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Cement

Not on track
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In this report

The direct CO2 intensity of cement production increased 1.8% per year during 2015-2020. In contrast, 3% annual declines to 2030 are necessary to get on track with the Net Zero Emissions by 2050 Scenario. Sharper focus is needed in two key areas: reducing the clinker-to-cement ratio (including through greater uptake of blended cements) and deploying innovative technologies (including CCUS). Governments can stimulate investment and innovation in these areas by funding R&D and demonstration, and adopting mandatory CO2 emissions reduction policies.

Direct CO2 intensity of cement production in the Net Zero Scenario, 2015-2030

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Tracking progress

Reducing CO2 emissions while producing enough cement to meet demand will be challenging, especially since demand growth is expected to resume as the slowdown in Chinese activity is offset by expansion in other markets. 

Key strategies to cut carbon emissions in cement production include improving energy efficiency, switching to lower-carbon fuels, promoting material efficiency (to reduce the clinker-to-cement ratio and total demand) and advancing process and technology innovations such as CCS. The latter two contribute the most to direct emissions reductions in the Net Zero Emissions by 2050 Scenario. 

Demand for cement in the construction industry drives production and is thus an important determinant of cement subsector energy consumption and CO2 emissions. Initial estimates suggest that 4.3 Gt of cement were produced globally in 2020. This is a modest increase from 4.2 Gt the previous year, driven in large part by infrastructure-related stimulus projects in China. China is the largest cement producer, accounting for about 55% of global production, followed by India at 8%. 

Global cement production in the Net Zero Scenario, 2010-2030

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In the Net Zero Emissions by 2050 Scenario, global cement production stays relatively flat to 2030. Production is likely to decline in China in the long term, but increases are anticipated in India, other developing Asian countries and Africa as these regions develop their infrastructure.  

Adopting material efficiency strategies to optimise the use of cement can help reduce demand along the entire construction value chain, helping to cut CO2 emissions from cement production. Therefore, demand in 2030 in the Net Zero Emissions by 2050 Scenario is 6% lower than in a baseline scenario in which no steps are taken to reduce demand. 

Actions to reduce cement demand include optimising the use of cement in concrete mixes, using concrete more efficiently, minimising waste in construction, and maximising the design life of buildings and infrastructure. Material efficiency efforts have gained increasing support in recent years. 

Globally, the energy intensities of thermal energy and electricity have continued to decline gradually as dry-process kilns – including staged preheaters and precalciners (considered state-of-the-art technology) – replace wet-process kilns, and as more efficient grinding equipment is deployed. 

The global thermal energy intensity of clinker is estimated to have remained relatively flat over the past five years, at 3.4-3.5 GJ/t. Although it has declined in some regions, a slight increase in energy intensity in China has led to an overall global increase. Fossil fuels continue to provide the majority of energy in the cement sector, with bioenergy and biomass-based wastes accounting for only 3% of thermal energy used in 2020. 

In the Net Zero Emissions by 2050 Scenario, the thermal energy intensity of clinker production declines 0.8% per year to a global average of 3.2 GJ/t, and the electricity intensity of cement production falls by 1.9% per year to 84 kWh/t. This excludes additional energy required for emissions reductions technologies such as CCUS. 

The share of bioenergy and renewable waste grows considerably to 15% in 2030 in the Net Zero Emissions by 2050 Scenario. Meanwhile, the share of fossil-based waste (such as tyres, waste oil and plastics) remains at ~5% of fuel use.  

Global thermal energy intensity and fuel consumption of clinker production in the Net Zero Scenario, 2015-2030

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Clinker is the main ingredient in cement, and the amount used is directly proportional to the CO2 emissions generated in cement manufacturing, due to both the combustion of fuels and the decomposition of limestone in the clinker production process. 

From 2015 to 2020, the global clinker-to-cement ratio is estimated to have increased at an average of 1.6% per year, reaching an estimated 0.72 in 2020; this rise was the main reason for the increase in direct CO2 intensity of cement production over the period. 

Although China has one of the lowest clinker-to-cement ratios globally, its ratio rose from 0.57 to 0.66 during 20152020. The main causes are overcapacity, which reduces momentum for more blending to replace clinker, and changes to cement standards, which have eliminated a grade of composite cement. While China was the main force behind the global increase, the clinker-to-cement ratio has also risen moderately in a number of other regions.  

