Combustion characteristics of fuel briquettes made from charcoal particles and sawdust agglomerates

H.A. Ajimotokan of the Department of Mechanical Engineering, University of Ilorin, PMB 1515, Ilorin, Nigeria conduct a recent study to investigate the combustion characteristics of fuel briquettes made from Idigbo (Terminalia ivorensis) charcoal particles, pinewood (Pinus caribaea) sawdust and their agglomerates using gelatinized cassava peels.

The charcoal particles and pine sawdust were blended in the mixing ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively and vice-versa. More so, briquettes were produced from pure charcoal particles and pine sawdust separately for the purpose of comparison with the blended briquettes. The gelatinized binder was 5% of the total briquettes weight. The briquettes were produced using a pressure of 5 MPa with a dwelling time of 5 min in a hydraulic briquetting machine. Proximate, elemental compositions and heating value analyses were carried out on the raw charcoal, sawdust, cassava peel, and their briquettes.

Results from the study showed that variations in the mixing ratios of the bio-residues had significant effects on all the properties investigated. An increase in the charcoal particles led to an increase in the fixed carbon content and heating value of the briquettes. Conversely, higher pine sawdust content in the briquette resulted in higher volatile matter content and lower heating value. The briquette made from pure charcoal particles had the highest heating value (24.9 MJ/kg) and ash content (6.0%). Its carbon, hydrogen, and oxygen contents were in the range of 44.6–50.1%, 5.1–5.6% and 34.4–41.5%, respectively. The proximate analysis, elemental composition analysis, and heating values of the produced fuel briquettes depicted that they have better combustion properties when compared to the raw charcoal, pine dust, and cassava peel.

He therefore concluded that the produced briquettes would serve as good fuel for domestic and industrial applications.