Earth:Biochar

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Short description: Lightweight black residue, made of carbon and ashes, after pyrolysis of biomass
A hand holding a piece of biochar with a bucket of it in the background
Biochar produced from residual wood
Small pellets of biochar
Smaller pellets of biochar
A large pile of biochar
Biochar after production, in a large pile

Biochar is the lightweight black residue, made of carbon and ashes, remaining after the pyrolysis of biomass, and is a form of charcoal.[1] Biochar is defined by the International Biochar Initiative as "the solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment".[2] Biochar is a stable solid that is rich in pyrogenic carbon and can endure in soil for thousands of years.[3]

The refractory stability of biochar leads to the concept of pyrogenic carbon capture and storage (PyCCS),[4] i.e. carbon sequestration in the form of biochar.[3] It may be a means to mitigate climate change due to its potential of sequestering carbon with minimal effort.[5][6][7] Biochar may increase the soil fertility of acidic soils and increase agricultural productivity.[8] Biochar is mainly used for soil application and is known to improve soil nutrient availability, aeration in soil, and soil water filtration. There exist various approaches for utilizing biochar, including but not limited to soil amendment, slash-and-char, water retention, stock fodder, and concrete additive.

Biochar has been widely viewed as an environmentally positive material for soil. However, it is crucial to take into account the potential adverse effects of biochar, such as disturbing soil pH levels, or introducing harmful chemical characteristics that cause problems at the micro dimension. Therefore, caution should be exercised when considering the applications of biochar as research continues to explore the positive and negative effects of biochar.

History

The word "biochar" is a late 20th century English neologism derived from the Greek word βίος, bios, "life" and "char" (charcoal produced by carbonization of biomass).[9] It is recognized as charcoal that participates in biological processes found in soil, aquatic habitats and in animal digestive systems.

Pre-Columbian Amazonians produced biochar by smoldering agricultural waste (i.e., covering burning biomass with soil)[10] in pits or trenches.[11] It is not known if they intentionally used biochar to enhance soil productivity.[11] European settlers called it terra preta de Indio.[12] Following observations and experiments, a research team working in French Guiana hypothesized that the Amazonian earthworm Pontoscolex corethrurus was the main agent of fine powdering and incorporation of charcoal debris in the mineral soil.[13]

Production

Biochar is a high-carbon, fine-grained residue that is produced via pyrolysis; it is the direct thermal decomposition of biomass in the absence of oxygen (preventing combustion), which produces a mixture of solids (the biochar proper), liquid (bio-oil), and gas (syngas) products.

Gasifiers produce most of the biochar sold in the United States.[14] The gasification process consists of four main stages: oxidation, drying, pyrolysis, and reduction.[15] Temperature during pyrolysis in gasifiers is 250–550 °C (523–823 K), 600–800 °C (873–1,073 K) in the reduction zone and 800–1,000 °C (1,070–1,270 K) in the combustion zone.[16]

The specific yield from pyrolysis is dependent on process conditions such as temperature, residence time, and heating rate.[17] These parameters can be tuned to produce either energy or biochar.[18] Temperatures of 400–500 °C (673–773 K) produce more char, whereas temperatures above 700 °C (973 K) favor the yield of liquid and gas fuel components.[19] Pyrolysis occurs more quickly at higher temperatures, typically requiring seconds rather than hours. The increasing heating rate leads to a decrease of biochar yield, while the temperature is in the range of 350–600 °C (623–873 K).[20] Typical yields are 60% bio-oil, 20% biochar, and 20% syngas. By comparison, slow pyrolysis can produce substantially more char (≈35%);[19] this contributes to soil fertility. Once initialized, both processes produce net energy. For typical inputs, the energy required to run a "fast" pyrolyzer is approximately 15% of the energy that it outputs.[21] Pyrolysis plants can use the syngas output and yield 3–9 times the amount of energy required to run.[11]

Besides pyrolysis, torrefaction and hydrothermal carbonization processes can also thermally decompose biomass to the solid material. However, these products cannot be strictly defined as biochar. The carbon product from the torrefaction process contains some volatile organic components, thus its properties are between that of biomass feedstock and biochar.[22] Furthermore, even the hydrothermal carbonization could produce a carbon-rich solid product, the hydrothermal carbonization is evidently different from the conventional thermal conversion process.[23] Therefore, the solid product from hydrothermal carbonization is defined as "hydrochar" rather than "biochar".

The Amazonian pit/ trench method[11] harvests neither bio-oil nor syngas, and releases CO
2
, black carbon, and other greenhouse gases (GHGs) (and potentially, toxicants) into the air, though less greenhouse gasses than captured during the growth of the biomass. Commercial-scale systems process agricultural waste, paper byproducts, and even municipal waste and typically eliminate these side effects by capturing and using the liquid and gas products.[24][25] The 2018 winner of the X Prize Foundation for atmospheric water generators harvests potable water from the drying stage of the gasification process.[26][27] The production of biochar as an output is not a priority in most cases.

Smallholder biochar production with fruit-orchard prunings; per the World Bank, "biochar retains between 10 percent and 70 percent (on average about 50 percent) of the carbon present in the original biomass and slows down the rate of carbon decomposition by one or two orders of magnitude, that is, in the scale of centuries or millennia"[28]

Smallholder farmers in developing countries easily produce their own biochar without special equipment. They make piles of crop waste (e.g., maize stalks, rice straw or wheat straw), light the piles on the top and quench the embers with dirt or water to make biochar. This method greatly reduces smoke compared to traditional methods of burning crop waste. This method is known as the top down burn or conservation burn.[29][30][31]

Centralized, decentralized, and mobile systems

In a centralized system, unused biomass is brought to a central plant[32] for processing into biochar. Alternatively, each farmer or group of farmers can operate a kiln. Finally, a truck equipped with a pyrolyzer can move from place to place to pyrolyze biomass. Vehicle power comes from the syngas stream, while the biochar remains on the farm. The biofuel is sent to a refinery or storage site. Factors that influence the choice of system type include the cost of transportation of the liquid and solid byproducts, the amount of material to be processed, and the ability to supply the power grid.

Common crops used for making biochar include various tree species, as well as various energy crops. Some of these energy crops (i.e. Napier grass) can store much more carbon on a shorter timespan than trees do.[33]

For crops that are not exclusively for biochar production, the Residue-to-Product Ratio (RPR) and the collection factor (CF), the percent of the residue not used for other things, measure the approximate amount of feedstock that can be obtained. For instance, Brazil harvests approximately 460 million tons (MT) of sugarcane annually,[34] with an RPR of 0.30, and a CF of 0.70 for the sugarcane tops, which normally are burned in the field.[35] This translates into approximately 100 MT of residue annually, which could be pyrolyzed to create energy and soil additives. Adding in the bagasse (sugarcane waste) (RPR=0.29 CF=1.0), which is otherwise burned (inefficiently) in boilers, raises the total to 230 MT of pyrolysis feedstock. Some plant residue, however, must remain on the soil to avoid increased costs and emissions from nitrogen fertilizers.[36]

Various companies in North America, Australia , and England sell biochar or biochar production units. In Sweden the 'Stockholm Solution' is an urban tree planting system that uses 30% biochar to support urban forest growth.[37]

At the 2009 International Biochar Conference, a mobile pyrolysis unit with a specified intake of 1,000 pounds (450 kg) was introduced for agricultural applications.[38]

Thermo-catalytic depolymerization

Alternatively, "thermo-catalytic depolymerization", which utilizes microwaves, has been used to efficiently convert organic matter to biochar on an industrial scale, producing ≈50% char.[39][40]

Properties of biochar and activated biochar

The physical and chemical properties of biochars as determined by feedstocks and technologies are crucial. Characterization data explain their performance in a specific use. For example, guidelines published by the International Biochar Initiative provide standardized evaluation methods.[2] Properties can be categorized in several respects, including the proximate and elemental composition, pH value, and porosity. The atomic ratios of biochar, including H/C and O/C, correlate with the properties that are relevant to organic content, such as polarity and aromaticity.[41] A van-Krevelen diagram can show the evolution of biochar atomic ratios in the production process.[42] In the carbonization process, both the H/C and O/C atomic ratios decrease due to the release of functional groups that contain hydrogen and oxygen.[43]

