Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application
Grass and other herbaceous biomass are abundant, but often under- or not utilized as a renewable resource. Here, the production of biochar from extensive late-harvest grass via multiple thermochemical conversion technologies was investigated at lab and farm scale for use in soil applications. While...
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MDPI AG
2023-02-01
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| Online Access: | https://www.mdpi.com/1996-1073/16/4/1896 |
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| author | Thomas Heinrich Korbinian Kaetzl Judy A. Libra Thomas Hoffmann |
| author_facet | Thomas Heinrich Korbinian Kaetzl Judy A. Libra Thomas Hoffmann |
| author_sort | Thomas Heinrich |
| collection | DOAJ |
| description | Grass and other herbaceous biomass are abundant, but often under- or not utilized as a renewable resource. Here, the production of biochar from extensive late-harvest grass via multiple thermochemical conversion technologies was investigated at lab and farm scale for use in soil applications. While biochar is a product with highly diverse potential applications, it has a multitude of benefits for agricultural usage as a soil amendment, if the quality adheres to certain limit values of potentially toxic constituents. The results show that the biochar can adhere to all limit values of the European Biochar Certificate (EBC) for utilization in agriculture. Generally, the contents of heavy metals were well below the proposed EBC limits and very low PAH concentrations in the biochar were achieved. The high ash content in the grass of 7.71 wt%<sub>db</sub> resulted in high nutrient concentrations in the biochar, of benefit in soil applications, but the ash also contains chlorine, nitrogen and sulphur, which presents a challenge for the operation of the thermochemical processes themselves due to corrosion and emission limits. In the farm-scale processes, ash retention ranged from 53.7 wt%<sub>db</sub> for an autothermal batch process, reaching up to 93.7 wt%<sub>db</sub> for a batch allothermal process. The release of Cl, N and S was found to differ substantially between processes. Retention ranged from 41.7%, 22.9% and 27.6%, respectively, in a continuous allothermal farm-scale pyrolysis process, to 71.7%, 49.7% and 73.9%, with controlled lab-scale pyrolysis at 450 °C, demonstrating that process optimization may be possible. |
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| id | doaj.art-ce72b3f1a58b4bf0954834b65e8401f0 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T08:53:13Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
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| series | Energies |
| spelling | doaj.art-ce72b3f1a58b4bf0954834b65e8401f02023-11-16T20:19:18ZengMDPI AGEnergies1996-10732023-02-01164189610.3390/en16041896Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil ApplicationThomas Heinrich0Korbinian Kaetzl1Judy A. Libra2Thomas Hoffmann3Department of Postharvest Technologies, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, GermanySection of Grassland Science and Renewable Plant Resources, Faculty of Organic Agricultural Sciences, University of Kassel, Steinstr. 19, 37213 Witzenhausen, GermanyDepartment of Postharvest Technologies, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, GermanyDepartment of Postharvest Technologies, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, GermanyGrass and other herbaceous biomass are abundant, but often under- or not utilized as a renewable resource. Here, the production of biochar from extensive late-harvest grass via multiple thermochemical conversion technologies was investigated at lab and farm scale for use in soil applications. While biochar is a product with highly diverse potential applications, it has a multitude of benefits for agricultural usage as a soil amendment, if the quality adheres to certain limit values of potentially toxic constituents. The results show that the biochar can adhere to all limit values of the European Biochar Certificate (EBC) for utilization in agriculture. Generally, the contents of heavy metals were well below the proposed EBC limits and very low PAH concentrations in the biochar were achieved. The high ash content in the grass of 7.71 wt%<sub>db</sub> resulted in high nutrient concentrations in the biochar, of benefit in soil applications, but the ash also contains chlorine, nitrogen and sulphur, which presents a challenge for the operation of the thermochemical processes themselves due to corrosion and emission limits. In the farm-scale processes, ash retention ranged from 53.7 wt%<sub>db</sub> for an autothermal batch process, reaching up to 93.7 wt%<sub>db</sub> for a batch allothermal process. The release of Cl, N and S was found to differ substantially between processes. Retention ranged from 41.7%, 22.9% and 27.6%, respectively, in a continuous allothermal farm-scale pyrolysis process, to 71.7%, 49.7% and 73.9%, with controlled lab-scale pyrolysis at 450 °C, demonstrating that process optimization may be possible.https://www.mdpi.com/1996-1073/16/4/1896grassbiocharpyrolysishydrothermal carbonizationashbiomass |
| spellingShingle | Thomas Heinrich Korbinian Kaetzl Judy A. Libra Thomas Hoffmann Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application Energies grass biochar pyrolysis hydrothermal carbonization ash biomass |
| title | Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application |
| title_full | Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application |
| title_fullStr | Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application |
| title_full_unstemmed | Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application |
| title_short | Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application |
| title_sort | influence of thermochemical conversion technologies on biochar characteristics from extensive grassland for safe soil application |
| topic | grass biochar pyrolysis hydrothermal carbonization ash biomass |
| url | https://www.mdpi.com/1996-1073/16/4/1896 |
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