Potential of Biochar Derived from Agricultural Residues for Sustainable Management

A horizontal drum kiln is a traditional method widely used in Southeast Asian countries for producing biochar. An understanding of temperature conditions in the kiln and its influence on biochar properties is crucial for identifying suitable biochar applications. In this study, four agricultural residues (corncob, coconut husk, coconut shell, and rice straw) were used for drum kiln biochar production. The agricultural residues were turned into biochar within 100-200 min, depending on their structures. The suitability of biochar for briquette fuels was analyzed using proximate, ultimate, and elemental analysis. The biochar's physical and chemical properties were characterized via bulk density, iodine number, pH(p)(zc), SEM, and FTIR measurements. All biochars had low O/C and H/C ratios and negative charge from both carbonyl and hydroxyl groups. Coconut husk and shell biochar had desirable properties such as high heating value and a high amount of surface functional groups which can interact with nutrients in soil. These biochars are thus suitable for use for a variety of purposes including as biofuels, adsorbents, and as soil amendments.

Automated summary

This study produced biochar from agricultural residues (such as corncob, coconut husk, coconut shell, and rice straw) using a horizontal drum kiln. The biochars had low O/C and H/C ratios, negative charge from functional groups, and desirable properties such as high heating value and surface functional groups suitable for various applications including biofuels, adsorbents, and soil amendments. Coconut husk and shell biochars, in particular, were identified as having ideal properties for these purposes.