Production temperatures influence biochar properties in several ways. The molecular carbon structure of the solid biochar matrix is particularly affected. Initial pyrolysis at 450–550 °C leaves an amorphous carbon structure. Temperatures above this range will result in the progressive thermochemical conversion of amorphous carbon into turbostratic graphene sheets. Biochar conductivity also increases with production temperature.[44][45][46] Important to carbon capture, aromaticity and intrinsic recalcitrance increases with temperature.[47]

Applications

Carbon sink

Biomass burning and natural decomposition releases large amounts of carbon dioxide and methane to the Earth's atmosphere. The biochar production process also releases CO
2
(up to 50% of the biomass); however, the remaining carbon content becomes indefinitely stable.[7] Biochar carbon remains in the ground for centuries, slowing the growth in atmospheric greenhouse gas levels. Simultaneously, its presence in the earth can improve water quality, increase soil fertility, raise agricultural productivity, and reduce pressure on old-growth forests.[48]

Biochar can sequester carbon in the soil for hundreds to thousands of years, like coal.[49][50][51][52][53] Early works proposing the use of biochar for carbon dioxide removal to create a long-term stable carbon sink were published in the early 2000s.[54][55][56] This technique is advocated by scientists including James Hansen[57] and James Lovelock.[58]

A 2010 report estimated that sustainable use of biochar could reduce the global net emissions of carbon dioxide (CO2), methane, and nitrous oxide by up to 1.8  billion tonnes carbon dioxide equivalent (CO2e) per year (compared to the about 50 billion tonnes emitted in 2021), without endangering food security, habitats, or soil conservation.[7] However a 2018 study doubted enough biomass would be available to achieve significant carbon sequestration.[59] A 2021 review estimated potential CO
2
removal from 1.6 to 3.2 billion tonnes per year,[60] and by 2023 it had become a lucrative business renovated by carbon credits.[61]

As of 2023, significance of biochar's potential as a carbon sink is widely accepted. Biochar is found to have the technical potential to sequester 7% of carbon dioxide in average of all countries, with twelve nations able to sequester over 20% of their greenhouse gas emissions.[62] Bhutan leads this proportion (68%), followed by India (53%).

In 2021 the cost of biochar ranged around European carbon prices,[63] but was not yet included in the EU or UK Emissions Trading Scheme.[64]

In developing countries, biochar derived from improved cookstoves for home-use can contribute[clarification needed] to lower carbon emissions if use of original cookstove is discontinued, while achieving other benefits for sustainable development.[65]

Soil amendment

Biochar in a white tarp
Biochar in preparation as a soil amendment

Biochar offers multiple soil health benefits in degraded tropical soils but is less beneficial in temperate regions.[66] Its porous nature is effective at retaining both water and water-soluble nutrients. Soil biologist Elaine Ingham highlighted its suitability as a habitat for beneficial soil micro organisms.[67] She pointed out that when pre-charged with these beneficial organisms, biochar promotes good soil and plant health.

Biochar reduces leaching of E-coli through sandy soils depending on application rate, feedstock, pyrolysis temperature, soil moisture content, soil texture, and surface properties of the bacteria.[68][69][70]

For plants that require high potash and elevated pH,[71] biochar can improve yield.[72]

Biochar can improve water quality, reduce soil emissions of greenhouse gases, reduce nutrient leaching, reduce soil acidity,[73] and reduce irrigation and fertilizer requirements.[74] Under certain circumstances biochar induces plant systemic responses to foliar fungal diseases and improves plant responses to diseases caused by soilborne pathogens.[75][76][77]

Biochar's impacts are dependent on its properties[78] as well as the amount applied,[77] although knowledge about the important mechanisms and properties is limited.[79] Biochar impact may depend on regional conditions including soil type, soil condition (depleted or healthy), temperature, and humidity.[80] Modest additions of biochar reduce nitrous oxide (N2O)[81] emissions by up to 80% and eliminate methane emissions, which are both more potent greenhouse gases than CO
2
.[82]

Studies reported positive effects from biochar on crop production in degraded and nutrient–poor soils.[83] The application of compost and biochar under FP7 project FERTIPLUS had positive effects on soil humidity, crop productivity and quality in multiple countries.[84] Biochar can be adapted with specific qualities to target distinct soil properties.[85] In Colombian savanna soil, biochar reduced leaching of critical nutrients, created a higher nutrient uptake, and provided greater nutrient availability.[86] At 10% levels biochar reduced contaminant levels in plants by up to 80%, while reducing chlordane and DDX content in the plants by 68 and 79%, respectively.[87] However, because of its high adsorption capacity, biochar may reduce pesticide efficacy.[88][89] High-surface-area biochars may be particularly problematic.[88]

Biochar may be plowed into soils in crop fields to enhance their fertility and stability and for medium- to long-term carbon sequestration in these soils. It has meant a remarkable improvement in tropical soils showing positive effects in increasing soil fertility and improving disease resistance in West European soils.[84] Gardeners taking individual action on climate change add biochar to soil,[90] increasing plant yield and thereby drawing down more carbon.[91] The use of biochar as a feed additive can be a way to apply biochar to pastures and to reduce methane emissions.[92][93]

Application rates of 2.5–20 tonnes per hectare (1.0–8.1 t/acre) appear required to improve plant yields significantly. Biochar costs in developed countries vary from $300–7000/tonne, which is generally impractical for the farmer/horticulturalist and prohibitive for low-input field crops. In developing countries, constraints on agricultural biochar relate more to biomass availability and production time. A compromise is to use small amounts of biochar in lower-cost biochar-fertilizer complexes.[94]

Slash-and-char

Switching from slash-and-burn to slash-and-char farming techniques in Brazil can decrease both deforestation of the Amazon basin and carbon dioxide emission, as well as increase crop yields. Slash-and-burn leaves only 3% of the carbon from the organic material in the soil.[95] Slash-and-char can retain up to 50%.[96] Biochar reduces the need for nitrogen fertilizers, thereby reducing cost and emissions from fertilizer production and transport.[97] Additionally, by improving soil's till-ability, its fertility and its productivity, biochar-enhanced soils can indefinitely sustain agricultural production, whereas slash/ burn soils quickly become depleted of nutrients, forcing farmers to abandon the fields, producing a continuous slash and burn cycle. Using pyrolysis to produce bio-energy does not require infrastructure changes the way, for example, processing biomass for cellulosic ethanol does. Additionally, biochar can be applied by the widely used machinery.[98]

Water retention

Biochar is hygroscopic due to its porous structure and high specific surface area.[99] As a result, fertilizer and other nutrients are retained for plants' benefit.

Stock fodder

Biochar has been used in animal feed for centuries.[100]

Doug Pow, a Western Australian farmer, explored the use of biochar mixed with molasses as stock fodder. He asserted that in ruminants, biochar can assist digestion and reduce methane production. He also used dung beetles to work the resulting biochar-infused dung into the soil without using machinery. The nitrogen and carbon in the dung were both incorporated into the soil rather than staying on the soil surface, reducing the production of nitrous oxide and carbon dioxide. The nitrogen and carbon added to soil fertility. On-farm evidence indicates that the fodder led to improvements of liveweight gain in Angus-cross cattle.[101]

Doug Pow won the Australian Government Innovation in Agriculture Land Management Award at the 2019 Western Australian Landcare Awards for this innovation.[102][101] Pow's work led to two further trials on dairy cattle, yielding reduced odour and increased milk production.[103]

Concrete Additive

Ordinary Portland cement (OPC), an essential component of concrete mix, is energy- and emissions-intensive to produce; cement production accounts for around 8% of global CO2 emissions.[104] The concrete industry has increasingly shifted to using supplementary cementitious materials (SCMs), additives that reduce the volume of OPC in a mix while maintaining or improving concrete properties.[105] Biochar has been shown to be an effective SCM, reducing concrete production emissions while maintaining required strength and ductility properties.[106][107]

Studies have found that a 1-2% weight concentration of biochar is optimal for use in concrete mixes, from both a cost and strength standpoint.[106] A 2 wt.% biochar solution has been shown to increase concrete flexural strength by 15% in a three-point bending test conducted after 7 days, compared to traditional OPC concrete.[107] Biochar concrete also shows promise in high temperature resistance and permeability reduction.[108]

A cradle-to-gate life cycle assessment of biochar concrete showed decreased production emissions with higher concentrations of biochar, which tracks with a reduction in OPC.[109] Compared to other SCMs from industrial waste streams (such as fly ash and silica fume), biochar also showed decreased toxicity.

