Experimental studies on combustible fuel block strategy for cooking

Abstract

This paper presents experimental results of a study on the feasibility of making highly densified fuel block from agro residues that could be used for applications such as domestic cooking and barbecuing. A strategy had been adopted to determine the best suitable raw materials which meet both the criteria of performance and economy. In this regard several experiments were conducted with various raw materials in different proportions and it was found that fuel block composed of 40% biomass, 40% charcoal powder, 15% binder and 5% oxidizer fulfills the requirement of performance as well as economy. The unique geometry of this kind of fuel block (cylindrical one with a number of holes extending from top to bottom unlike traditional biomass briquette with single or no holes) helps in smokeless operation with reasonably steady thermal output. The geometry of the fuel block is so designed that it operates in partially premixed mode of combustion thus leading to better combustion and thereby lower emission. A typical fuel block for cooking weighing about 700-800g provides a thermal output of 1.5 kWth, with a burn time of 1.5 hours. Water boiling tests have indicated a thermal efficiency in the range of 55-58%.