Proximate Analysis and Calorific Value of Fuel Briquettes from Wood and Coffee Skins Biomass as a Renewable Energy Source

One of the fuels made from biomass are Charcoal briquettes. The biomass used in this study was coffee husk and coffee wood. This study aims to find out the ratio of coffee husk and coffee wood that accordance the briquette standards of the Minister of Energy and Mineral Resources (ESDM) and (Indonesian Nasional Standard) SNI 01-6235-2000. In this research, a comparison was made between coffee fruit skin charcoal and coffee wood charcoal with a ratio of 100:0 (KK 1 ), 75:25 (KK 2 ), 50:50 (KK 3 ), 25:75 (KK 4 ), 0:100 (KK 5 ). The resulting briquettes were tested for their proximate value using a furnace, for the calorific value they were tested using a boom calorimeter. Apart from that, a combustion rate test was also carried out by burning briquettes in a combustion furnace. The results of the analysis of proximate obtained were water content of the briquettes ranging from 3.39–5.91%, all of which in accordance with SNI and also which in accordance with the regulation of ESDM, the ash content that which in accordance with SNI was KK 4 and KK 5 , namely 6.71% respectively. and 6.47% and those that comply with the ESDM Ministerial Regulation are KK 3 , KK 4 and KK 5 with ash content values of 9.62%, 6.71% and 6.47% respectively. Meanwhile, the volatile matter value ranges from 32.31–35.59%, not yet accordance with SNI. for fixed carbon values ranging from 50.1–54.55%, this also does not accordance with SNI. However, for the calorific value of 4536–6723 Cal/g, all of them meet the ESDM Ministerial Regulation, and those that accordance with SNI is KK 2 , KK 3 , KK 4 and KK 5 with calorific values of 5650, 5821, 5866 and 6723 Cal/g respectively. Meanwhile, the combustion rate ranges from 0.341 to 0.711 g/min. Coffee husk waste combined with coffee wood has the potential to be used as fuel briquettes where the KK 4 composition has water content, ash content and calorific value that meets SNI and ESDM regulations, even though the volatile matter and fixed carbon values do not yet meet.