Technology Roadmap Low-Carbon Transition in the Cement Industry

2
 emissions in cement production by scenario
3 000
3 400
3 800
4 200
5 000
0
500
1 000
1 500
2 000
2 500
2014
2020
2025
2030
2035
2040
2045
2050
C
e
m
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n
t
p
ro
d
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(M
t
ce
m
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t
/y
r)
D
ir
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ct
C
O
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m
is
si
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s
(M
tC
O
/y
r)
2
2
2DS Process CO
2
2DS Energy-related CO
2
RTS Direct CO
2
B2DS Direct CO
2
Cement production
4 600
KEY MESSAGE: The B2DS would require the cement industry to increase by about 45%
the cumulative carbon emissions reductions effort compared to the 2DS, which is
the reference carbon emissions reduction scenario for this roadmap’s vision.

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21
3. The vision
Figure 6: Global final energy demand and direct CO
2
 intensity of cement 
production in the roadmap vision (2DS)
Notes: Waste includes biogenic and non-biogenic waste sources. Petroleum coke is reported within oil.
0.00
0.15
0.30
0.45
0.60
0
2
4
6
8
10
12
14
2014 2020 2025 2030 2035 2040 2045 2050
Fi
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d
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a
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(E
J)
Low-variability case
Electricity
Waste
Biomass
Natural gas
Oil
Coal
Direct CO intensity - 2DS
2
Direct CO intensity - RTS
2
0.00
0.15
0.30
0.45
0.60
0
2
4
6
8
10
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14
2014 2020 2025 2030 2035 2040 2045 2050
D
ir
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C
O
in
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ty
(t
C
O
/t
ce
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t)
2
2
High-variability case
Total CO
2
emissions from cement making can be 
decreased by reducing the clinker to cement ratio.
14
Process CO
2
emissions released from raw materials 
during the production of clinker can therefore 
be decreased by integrating alternative cement 
constituents that reduce the clinker to cement ratio, 
which drops by 5% globally by 2050 in the roadmap 
vision. This enables a reduction of the process CO
2
intensity of cement of 30% by 2050 from current 
levels, with 364 million tonnes of carbon dioxide 
(MtCO
2
) of carbon emissions savings. This is 
equivalent to 16% of current global direct CO
2
emissions from cement making. 
The reduction of the clinker to cement ratio also 
enables CO
2
emissions savings related to the 
avoided thermal energy consumption that results 
from a lower clinker demand for the same amount 
of cement produced. Cement constituents that 
can be used instead of clinker include gypsum, 
natural volcanic materials, limestone and industrial 
by-products such as GGBFS (generated in the iron 
and steel industry) and fly ash (produced in coal-
fired thermal plants), as well as others derived from 
widely available resources such as calcined clay. 
14. Clinker is the main constituent of most types of cement. The 
share of clinker in cement on a mass basis is defined as the 
clinker to cement ratio.
KEY MESSAGE: A reduction in the direct CO
2
 intensity of cement of 32-38% is supported by a global 
reduction of the share of fossil fuels in cement kilns of 24-27% by 2050 in the roadmap vision.
The calcination process of raw clay would incur 
additional thermal energy needs. These are 
estimated to increase the thermal energy intensity 
of clinker by 11% globally in the roadmap vision 
by 2050 compared to the average thermal 
energy intensity of clinker in that same year. The 
reduction of the clinker content in cement is highly 
dependent on the local availability of cement 
constituents instead of clinker, as well as on the 
required properties for the final cement product, 
which are dictated by local standards and technical 
requirements of the end-use applications.
The roadmap vision assumes that the integration of 
carbon capture technologies in cement production 
reaches commercial scale by 2030. Captured CO
2
emissions represent 25% of the total emitted CO
2
in the sector globally in 2050, or 552 MtCO
2
/yr as