Production of solid fuel by hydrothermal treatment using Terminalia catappa peels waste as renewable energy sources

Abstract

The problem encountered in solid biofuels is their low quality, especially in terms of heating value. One treatment can improve this quality by employing a hydrothermal process. This study aims to determine the effect of a hydrothermal treatment of Terminalia catappa peels waste on the heating value and chemical composition. The experiment was conducted using temperature variations of 160°C and 220°C with holding times of 30 and 60 minutes. The water to biomass ratio used is 1:4. Furthermore, a heating value analysis and a proximate analysis was also conducted. The highest heating value is generated at a temperature variation of 220°C with a holding time of 60 minutes by 4,675.25 cal/gram. This value meets the Austrian solid fuel heating value standard (ONORM M 7135) i.e. ≥4,299.5 cal/gram. In the proximate analysis composition, the product showed a decrease in moisture content, ash content, and volatile matter, and an increase in fixed carbon along with an increasing temperature variation and its holding time. In this variation, the moisture content had reached 6.41%, with a volatile matter of 51.8%, an ash content of 2.2%, and a fixed carbon level of 39.59%. These results indicate a significant improvement in the quality of solid fuel. Therefore, hydrothermal treatment is able to answer the alternative fuels’ needs in regards to environmental friendliness.