Energy carrier

Biochar mixed with liquid media such as water or organic liquids (ethanol, etc) is an emerging fuel type known as biochar-based slurry.[110] Adapting slow pyrolysis in large biomass fields and installations enables the generation of biochar slurries with unique characteristics. These slurries are becoming promising fuels in countries with regional areas where biomass is abundant, and power supply relies heavily on diesel generators. [111] This type of fuel resembles a coal slurry, but with the advantage that it can be derived from biochar from renewable resources.

Research

Agricultural worker distributing biochar over a planting plot
Biochar applied to the soil in research trials in Namibia

Research into aspects involving pyrolysis/biochar is underway around the world, but (As of 2018) was still in its infancy.[59] From 2005 to 2012, 1,038 articles included the word "biochar" or "bio-char" in the topic indexed in the ISI Web of Science.[112] Research is in progress by Cornell University, University of Edinburgh (which has a dedicated research unit),[113] University of Georgia,[114][115] the Agricultural Research Organization (ARO) of Israel, Volcani Center,[116] the Swedish University of Agricultural Sciences,[117] and University of Delaware.

Long-term effects of biochar on carbon sequestration have been examined using soil from arable fields in Belgium with charcoal-enriched black spots dating from before 1870 from charcoal production mound kilns. Topsoils from these 'black spots' had a higher organic C concentration [3.6 ± 0.9% organic carbon (OC)] than adjacent soils outside these black spots (2.1 ± 0.2% OC). The soils had been cropped with maize for at least 12 years which provided a continuous input of C with a C isotope signature (δ13C) −13.1, distinct from the δ13C of soil organic carbon (−27.4 ‰) and charcoal (−25.7 ‰) collected in the surrounding area. The isotope signatures in the soil revealed that maize-derived C concentration was significantly higher in charcoal-amended samples ('black spots') than in adjacent unamended ones (0.44% vs. 0.31%; p = 0.02). Topsoils were subsequently collected as a gradient across two 'black spots' along with corresponding adjacent soils outside these black spots and soil respiration, and physical soil fractionation was conducted. Total soil respiration (130 days) was unaffected by charcoal, but the maize-derived C respiration per unit maize-derived OC in soil significantly decreased about half (p < 0.02) with increasing charcoal-derived C in soil. Maize-derived C was proportionally present more in protected soil aggregates in the presence of charcoal. The lower specific mineralization and increased C sequestration of recent C with charcoal are attributed to a combination of physical protection, C saturation of microbial communities and, potentially, slightly higher annual primary production. Overall, this study evidences the capacity of biochar to enhance C sequestration through reduced C turnover.[118]

Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. Laboratory studies have evidenced effects of biochar on C-mineralization using 13C signatures.[119]

Fluorescence analysis of biochar-amended soil dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-carbon in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-carbon in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar. The co-localization of aromatic-C: polysaccharides-C was consistently reduced upon biochar application. These finding suggested that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.[120]

Research and practical investigations into the potential of biochar for coarse soils in semi-arid and degraded ecosystems are ongoing. In Namibia biochar is under exploration as climate change adaptation effort, strengthening local communities' drought resilience and food security through the local production and application of biochar from abundant encroacher biomass.[121]

In recent years, biochar has attracted interest as a wastewater filtration medium as well as for its adsorbing capacity for the wastewater pollutants, such as pharmaceuticals, personal care products,[122] and per- and polyfluoroalkyl substances.[123][124][125]

In some areas, citizen interest and support for biochar motivates government research into the uses of biochar.[126][127]

