich möchte Pflanzenkohle im Stall testen und würde mir gemeinsam mit EM wertvolleren Dünger und somit eine Verbesserung unserer übernützten Böden erwarten. Wo kann ich ca. 2000 kg Planzenkohle zu leistbaren Bedingungen erhalten. Ich wohne im Bregenzerwald, in Vorarlberg.
    Preis und Transport, allenfalls Adresse des nähesten Vertreibers bitte mitteilen. Danke

  11. judyofthewoods
    Title: city water

    Great article. A friend and I were just investigating production of charcoal and there are a lot of ideas for markets we have not thought about.

    As to the problem with city water, the solution is right here in the article – no. 27/28. I also suspect that if chlorine is the culprit, that standing the water for a while before using it to water the plants might help to evaporate the chlorine.

    By the way, I have had amzing results from taking charcoal for a bad belly (cramps, and also nausea). I have used charcoal from my fireplace, but chewing the stuff is not a nice experience. After discovering that you can buy tablets of activated charcoal, I use that instead. Still, the plain old lumps do the trick.

    One other use of charcoal I read about is for lightening up your teeth if they are stained from tobacco, tea or coffee. You grind up charcoal to a powder (those tablets are probably best) and apply it to your teeth, wait for 5 minutes or so and rinse well. If your teeth are naturally dark, it won’t work. Sadly, dark teeth can be a side effect of certain antibiotics taken in childhood. That was particularly prevelant in the 60s for any minor illness.

  12. Hossein Ghafourian

    Dear Sir,
    I have published a book with Amazon in July 2016 under the title:
    “Nano-Biochar Biochar Charcoal & Coal Based Biochar Design of Pyrolysis Reactors Production Methods & Applications: Strawberry Production in Soilless Culture Using Nano-biochar”
    Part of this book is general information and another parts is about our 10 years experiment with Nano carbon.
    I will be very glad that you inform your membership.
    Thanks and best regards
    Prof. Dr. H. Ghafourian

  13. Jim Brown

    Mr. Levine, with your 30 years of experience could you explain how to store production gas? Biochar is new to almost all of us. With any new industry there is a learning curve; for both the manufacturers and consumers. Not all biochar is the same; this is probably why there are occasionally poor results. Char produced at high temperatures will have high pH; as high as 11. This obviously is not good for most soils. Using biochar on very poor soils can have an initial effect on plants; but they usually rebound and outperform the non treated plants. The biochar will absorb the nutrients first before making available to the plant. The tests that have really hit home for me is the improved Cation Exchange Capacity; enabling plants to absorb more nutrients; resulting in bigger stronger more healthy plants that produce more. This has also been proven in livestock.

  14. jack

    In order for biochar to protect against electromagnetic radiation,
    must it be inoculated with microbes or, can it be raw carbon?

    Same question concerning it’s thermal insulative/humidity property.

  15. hps

    the electromagnetic shielding should be independent of microbial interactions as it is a rather physical effect of the biochar quality. Same for insulation and humidty dynamics. However, microbes may to a certain extend effect these properties though rather indirect than direct (means the microbes do not effect these properties itself but their activity might affect the physico-chemical properties of the char… very speculative though)

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