The cement industry must do better to meet climate change targets

“From 2014 to 2016, the direct CO₂ intensity of cement showed little change, as thermal energy efficiency improvements were offset by a slight increase in the global clinker-to-cement ratio,” said the IEA’s TCEP assessment of the cement industry. “To meet the IEA SDS objectives, the direct CO₂ intensity of cement needs to decline by 0.3% annually through to 2030, even as cement production is expected to grow.”

According to the IEA, the thermal energy intensity of clinker production must fall by 0.1% a year to a global average of 3.3 GJ per tonne of clinker, while electricity intensity must fall by 0.3% to 87 kWh per tonne of cement. “Progress is particularly needed in Eurasia, which has the highest thermal energy intensity of clinker production at 5.7 GJ per tonne [of clinker], primarily due to the continued use of wet-process kilns,” the IEA said.

The use of alternative fuels as a proportion of thermal energy use in cement manufacture will also need to rise from 6% in 2016 to 18% in order to meet the SDS goals by 2030. Meanwhile, the clinker-to-cement ratio needs to fall to a global average of 0.64 by 2030 through the use of blended cements and clinker substitutes, such as blastfurnace slag and flyash.

“In the long run, alternative clinker replacements that are widely available, such as calcined clay in combination with limestone, become more important, as the decarbonisation of power generation and iron and steelmaking reduced the availability of these industrial byproducts,” added the IEA.

A final piece in the sustainability jigsaw will be the development of carbon capture technologies, including oxyfuel and post-combustion capture, at a commercial scale.

“These objectives must all be met while annual cement production continues to grow through to 2030 at an average annual rate of 0.2%,” concluded the IEA. “Production is likely to decline in China in the long term, but growth is expected in India, other developing Asian countries and Africa as these regions develop their infrastructure.”

“Adopting material efficiency strategies to optimise the use of cement in concrete would help reduce emissions along the whole construction value chain through reduced demand growth.”

Read the article online at: https://www.worldcement.com/special-reports/30052018/the-cement-industry-must-do-better-to-meet-climate-change-targets/