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Data from: Emissions and char quality of flame-curtain "Kon Tiki" kilns for farmer-scale charcoal/biochar production

Cite this dataset

Cornelissen, Gerard et al. (2017). Data from: Emissions and char quality of flame-curtain "Kon Tiki" kilns for farmer-scale charcoal/biochar production [Dataset]. Dryad.


Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies often used for charcoal production are slow and without treatment of the pyrolysis gases, . This resultings in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contributes to greenhouse gas emissions, the most important being methane, carbon monoxide and aerosols. In rRetort kilns where pyrolysis gases are led back to a combustion chamber. This are faster and can reduce emissions substantially, but isare costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysisrocess, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar toachieved in the retort kilns)., also avoiding use of external fuel for start-up. By adding feedstock layer by layer in an open cone-shaped kiln, the pyrolysis gases formed underneath the flame curtain are combusted, at the same time creating enough heat to avoid use of external fuel for start-up. The rResults from this aA field study in Nepal using various feedstocksmixtures of the ubiquitous invasive shrub Eupatorium, rice husk and wood as feedstocks showed char yields of 22 ± 5 % on a dry weight basis and 40 ± 11 % on a C basis. Total pyrolysis time was one to four hours per m3 of produced biochar. Biochars with high C contents (76 ± 9%; n=57), average surface areas (11 to 215 m2 g-1), low EPA16 - PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in. Overall, the analytical data of all biocharsthe produced with this new technologybiochars complianceed with the European Biochar Certificate (EBC). The mMean emission factors for the flame curtain kilns found in this study were (in g kg-1 biochar for all feedstocks); carbon dioxide (CO2)= 4300 ± 1700, carbon monoxide (CO)= 54 ± 35, non-methane volatile organic compounds (NMVOC)= 6 ± 3, methane (CH4)= 30 ± 60, aerosols (total suspended particles, TSP, derived from (PM10) = 11 ± 15, total products of incomplete combustion (PIC)= 100 ± 83 and nitric oxides (NOx)= 0.4 ± 0.3. The Kon Tikiflame curtain kilns emitted statistically significantly (p<0.05) lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2. With benefits such as high quality biochar, low emission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap construction and operation the flame curtain technology represent thus a promising possibility for sustainable rural biochar production.

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