See also

References

  1. Khedulkar, Akhil Pradiprao; Dang, Van Dien; Thamilselvan, Annadurai; Doong, Ruey-an; Pandit, Bidhan (2024-01-30). "Sustainable high-energy supercapacitors: Metal oxide-agricultural waste biochar composites paving the way for a greener future". Journal of Energy Storage 77: 109723. doi:10.1016/j.est.2023.109723. ISSN 2352-152X. 
  2. 2.0 2.1 "Standardized production definition and product testing guidelines for biochar that is used in soil". 2015. https://www.biochar-international.org/wp-content/uploads/2018/04/IBI_Biochar_Standards_V2.1_Final.pdf. 
  3. 3.0 3.1 Lean, Geoffrey (7 December 2008). "Ancient skills 'could reverse global warming'". The Independent. https://www.independent.co.uk/environment/climate-change/ancient-skills-could-reverse-global-warming-1055700.html. 
  4. Constanze Werner, Hans-Peter Schmidt, Dieter Gerten, Wolfgang Lucht und Claudia Kammann (2018). Biogeochemical potential of biomass pyrolysis systems for limiting global warming to 1.5 °C. Environmental Research Letters, 13(4), 044036. doi.org/10.1088/1748-9326/aabb0e
  5. Yousaf, Balal; Liu, Guijian; Wang, Ruwei; Abbas, Qumber; Imtiaz, Muhammad; Liu, Ruijia (2016). "Investigating the biochar effects on C-mineralization and sequestration of carbon in soil compared with conventional amendments using stable isotope (δ13C) approach". Global Change Biology Bioenergy 9 (6): 1085–1099. doi:10.1111/gcbb.12401. 
  6. "Geoengineering the climate: science, governance and uncertainty". The Royal Society. 2009. http://royalsociety.org/Geoengineering-the-climate/. 
  7. 7.0 7.1 7.2 Dominic Woolf; James E. Amonette; F. Alayne Street-Perrott; Johannes Lehmann; Stephen Joseph (August 2010). "Sustainable biochar to mitigate global climate change". Nature Communications 1 (5): 56. doi:10.1038/ncomms1053. ISSN 2041-1723. PMID 20975722. Bibcode2010NatCo...1...56W. 
  8. "Slash and Char". http://www.biochar.org/joomla/index2.php?option=com_content&do_pdf=1&id=24. 
  9. biochar (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=biochar  (Subscription or UK public library membership required.)
  10. Solomon, Dawit; Lehmann, Johannes; Thies, Janice; Schäfer, Thorsten; Liang, Biqing; Kinyangi, James; Neves, Eduardo; Petersen, James et al. (May 2007). "Molecular signature and sources of biochemical recalcitrance of organic C in Amazonian Dark Earths". Geochimica et Cosmochimica Acta 71 (9): 2285–2298. doi:10.1016/j.gca.2007.02.014. ISSN 0016-7037. Bibcode2007GeCoA..71.2285S. http://dx.doi.org/10.1016/j.gca.2007.02.014. Retrieved 9 August 2021. ""Amazonian Dark Earths (ADE) are a unique type of soils apparently developed between 500 and 9000 years B.P. through intense anthropogenic activities such as biomass-burning and high-intensity nutrient depositions on pre-Columbian Amerindian settlements that transformed the original soils into Fimic Anthrosols throughout the Brazilian Amazon Basin". 
  11. 11.0 11.1 11.2 11.3 Lehmann 2007a, pp. 381–387 Similar soils are found, more scarcely, elsewhere in the world. To date, scientists have been unable to completely reproduce the beneficial growth properties of terra preta. It is hypothesized that part of the alleged benefits of terra preta require the biochar to be aged so that it increases the cation exchange capacity of the soil, among other possible effects. In fact, there is no evidence natives made biochar for soil treatment, but rather for transportable fuel charcoal; there is little evidence for any hypothesis accounting for the frequency and location of terra preta patches in Amazonia. Abandoned or forgotten charcoal pits left for centuries were eventually reclaimed by the forest. In that time, the initially harsh negative effects of the char (high pH, extreme ash content, salinity) wore off and turned positive as the forest soil ecosystem saturated the charcoals with nutrients. supra note 2 at 386 ("Only aged biochar shows high cation retention, as in Amazonian Dark Earths. At high temperatures (30–70 °C), cation retention occurs within a few months. The production method that would attain high CEC in soil in cold climates is not currently known.") (internal citations omitted).
  12. Glaser, Lehmann & Zech 2002, pp. 219–220 "These so-called Terra Preta do Indio (Terra Preta) characterize the settlements of pre-Columbian Indios. In Terra Preta soils large amounts of black C indicate a high and prolonged input of carbonized organic matter probably due to the production of charcoal in hearths, whereas only low amounts of charcoal are added to soils as a result of forest fires and slash-and-burn techniques." (internal citations omitted)
  13. Jean-François Ponge; Stéphanie Topoliantz; Sylvain Ballof; Jean-Pierre Rossi; Patrick Lavelle; Jean-Marie Betsch; Philippe Gaucher (2006). "Ingestion of charcoal by the Amazonian earthworm Pontoscolex corethrurus: a potential for tropical soil fertility". Soil Biology and Biochemistry 38 (7): 2008–2009. doi:10.1016/j.soilbio.2005.12.024. https://hal.archives-ouvertes.fr/hal-00495398/file/Article_SBB.pdf. Retrieved 24 January 2016. 
  14. Amonette, James E; Blanco-Canqui, Humberto; Hassebrook, Chuck; Laird, David A; Lal, Rattan; Lehmann, Johannes; Page-Dumroese, Deborah (January 2021). "Integrated biochar research: A roadmap". Journal of Soil and Water Conservation 76 (1): 24A–29A. doi:10.2489/jswc.2021.1115A. https://www.jswconline.org/content/76/1/24A. "Large-scale wood gasifiers used to generate bioenergy, however, are relatively common and currently provide the majority of the biochar sold in the United States. Consequently, one of these full-scale facilities would be used to produce a standard wood biochar made from the same feedstock to help calibrate results across the regional sites.". 
  15. Akhtar, Ali; Krepl, Vladimir; Ivanova, Tatiana (July 5, 2018). "A Combined Overview of Combustion, Pyrolysis, and Gasification of Biomass". Energy Fuels 32 (7): 7294–7318. doi:10.1021/acs.energyfuels.8b01678. 
  16. Rollinson, Andrew N (1 August 2016). "Gasification reactor engineering approach to understanding the formation of biochar properties". Proceedings of the Royal Society 472 (2192). doi:10.1098/rspa.2015.0841. PMID 27616911. Bibcode2016RSPSA.47250841R. "Figure 1. Schematic of downdraft gasifier reactor used for char production showing (temperatures) energy transfer mechanisms and thermal stratification. (and) Many authors define highest treatment temperature (HTT) during pyrolysis as an important parameter for char characterization.". 
  17. Tripathi, Manoj; Sabu, J.N.; Ganesan, P. (21 November 2015). "Effect of process parameters on production of biochar from biomass waste through pyrolysis: A review". Renewable and Sustainable Energy Reviews 55: 467–481. doi:10.1016/j.rser.2015.10.122. ISSN 1364-0321. 
  18. Gaunt & Lehmann 2008, pp. 4152, 4155 ("Assuming that the energy in syngas is converted to electricity with an efficiency of 35%, the recovery in the life cycle energy balance ranges from 92 to 274 kg CO2 MWn−1 of electricity generated where the pyrolysis process is optimized for energy and 120 to 360 kg CO
    2
    MWn−1 where biochar is applied to land. This compares to emissions of 600–900 kg CO2 MWh−1 for fossil-fuel-based technologies.)
  19. 19.0 19.1 Winsley, Peter (2007). "Biochar and bioenergy production for climate change mitigation". New Zealand Science Review 64.  (See Table 1 for differences in output for Fast, Intermediate, Slow, and Gasification).
  20. Aysu, Tevfik; Küçük, M. Maşuk (16 December 2013). "Biomass pyrolysis in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and characterization of products". Energy 64 (1): 1002–1025. doi:10.1016/j.energy.2013.11.053. ISSN 0360-5442. 
  21. Laird 2008, pp. 100, 178–181 "The energy required to operate a fast pyrolyzer is ≈15% of the total energy that can be derived from the dry biomass. Modern systems are designed to use the syngas generated by the pyrolyzer to provide all the energy needs of the pyrolyzer."
  22. Kambo, Harpreet Singh; Dutta, Animesh (14 February 2015). "A comparative review of biochar and hydrochar in terms of production, physicochemical properties and applications". Renewable and Sustainable Energy Reviews 45: 359–378. doi:10.1016/j.rser.2015.01.050. ISSN 1364-0321. 
  23. Lee, Jechan; Sarmah, Ajit K.; Kwon, Eilhann E. (2019). Biochar from biomass and waste - Fundamentals and applications. Elsevier. pp. 1–462. doi:10.1016/C2016-0-01974-5. ISBN 978-0-12-811729-3. https://www.sciencedirect.com/book/9780128117293/biochar-from-biomass-and-waste. Retrieved 23 March 2019. 
  24. Bora, Raaj R.; Tao, Yanqiu; Lehmann, Johannes; Tester, Jefferson W.; Richardson, Ruth E.; You, Fengqi (2020-04-13). "Techno-Economic Feasibility and Spatial Analysis of Thermochemical Conversion Pathways for Regional Poultry Waste Valorization". ACS Sustainable Chemistry & Engineering 8 (14): 5763–5775. doi:10.1021/acssuschemeng.0c01229. https://doi.org/10.1021/acssuschemeng.0c01229. 
  25. Bora, Raaj R.; Lei, Musuizi; Tester, Jefferson W.; Lehmann, Johannes; You, Fengqi (2020-06-08). "Life Cycle Assessment and Technoeconomic Analysis of Thermochemical Conversion Technologies Applied to Poultry Litter with Energy and Nutrient Recovery". ACS Sustainable Chemistry & Engineering 8 (22): 8436–8447. doi:10.1021/acssuschemeng.0c02860. https://doi.org/10.1021/acssuschemeng.0c02860. 
  26. "XPrize-winning team sources fresh water from the air". KCRW. 24 October 2018. https://www.kcrw.com/news-culture/shows/design-and-architecture/xprize-winning-team-sources-fresh-water-from-the-air. Retrieved 26 October 2018. 
  27. "We Won - All Power Labs". 8 December 2018. https://www.allpowerlabs.com/news/we-won.html. Retrieved 30 October 2022. 
