Production and characterization of corncob biochar for agricultural use

Biochar is a natural carbon-rich material that when applied to soil, can improve soil fertility and water taking-up capacity. The use of biochar is useful in organic agriculture, indirectly preventing the release of CO₂ into the atmosphere. The objective of this work was to produce and analyze the Physico-chemical properties of corncob biochar from slow pyrolysis that were related to the improvement of the soil for cultivation. Biochar was produced at 500 °C and 60 min of pyrolysis temperature and residence time. At this condition, yield and some properties of biochar were most suitable. Moisture, volatile, fixed carbon, and ash contents the biochar obtained were 1.8%, 33.1%, 59.0%, and 6.1%, respectively, with an average biochar yield of nearly 34%. Carbon, hydrogen, nitrogen, oxygen and sulfur content achieved were 71.5%, 3.1%, 0.9%, 10.3% and 0.03%, respectively. Highest heating value and pH of the biochar were 24.85 MJ/kg and 8.59. The surface area of 8.1999 m²/g, cumulative absorption value, and pore of 0.009134 cm³/g and 65.022 Å were obtained. They were found to increase with increasing pyrolysis temperature and residence time. The electrical conductivity and cation exchange capacity obtained were 1,340 µS/cm and 123.17 cmol/kg. Biochar obtained here appeared to have good properties for soil improvement.