Abstract
Durian (Durio zibethinus) fruit processing discards out waste shells, which accounts for more than 60 % by weight of the fruit into landfills, leading to serious issues regarding environmental pollution and public health risks. Despite the extensive research available on converting this biomass source into high carbon content biochar, little has been discussed on its susceptibility towards microbial degradation and fungal growth and the effects these contaminations may have on the obtained products. In this study, two types of durian shells, composted and non-composted types are collected by an evaluation of pretreatment conditions, and carbonised for recovery of biochar material. FTIR, SEM and TGA/DTG were utilised to show significant differences in the structure and thermal properties between the composted durian shell and the non-contaminated one. By making use of these differences, for the first time ever, novel briquetting methods of mechanically pressing at normal and elevated temperature were applied on composted shells to produce biochar fuels with varying shapes and combustion properties to suit different applications. A higher yield of more than 50 % with a higher fixed carbon content of up to 51 % could be attained without any need for a binding material from the composted material by the pressing method with incorporation of heat. The results from this research can encourage developing different approaches towards making use of source materials with recalcitrant structures for specific desirable properties.
