Supplementary binders help global cement industry cut CO2 emissions 17 percent
- Written by CP Staff
The World Business Council for Sustainable Development (WBCSD) Cement Sustainability Initiative’s Getting the Numbers Right (GNR) database indicates producers reduced specific net carbon dioxide emissions per ton of cementitious product to 1,261 lb. (629 kg/tonne) in 2011 from 1,515 lb. (756 kg/tonne) in 1990. CSI membership includes all multinational companies with integrated North American operations.
The latest GNR data spans 55 percent of cement milling outside China and reflects key emissions reduction drivers during the past two decades: lower clinker content via blended-powder offerings; investment in more efficient kiln technology; increasing substitution of coal with alternative fuels; and, an 8 percent decrease in electricity use per ton of cement. WBSCD officials note how the figures evidence significant environmental progress through a gradual decoupling of emissions and output: GNR companies increased cement shipments 74 percent between 1990 and 2011, while increasing absolute CO2 emissions only 44 percent.
CSI’s clinker-to-total binder ratio underscores the scale of supplementary materials adoption. Although the figures exhibit some variations in different regions due to the specific minerals added in concrete production, the clinker-to-total binder ratio globally measured 76 percent in 2011, against a 1990 average of 83 percent.
“GNR demonstrates how an effective measuring, reporting and verification system can be developed and managed by an entire industry sector,” says WBCSD Managing Director Philippe Fonta, adding that the database “has become established as a valuable source of independently verified emissions data [for] the cement industry to improve energy efficiency and further reduce emissions.”