Studies have shown that the quality of a fuel briquette is highly dependent on the
choice of appropriate binders and the moisture content of the waste material. The
quality is also affected by the merge process parameters for the roll press. To obtain
suitable fuel briquettes from the roll press required the addition of about 8 wt.% of
unmodified starch to achieve a moisture content of 24%–25%.
This high hydration fuel needs to be dried and then cured in containers or bags,
so that it acquires a high mechanical resistance. The addition of woody biomass to
fine coal produces briquettes without the use of any binder. Biomass content can be
up to 20% by total mass. The use of unmodified starch binders for the production of
briquettes from fine coal waste is suitable. Attempts to utilize molasses as a binder
failed; it is not a very good binder for coal. Fine coal waste combined with woody
biomass can be effectively used for the production of alternative fuels. The addition
of biomass improves the combustion processes, particularly by the reduction of sulfur
and ash content. These briquettes are acceptable as a commercial product for the
power industry and for individual consumers.