Evaluating the quality of briquettes sold in selected suburbs of Kampala

Abstract

Biomass is receiving greater attention especially in developed countries as a means of reducing greenhouse gas emissions, increasing energy supply security and decreasing their heavy reliance on imported fossil fuels. Fuel briquettes are made by compressing biomass material into a uniform solid and present an opportunity for good quality cooking fuel. The study evaluated the quality of briquettes sold in selected suburbs of Kampala and their physical, thermal chemical properties and burning characteristics of biomass briquettes. The obtained briquettes were made from sawdust and charcoal dust which was blended with cassava floor. Sawdust and charcoal dust were selected because of their abundance throughout the selected areas. The briquettes were subjected to several standard methods to verify their suitability as fuels. The briquette parameters that were tested included; density, moisture content, compressive strength, volatile matter, ash content, thermal fuel efficiency, calorific value, ignition time, burning rate and water boiling time. The data was analyzed using Microsoft excel and results were compared using one-way analysis of variance (ANOVA) to determine if there was a significant difference (p≤0.05) among the different briquetting parameters. Results showed that briquettes made from charcoal dust had a higher density (1.062 g/cm3), moisture content (9.39%), ash content (31.27%), thermal fuel efficiency (35.5%), Ignition time (5.3 seconds), water boiling time (43.2 minutes) with lower compressive strength (16.059N/mm2), volatile matter (68.73%), calorific value (1.67Kcal/g), and burning time (2g/min). Furthermore, briquettes made from sawdust had a lower density (0.978 g/cm3), moisture content (6.27 %), ash content (6.2 %), thermal fuel efficiency (28.5%), ignition time (3.6 minutes), water boiling time (19.4 minutes) with higher a compressive strength (54050.080 N/mm2), volatile matter (98.80%),calorific value (4.24 Kcal/g)and burning rate (6 g/min). Generally, briquettes made of sawdust were of good quality compared to those made from charcoal dust. However, more research is needed on using other binder types rather than cassava flour which is considered as food.