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

Abstract

• The combustion characteristics of charcoal particles and pine sawdust agglomerated briquettes were investigated. • Variations in the mixing ratio of the bio-residues significantly affect all properties examined. • The increment in charcoal particles increased the fixed carbon content and the heating values of the briquettes. • Higher volatile matter content with lower heating value was observed with higher pine sawdust in the briquette. The combustion characteristics of fuel briquettes made from Idigbo ( Terminalia ivorensis ) charcoal particles, pinewood ( Pinus caribaea ) sawdust and their agglomerates using gelatinized cassava peels were investigated. 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. The results 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. Thus, the produced briquettes would serve as good fuel for domestic and industrial applications.