  28. Scholz, Sebastian B.; Sembres, Thomas; Roberts, Kelli; Whitman, Thea; Wilson, Kelpie; Lehmann, Johannes (2014-06-23) (in en). Biochar Systems for Smallholders in Developing Countries: Leveraging Current Knowledge and Exploring Future Potential for Climate-Smart Agriculture. The World Bank. doi:10.1596/978-0-8213-9525-7. ISBN 978-0-8213-9525-7. http://elibrary.worldbank.org/doi/book/10.1596/978-0-8213-9525-7. 
  29. (in en) Top Down Burn of Maize Stalks - Less Smoke - Make Biochar, https://www.youtube.com/watch?v=5M4ntJi_JmY, retrieved 2022-12-17 
  30. (in en) STOP BURNING BRUSH!, Make Easy Biochar, Every Pile is an Opportunity!, https://www.youtube.com/watch?v=ixtxNfU9Rb8, retrieved 2022-12-17 
  31. "Top-Down Burn with Maize Stalks - Trials in Malawi.docx" (in en). https://docs.google.com/document/d/15ANxl15r8RM5fi27TcLKO7kXeLJsuUSA/edit?usp=sharing&ouid=112234683056230543280&rtpof=true&sd=true&usp=embed_facebook. 
  32. Crowe, Robert (2011-10-31). "Could Biomass Technology Help Commercialize Biochar?" (in en-US). https://www.renewableenergyworld.com/storage/could-biomass-technology-help-commercialize-biochar/. 
  33. Menezes, Bruna Rafaela da Silva; Daher, Rogério Figueiredo; Gravina, Geraldo de Amaral; Pereira, Antônio Vander; Pereira, Messias Gonzaga; Tardin, Flávio Dessaune (2016-09-20). "Combining ability in elephant grass (Pennisetum purpureum Schum.) for energy biomass production". Australian Journal of Crop Science 10 (9): 1297–1305. doi:10.21475/ajcs.2016.10.09.p7747. http://www.cropj.com/meneze_10_9_2016_1297_1305.pdf. Retrieved 3 May 2019. 
  34. "Production Quantity Of Sugar Cane In Brazil In 2006". FAOSTAT. 2006. http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567. 
  35. "06/00891 Assessment of sustainable energy potential of non-plantation biomass resources in Sri Lanka". Fuel and Energy Abstracts 47 (2): 131. March 2006. doi:10.1016/s0140-6701(06)80893-3. ISSN 0140-6701. http://dx.doi.org/10.1016/s0140-6701(06)80893-3. Retrieved 9 August 2021.  (showing RPRs for numerous plants, describing method for determining available agricultural waste for energy and char production).
  36. Laird 2008, pp. 179 "Much of the current scientific debate on the harvesting of biomass for bioenergy is focused on how much can be harvested without doing too much damage."
  37. O'Sullivan, Feargus (20 December 2016). "Stockholm's Ingenious Plan to Recycle Yard Waste". https://www.citylab.com/solutions/2016/12/stockholm-throw-out-old-christmas-trees-biochar-environment/511196/. 
  38. Austin, Anna (October 2009). "A New Climate Change Mitigation Tool". Biomass Magazine (BBI International). http://www.biomassmagazine.com/article.jsp?article_id=3091&q=&page=all. 
  39. Karagöz, Selhan; Bhaskar, Thallada; Muto, Akinori; Sakata, Yusaku; Oshiki, Toshiyuki; Kishimoto, Tamiya (1 April 2005). "Low-temperature catalytic hydrothermal treatment of wood biomass: analysis of liquid products". Chemical Engineering Journal 108 (1–2): 127–137. doi:10.1016/j.cej.2005.01.007. ISSN 1385-8947. 
  40. Jha, Alok (13 March 2009). "'Biochar' goes industrial with giant microwaves to lock carbon in charcoal". The Guardian. https://www.theguardian.com/environment/2009/mar/13/charcoal-carbon. 
  41. Crombie, Kyle; Mašek, Ondřej; Sohi, Saran P.; Brownsort, Peter; Cross, Andrew (21 December 2012). "The effect of pyrolysis conditions on biochar stability as determined by three methods". Global Change Biology Bioenergy 5 (2): 122–131. doi:10.1111/gcbb.12030. ISSN 1757-1707. https://www.pure.ed.ac.uk/ws/files/14931650/Crombie_et_al_2013_Author_copy.pdf. Retrieved 1 September 2020. 
  42. Krevelen D., van (1950). "Graphical-statistical method for the study of structure and reaction processes of coal". Fuel 29: 269–284. https://ci.nii.ac.jp/naid/10027945730/en/. Retrieved 24 February 2019. 
  43. Weber, Kathrin; Quicker, Peter (1 April 2018). "Properties of biochar". Fuel 217: 240–261. doi:10.1016/j.fuel.2017.12.054. ISSN 0016-2361. 
  44. Mochidzuki, Kazuhiro; Soutric, Florence; Tadokoro, Katsuaki; Antal, Michael Jerry; Tóth, Mária; Zelei, Borbála; Várhegyi, Gábor (2003). "Electrical and Physical Properties of Carbonized Charcoals". Industrial & Engineering Chemistry Research 42 (21): 5140–5151. doi:10.1021/ie030358e. https://pubs.acs.org/doi/abs/10.1021/ie030358e. "(observed five) orders of magnitude decrease in the electrical resistivity of charcoal with increasing HTT from 650 to 1050°C". 
  45. Kwon, Jin Heon; Park, Sang Bum; Ayrilmis, Nadir; Oh, Seung Won; Kim, Nam Hun (2013). "Effect of carbonization temperature on electrical resistivity and physical properties of wood and wood-based composites". Composites Part B: Engineering 46: 102–107. doi:10.1016/j.compositesb.2012.10.012. https://www.sciencedirect.com/science/article/pii/S135983681200666X. "When carbonized under 500 °C, wood charcoal can be used as electric insulation". 
  46. "Electrical Conductivity of Wood-derived Nanoporous Monolithic Biochar". https://tspace.library.utoronto.ca/bitstream/1807/110772/1/Gabhi_Randeep_Singh_202203_MAS_thesis.pdf. "The conductivity of all biochar increases with increase in heating temperature, due to increasing degree of carbonization and degree of graphitization" 
  47. Budai, Alice; Rasse, Daniel P.; Lagomarsino, Alessandra; Lerch, Thomas Z.; Paruch, Lisa (2016). "Biochar persistence, priming and microbial responses to pyrolysis temperature series". Biology and Fertility of Soils 52 (6): 749–761. doi:10.1007/s00374-016-1116-6. Bibcode2016BioFS..52..749B. "...biochars produced at higher temperatures contain more aromatic structures, which confer intrinsic recalcitrance...". 
  48. Laird 2008, pp. 100, 178–181
  49. Lehmann, Johannes. "Terra Preta de Indio". Soil Biochemistry (Internal Citations Omitted). http://www.css.cornell.edu/faculty/lehmann/research/terra%20preta/terrapretamain.html. Retrieved 15 September 2009.  Not only do biochar-enriched soils contain more carbon - 150gC/kg compared to 20-30gC/kg in surrounding soils - but biochar-enriched soils are, on average, more than twice as deep as surrounding soils.[citation needed]
  50. Lehmann 2007b "this sequestration can be taken a step further by heating the plant biomass without oxygen (a process known as low-temperature pyrolysis)."
  51. Lehmann 2007a, pp. 381, 385 "pyrolysis produces 3–9 times more energy than is invested in generating the energy. At the same time, about half of the carbon can be sequestered in soil. The total carbon stored in these soils can be one order of magnitude higher than adjacent soils.
  52. Winsley, Peter (2007). "Biochar and Bioenergy Production for Climate Change Mitigation". New Zealand Science Review 64 (5): 5. http://www.biochar-international.org/images/NZSR64_1_Winsley.pdf. Retrieved 10 July 2008. 
  53. Kern, DC; de LP Ruivo, M; Frazão, FJL (2009), "Terra Preta Nova: The Dream of Wim Sombroek", Amazonian Dark Earths: Wim Sombroek's Vision (Dordrecht: Springer Netherlands): pp. 339–349, doi:10.1007/978-1-4020-9031-8_18, ISBN 978-1-4020-9030-1, http://dx.doi.org/10.1007/978-1-4020-9031-8_18, retrieved 2021-08-09 
  54. Ogawa, Makoto; Okimori, Yasuyuki; Takahashi, Fumio (2006-03-01). "Carbon Sequestration by Carbonization of Biomass and Forestation: Three Case Studies" (in en). Mitigation and Adaptation Strategies for Global Change 11 (2): 429–444. doi:10.1007/s11027-005-9007-4. ISSN 1573-1596. Bibcode2006MASGC..11..429O. https://doi.org/10.1007/s11027-005-9007-4. 
  55. Lehmann, Johannes; Gaunt, John; Rondon, Marco (2006-03-01). "Bio-char Sequestration in Terrestrial Ecosystems – A Review" (in en). Mitigation and Adaptation Strategies for Global Change 11 (2): 403–427. doi:10.1007/s11027-005-9006-5. ISSN 1573-1596. Bibcode2006MASGC..11..403L. https://doi.org/10.1007/s11027-005-9006-5. 
  56. Möllersten, K.; Chladna, Z.; Chladny, M.; Obersteiner, M. (2006), Warnmer, S. F., ed., "Negative emission biomass technologies in an uncertain climate future", Progress in biomass and bioenergy research (NY: Nova Science Publishers), ISBN 978-1-60021-328-1, https://kth.diva-portal.org/smash/record.jsf?pid=diva2%3A1813115&dswid=-8586, retrieved 2023-11-23 
  57. Hamilton, Tyler (22 June 2009). "Sole option is to adapt, climate author says". The Star (Toronto). https://www.thestar.com/sciencetech/article/654444. 
  58. Vince 2009
  59. 59.0 59.1 "Final Report on fertilisers". https://ec.europa.eu/info/sites/default/files/food-farming-fisheries/farming/documents/final-report-egtop-fertilizers-iii_en.pdf. 
  60. Lehmann, Johannes; Cowie, Annette; Masiello, Caroline A.; Kammann, Claudia; Woolf, Dominic; Amonette, James E.; Cayuela, Maria L.; Camps-Arbestain, Marta et al. (December 2021). "Biochar in climate change mitigation" (in en). Nature Geoscience 14 (12): 883–892. doi:10.1038/s41561-021-00852-8. ISSN 1752-0908. Bibcode2021NatGe..14..883L. https://www.nature.com/articles/s41561-021-00852-8. 
  61. Journal, Amrith Ramkumar | Photographs by Alexandra Hootnick for The Wall Street (25 February 2023). "Ancient Farming Practice Draws Cash From Carbon Credits". Wall Street Journal. https://www.wsj.com/articles/ancient-farming-practice-draws-cash-from-carbon-credits-a803aee1. 
  62. Karan, Shivesh Kishore; Woolf, Dominic; Azzi, Elias Sebastian; Sundberg, Cecilia; Wood, Stephen A. (December 2023). "Potential for biochar carbon sequestration from crop residues: A global spatially explicit assessment" (in en). GCB Bioenergy 15 (12): 1424–1436. doi:10.1111/gcbb.13102. ISSN 1757-1693. Bibcode2023GCBBi..15.1424K. https://onlinelibrary.wiley.com/doi/10.1111/gcbb.13102. 
