Pyrolysis of maize cob at different temperatures for biochar production: Proximate, ultimate and spectroscopic characterisation

Abstract

Adopting the concept of the waste to wealth approach, agricultural waste from maize cob could be transformed into a renewable form of energy through thermo-chemical methods of treating the biomass. This method can be utilised for biochar production. The utilisation of biochar has several significant applications. These applications include the enhancement of the soil through amendment, stimulation of crop production by a variety nutrient inputs in the soil, etc. In this research work, a biochar was obtained through a slow pyrolysis process of maize cob waste. This experiment was carried out using a small-scale muffle furnace and subjecting the feedstock to heating at different temperatures (300, 400, 500 °C). The biochar was produced and characterised by a proximate analysis, scan electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, while the surface area was determined by Saer's method. The effect of the temperature on the yield of the biochar was investigated. The results show that the biochar yield decreases with an increasing temperature for the maize cob biochar at 300, 400 and 500 °C. The results of the physiochemical properties showed that the temperature has a great impact on the physicochemical properties of the biochar. The biochar produced at 300 °C has the highest fixed carbon content of 60.5%. The largest surface area was (281.8 m2·g<sup>–1</sup>) at 500 °C.