Properties of briquette fuel made from coffee husks

Huge amounts of coffee husks exist in most coffee processing plants. These husks are finally disposed off by burning. If converted to briquettes, coffee husks can be utilized as fuel for cooking or any other heating application. This will help reduce the use of firewood resources in the areas where coffee husks are readily available. Loose coffee husks can be converted in to briquettes using a piston press machine or a screw press machine. The coffee husks briquettes can be made from crushed coffee husks or uncrushed coffee husks. To make coffee husks briquettes one can use a binder to bind the husks together, or instead of a binder, they can be mixed with water, moulded and put to dry. Crushed coffee husks briquettes have a high bulk density compared to uncrushed coffee husks, so it is recommended that coffee husks briquettes should be made from crushed husks. In this research cassava and paper binders were used. The cassava binder was found to produce briquettes having high compressive strength and have high percentage of resistance to gravity drop test as compared to paper binders. Test results show rice husks to have low bulk density, good heating values, low ash contents, low moisture contents, low volatile matter and high carbon contents. The results from experiments show that the briquettes made had bulk density 198kg/m3, HHV of 17.63MJ/kg and particle size ranging from 4.75mm to 0.125mm.