The Potential of Coffee Husk and Pulp as an Alternative Source of Environmentally Friendly Energy

Abstract

In Ethiopia enormous amounts of coffee husk and pulp are generated anually from coffee processing industries. However, they have been poorly utilized or left to decompose or otherwise dumped in the environment. Therefore, this research was conducted at Teppi and Limu coffee farms in Ethiopia to produce briquettes from coffee husk and pulp. The objectives of the study were to evaluate the energy potential of briquette produced from coffee husk and pulp and characterize their fuel properties. The coffee husk and pulp were carbonized in an oxygen-deficient environment separately by using carbonizing kiln at Jimma Agricultural Mechanization Research Centre. Then the carbonized materials were ground to fine particles and mixed with a binder and converted to briquettes by using a briquette extruder machine. Triplicate samples of the briquettes were sent to Geological Survey of Ethiopia for analysis. The calorific value of the briquettes produced from coffee husk and pulp ranged between 5041.1±168.60 and 4037.6±219.39cal/g, respectively. Further analysis showed that through conversion of the coffee husk and pulp in to briquette, annually the two farms could generate 1.3×1013cal of energy and substitutes 5,284.35 m3 of firewood or save 52.84 to 66.05 ha of tropical forests from deforestation. The results of the study have shown that briquettes produced from coffee husk have more positive attributes than briquettes produced from coffee pulp at both farms. It is concluded that briquettes produced from coffee husk and pulp could be used as an alternative source of energy and waste management option.

Keywords: Briquette; Carbon Sequestration; Coffee Husk; Coffee Pulp