Page 64 - 2023 Sustainability Report

ENVIRONMENTAL STEWARDSHIP

Understanding the Impact of Blending Alternate Fuel Use
and Fuel Choice
Similarly, not only is clinker substitution different around
While we are proud of these achievements — and, in fact, the world, but the reported numbers are being generated
as discussed below, we have committed to further reduce using different calculation methods. Our reported intensity
the carbon intensity of our cement and Magnesia is based upon the USEPA Clean Air Act Part 98 and the
Specialties businesses — we also believe it is important to data generated by our Continuous Emission Monitors
recognize both critical regulatory differences between the (CEMs) and reflects actual measured CO . If instead of this
2
U.S. and the EU (and other international jurisdictions) and method, we were simply to switch to the Global Cement
differing calculation methodologies that result in and Concrete Association (GCCA) calculation method, and
meaningful differences in the makeup of corresponding make no change to our actual clinker factor, our intensity
end-products and reported emissions metrics. Those would drop from 0.619 to 0.564.
differences, in turn, make like-for-like comparisons of the
In addition, alternative fuel use by the cement industry
emissions performance of such companies challenging.
in the United States averages only 15 percent of the fuel mix,
compared to 36 percent of the fuel mix used in the European
Clinker Substitution and Blending
Union and as high as 60 percent in Germany. In large part,
2
this is because combustion of secondary alternate fuels is
For example, outside of the U.S., the allowable rate of
incentivized in the European Union, whereas in the U.S.
“clinker substitution” — the replacement of ground clinker
environmental laws and USEPA regulations create hurdles to
in cement with alternate materials such as pozzolan, slag
using these materials as fuel sources. Moreover, the
and fly ash — is much higher than it is in the U.S. because
calculation of reportable CO emissions under international
2
of the limitations imposed by ASTM and Department of
regulations differs materially from the calculation allowed
Transportation (DOT) standards for cement. While our
under USEPA regulation. The European Union Gross CO 2
clinker substitution rate (like other U.S. producers)
Emission rates exclude CO emissions from biogenic fuels
2
generally does not exceed 20 percent, the average clinker
while the widely reported Net CO emission rates using the
2
substitution rate for international cement companies is in
GCCA method as noted above do not include the biogenic or
the range of 28 percent to 50 percent, depending on the
alternative fuel CO contributions. Again, if we used a
2
type of cement. Accordingly, even where their clinker
1
hypothetical 75% clinker factor and calculated our
intensity (the amount of CO generated in producing a
2
emissions using the GCCA calculation method and our
tonne of clinker) is comparable to our 2023 rate of 0.760
current fuel mix, we estimate that our carbon intensity
gross metric tonnes of CO /metric tonnes of clinker (and in
2
would see a further reduction to approximately 0.519
many cases is actually higher), international cement
net metric tonnes of CO /metric tonnes of cement
2
companies can reduce the carbon intensity they publicly
equivalent basis.
report by simply substituting higher percentages of non-
clinker products for clinker in their end product, rather
than actually reducing total emissions or improving
efficiencies in the manufacturing process.
In fact, if we used a hypothetical 75% clinker factor
for our cements, we estimate our carbon intensity
would be reduced from 0.619 to approximately 0.570
gross metric tonnes of CO /metric tonnes of cement
2
equivalent.
1 European cement standard EN 197-1 “Cement – Part 1: composition, specifications and conformity criteria for common cements”, as reported by CEMBUREAU.

62 2023 SUSTAINABILITY REPORT