Windeatt, JH, Ross, AB, Williams, PT orcid.org/0000-0003-0401-9326 et al. (3 more authors) (2014) Characteristics of biochars from crop residues: Potential for carbon sequestration and soil amendment. Journal of Environmental Management, 146. pp. 189-197. ISSN 0301-4797
Abstract
Biochar has potential to sequester carbon in soils and simultaneously improve soil quality and plant growth. More understanding of biochar variation is needed to optimise these potential benefits. Slow pyrolysis at 600°C was undertaken to determine how yields and characteristics of biochars differ when produced from eight different agricultural residues. Biochar properties such as carbon content, surface area, pH, ultimate and proximate analysis, nutrient and metal content and the R50 recalcitrance index were determined. Significant variations seen in biochar characteristics were attributed to feedstock variation since pyrolysis conditions were constant. Biochar yields varied from 28% to 39%. Average carbon content was 51%. Ash content of both feedstocks and biochars were correlated with biochar carbon content. Macronutrients were concentrated during pyrolysis, but biochar macronutrient content was low in comparison to biochars produced from more nutrient rich feedstocks. Most biochars were slightly alkaline, ranging from pH 6.1 to pH 11.6. pH was correlated with biochar K content. Aromaticity was increased with pyrolysis, shown by a reduction in biochar H/C and O/C ratios relative to feedstock values. The R50 recalcitrance index showed biochars to be either class 2 or class 3. Biochar carbon sequestration potential was 21.3%-32.5%. The R50 recalcitrance index is influenced by the presence of alkali metals in the biochar which may lead to an under-estimation of biochar stability. The residues assessed here, at current global availability, could produce 373Mt of biochar. This quantity of biochar has the potential to sequester 0.55PgCO2yr-1 in soils over long time periods.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Keywords: | Biochar; Carbon; Crop residue; Pyrolysis; Recalcitrance; Sequestration |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number EPSRC (Engineering and Physical Sciences Research Council) EP/I014721/1 US Department of Energy Project 1552083 Royal Society WRM110067 |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Mar 2015 10:43 |
Last Modified: | 20 Jun 2021 08:37 |
Published Version: | http://dx.doi.org/10.1016/j.jenvman.2014.08.003 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jenvman.2014.08.003 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:83145 |