Proximate Analysis of the Torrefied Coconut Shells

Biomass is biodegradable and non-fossilized organic materials derived from abundant, clean, and carbon-neutral plants, algae, and animals that can potentially be used as a bioenergy resource to replace fossil fuels. Coconut is one of the biomass feedstocks that are plentiful in tropical countries. The 347 million coconut trees planted in the Philippines produced 14.7 MT of nuts in 2020. The coconut shells (endocarp) comprise 15.18% of each coconut fruit, accounting for 2.2 MT of the total volume of coconuts. Torrefaction, the slow heating process from 200 degrees C to 300 degrees C, is a vital preprocessing step for improving biomass's physical qualities and chemical content. Coconut shells were torrefied using 200 degrees C, 225 degrees C, 250 degrees C, 275 degrees C, and 300 degrees C at a residence time of 10mins, 15mins, and 30mins At 275 degrees C and residence time of 30mins, it was found that the moisture content was 2.00%, ash content was 0.60%, the volatile matter was 0.66%, fixed carbon was 96.70%, and the optimal high heating value (HHV) of 34.37 MJ/kg was achieved. The improvement indicates an increase of 11.64% from the heating value of raw coconut shells (RCS) at 30.79 MJ/kg. The study concurs with other researchers on the positive effect of torrefying biomass feedstock, particularly the coconut shells. It is concluded that torrefaction at 275 degrees C and residence time of 30 mins will significantly improve the HHV of the coconut shells.