Conversely, the clinker-to-cement ratio falls 0.8% per year to a global average of 0.65 by 2030 in the Net Zero Emissions by 2050 Scenario, owing to greater use of blended cements and clinker substitutes, including industrial by-products such as blast furnace slag and fly ash. 

In the long term, however, alternative clinker replacements that are widely available – such as calcined clay in combination with limestone – will become more important, as the decarbonisation of power generation as well as of iron- and steelmaking will reduce the availability of these industrial by-products.  

CCUS will be crucial to reduce cement sector CO2 emissions, particularly the process emissions released during limestone calcination. While commercial deployment of CCUS is currently limited, a number of innovation efforts are under way in recent years. 

To be on track to achieve Net Zero Emissions by 2050, capture technologies in cement production should be commercialised by 2030. Current efforts include: 

  • commercial-scale CCS facility in Texas that began operating in 2014, capturing 15% of emissions using chemical absorption, the most advanced post-combustion CO2 capture technology. Closer to full capture rates have been achieved by a pilot project (50 ktCO2/yr) that began operating in 2018 at an Anhui Conch plant in China. Higher capture rates are also being targeted by several other projects, including a full-scale Norcem plant in Norway aiming to become operational by 2024, a Lehigh cement plant in Canada for which a feasibility study is being conducted, and a large-scale demonstration at a Dalmia cement plant in India announced in 2019. 
  • The CLEANKER project, which in October 2020 inaugurated a pre-commercial demonstration of a calcium looping carbon capture process at a cement plant in Vernasca, Italy.  
  • joint research initiative launched by four European cement producers in late 2019, which plans to build a semi-industrial oxyfuel test facility in Germany. 
  • Canada’s CO2ment project, which completed its second-phase trials in early 2021, capturing 1 tonne of CO2 per day using a novel physical adsorption technology at a Lafarge Holcim cement plant. In early 2020, several companies initiated a joint study to assess the feasibility of a commercial facility using the same technology in the United States. 
  • Direct separation, which captures process CO2 emissions by applying indirect heating in the calciner. It was successfully piloted by the LEILAC project at a cement plant in Belgium in 2019, and plant design is under way for large-scale demonstration in Germany, to be completed by 2025. 

While at a considerably earlier stage of development than CCUS, electrification of cement production could also help reduce emissions by using low-emissions electricity and by facilitating the capture of process CO2 emissions (i.e. emissions from limestone decomposition during clinker production). 

In Sweden, cement producer Cementa (a subsidiary of HeidelbergCement) and energy producer Vattenfall are working together on the CemZero project to electrify cement production. The feasibility study, completed in early 2019, showed that electrified cement production is technically possible and likely cost-competitive with other options to substantially reduce emissions. The project is continuing with an investigation on how a pilot plant can be built. Similarly, the ELSE project in Norway is investigating kiln electrification, while the UK Mineral Products Association is trialling fuelling kilns with a blend of biomass, hydrogen and electrical plasma.  

Alternative binding materials could also be key to reduce cement production emissions, particularly process emissions. They rely on raw materials or mixes different from those of ordinary Portland cement clinker and are currently at various stages of development. 

Several alternative binding materials are already commercially available, although their use so far has been relatively limited to niche applications. Recent innovation on an alternative binding material developed by Solidia Technologies with potential for very low emissions – carbonation of calcium silicates – led to the launch of a first commercial venture in 2019. However, application is limited to precast products. Continued innovation could further develop and advance opportunities to deploy various alternative binding materials. 

In September 2020, the Global Cement and Concrete Association – comprised of 40 member companies representing ~40% of global cement production – announced its commitment to deliver carbon-neutral concrete production by 2050. This makes cement the first industry subsector to have a global association set a net zero commitment. In October 2021, the association launched its 2050 Net Zero Roadmap , which establishes a pathway and implementation plan to achieve this objective.  

In turn, governments need to create a policy environment that helps cement producers pursue ambitious CO2 emissions reductions. To this end, a number of countries have established carbon pricing systems that cover the cement subsector.  