  63. Fawzy, Samer; Osman, Ahmed I.; Yang, Haiping; Doran, John; Rooney, David W. (2021-08-01). "Industrial biochar systems for atmospheric carbon removal: a review" (in en). Environmental Chemistry Letters 19 (4): 3023–3055. doi:10.1007/s10311-021-01210-1. ISSN 1610-3661. Bibcode2021EnvCL..19.3023F. 
  64. "Greenhouse Gas Removals: Summary of Responses to the Call for Evidence". https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1026494/ggr-cfe-summary-of-responses.pdf. 
  65. Sundberg, Cecilia; Karltun, Erik; Gitau, James K.; Kätterer, Thomas; Kimutai, Geoffrey M.; Mahmoud, Yahia; Njenga, Mary; Nyberg, Gert et al. (2020-08-01). "Biochar from cookstoves reduces greenhouse gas emissions from smallholder farms in Africa" (in en). Mitigation and Adaptation Strategies for Global Change 25 (6): 953–967. doi:10.1007/s11027-020-09920-7. ISSN 1573-1596. Bibcode2020MASGC..25..953S. 
  66. Vijay, Vandit; Shreedhar, Sowmya; Adlak, Komalkant; Payyanad, Sachin; Sreedharan, Vandana; Gopi, Girigan; Sophia van der Voort, Tessa; Malarvizhi, P et al. (2021). "Review of Large-Scale Biochar Field-Trials for Soil Amendment and the Observed Influences on Crop Yield Variations". Frontiers in Energy Research 9: 499. doi:10.3389/fenrg.2021.710766. ISSN 2296-598X. 
  67. "Interview with Dr Elaine Ingham - NEEDFIRE". 2015-02-17. http://www.needfire.info/home/interview-with-dr-elaine-ingham. 
  68. Bolster, C.H.; Abit, S.M. (2012). "Biochar pyrolyzed at two temperatures affects Escherichia coli transport through a sandy soil". Journal of Environmental Quality 41 (1): 124–133. doi:10.2134/jeq2011.0207. PMID 22218181. Bibcode2012JEnvQ..41..124B. 
  69. Abit, S.M.; Bolster, C.H.; Cai, P.; Walker, S.L. (2012). "Influence of feedstock and pyrolysis temperature of biochar amendments on transport of Escherichia coli in saturated and unsaturated soil". Environmental Science & Technology 46 (15): 8097–8105. doi:10.1021/es300797z. PMID 22738035. Bibcode2012EnST...46.8097A. 
  70. Abit, S.M.; Bolster, C.H.; Cantrell, K.B.; Flores, J.Q.; Walker, S.L. (2014). "Transport of Escherichia coli, Salmonella typhimurium, and microspheres in biochar-amended soils with different textures". Journal of Environmental Quality 43 (1): 371–378. doi:10.2134/jeq2013.06.0236. PMID 25602571. Bibcode2014JEnvQ..43..371A. 
  71. Lehmann, Johannes; Pereira da Silva, Jose; Steiner, Christoph; Nehls, Thomas; Zech, Wolfgang; Glaser, Bruno (2003-02-01). "Nutrient availability and leaching in an archaeological Anthrosol and a Ferralsol of the Central Amazon basin: fertilizer, manure and charcoal amendments" (in en). Plant and Soil 249 (2): 343–357. doi:10.1023/A:1022833116184. ISSN 1573-5036. https://doi.org/10.1023/A:1022833116184. Retrieved 16 August 2021. 
  72. Tenic, E.; Ghogare, R.; Dhingra, A. (2020). "Biochar—A Panacea for Agriculture or Just Carbon?". Horticulturae 6 (3): 37. doi:10.3390/horticulturae6030037. 
  73. Joseph, Stephen; Cowie, Annette L.; Zwieten, Lukas Van; Bolan, Nanthi; Budai, Alice; Buss, Wolfram; Cayuela, Maria Luz; Graber, Ellen R. et al. (2021). "How biochar works, and when it doesn't: A review of mechanisms controlling soil and plant responses to biochar" (in en). GCB Bioenergy 13 (11): 1731–1764. doi:10.1111/gcbb.12885. ISSN 1757-1707. Bibcode2021GCBBi..13.1731J. 
  74. "06/00595 Economical CO2, SOx, and NOx capture from fossil-fuel utilization with combined renewable hydrogen production and large-scale carbon sequestration". Fuel and Energy Abstracts 47 (2): 92. March 2006. doi:10.1016/s0140-6701(06)80597-7. ISSN 0140-6701. http://dx.doi.org/10.1016/s0140-6701(06)80597-7. Retrieved 9 August 2021. 
  75. Elad, Y.; Rav David, D.; Meller Harel, Y.; Borenshtein, M.; Kalifa Hananel, B.; Silber, A.; Graber, E.R. (2010). "Induction of systemic resistance in plants by biochar, a soil-applied carbon sequestering agent". Phytopathology 100 (9): 913–921. doi:10.1094/phyto-100-9-0913. PMID 20701489. 
  76. Meller Harel, Yael; Elad, Yigal; Rav-David, Dalia; Borenstein, Menachem; Shulchani, Ran; Lew, Beni; Graber, Ellen R. (2012-02-25). "Biochar mediates systemic response of strawberry to foliar fungal pathogens". Plant and Soil 357 (1–2): 245–257. doi:10.1007/s11104-012-1129-3. ISSN 0032-079X. Bibcode2012PlSoi.357..245M. http://dx.doi.org/10.1007/s11104-012-1129-3. Retrieved 16 August 2021. 
  77. 77.0 77.1 Jaiswal, A.K.; Elad, Y.; Graber, E.R.; Frenkel, O. (2014). "Rhizoctonia solani suppression and plant growth promotion in cucumber as affected by biochar pyrolysis temperature, feedstock and concentration". Soil Biology and Biochemistry 69: 110–118. doi:10.1016/j.soilbio.2013.10.051. 
  78. Silber, A.; Levkovitch, I.; Graber, E. R. (2010). "pH-dependent mineral release and surface properties of corn straw biochar: Agronomic implications". Environmental Science & Technology 44 (24): 9318–9323. doi:10.1021/es101283d. PMID 21090742. Bibcode2010EnST...44.9318S. https://figshare.com/articles/pH_Dependent_Mineral_Release_and_Surface_Properties_of_Cornstraw_Biochar_Agronomic_Implications/2704741. 
  79. Glaser, Lehmann & Zech 2002, pp. 224 note 7 "Three main factors influence the properties of charcoal: (1) the type of organic matter used for charring, (2) the charring environment (e.g. temperature, air), and (3) additions during the charring process. The source of charcoal material strongly influences the direct effects of charcoal amendments on nutrient contents and availability."
  80. Dr. Wardle points out that improved plant growth has been observed in tropical (depleted) soils by referencing Lehmann, but that in the boreal (high native soil organic matter content) forest this experiment was run in, it accelerated the native soil organic matter loss. Wardle, supra note 18. ("Although several studies have recognized the potential of black C for enhancing ecosystem carbon sequestration, our results show that these effects can be partially offset by its capacity to stimulate loss of native soil C, at least for boreal forests.") (internal citations omitted) (emphasis added).
  81. "Biochar decreased N2O emissions from soils. [Social Impact. FERTIPLUS. Reducing mineral fertilisers and agro-chemicals by recycling treated organic waste as compost and biochar products (2011-2015). Framework Programme 7 (FP7)."]. http://sior.ub.edu/jspui/cris/socialimpact/socialimpact00542. 
  82. Lehmann 2007a, pp. note 3 at 384 "In greenhouse experiments, NOx emissions were reduced by 80% and methane emissions were completely suppressed with biochar additions of 20 g kg-1 (2%) to a forage grass stand."
  83. "Biochar fact sheet". csiro.au. http://www.csiro.au/resources/Biochar-Factsheet.html. 
  84. 84.0 84.1 "Improvement of soil quality. [Social Impact. FERTIPLUS. Reducing mineral fertilisers and agro-chemicals by recycling treated organic waste as compost and biochar products (2011-2015). Framework Programme 7 (FP7)."]. http://sior.ub.edu/jspui/cris/socialimpact/socialimpact00544. 
  85. Novak, Jeff. "Development of Designer Biochar to Remediate Specific Chemical and Physical Aspects of Degraded Soils. Proc. of North American Biochar Conference 2009". https://www.ars.usda.gov/research/publications/publication/?seqNo115=238024. 
  86. Major, Julie; Rondon, Marco; Molina, Diego; Riha, Susan J.; Lehmann, Johannes (July 2012). "Nutrient Leaching in a Colombian Savanna Oxisol Amended with Biochar". Journal of Environmental Quality 41 (4): 1076–1086. doi:10.2134/jeq2011.0128. ISSN 0047-2425. PMID 22751049. Bibcode2012JEnvQ..41.1076M. http://dx.doi.org/10.2134/jeq2011.0128. 
  87. Elmer, Wade, Jason C. White, and Joseph J. Pignatello. Impact of Biochar Addition to Soil on the Bioavailability of Chemicals Important in Agriculture. Rep. New Haven: University of Connecticut, 2009. Print.
  88. 88.0 88.1 Graber, E. R.; Tsechansky, L.; Gerstl, Z.; Lew, B. (2011-10-15). "High surface area biochar negatively impacts herbicide efficacy". Plant and Soil 353 (1–2): 95–106. doi:10.1007/s11104-011-1012-7. ISSN 0032-079X. http://dx.doi.org/10.1007/s11104-011-1012-7. Retrieved 16 August 2021. 
  89. Graber, E. R.; Tsechansky, L.; Khanukov, J.; Oka, Y. (July 2011). "Sorption, Volatilization, and Efficacy of the Fumigant 1,3-Dichloropropene in a Biochar-Amended Soil". Soil Science Society of America Journal 75 (4): 1365–1373. doi:10.2136/sssaj2010.0435. ISSN 0361-5995. Bibcode2011SSASJ..75.1365G. http://dx.doi.org/10.2136/sssaj2010.0435. 
  90. "Biochar Market Report by Feedstock Type (Woody Biomass, Agricultural Waste, Animal Manure, and Others), Technology Type (Slow Pyrolysis, Fast Pyrolysis, Gasification, Hydrothermal Carbonization, and Others), Product Form (Coarse and Fine Chips, Fine Powder, Pellets, Granules and Prills, Liquid Suspension), Application (Farming, Gardening, Livestock Feed, Soil, Water and Air Treatment, and Others), and Region 2023-2028". IMARC Services Private Limited. https://www.imarcgroup.com/biochar-market. 
  91. Allohverdi, Tara; Kumar Mohanty, Amar; Roy, Poritosh; Misra, Manjusri (14 September 2021). "A Review on Current Status of Biochar Uses in Agriculture". Molecules 26 (18): 5584. doi:10.3390/molecules26185584. PMID 34577054. 
  92. Schmidt, Hans-Peter; Hagemann, Nikolas; Draper, Kathleen; Kammann, Claudia (2019-07-31). "The use of biochar in animal feeding". PeerJ 7: e7373. doi:10.7717/peerj.7373. ISSN 2167-8359. PMID 31396445. 
  93. Cusack, Mikki (2020-02-07). "Can charcoal make beef better for the environment?" (in en). https://www.bbc.com/future/article/20200206-can-charcoal-cut-cows-methane-to-fight-climate-change. 
  94. Joseph, S; Graber, ER; Chia, C; Munroe, P; Donne, S; Thomas, T; Nielsen, S; Marjo, C et al. (June 2013). "Shifting paradigms: development of high-efficiency biochar fertilizers based on nano-structures and soluble components". Carbon Management 4 (3): 323–343. doi:10.4155/cmt.13.23. ISSN 1758-3004. Bibcode2013CarM....4..323J. http://dx.doi.org/10.4155/cmt.13.23. 
