Page 18 - CleanIndiaJournal June Digital Issue

Cover Story

in. A perfectly sealed system – with system along the road from the
no cracks and leakages plugged – is limestone mine to the crushing unit
essential. of the plant; it switches on every 15
minutes and settles the dust left in
Vacuum systems the wake of transport trucks. In a way, a cement plant
Both centralised vacuum systems Reducing emissions is not just zero-waste,
with multiple points for collection, but also waste-positive.
as well as mobile vacuum machines The cement industry is one of the
which can be moved periodically, largest emitters of carbon dioxide in Our kilns consume large
are in use. Bag filters are installed the world. While some companies quantities of waste
at practically all transfer points; are working on carbon recapture,
suction machines can be connected it has not yet reached commercial generated by other
to them to pick up the dust. viability. industries.
“Vacuum systems with The main source of carbon
appropriate piping collect spilled dioxide is calcium carbonate Tikam Chand Solanki
dust, which goes back into the raw from limestone, which releases
material hopper. Dust collected carbon dioxide after burning. By
from road sweeping, and from the choosing to use or blend in low-
packaging plant, is also channeled grade limestone – which has lower Alternative fuels
here”, said Solanki. calcium carbonate content, but can “In a way, a cement plant is not
still produce good-quality cement – just zero-waste, but also waste-

External areas some cement companies are trying positive. Our kilns consume large
to reduce their carbon emissions.
Dust generated during material Sulphur dioxide generated by quantities of waste generated by
handling in open areas can be captive power plants is trapped other industries”, said Solanki.
tackled with a dry fog system and by flue gas desulphurisation units. Cement plants generate no waste
water sprinkler system. Truck Selective non-catalytic reduction of their own. Various streams of
mounted vacuums and road processes reduce emissions of waste are transported to a cement
sweepers are both in vogue. nitrogen oxides. Norms for these plant as a source of fuel – one
One of our respondents described are set by pollution control boards, of the major ways in which the
industry gains carbon credits. As
an automated water sprinkling and monitored online.
part of the circular economy, the
alternate fuel systems of their
integrated units use municipal
waste, bio waste and plastic waste
as fuel, reducing dependence on
coal.
“The excess moisture content
of waste from other industries can
increase the amount of heat needed
to evaporate it. This waste can be
sticky in nature, and the moisture
may block pipes and chutes. The
biggest challenge is the inconsistent
calorific value of such alternative
fuels. The variation has to be
absorbed by coal, which is the main
fuel. This fluctuation affects clinker
production”, warned Vasavada.

Heat recovery
Normally, the heat efficiency
of the machinery which produces

JUNE 2023•Clean India Journal
18 www.cleanindiajournal.com