Decarbonising the cement industry

This week over 40 leading cement and concrete companies, gathered under the umbrella of the Global Cement and Concrete Association (GCCA), unveiled the industry's '2050 Climate Ambition' and commitment to achieving carbon neutrality:

"GCCA members commit to continue to drive down the CO₂ footprint of their operations and products, and aspire to deliver society with carbon neutral concrete by 2050. GCCA will work across the build environment value chain to deliver this aspiration in a circular economy, whole life context."

The GCCA is a continuation of the Cement Sustainability Initiative, which was established in 2001 to monitoring and report on cement industry carbon emissions. Under the GCCA, the industry has reaffirmed its commitments to CO₂ reduction – in line with the Paris Agreement – while injecting greater urgency to the task by seeking to accelerate the industry’s progress and push innovation across the sector, for example through the Innovandi research network.

Crucially, and unlike the CSI, the scope of the GCCA includes concrete as well as cement. This is logical and acknowledges the fact that much of the CO₂ savings will result from improved concrete formulations, increased recycling of end-of-life concrete, as well as the inclusion of recarbonation in the assessment of the industry’s ability to produce carbon-neutral concrete. Through recarbonation, or carbon uptake, concrete is able to absorb the equivalent of 25 per cent of process CO₂ emissions of the course of its lifetime.

Technology is the solution
While the ambition for carbon-neutral concrete is now the universal target for the cement industry, getting there is another thing altogether. The industry has been striving to reduce CO₂ emissions for decades. Indeed, important progress has been made. GNR global data shows a steady improvement with net CO₂/t cementitious product falling from 755kg CO₂/t in 1990 to 635kg CO₂/t in 2018, or 16 per cent. The challenge is that this trend has not been sustained and the needle has hardly moved over the last eight years, when only a three per cent reduction was achieved (654kg CO₂/t in 2010 vs 635kg CO₂/t in 2018).

Meanwhile, as the GCCA points out, the world’s population is set to grow by one third to almost 10bn people by 2050, 68 per cent of whom will live in urban areas, increasing demand for infrastructure and housing.

As cement consumption increases, a step-change in CO₂ reduction measures will need to be realised. To some extent, the technologies to achieve the decarbonisation of the cement industry already exist.

Advances in co-processing mean that it is technically feasible for a cement plant to substitute 100 per cent of fossil fuels, yet the global average is only 5.6 per cent (while countries such as Germany have exceeded 65 per cent). The problem here lies not with the cement industry but with domestic policies and waste management.

Advances in renewable energy are moving forward rapidly, with wind and solar now offering cement producers the potential to greatly reduce reliance on fossil fuel generated electricity. Projects such as Bharati Cement’s new 10MW solar farm are becoming more and more common.

New binder concepts, in particular calcined clay and pozzolans, offer huge potential for clinker reduction and solutions to tightening supply of traditional SCMs such as fly ash and GGBS. Major equipment suppliers are now promoting flash calciner technologies and other enabling technologies in this space.

Industry 4.0 is also transforming potential for increasing the reliability and efficiency of cement plants, with McKinsey estimating that plants should be able to increase productivity by at least five per cent by embracing the digital plant, while minimising emissions.

Collectively, these technologies will play a vital role as the industry progresses towards full decarbonisation, but alone they are insufficient. Carbon capture, utilisation and storage (CCUS) technologies are expected to take on the majority burden of the abatement task. There are several promising technologies, from post-combustion amine technologies to direct separation technologies under development by the LEILAC consortium. However, it will be many years before they can be widely deployed.

The GCCA will follow up on its ambition statement in 2021 when a detailed implementation strategy will be published with a roadmap to carbon neutrality.

To explore the latest CO₂ reduction technologies and how they will impact the industry in the short and long term, register today for Cemtech’s forthcoming conference: Decarbonising the cement industry