Page 57 - 2022 Sustainability Report
P. 57

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
        businesses — we also believe it is important to recognize  data generated by our Continuous Emission Monitors
        both critical regulatory differences between the U.S. and  (CEMs) and reflects actual measured CO . If instead of this
                                                                                                2
        the EU (and other international jurisdictions) and differing  method, we were simply to switch to the World Business
        calculation methodologies that result in meaningful   Council For Sustainable Development (WBCSD) calculation
        differences in the makeup of corresponding end-products  method, and make no change to our actual clinker factor,
        and reported emissions metrics. Those differences, in turn,  our intensity would drop from 0.725 to 0.62.
        make like-for-like comparisons of the emissions
                                                              In addition, alternative fuel use by the cement industry
        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
                                                                                                   2
                                                              Union and as high as 60 percent in Germany. In large part,
                                                              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
                                                              WBCSD method as noted above do not include the biogenic
        the range of 28 percent to 50 percent, depending on the
                                                              or alternative fuel CO contributions. Again, if we used a
                                                                               2
                      1
        type of cement. Accordingly, even where their clinker
                                                              hypothetical 75% clinker factor and calculated our
        intensity (the amount of CO generated in producing a
                                2
                                                              emissions using the Global Cement and Concrete
        tonne of clinker) is comparable to our 2022 rate of 0.829
                                                              Association (GCCA)/European calculation method and
        gross metric tonnes of CO /metric tonnes of clinker (and in
                               2
                                                              our current fuel mix, we estimate that our intensity
        many cases is actually higher), international cement
                                                              would see a further reduction to approximately 0.53
        companies can reduce the carbon intensity they publicly
                                                              net metric tonnes of CO /metric tonnes of cement
                                                                                   2
        report by simply substituting higher percentages of non-
                                                              equivalent basis.
        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 intensity would be
        reduced from 0.725 to approximately 0.62 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.


                                                                                            MARTIN MARIETTA 55
   52   53   54   55   56   57   58   59   60   61   62