Biochar from Agro-byproducts for Use as a Soil Amendment and Solid Biofuel

초록

PurposeBiochar can be used for carbon sequestration to help mitigate global warming. Previous studies on biochar have not simultaneously considered its potential use as a soil amendment and solid fuel. Here, we investigated the conversion of agro-byproducts into biochar through pyrolysis at 300 degrees C, 400 degrees C, and 500 degrees C for 1 h.MethodsAn electrical furnace and stainless-steel cans were used for biochar production. Wood pellet, pepper stem pellet, perilla stem pellet, and rice chaff were placed in separate cans. Pyrolysis process was performed at 300 degrees C, 400 degrees C, and 500 degrees C for 1 h, separately. As Fertilizer Control Act, to evaluate the potential application of biochar as a fertilizer, pH, electric conductivity (EC), organic matter (OM), available phosphorus (Av. P2O5), total nitrogen (TN), total carbon (TC), exchangeable cation (Ex. cation), and cation exchange capacity (CEC) were analyzed. For evaluating as solid fuel, element analysis and proximate analysis were conducted. Based on analysis results, combustibility index (CI) and fuel ratio (FR) were calculated.ResultsThe biomass yield ranged from 28.53 to 73.74%. At higher process temperatures, the biochar pH, whereas electrical conductivity and organic matter content tended to decrease and then increase. Proximate and elemental analyses were conducted to evaluate the use of biochar as a fuel. The proximate analysis showed that commercial biochar had a high moisture content. The increase in process temperature decreased the volatile matter content and increased fixed carbon and fuel levels in all biomass samples. Based on the combustibility index, we recommend temperatures below 300 degrees C for processing both wood pellets and commercial biochar for biomass-only combustion and agro-byproducts for coal co-firing. The optimum process temperature to produce biochar as a soil amendment was 400 degrees C.ConclusionBiochar produced from agro-byproducts at temperatures below 300 degrees C and from wood pellets at temperatures 300 degrees C and 400 degrees C is recommended for fuel use.

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