Brazil is the largest worldwide producer of alcohol and sugar from sugar-cane and has an extensive alternative
program for car fuel which is unique. In the bagasse burning process, black fumes are expelled
through the chimney (fly ash recovered in the gas washer), and a
clearer ash falls to the bottom of the boiler (bottom ash). Tens of
thousands of tons of this fly ash (principally carbon and silica)
are released into the atmosphere (airborne fly ash) every year
and can be a health hazard.
In the search for new alternative sources of ecologically
friendly energy, the utilization of charcoal powder from fly ash
for the production of briquettes has become a good alternative.
In the production of charcoal, this residue is not dumped on the
soil but is used to produce energy, and trees are saved. Conventional
charcoal production in Brazil is a destructive element of
natural forests. Therefore, the objective of this study is to
demonstrate the feasibility of recovering fine charcoal from fly
ash to produce charcoal briquettes.
Results also show that the procedure adopted for the production
of briquettes based on charcoal powder from the ash of sugar-
cane bagasse and cassava starch as the binder is efficient,
yielding briquettes with properties that meet market technical
requirements. Moreover, the most representative parameters are compatible
with or better than those parameters obtained utilizing other
sources of charcoal. The average briquette properties obtained
are: a calorific value of 25,551 kJ/kg, a density of 1.12 g/cm3, a
mechanical resistance to compression of >7 MPa and a residual
ash of 13.2% after burning.