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. All these solid residues of bottom
and fly ash collected at the smoke washer, are again dumped into
the environment, increasing the concentration of sand in the soil
and making it impermeable due to the fine charcoal powder. In
the present work (see Section 3), it was determined that the black
fumes that pass through the gas washer contain gases and solid
particles (organic and inorganic). The inorganic particles are composed
mainly of charcoal and a small volumetric portion of inorganic
materials (silicon, iron oxides and other minerals). Today
not all mills have filters or gas washers, but Brazilian environmental
legislation has mandated a time limit for improvement of this
pollution control.
0956-053X/$ - see front matter 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/