Carbon dioxide emissions from the global cement industry

The cement industry contributes about 5% to global anthropogenic CO₂ emissions, making the cement industry an important sector for CO₂-emission mitigation strategies. CO₂ is emitted from the calcination process of limestone, combustion of fuels in the kiln, as well as from power generation. In this paper we review the total CO₂ emissions from cement making, including process and energy-related emissions. Currently, most available data only includes the process emissions. We also discuss CO₂ emission mitigation options for the cement industry. Estimated total carbon emissions from cement production in 1994 were 307 Million Metric tonnes of Carbon (MtC), 160 MtC from process carbon emissions and 147 MtC from energy use. Overall, the top ten cement producing countries in 1994 accounted for 63% of global carbon emissions from cement production. The average intensity of carbon dioxide emissions from total global cement production is 222 kgC/tonne cement. Emission mitigation options include energy efficiency improvement, new processes, shift to low carbon fuels, application of waste fuels, increased use of additives in cement making, and on the long turn alternative cements and CO₂ removal from flue gases in clinker kilns.