  95. Glaser, Lehmann & Zech 2002, pp. note 7 at 225 "The published data average at about 3% charcoal formation of the original biomass C."
  96. Lehmann, Johannes; Gaunt, John; Rondon, Marco (March 2006). "Bio-char Sequestration in Terrestrial Ecosystems – A Review". Mitigation and Adaptation Strategies for Global Change 11 (2): 403–427. doi:10.1007/s11027-005-9006-5. ISSN 1381-2386. Bibcode2006MASGC..11..403L. http://dx.doi.org/10.1007/s11027-005-9006-5. "supra note 11 at 407 ("If this woody above-ground biomass were converted into biochar by means of simple kiln techniques and applied to soil, more than 50% of this carbon would be sequestered in a highly stable form.")". 
  97. Gaunt & Lehmann 2008, pp. 4152 note 3 ("This results in increased crop yields in low-input agriculture and increased crop yield per unit of fertilizer applied (fertilizer efficiency) in high-input agriculture as well as reductions in off-site effects such as runoff, erosion, and gaseous losses.")
  98. Lehmann 2007b, pp. note 9 at 143 "It can be mixed with manures or fertilizers and included in no-tillage methods, without the need for additional equipment."
  99. Ricigliano, Kristin (2011). "Terra Pretas: Charcoal Amendments Influence on Relict Soils and Modern Agriculture". Journal of Natural Resources and Life Sciences Education 40 (1): 69–72. doi:10.4195/jnrlse.2011.0001se. ISSN 1059-9053. Bibcode2011NScEd..40...69R. http://dx.doi.org/10.4195/jnrlse.2011.0001se. Retrieved 16 August 2021. 
  100. Schmidt, H. P.; Hagemann, N.; Draper, K.; Kammann, C. (2019). "The use of biochar in animal feeding". PeerJ 7: e7373. doi:10.7717/peerj.7373. PMID 31396445. "(During the 19th century and early 20th century) in the USA, charcoal was considered a superior feed additive for increasing butterfat content of milk". 
  101. 101.0 101.1 Daly, Jon (18 October 2019). "Poo-eating beetles and charcoal used by WA farmer to combat climate change". ABC News (Australian Broadcasting Corporation). https://www.abc.net.au/news/rural/2019-10-18/wa-farmer-uses-beetles-and-charcoal-to-combat-climate-change/11613846. "Mr Pow said his innovative farming system could help livestock producers become more profitable while helping to address the impact of climate change." 
  102. "2019 State & Territory Landcare Awards Celebrate Outstanding Landcare Champions". 2019. https://landcareaustralia.org.au/landcareawards2019. 
  103. "Manjimup farmer employing dung beetle to tackle climate-change set to represent WA on national stage". October 2019. https://landcareaustralia.org.au/news/manjimup-farmer-employing-dung-beetle-to-tackle-climate-change-set-to-represent-wa-on-national-stage/. 
  104. "Making Concrete Change: Innovation in Low-carbon Cement and Concrete" (in en). 2018-06-13. https://www.chathamhouse.org/2018/06/making-concrete-change-innovation-low-carbon-cement-and-concrete. 
  105. Arvaniti, Eleni C.; Juenger, Maria C. G.; Bernal, Susan A.; Duchesne, Josée; Courard, Luc; Leroy, Sophie; Provis, John L.; Klemm, Agnieszka et al. (November 2015). "Physical characterization methods for supplementary cementitious materials" (in en). Materials and Structures 48 (11): 3675–3686. doi:10.1617/s11527-014-0430-4. ISSN 1359-5997. http://link.springer.com/10.1617/s11527-014-0430-4. 
  106. 106.0 106.1 Gupta, Souradeep; Kua, Harn Wei; Koh, Hui Jun (2018-04-01). "Application of biochar from food and wood waste as green admixture for cement mortar" (in en). Science of the Total Environment 619-620: 419–435. doi:10.1016/j.scitotenv.2017.11.044. ISSN 0048-9697. PMID 29156263. Bibcode2018ScTEn.619..419G. https://www.sciencedirect.com/science/article/pii/S0048969717331029. 
  107. 107.0 107.1 Suarez-Riera, D.; Restuccia, L.; Ferro, G. A. (2020-01-01). "The use of Biochar to reduce the carbon footprint of cement-based materials" (in en). Procedia Structural Integrity. 1st Mediterranean Conference on Fracture and Structural Integrity, MedFract1 26: 199–210. doi:10.1016/j.prostr.2020.06.023. ISSN 2452-3216. 
  108. Gupta, Souradeep; Kua, Harn Wei; Pang, Sze Dai (2020-02-20). "Effect of biochar on mechanical and permeability properties of concrete exposed to elevated temperature" (in en). Construction and Building Materials 234: 117338. doi:10.1016/j.conbuildmat.2019.117338. ISSN 0950-0618. https://www.sciencedirect.com/science/article/pii/S0950061819327904. 
  109. Campos, J.; Fajilan, S.; Lualhati, J.; Mandap, N.; Clemente, S. (2020-06-01). "Life Cycle Assessment of Biochar as a Partial Replacement to Portland Cement". IOP Conference Series: Earth and Environmental Science 479 (1): 012025. doi:10.1088/1755-1315/479/1/012025. ISSN 1755-1307. Bibcode2020E&ES..479a2025C. 
  110. Cueva Zepeda, Lolita; Griffin, Gregory; Shah, Kalpit; Al-Waili, Ibrahim; Parthasarathy, Rajarathinam (2023-05-01). "Energy potential, flow characteristics and stability of water and alcohol-based rice-straw biochar slurry fuel". Renewable Energy 207: 60–72. doi:10.1016/j.renene.2023.02.104. ISSN 0960-1481. 
  111. Liu, Pengfei; Zhu, Mingming; Zhang, Zhezi; Leong, Yee-Kwong; Zhang, Yang; Zhang, Dongke (2017-02-01). "Rheological behaviour and stability characteristics of biochar-water slurry fuels: Effect of biochar particle size and size distribution". Fuel Processing Technology 156: 27–32. doi:10.1016/j.fuproc.2016.09.030. ISSN 0378-3820. https://www.sciencedirect.com/science/article/pii/S037838201630621X. 
  112. Verheijen, F.G.A.; Graber, E.R.; Ameloot, N.; Bastos, A.C.; Sohi, S.; Knicker, H. (2014). "Biochars in soils: new insights and emerging research needs". European Journal of Soil Science 65 (1): 22–27. doi:10.1111/ejss.12127. Bibcode2014EuJSS..65...22V. 
  113. "UK Biochar Research Centre" (in en). https://www.ed.ac.uk/geosciences/facilities. 
  114. "Can Biochar save the planet?". CNN. http://edition.cnn.com/2009/TECH/science/03/30/biochar.warming.energy/index.html#cnnSTCVideo. 
  115. "Biochar nearly doubles peanut yield in student's research - News and Events". Innovation Lab for Peanut. https://ftfpeanutlab.caes.uga.edu/news-and-events/news/biochar-nearly-doubles-peanut-yield-in-students-research.html. 
  116. "iBRN Israel Biochar Research Network". https://sites.google.com/site/ibrnisraelbiocharnetwork/. 
  117. "SLU Biochar network" (in en). https://www.slu.se/en/Collaborative-Centres-and-Projects/slu-biochar-network/. 
  118. Hernandez-Soriano, Maria C.; Kerré, Bart; Goos, Peter; Hardy, Brieuc; Dufey, Joseph; Smolders, Erik (2016). "Long-term effect of biochar on the stabilization of recent carbon: soils with historical inputs of charcoal" (in en). GCB Bioenergy 8 (2): 371–381. doi:10.1111/gcbb.12250. ISSN 1757-1707. Bibcode2016GCBBi...8..371H. https://onlinelibrary.wiley.com/doi/abs/10.1111/gcbb.12250. Retrieved 9 August 2021. 
  119. Kerré, Bart; Hernandez-Soriano, Maria C.; Smolders, Erik (2016-03-15). "Partitioning of carbon sources among functional pools to investigate short-term priming effects of biochar in soil: A 13C study" (in en). Science of the Total Environment 547: 30–38. doi:10.1016/j.scitotenv.2015.12.107. ISSN 0048-9697. PMID 26780129. Bibcode2016ScTEn.547...30K. https://www.sciencedirect.com/science/article/abs/pii/S0048969715312614. Retrieved 9 August 2021. 
  120. Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik (2016-04-26). "Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study" (in en). Scientific Reports 6 (1): 25127. doi:10.1038/srep25127. ISSN 2045-2322. PMID 27113269. Bibcode2016NatSR...625127H. 
  121. De-bushing Advisory Service Namibia (2020-09-23). "Kick-start for Biochar Value Chain: Practical Guidelines for Producers Now Published". https://www.dasnamibia.org/practical-guidelines-for-producers-now-published/. 
  122. Mukarunyana, Brigitte; Boman, Christoffer; Kabera, Telesphore; Lindgren, Robert; Fick, Jerker (2023-11-01). "The ability of biochars from cookstoves to remove pharmaceuticals and personal care products from hospital wastewater". Environmental Technology & Innovation 32: 103391. doi:10.1016/j.eti.2023.103391. ISSN 2352-1864. 
  123. Dalahmeh, Sahar; Ahrens, Lutz; Gros, Meritxell; Wiberg, Karin; Pell, Mikael (2018-01-15). "Potential of biochar filters for onsite sewage treatment: Adsorption and biological degradation of pharmaceuticals in laboratory filters with active, inactive and no biofilm" (in en). Science of the Total Environment 612: 192–201. doi:10.1016/j.scitotenv.2017.08.178. ISSN 0048-9697. PMID 28850838. Bibcode2018ScTEn.612..192D. https://www.sciencedirect.com/science/article/pii/S0048969717321769. Retrieved 28 September 2021. 
  124. Perez-Mercado, Luis; Lalander, Cecilia; Berger, Christina; Dalahmeh, Sahar (2018-12-12). "Potential of Biochar Filters for Onsite Wastewater Treatment: Effects of Biochar Type, Physical Properties and Operating Conditions" (in en). Water 10 (12): 1835. doi:10.3390/w10121835. ISSN 2073-4441. 
  125. Sörengård, Mattias; Östblom, Erik; Köhler, Stephan; Ahrens, Lutz (2020-06-01). "Adsorption behavior of per- and polyfluoralkyl substances (PFASs) to 44 inorganic and organic sorbents and use of dyes as proxies for PFAS sorption". Journal of Environmental Chemical Engineering 8 (3): 103744. doi:10.1016/j.jece.2020.103744. ISSN 2213-3437. https://www.sciencedirect.com/science/article/pii/S2213343720300920. 
  126. "Biochar-ging Ahead to Engage Citizens in Combating Climate Change". Bloomberg IP Holdings LLC. https://www.bloomberg.org/blog/biochar-ging-ahead-engage-citizens-combating-climate-change/. 
  127. "How You Can Support Biochar Research". https://www.ncat.org/how-you-can-support-biochar-research/. 

