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Bioenergy > Technologies > By-products > Char

Char, also known as agrichar (Note), biochar (bio-char), or biomass-derived black carbon, is a form of charcoal produced from biomass. Char is most commonly used as a fertilizer or soil amendment. Char may also have the potential to sequester large amounts of carbon in the soil. Much of the interest in char has been stimulated by research on terra preta, "dark earth" in the Amazon. While most soil in the Amazon is relatively infertile, there are large areas of deep, rich soil which were most likely created by agricultural communities over hundreds, if not thousands, of years. Citation needed



See books, reports, scientific papers, position papers and websites for additional useful resources.

  • Biochar: A critical review of science and policy by Biofuelwatch, 2011. "This report takes a critical look at the claims around biochar, reviews the science underlying the claims, provides an overview of what biochar advocates are pushing for in terms of policies and supports, and presents an outline of the companies involved."


  • - A website devoted to discussions on char, also known as terra preta, a Portugese expression meaning dark earth. Terra preta soils contain biochar but are themselves a much more complex system. Biochar is used today to improve soils for agriculture and sequester carbon in soil.

Commercial websites:








  • NRDC Assesses Biochar - Says High Hopes For Carbon Storage Premature , 29 November 2010 by Treehugger: "There's been lots of back and forth in the past year on biochar, ranging from research showing it has huge potential for absorbing carbon emissions on one side, to uncertainty about its potential, to outright hostility towards the enthusiasm shown towards it--and all from people with good environmental credentials. A new report from NRDC tries to sort it all out, and comes down somewhere in the middle."
  • Biochar research yields significant results, 12 August 2010 by Biomass Magazine: "Although it will not solve climate change entirely, biochar has the potential to mitigate up to a tenth of current greenhouse gas emissions, according to a new study."
    • The study, "Sustainable biochar to mitigate global climate change", which "centered on the carbon sequestration capabilities of biochar was published this week in Nature Communication, and co-author James Amonette hopes it will have great influence on those in the scientific community who doubt biochar’s climate mitigation potential."
    • "Amonette and fellow researchers calculated that when taking into consideration all biomass resources presently available, biochar has the potential to sequester one to two gigatons of carbon per year."
    • "A surprising determination of the resource analysis was that a significant amount of biomass is already spoken for in one way or another, Amonette said. 'There’s not a lot of it just lying around. We were very careful, getting back to the sustainability issues, not to consider breaking natural ground and converting it to biomass plantations because that was absolutely not the right way to go; the carbon debt from doing that is very large.'"[2]
Sketch of an apparatus for testing biofuel potential of various agricultural wastes, created by the RPI spring 2010 biomass capstone group. Image from The New York Times blog article A New Approach to Biofuel in Africa
  • A New Approach to Biofuel in Africa, 12 July 2010 by Ron Eglash: "The biofuel concept: If you just burn plant materials, you put out a lot of bad pollutants. But if you heat the materials in a container without oxygen (“pyrolysis”), you leave most of the carbon as “biochar,” which makes an excellent soil additive (in fact Amazon Indians built up rich soils over hundreds of years using biochar). The gas that is given off by pyrolysis can be processed into clean-burning fuel."
    • "All of which sounds great, but skeptics point out that Africa is a prime target for biofuel land grabs, which destroy small farms and forest preserves. Hence the importance of using agricultural residues like corn cobs, and researching the impact."[3]
  • Haiti's Rebuild May Be Biochar's Big Breakthough, 4 March 2010 by TreeHugger: "Biochar, the 'co product' of burning wood or agricultural waste in a pyrolitic (oxygen free) environment, has garnered both praise and criticism for its possibilities as a CO2 sequestration tool."
    • "WorldStoves, a company that makes a number of pyrolitic stoves, has partnered with the NGO International Lifeline Fund and a private Haitian company to bring its 'Lucia' stove designs to Haiti. In Haiti, the use of wood for charcoal for home cooking needs is widespread, which has led to a continuing cycle of deforestation and soil [degradation]."
    • "What makes the Lucia stove so magic is that a Haitian woman or man could cook for a five-person family using just about 300 grams of twigs, groundnut shells, rice husk or dung."
    • "[If] biochar is included in the UN's Certified Emission Reductions (CER) and Clean Development Mechanism (CDM) schemes, creating it in cookstoves and sequestering it in soil could help Haiti economically as well."[4]
