Cement Americas

APR 2019

Cement Americas provides comprehensive coverage of the North and South American cement markets from raw material extraction to delivery and tranportation to end user.

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22 CEMENT AMERICAS • Spring 2019 • www.cementamericas.com FEATURE emissions between 2000 and 2015. In contrast, GHG emis- sions in the Chinese cement industry increased by more than 200 percent over the same timeframe, which the paper neglects to mention in its efforts to position the Chi- nese cement industry as a model of environmental perfor- mance. The California cement industry's achievements are impres- sive by almost any standard, not just in comparison to Chi- na. For instance, the 20 percent decrease in the California cement industry's emissions is three times greater than the 6.4 percent reduction in statewide GHG emissions over the same timeframe. Given these facts, the California cement industry's perfor- mance in recent years is best described as an environmen- tal policy trifecta – reduction of GHG emissions, improve- ment in energy efficiency and greater use of lower-carbon fuels. All of this was accomplished while minimizing GHG emissions leakage, recovering from one of the most severe downturns in the industry's history, and complying with California's other stringent environmental regulations. The California Cement Industry Is Just As Carbon Efficient As Other High-Performing Cement Industries When Com- pared On An Apples-To-Apples Basis. The paper's conclusion that the California cement industry is "substantially dirtier" than cement industries in other nations is based exclusively on the results of its so-called "benchmarking " analysis. Although the benchmarking analysis is flawed in several respects, the authors' most egregious error is in manufacturing "apples-to-oranges" comparisons. Specifically, the authors measure CO2 intensity on a per- ton-of-cement basis, which introduces an extreme bias against the California cement industry. To understand the nature of this bias, note that the primary purpose of a cement plant is to produce clinker, which is the key bind- ing agent in cement and accounts for the vast majority of GHG emissions in the concrete supply chain. Various types of cement are then created by blending clinker with other substances, including gypsum, limestone and supplemen- tary cementitious materials (SCMs). The addition of these other substances effectively "dilutes" the amount of clinker, which reduces the amount of GHGs per ton of cement without any change in the environmen- tal performance of the plant. This bias is compounded by the fact that SCM blending can happen at either the cement plant or the ready-mix concrete facility. In fact, in most countries, it is customary to add SCMs at the cement plant. As the paper states, however, "in the United States (includ- ing California), most SCMs are added at ready-mixed con- crete facilities." The Sierra Club paper acknowledges this important distinc- tion in several places, but then inexplicably ignores it when conducting the benchmarking analysis. By conducting their benchmarking exercise on a cement basis, the authors virtually ensure that the California cement industry will appear to be worse than all other cement industries.

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