Comparative Studies of Burning Rates and Water Boiling Time of Wood Charcoal and Briquettes Produced from Carbonized <i>Martynia annua</i> woody Shells

Abstract

This study was conducted to compare the combustion properties of briquettes produced from carbonized Martynia annua woody shells and wood charcoal. Two different briquette samples were produced: Sample (A), is made up of carbonized shells powder plus starch as binding agent while Sample (B), consists of carbonized shells plus waste paper as binding agent. The parameters investigated include calorific value, ignition time, burning rate, and specific fuel consumption. Water boiling time and time taking by the Samples to burn to ashes were also determined. Water boiling time of the briquettes Sample A competed favorably with wood charcoal. Sample B has the lowest calorific value (5479.31 ± 4.14cal/g), wood charcoal (6815.12±0.53cal/g) was the highest, followed closely by fuel briquettes Sample A (6811.18 ± 4.33cal/g). The calorific values of Sample A and wood charcoal were not significantly different (P>0.05). The burning rate of the fuel briquettes and wood charcoal ranged from 3.16 ± 0.06 g/min in Sample A to 3.03 ± 0.05 g/min. The time taken by Sample A and wood charcoal to burn to ashes were 95.0 ± 2.5 min. and 99.2 ± 4.2 minutes respectively. Briquettes sample B took 73.5 ± 3.2 min to completely burn to ashes. The values for the water boiling time and specific fuel consumption for Sample A and wood charcoal were also not significantly different (P>0.05). Sample B has the shortest ignition time and highest burning rate compare to Sample A and wood charcoal. The results confirmed that, the fuel briquettes from carbonized Martynia annua woody shells can serve as supplement or alternative energy sources to wood charcoal for domestic cooking and heating.

Key words: Biomass, Martynia annua, Woody shells, Carbonization, Briquettes