SOME ENERGY PROPERTIES OF NON-TIMBER FOREST TREE RESIDUES FOR FUEL

Abstract

A study was undertaken to determine some energy properties of three non-timber forest tree residues: Bush Mango (Irvingia), Achi (Brachystegia eurycoma) and Para Rubber (Hevea brasiliensis) shells for fuel. The ultimate properties (Carbon, Hydrogen, Oxygen, Sulphur and Nitrogen contents) of the ground shells were determined. The proximate properties determined were volatile matter, ash and fixed Carbon contents, and calorific values. The shells for the three samples were reduced with a hammer mill to 1.00 mm, 2.00 mm and 4.75 mm particle sizes. The mean of the energy properties of the samples were compared using the New Duncan’s Multiple Range Test to determine if there were significant differences at (P ≤ 0.05). Results obtained showed that Irvingia shells had the highest volatile matter content of 75.03% and calorific value of 19.53 MJ/kg. The volatile matter content of the three shells was of the order: Irvingia (75.03%) > Rubber (62.33%) > B. eurycoma (58.77%). The higher heat value of Rubber, B. eurycoma and Irvingia shells were 15.87, 15.20 and 19.53 MJ/kg, respectively. The ash content obtained from the shell samples were of the order: Irvingia (5.10%) < Rubber (21.57%) < B. eurycoma (23.20%) while, fixed carbon were of the order: Rubber (2.50%) < Irvingia (7.17%) < B. eurycoma (10.70%). Bulk density of the shell samples were of the order: B. eurycoma (431.3 kg/m³) > Rubber (247.3 kg/m³) > Irvingia 121.7 kg/m³). The Irvingia shell had the most favourable energy properties for fuel due to its high calorific values, volatile matter content and it also had the least ash content.