  • Dead Forests to Fuel Vehicles, 15 September 2009 by CleanTechnica: "The University of Georgia Research Foundation has developed an innovative way to turn dead trees into a liquid fuel and has licensed it to Tolero Energy in California. We could be driving on our dead forests as soon as 2010."
    • "Tolero will use this low-cost, on-site process to turn waste biomass into sustainable and renewable forms of energy and industrial products. The biomass is heated at carefully controlled high temperatures in the absence of oxygen, a process known as fast pyrolysis. The vapors produced during pyrolysis rapidly condense into a bio-oil that can be added to biodiesel or petroleum diesel. Other pyrolysis by-products are gas and bio-char, which can be used as a soil amendment."[5]
  • House Committee on Small Business Takes Notice of Biochar, 21 July 2009 by re:char (with video): "On Thursday, May 21 University of Georgia Professor of Biological and Agricultural Engineering K.C. Das testified before the house Committee on Small Business. The hearing’s purpose was to discuss 'the impacts of outstanding regulatory policy on small biofuels producers and family farmers including biochar carbon sequestration.'"
    • Das stated: "'From what I see there is very little discussion at the national level, at the federal agencies, or within the existing legislature or outstanding legislature legislations that discuss biochar as a means of addressing the excessive carbon levels already in the atmosphere], and I’d like to bring that to your attention."[6]
  • Here comes the latest utopian catastrophe: the plan to solve climate change with biochar, 24 March 2009 by George Monbiot, columnist for The Guardian: "Biomass is suddenly the universal answer to our climate and energy problems. Its advocates claim that it will become the primary source of the world's heating fuel, electricity, road transport fuel (cellulosic ethanol) and aviation fuel (bio-kerosene)....Now an even crazier use of woodchips is being promoted everywhere....The great green miracle works like this: we turn the planet’s surface into charcoal."
    • "Now we say biochar. The idea is that wood and crop wastes are cooked to release the volatile components (which can be used as fuel), then the residue - the charcoal - is buried in the soil. According to the magical thinkers who promote it, the new miracle stops climate breakdown, replaces gas and petroleum, improves the fertility of the soil, reduces deforestation, cuts labour, creates employment," etc.
    • "This miracle solution has suckered people who ought to know better....At the UN climate negotiations beginning in Bonn on Sunday, several national governments will demand that biochar is eligible for carbon credits".
    • "The energy lecturer Peter Read proposes new biomass plantations of trees and sugar covering 1.4 billion ha....Were we to follow Read's plan, we would either have to replace all the world's crops with biomass plantations, causing instant global famine, or we would have to double the cropped area of the planet, trashing most of its remaining natural habitats."[7]
  • Scientist says ancient technique cuts greenhouse gas, 5 December 2008 by Reuters: "An ancient technique of plowing charred plants into the ground to revive soil may also trap greenhouse gases for thousands of years and forestall global warming, scientists said on Friday."
    • "Heating plants such as farm waste or wood in airtight conditions produces a high-carbon substance called biochar, which can store the greenhouse gas carbon dioxide and enhance nutrients in the soil.
    • "'I feel confident that the (carbon storage) time of stable biochar is from high hundreds to a few thousand years,' said Cornell University's Johannes Lehmann, at an event on the sidelines of U.N. climate talks in the Polish city of Poznan."
    • "Lehmann estimated that under ambitious scenarios biochar could store 1 billion tons of carbon annually -- equivalent to more than 10 percent of global carbon emissions, which amounted to 8.5 billion tons in 2007."
    • "The technique rings alarm bells among some environmentalists worried it could spur deforestation, but its chief problem may be that it is barely proven on a commercial scale."[8]


Agrichar™ is the global brand name and US registered trademark for the Biochar produced from the BEST Energies slow pyrolysis process.

By-products of bioenergy production edit

Ethanol production: Dried Distillers Grains (DDG) | Wet Distillers Grains | Bagasse
Biodiesel production : Glycerin
Pyrolysis: Char

Charcoal edit

Char (Agrichar/Biochar) (International Biochar Initiative)
Bamboo | Wood charcoal
Soil carbon sequestration

Bioenergy conversion technologies edit
Technologies categorized by bioenergy processes:

Biochemical: Aerobic, Anaerobic, Landfill gas collection (LFG), Biodiesel production, Ethanol production
Thermochemical: Combustion, Gasification, Pyrolysis, Depolymerization

Technologies categorized by feedstock:
Algae | Cellulosic technology

Technologies by commercialization status:

Analysis of technologies: Life-cycle analysis


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