Selected Publication:
Mikula, K; Soja, G; Segura, C; Berg, A; Pfeifer, C.
(2020):
Carbon Sequestration in Support of the "4 per 1000" Initiative Using Compost and Stable Biochar from Hazelnut Shells and Sunflower Husks
PROCESSES. 2020; 8(7), 764
FullText
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- Abstract:
- The achievement of carbon neutrality till 2050 will require the deployment of negative carbon emission technologies like the production and soil incorporation of biochar, produced from pyrolyzed plant-based residues. The carbon sequestration potential of biochar (BC) from hazelnut (Corylus avellanaL.) shells (HNS) and sunflower (Helianthus annuusL.) husks (SFH) was evaluated when the biomass was carbonized in a fixed bed reactor, in a rotary kiln and in a screw reactor. In all tested reactors, higher temperatures (>500 degrees C) and longer retention times increased the C concentration and stability of the biochar, with negligible effects of the reactor type and feedstock. A national case study was developed for Austria concerning the potential use of SFH- and HNS-BC in combination with compost for reaching the "4 per mille" objective. An annual soil organic carbon increase of 2.5 Mt C would be needed, requiring amendment rates of 2.2 Mt C a(-1)for all annual crop areas and 0.3 Mt C a(-1)for all vineyards and orchards. If compost only were used, the annual cost would be about 200 EUR ha(-1)but short-term re-mineralization would have to be considered. If the more recalcitrant biochar were used only, about 2.3 t BC ha(-1)would be needed at a cost of 1400-1870 EUR ha(-1). The study shows in principle the feasibility of applying compost-biochar mixtures for achieving the "4 per mille" objective but in practice, supplemental soil management strategies for sequestering C will be required.
- Authors BOKU Wien:
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Mikula Klaus
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Pfeifer Christoph
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Soja Gerhard
- Find related publications in this database (Keywords)
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soil organic carbon (SOC)
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pyrolysis
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screw reactor
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rotary kiln
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fixed bed reactor
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