Exploring the benefits of biochar: A review of production methods, characteristics, and applications in soil health and environment

Authors: GVANWALI, PRASHANT - Tribhuvan University; KHANAL, RENUKA - Tribhuvan University; POKHREL, SHOVA - Tribhuvan University; Adhikari, Kabindra

Submitted to: Egyptian Journal Soil Science
Publication Type: Review Article
Publication Acceptance Date: 3/13/2024
Publication Date: 4/27/2024
Citation: Gyanwali, P., Khanal, R., Pokhrel, S., Adhikari, K. 2024. Exploring the benefits of biochar: A review of production methods, characteristics, and applications in soil health and environment. Egyptian Journal Soil Science. 64(3):855-884. https://doi.org/10.21608/EJSS.2024.270380.1725.
DOI: https://doi.org/10.21608/EJSS.2024.270380.1725

Interpretive Summary: Biochar, which is also called black carbon, is a carbon rich solid by-product of biomass sources, and has several benefits in soil including carbon sequestration. This review article explores biochar production methods, its characteristics, and usage and importance in agriculture and as a climate change mitigation tool. The article also identifies research gaps, future scope and its adoption among farmers.

Technical Abstract: Biochar is a carbon-rich solid by-product formed by the treatment of biomass to high temperatures in an oxygen-deprived environment, which has recently increased in popularity due to its positive impacts on soils and climate change mitigation among others. Four production processes of biochar have been described in this review; Pyrolysis, Hydrothermal carbonization, Torrefaction, and Gasification. These processes differ in their temperatures, heating rates, usable feedstock, reaction environment, and complexity, ultimately determining the characteristics of biochar produced and their usage. Depending upon the temperature, biochar, syngas, and bio-oil are produced in different quantities, and the feedstock used determines their qualities. Biochar usage includes and is not limited to soil management, organic waste management, water purification, greenhouse gas emission, carbon sequestration, fuel alternative, and land reclamation. This review finds biochar to be extremely important in climate-smart agriculture, mitigating global warming, and contributing a small part to fulfilling global energy needs. The gap in research regarding the effect of biochar from different feedstock and the long-term effects of biochar in soil needs to be minimized, along with the standardization of production methods and application of biochar in various fields to increase the benefits while decreasing the harmful effects on the environment and human health. In addition to current research gaps, the potential drawbacks of biochar, its adoption, and its future scope were also described.