Quality of Cooking Fuel Briquettes Produced Locally from Charcoal Dust and Sawdust in Kenya

Abstract

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 locally produced fuel briquettes in Kenya and their combustion properties, chemical composition and emissions of gases and fine particulate matter. Briquette made from charcoal dust bonded with paper, soil or corn starch and sawdust briquettes bonded with gum arabica were studied. Charcoal dust briquettes bonded with corn starch or paper had the highest calorific values of 23.6 kJ/g and 21.4 kJ/g respectively. Contaminants comprising of chromium, mercury and lead were high in briquettes made from material sourced from garbage heaps in informal settlements and dumpsites. Charcoal dust briquettes bonded with soil was the safest in terms of indoor air concentrations of carbon monoxide and fine particulate matter when burned. Burning sawdust briquettes bonded with gum arabica caused the release of high concentrations of fine particulate matter. When briquettes intended as cooking fuel are produced, the effect of raw materials should be taken into account.