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Energy-use
Benchmarks for the Cement Sector
By Kamala Ernest
The
trend in energy consumption, particularly in energy intensive
industries such as cement, rubber and iron & steel, is
of growing concern. Cement is the largest energy-consuming
commodity in the building material classification. Cement
production accounts for two percent of world primary energy
consumption and up to six percent of total energy consumption
in cement producing countries. Malaysia ranks among the top
10 countries in terms of growth of cement production. Between
1970 and 1994, cement production grew at an average rate of
10 percent.
For
these companies, energy cost alone would take up to 10 percent
of their total operating costs. Companies in Malaysia are
now seeking ways to reduce their energy consumption as a means
of reducing operating costs and staying ahead in the global
market. One of the cheapest and easiest options is benchmarking.
Benchmarking
is an effective tool to assist industries detect their energy
inefficiencies by measuring and comparing the energy intensity
at process level and overall company level against peers or
industries recognised as the "leader".
The
MIEEIP team, in its efforts to promote the above, organised
a seminar titled "Dissemination of Energy-use Benchmark
for Cement Sector" on 26 July 2002. The seminar was held
in collaboration with the Cement and Concrete Association
(C&CA) Malaysia and the National Productivity Corporation
(NPC). The highlight was to disseminate the findings from
the energy audit and benchmark analysis.
For
the benchmarking exercise, the three cement companies involved
in the energy audit were referred to. The companies are integrated
plant producing Ordinary Portland Cement (OPC) and Masonry
Cement. The analysis was done to compare the specific energy
consumption (SEC) i.e. the amount of energy consumed to produce
one unit of output. The chart below shows the difference in
SECs of the audited companies.
The average SEC for Malaysia is 4.00 GJ/tonne.
This figure is relatively low compared to the international
benchmark due to the concentration on dry cement production
here.
Even then, the local companies can still improve
their specific energy consumption by implementing energy saving
measures identified during the energy audit.
Findings from the energy audit revealed that the cement sector
has potential for energy saving up to 45 percent, of which
17 percent reduction can be achieved without any investment.
For
example, if Company A with an SEC of 3.93 GJ/tonne, the benchmark
for Malaysia, were to implement "no cost", "low
cost" and "high cost" measures, it can improve
its SECs as shown in the graph below. With these changes,
Company A's international ranking can improve dramatically.
The companies can implement the no cost and low cost measures
with their in-house expertise.
Energy saving measures for the cement sector mainly concentrate
on improving the fuel consumption, since more than 88 percent
of the energy composition is thermal energy.
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Use
of biomass as an alternative/supplementary fuel for drying
and heating systems |
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Heat
recovery from the kiln flue gas for raw mill air heaters
and pre-heaters |
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Reduce
the leakage and insulate pre-heaters |
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Application
of variable speed drives for fans and pumps |
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Reduce
the leakage in compressed air system |
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Improve
handling of coal storage and transport to reduce the loss |
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Benchmarking
is a journey towards industrial excellence, and the first
step is to understand the current situation. In the process
of benchmarking, best practices are identified and shared.
This will create an environment for creativity and innovation.
The
MIEEIP team recommends industries to adopt energy-use benchmarking
as a daily productivity improvement tool and are invited to
use NPC's online data collection system where the Industrial
EE Community has been established.
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