118. Biochar, Activated Biochar & Application By: Prof. Dr. H. Ghafourian (Author) Book Amazon

Sources

  • Ameloot, N.; Graber, E.R.; Verheijen, F.; De Neve, S. (2013). "Effect of soil organisms on biochar stability in soil: Review and research needs". European Journal of Soil Science 64 (4): 379–390. doi:10.1111/ejss.12064. 
  • Aysu, Tevfik; Küçük, M. Maşuk (16 December 2013). "Biomass pyrolysis in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and characterization of products". Energy 64 (1): 1002–1025. doi:10.1016/j.energy.2013.11.053. ISSN 0360-5442. 
  • Badger, Phillip C.; Fransham, Peter (2006). "Use of mobile fast pyrolysis plants to densify biomass and reduce biomass handling costs—A preliminary assessment". Biomass & Bioenergy 30 (4): 321–325. doi:10.1016/j.biombioe.2005.07.011. Bibcode2006BmBe...30..321B. 
  • Biederman, Lori A.; W. Stanley Harpole (2011). "Biochar and Managed Perennial Ecosystems". Iowa State Research Farm Progress Reports. http://lib.dr.iastate.edu/farms_reports/136/. Retrieved 12 February 2013. 
  • Brewer, Catherine (2012). Biochar Characterization and Engineering (dissertation). Iowa State University. Retrieved 12 February 2013.
  • Crombie, Kyle; Mašek, Ondřej; Sohi, Saran P.; Brownsort, Peter; Cross, Andrew (21 December 2012). "The effect of pyrolysis conditions on biochar stability as determined by three methods". Global Change Biology Bioenergy 5 (2): 122–131. doi:10.1111/gcbb.12030. ISSN 1757-1707. https://www.pure.ed.ac.uk/ws/files/14931650/Crombie_et_al_2013_Author_copy.pdf. 
  • Gaunt, John L.; Lehmann, Johannes (2008). "Energy Balance and Emissions Associated with Biochar Sequestration and pyrolysis Bioenergy Production". Environmental Science & Technology 42 (11): 4152–4158. doi:10.1021/es071361i. PMID 18589980. Bibcode2008EnST...42.4152G. 
  • Glaser, Bruno; Lehmann, Johannes; Zech, Wolfgang (2002). "Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal – a review". Biology and Fertility of Soils 35 (4): 219–230. doi:10.1007/s00374-002-0466-4. Bibcode2002BioFS..35..219G. 

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