CO Capture and Storage - Energy and Climate: How to Achieve a Successful Energy Transition - page 113

The main application expected in the future is the recovery and storage
of CO 2 emitted by fossil fuel power plants, which amounts to 40%of CO 2
emitted worldwide.
Coal-fired power plants clearly represent the main target to be consid-
ered. The first way to reduce their emissions is to improve the efficiency of
the plant, by increasing the pressure at which steam is generated and the
temperature at which it is superheated. It requires the use of highly
performing steels.
The average efficiency of coal-fired power plants is around 30%
worldwide. It can approach 45% for the most modern installations
nowadays. In the near future, it might become close to 50% if ultra-
supercritical cycles are used 2 .
Emissions per kWh produced are inversely proportional to the efficien-
cy and increasing the efficiency is the first action to undertake, before
capturing and storing CO 2 .
Nevertheless, deploying CCS is the only way to curb sharply the
emissions from fossil fuel power plants in the future. In order to achieve
such a goal, it is necessary to overcome obstacles which are not only
technical but also economical. In the case of coal-fired power plants,
CO 2 emissions amount to around 600 kg perMWh of electricity pro-
duced for 50% of efficiency and 800 kg for 40%. This has to be
compared with 300 kg in the case of a gas-fired combined cycle with
efficiency close to 60%.
For a cost of 50 for each ton of CO 2 not emitted to the atmosphere as a

result of the application of CCS, an additional cost of

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40 perMWh has
to be taken into account, which means that the cost for each MWh of
electricity produced is almost doubled.
It is expected that CCS might become operational for fossil fuel power
plants by 2020.
During a first phase, CCS might be used mainly in conjunction with
EOR, the CO 2 source being provided by natural gas processing units.
During a second phase, beyond 2020, new industrial projects might
involve CO 2 recovery from flue gases and CO 2 injectionindeep
aquifers.
CCS can also be applied in other industrial sectors which are large
emitters of CO 2 . For its production, 1 ton of steel generates 1.8 ton of CO 2
and 1 ton of cement generates 0.89 ton of CO 2 .

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2 These are cycles inwhich steamreaches temperatures around 700 C, which is much higher than
the water critical temperature (374 C), requiring the use of compatible materials.