Development of Biobriquettes from Mixed Rice-straw and Longan Waste Residues

Abstract

Biobriquettes prerared from agricultural residues are an alternative energy sources suitable for application in such an agriculture-based country as Thailand. The objective of this study was to prepare biobriquettes using an optimum mixture of rice-straw (RS) and longan waste residues (LR) with tapioca paste as a binder. Biobriquettes were prepared by wet method under low-pressure compaction of 50 and 75 kg/cm2. The experiments were conducted using RS:LR ratios of 100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 (by weight). Physical properties, including shape, density as well as chemical properties, including moisture content, ash, volatile matter, fixed carbon and heating value of the biobriquettes were determined. The results showed that the optimum mixture formula of biobriquettes was RS:LR of 20:80 (by weight) with 6% tapioca paste, preparation should be made at a compaction pressure of 50 kg/cm2. The density of these biobriquette was 0.33 g/cm2, while the moisture content, ash, volatile
matter and fixed carbon contents were 7.39, 5.00, 85.73 and 1.88% (dry basis), respectively. The heating value was 3,698.46 cal/g and the thermal efficiency of this fuel was 10.64%.