Temperature effect on biochar properties from slow pyrolysis of coconut flesh waste

Abstract

The aim of this study was to investigate the effect of pyrolysis temperature on the biochar yield and properties via slow pyrolysis of coconut flesh waste. The temperature used in the slow pyrolysis experiment was varied between 350°C to 600°C at a constant heating rate of 5°C/min. The results indicated that higher pyrolysis temperature could reduce the percentage of biochar yield. The increment of pyrolysis temperature from 350°C to 600°C would reduce the biochar yield from 23.54 wt.% to 13.97 wt.%. The effect of pyrolysis temperature was also significant on the composition and physical properties of biochar yield. The physicochemical properties of biochar were identified by proximate, elemental, heating value, SEM images and BET surface area analyses. The increment of pyrolysis temperature from 350°C to 600°C increased the ash content of biochar from 4.63 wt.% to 8.19 wt.%, the fixed carbon content from 45.20 wt.% to 79.09 wt.% and carbon content from 72.70 wt.% to 83.25 wt.%. Meanwhile the volatile matter and oxygen content of biochar were decreased from 50.17 wt.% to 12.71 wt.% and 13.86 wt.% to 10.99 wt.%, respectively as the pyrolysis temperature was increased from 350°C to 600°C. The increment of pyrolysis temperature from 350°C to 600°C increased the surface area of biochar by 8 fold from 0.3971 m2/g to 3.4486 m2/g. Meanwhile, the higher heating value of biochar was decreased from 33.95 MJ/kg to 27.49 MJ/kg as the pyrolysis temperature was increased from 350°C to 600°C.