Valorization of Agricultural Byproducts Through Conversion to Biochar and Bio‐Oil
Byproducts from Agriculture and Fisheries
Thermochemical conversion to biochar and bio-oil via the pyrolysis technology may be an effective, value-added approach to reuse various agricultural byproducts including crop residues, forestry debris, animal manures, food processing refuses, and green waste. Pyrolysis (heating organic materials in the absence of air) of agricultural byproducts results in a black solid as biochar and a liquid vapor condensate as bio-oil as well as minor uncondensable syngas. Biochar is porous, environmentally recalcitrant, and nutrient and water retentive; the material has been used as a soil amendment in diverse agricultural and environmental applications to persistently sustain soil fertility, enhance soil quality, promote plant growth, and mitigate environmental contamination. Bio-oil is a mixture of numerous low molecular weight organic compounds that can be transformed to heating fuels, upgraded to transportation hydrocarbon fuels, and refined for industrial chemicals and materials. The yield and quality of biochar and bio-oil from pyrolytic treatment of agricultural byproducts vary significantly with the feedstock type and the pyrolysis conditions. Relative to forestry debris and crop residues, animal manures and food processing wastes engender biochars containing more slowly releasable nutrients and bio-oils carrying more impurities. The slow pyrolysis technique involving low feedstock pre-treatment requirements and low operating complexity and costs is recommended to produce biochar and bio-oil from agricultural byproducts. The global production and utilization of biochar has recently been expanding at a high rate and is estimated to reach a $3 billion market by 2025.
Guo, Mingxin; Xiao, Pengli; and Li, Hong, "Valorization of Agricultural Byproducts Through Conversion to Biochar and Bio‐Oil" (2019). College of Agriculture, Science, and Technology. 10.