Cement production is responsible for around 5% of global CO2 emissions. The European industry constitutes around 10% of global cement production and is therefore a key industry under EU targets to reduce emissions. The burning of fuels such as petroleum coke or coal in the calcination process that turns limestone into clinker, causes emissions of CO2 to the atmosphere. Almost twice as much CO2 is actually produced by the calcination reaction itself. Since the basic chemistry cannot be changed, the industry has had to find other ways to reduce the CO2 output. Nevertheless, emerging innovative products like the carbon negative cement Novacem, based on magnesium silicate, might reduce the energy consumption during the manufacturing process and push innovation in the ‘green’ low-carbon segment of the building materials sector.
In Europe, in order to reduce energy consumption and CO2
emissions, the industry is focusing on increasing the use of clinker
substitutes in cement, the use of alternative fuels and energy
efficiency measures. The new research assessed the cost-effectiveness
of several other energy efficiency measures, including modifications to
the reaction chamber (kiln), recycling waste heat and carbon capture
and storage (CCS) of CO2 from the waste gases.
Cost-effectiveness was estimated using a computer model to calculate
how long it would take for the savings from each measure to match the
cost of the initial investment, known as the Pay Back Period. The model
individually assessed 477 kilns in 294 production facilities within the
European Cement Association (CEMBUREAU). For some measures, the Pay
Back Period was less than a year. This included converting kilns from
traditional ‘wet’ facilities to ‘dry’ facilities, which require half as
When all measures with Pay Back Periods of less than two years were
considered, total energy consumption (across all cement facilities)
decreased by 9.2%. This figure was 10.8% for Pay Back Periods of less
than three years, and 15% for Pay Back Periods of less than 9 years. CO2
emissions were reduced by 3.4% for processes with Pay Back Periods of
less than two years, and up to 5% for Pay Back Periods of less than 9
years. The energy efficiency gap, that is, the lack of deployment of
all potential improvements at hand, independent of the decision
criterion considered (the payback period, the net present value or the
internal rate of return) requires a condusive policy environment that
combines support for both technology development and its deployment.
The results also demonstrate that recycling waste heat is close to
being cost-effective as the market price of electricity will affect the
decision on investment. The project’s required minimum electricity
price to make a worthwhile investment would be €0.08 per kWh.
Cement production could be an ideal candidate for CCS, since the
concentration of CO2 in the waste gases is very high. But at present,
CCS is far from being cost-effective (this is dependent on factors such
as electricity and CO2 allowance prices) and is not expected
to be available before 2025. The urgency of climate change action means
that there is little ground for further delaying implementation of at
least the most cost-effective measures. First steps could include
encouragement for phasing out ‘wet’ facilities, say the researchers.
The use of alternative raw materials and fuels and the decrease of
clinker to cement ratio are also likely to influence the industry in
To learn more about low-carbon technology innovations in the cement industry, please see: http://setis.ec.europa.eu/
Innovative Ways to Reduce CO2 Emissions from the Cement Industry
Technological advances in European cement production could reduce energy consumption by up to 10% and CO2 emissions by 4%, according to a new analysis. The research suggests that initial costs of some of the pending technological improvements could be recouped in as little as a year.