EFFECT OF PYROLYSIS TEMPERATURE ON THE PROPERTIES OF COCONUT FROND BIOCHAR
Biochar has attracted interest due to its benefits in agricultural sector and environmental sustainability. Biochar can act as a useful tool to sequester carbon and reduce carbon dioxide (CO2) which cause global warming and climate change. Biochar is also able to improve soil fertility and mitigate climate change by sequestering carbon. The functions of biochar depend greatly on its physical and chemical properties. The type of feedstock and pyrolysis conditions such as temperature, heating rate and residence time are the most important factors influencing the biochar properties. The objective of this study is to investigate and evaluate the effect of pyrolysis temperature on the biochar yield as well as the properties of biochar produced from slow pyrolysis of coconut frond (CF). The preliminary analysis such as proximate and elemental analysis, lignocellulosic determination and thermogravimetric (TG) analysis were carried out to determine the properties of CF feedstock. Laboratory-scale slow pyrolysis experiments were performed at five different temperatures, 400°C, 450°C, 500°C, 550°C and 600°C. Heating rate, residence time and nitrogen flowrate were set at 5°C/min, 1 hour and 0.5 L/min respectively. CF biochars produced at different temperatures were investigated using proximate and elemental analysis, Field Emission Scanning Electron Microscope (FESEM) and Brunauer–Emmett–Teller (BET) surface area analysis. The preliminary analysis results show that the CF is suitable to be used as feedstock for pyrolysis process. It contains high volatile matter of 75.27 mf wt% and low percentage of sulfur, 0.77%. CF feedstock also comprises of 21.46% of cellulose, 39.05% of hemicelluloses and 22.49% of lignin. The biochar yield decreased from 35.71 wt% to 28.53 wt% as the temperature increased from 400°C to 600°C. The fixed carbon of the CF biochar increases from 76.40 mf wt% to 78.38 mf wt% as the temperature increased from 400°C to 600°C. The FESEM shows the existence of pores at the wall of the fibrous strands of the CF biochar. The increment of pyrolysis temperature also lead to the formation of biochar with higher BET surface area and micropore volume. BET analysis reported maximum surface area of 215.30 m2/g and micropore volume of 0.07912 cm3/g at pyrolysis temperature of 600°C. The findings of this study show that an increased of pyrolysis temperature decreased the percentage yield and increase the fixed carbon, BET surface area and micropore volume of CF biochar. CF biochar therefore has the potential to be applied as soil amendments.
|Keywords: Biochar, Slow Pyrolysis, Coconut Frond, Pyrolysis Temperature, Characterization|
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