Technology Roadmap Low-Carbon Transition in the Cement Industry

Figure 11: Regional thermal energy mix in cement in the 2DS (continued)
Notes: Results shown for the thermal energy fuel mix of cement are based on the low-variability case of the 2DS. Waste includes biogenic and 
non-biogenic waste sources.
Sources: Base year data from CSI (2017), 
Global Cement Database on CO
2
 and Energy Information
, 
www.wbcsdcement.org/GNR
; SNIC 
(forthcoming), 
Low-Carbon Technology for the Brazilian Cement Industry
.
Waste
Coal
2030 - 2DS
2030 - 2DS
0.0
0.0
0.0
0.0
0.2
0.2
0.2
0.2
0.4
0.4
0.4
0.4
0.6
0.6
0.6
0.6
0.8
0.8
0.8
0.8
1.0
1.0
1.0
1.0
2014
China
2014
India
2014
Africa
2014
Middle East
0.0
0.0
0.0
0.0
0.2
0.2
0.2
0.2
0.4
0.4
0.4
0.4
0.6
0.6
0.6
0.6
0.8
0.8
0.8
0.8
1.0
1.0
1.0
1.0
America
Europe
Other Asia Pacific
Eurasia
2014
2030 - 2DS
2030 - 2DS
2014
2014
2014
2030 - 2DS
2030 - 2DS
2030 - 2DS
2030 - 2DS
Biomass
Natural gas
Oil
Waste
Coal
Biomass
Natural gas
Oil
Challenges to implementation
Although cement kilns could use up to 100% of 
alternative fuels, there are some practical limitations 
preventing that from happening. The physical and 
chemical properties of most alternative fuels differ 
significantly from those of conventional fuels. While 
some (such as meat and bone meal) can easily be 
used by the cement industry, many others can cause 
technical challenges. These are related, but not 
limited, to their low calorific value, high moisture 
content and high concentration of chlorine or other 
trace substances. For instance, metals (e.g. mercury, 
cadmium and thallium) must be managed carefully, 
and proper removal of cement kiln dust from the 
system is necessary. This means pre-treatment is 
often needed to ensure uniform composition and 
optimum combustion, as well as to minimise the 
content of potentially problematic substances.
There are several barriers to increasing the use of 
alternative fuels in the cement industry:
z
Waste management legislation
significantly 
affects availability. Higher substitution of fuels 
only takes place if local or regional waste 
legislation promotes energy recovery in cement 
kilns over landfilling or other less-efficient thermal 
treatment methods, and allows controlled waste 
collection and treatment of alternative fuels. 
z
Local waste collection networks
must be 
adequate.
z
Level of 
social acceptance
of co-processing 
waste fuels in cement plants can notably affect 
local uptake. People are often concerned about 
harmful emissions from co-processing, even 
though emissions levels from well-managed 
cement plants using alternative fuels do not 
represent a specific problem.
z
Complex bureaucracy:
in many cases, obtaining 
a permit for the use of alternative fuels involves 
lengthy procedures and several different 
administration requirements.