ABSTRACT

A study was undertaken to determine the energy properties of three non-timber forest tree residues, Bush Mango (irvingia), Achi (Brachystegia eurycoma) Wind Para Rubber (Hevea brasiliensis) as fuel. I he shells were ground and then densihed, 'i'he chemical composition (Carbon, Hydrogen, Oxygen, Sulphur and Nitrogen contents) of the ground shells and mechanical properties of the. densified shells were determined, The mechanical properties of the densified shells delermined were shatter resistance and durability index. The energy properties deteLuiined were volatile matter, ash and fixed Carbon contents, Others were the higher and lower healing values. These shells were ground with a hammer mill and densified by mixing with starch in the ratio 2:1 in a densification apparatus. The optimum densification was done at 100°C and 200 MPa. The Carbon, Hydrogen and Nitrogen were determined by using elemental analyser method while Oxygen was calculated. 'Ihe Sulphur were determined by atomic absorption speetromeiry method. The hulk dcnsit.y was determined from the weight and volume of the materials. 'the shatter resistance was determined by the weight loss afl:er dropping on concrete floor from the height of one metre. The durability index was determined by calculating the weight loss after tumbling. 'Ihe volatile matter and ash content were determined by burning in a furnace while fixed Carbon was calculated from them. The higher heating value was determined with a bomb calorimeter at a condensed steady flow exit. The lower heating value was obtained from the higher heating value using an empirical relationship. The energy properties of the densitied shells were compared using the Duncan's New Multiple Range Test to determine if there were significant. (P 0.05) differences between them. The energy properties of ground and densified shells were compared using the F-LSD to dctermmc i there were sgniflcant dIercnccs between them. Results obtained showed that Rubber had the highest volatile matter content and calorific xv values. The volatile matter content of the three densified shells was of the order: Rubber (75.03%) > Irvingia (69.13%) > B. eurycoma (50.3%). The 1-IHV of the Rubber, B. eulycoma and Irvingia was 15.97, 13.0 and 13.10 MJ/kg rcspcctivcly. The Rubber had the lowest ash and fixed carbon contents. The ash content was of the order: Rubber (4.8%) < Irvingia (5.1%) < B. eurycoma (13.57%). The flxcd carbon was of the order: Rubber (7.17%) < Irvingia (12.37%)