Production of biochar from elephant grass (Pernisetum purpureum) using an updraft biomass gasifier with retort heating

Abstract

The availability and non-competitive use of elephant grass (Pernisetum purpureum) makes it an excellent feedstock for the production of biochar for more beneficial applications. Exploiting this potential, an updraft fixed-bed biomass gasifier was designed and fabricated. The feedstock was gasified for 120 minutes with a peak temperature of 300 °C to give a biochar yield of 14.29 wt%. The raw grasses were characterised by FTIR(Fourier-transform infrared spectroscopy) and (X-ray fluorescence)XRF analysis while the biochar obtained was characterised by FTIR, XRF, (scanning electron microscope) SEM and (Brunauer, Emmett and Teller) BET analysis. Potassium (K) was the most dominant inorganic element in the feedstock, with a percentage composition of 41.86%; indium (In) closely followed at 32.08%, while other elements present were Si, Ca, Cl and Fe. The biochar was acicular with a table-like structure embedded with crystal clusters and was found to be highly porous, with a large surface area of 475.1 m²/g.

Keywords:

• Biochar
• elephant grass
• gasification
• biomass
• analysis

Acknowledgements

The efforts of Engr. Ndagi Mustapha of Mechanical Engineering Department, University of Ilorin, in the fabrication of the gasifier are acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.