STM Article Repository

The desirable characteristics of fuel briquettes are that they remain solid until they have served their
function and also performed well as a fuel. The first aspect which is related to its physical and
mechanical properties is mainly a function of the quality of the densification process for a given raw
material. This paper reports the findings of a study on the effect of species, particle size and
compacting pressure on impact resistance index and water resistance quality of fuel briquettes.
Briquettes were compacted at room temperature using compacting pressure levels of 10 to 50 MPa.
The briquetting process and physical properties test were conducted using standard laboratory
procedures. Results indicate that species, compacting pressure and particle size of sawdust at 5%
level of significance have significant effect on the impact resistance index and water resistance quality
of briquettes. Additionally, compacting pressure of 40 MPa was adequate to produce briquettes with
good impact resistance index irrespective of the species. However, briquettes produced did not have
good water resistance quality. The multiple correlation coefficient (R) and adjusted R2 for the
regression model between impact resistance index of briquettes, and species density and compacting
pressure were 0.74 and 0.54 respectively. Additionally, the multiple correlation coefficient and
adjusted R2 for the regression model between water resistance quality, and species density, particle
size and compacting pressure were 0.82 and 0.67 respectively. The above therefore suggests that
even though briquettes produced from sawdust of tropical hardwoods at room temperature using low
compacting pressure have adequate impact resistance index, they need to be protected from
moisture.