In the European Union, cement production is covered by the increasingly stringent EU emissions trading system, for which prices reached above EUR 60 (USD 70) in the second half of 2021. Other carbon pricing systems covering cement production include Korea’s ETS and Canada’s output-based carbon pricing system. In China, an emissions trading system came into force in February 2021 to cover just the power sector, but inclusion of several industry subsectors is planned, and experts suggest that cement could be included as soon as 2022

A number of energy efficiency policies also cover the cement sector. In India, it is included in the PAT scheme, a market-based mechanism instituted in 2012 to improve energy efficiency. Its first three cycles are now complete, involving close to 200 cement companies and saving an estimated 13 Mt CO2 emissions in total (equivalent to nearly 20% of one year’s cement sector fuel combustion emissions in India). As cycles are implemented on a rolling basis, the subsequent three cycles are currently under way.  

Nevertheless, further policy efforts in all countries will be required to achieve the Net Zero Emissions by 2050 level of cement decarbonisation. Countries will need to adopt very ambitious and comprehensive policy frameworks to bring the subsector’s CO2 emissions into alignment. 

Decarbonisation of the cement subsector is challenging because relatively few technology options are currently market ready for deep emission reductions and economic incentives to reduce emissions are limited in the absence of strong carbon pricing policies. 

Energy efficiency can be accelerated through collaborative efforts among industry, public sector and research partners to share best practices on state-of-the-art technologies and to develop plant-level action plans that would increase the speed and scale of technology deployment. Ensuring efficient equipment operations and maintenance would also help guarantee optimal energy performance, as would the use of energy management systems. 

The cement industry can also take advantage of opportunities for industrial symbiosis – including using the waste or by-products from one process to produce another product of value – to help close the material loop, reduce energy use and reduce emissions in the case of carbon capture and utilisation. Examples include using steel blast-furnace slag in cement production and waste from other industries as alternative fuels for cement production. 

Greater uptake of alternative fuels can be facilitated by redirecting waste from landfills to the cement industry and by coordinating the supply of sustainably sourced biomass across sectors to enable cost-competitive access for cement production. 

Accelerating innovation and deployment of innovative low-carbon technologies – particularly CCUS and alternative binding materials – will be key to reduce cement production emissions after 2030. RD&D over the next decade is therefore imperative. 

Governments and financial investors need to increase support for RD&D, particularly to advance the large-scale demonstration and deployment of technologies that have already shown promise. Public-private partnerships can help, as can green public procurement and contracts for difference that generate early demand and enable producers to gain experience and bring down costs. Government coordination of stakeholder efforts can also direct focus to priority areas and avoid overlap. 

Governments may also need to develop or modify regulations to facilitate technology uptake. For example, shifting from prescriptive to performance-based design standards (e.g. within building codes) would stimulate uptake of lower-carbon blended cements and cements that include alternative binding materials. 

It will also be important to begin planning and developing infrastructure for the eventual deployment of innovative processes, such as CCUS pipeline networks to transport CO2 for use or storage. Gaining social acceptance for building this infrastructure, particularly CO2 transport and storage facilities, will also be necessary. 

Policymakers can promote CO2 emissions reduction efforts by adopting mandatory reduction policies, such as a gradually rising carbon price or tradeable industry performance standards that require average CO2 intensity for production of each key material to decline across the economy and permit regulated entities to trade compliance credits. 

Adopting these policies at lower stringencies in the short term (within the next three to five years) will provide an early market signal, enabling industries to prepare and adapt as stringency increases over time. It can also help reduce the costs of low-carbon production methods, softening the impact on cement prices in the long term. Complementary measures may be useful in the short to medium term, such as differentiated market requirements (i.e. a government-mandated minimum proportion of low-emission cement in targeted products). 

While a considerable proportion of cement production is not exposed to cross-border competition, measures will be needed to help ensure a level global playing field if the strength of policy efforts differs considerably from one region to another. Governments can extend the reach of their efforts by partaking in multilateral forums to facilitate low-carbon technology transfer and to encourage other countries to also adopt mandatory CO2 emissions policies. 

Improving the collection, transparency and accessibility of cement subsector energy performance and CO2 emissions statistics would facilitate research, regulatory and monitoring efforts (including, for example, multi-country performance benchmarking assessments).  

Consistently reported data covering a larger share of global production is especially needed, as reporting from some key regions is currently limited. Industry participation and government coordination are both important to improve data collection and reporting. 

Notes and references
  1. US Geological Survey, Cement Statistics and Information, https://www.usgs.gov/centers/nmic/cement-statistics-and-information 

  2. GCCA (Global Cement and Concrete Association), Getting the Numbers Right, https://gccassociation.org/sustainability-innovation/gnr-gcca-in-numbers/  

Analysis