The influence of pyrolysis process conditions on the quality of coconut shells charcoal

The availability of biofuel from renewable raw material and its lower negative environmental impact, when compared to fossil fuels, are some of the properties that make a biofuel commendatory. In this study, the influence of residence time, temperature and particle size on the quality parameters such as ash content, moisture content and the calorific value of the coconut shell charcoal was studied. The charcoal was obtained by carbonising clean, thoroughly dried coconut shells in an oxygen-free environment at a temperature range of 250-450°C, the residence time of 15-75 minutes, and particle sizes of 5 mm and 25 mm. The charcoal was analysed in terms of the changes of these quality parameters as a result of thermal conversion of the coconut shells during the pyrolysis process. All the studied quality parameters were dependent on the pyrolysis process conditions. The calorific value and the ash content increased with an increase in the residence time from 25.99 MJ/kg to 29.54 MJ/kg and 1.02% to 1.13%, while the higher the residence time of the pyrolysis process, the lower the moisture content in the charcoal. An increase in pyrolysis temperature from 250°C to 450°C increased the ash content and the calorific value of the charcoal from 1.01% to 1.11% and 24.73 MJ/kg to 29.15 MJ/kg respectively. In the case of moisture content, it decreased with an increase in temperature from 2.43% to 1.21%.