This is the fourth and final article in a series to look at global cement sector trends over the past 40+ years. This time we take stock of recent events and how they will inform the exciting future of our industry...
1 Corporate - Models and economies
The first three articles in this series placed cement producers at the heart of the story, with technologies, energy, fuels, raw materials, products and corporate trends all discussed at length. This is due to the commoditised nature of the global cement sector during most of that time, when the steady production of large volumes of inexpensive cement would ensure success. The customer was mostly absent from the discussion, too busy waiting in line for their allocation: They got what they were given. This dynamic has already changed, with customer requirements rising up the priority lists of cement sector managing boards. In the future, we expect that the balance of power will shift even further towards customers, with their increasingly demanding and - on the face of it - contradictory requirements.
Over the coming decades, we can liken the ‘Great Ship Cement’ to that of Odysseus, the Greek King who took 10 years to reach home after the Trojan War. Among the challenges he faced were two sea-goddesses. On one side of the ship was the six-headed Scylla, who devoured those that got too close. On the other side was Charybdis, who drank and ‘belch’d forth’ the sea, wrecking any ship within range. The challenge to navigate safely between the two is complicated by their proximity. Odysseus managed it, although he lost a few sailors to Scylla rather than risk losing the entire ship to Charybdis. The goddesses have since been rationalised as submerged rocks and a whirlpool: less supernatural but still very dangerous, even for the best crew.
This is the challenge now faced by the global cement sector. On one side, Scylla: markets that demand more building materials than ever before due to massively growing populations and greedy economies that devour new projects - commercial, residential and public. Devastating modern wars will sadly add to this demand. This demand will present companies with the drivers to produce more materials. All of the sector’s collective experience to date appears to indicate that this is a demand for ‘cement,’ but that’s not necessarily the case.
On the other side, Charybdis: a never-ending swirl of demands for net-zero-CO2 cement with increasingly sophisticated properties. This presents the opportunity to attract customers by offering innovative solutions, as all parties seek to develop buildings that are fully connected, automated, breathable, smart and secure. This list will only continue to grow in the future, with pressures to improve an increasing number of sustainability metrics: Scope 3 emissions, zero-waste, low water demand and more - all while ensuring resilience against flood, fire, wind and extreme heat.
The Great Ship Cement must navigate the tricky waters between its own Scylla and Charybdis and - in the face of climate change - turning back is not an option. To reach ‘home’ - in this case a steady sustainable new normal - producers must pay attention to both demands. Focusing too much on one risks neglecting the other and - with it - disaster. Only the best crews will make it through unscathed.
This means that the business model of the 21st Century will be to do more - and better - with less. The prospect of meeting rising demand with net zero construction practices and products that don’t yet exist is certainly daunting, but to paraphrase Jeff Bezos... “When the world changes against you, what used to be a tail-wind is now a head-wind. You have to lean into that and figure out what to do, because complaining isn’t a strategy.”
So what is the strategy? In short, there are many. There will be fundamental changes in the way construction projects are studied, engineered, procured and executed. The coming transition will require us to redefine what ‘cement’ is and how it is made. It will blur the lines between producer and consumer. It will require the construction sector to use every tool in the box to develop new kinds of architecture, new kinds of cities, decarbonised manufacturing technologies and innovative, low- or no-clinker cement blends.
Within this, the cement industry will be forced to innovate like renewable energy or AI developers do today, not only by developing new products, but entirely new markets and mindsets. As oil producers are morphing into energy suppliers, so cement producers must morph into building materials suppliers or even building suppliers. Some are already taking the initial steps.
Beyond this, all organisations, from start-ups to giant corporations, will have to partner across the complete supply chain to design and optimise what is being built before it is actually built. They will need to plan what, where and how to build. This will apply not only to the buildings themselves, but the infrastructure we build to produce the necessary building materials.
The push from national, regional and municipal authorities will also become stronger. They are already becoming more involved through prescriptive specifications and leading the push to sustainable and healthy cities, lower water demand and all the other modern priorities. As a sign of how this is changing, the authors have worked in the cement sector for more than 40 years, but did not meet with local authority staff until the 2020s.
The flowering of new technologies, products, partnerships and business models will lead to many losers. Some existing cement companies - as well as others in the supply chain - will simply not be able to please the new customers, markets and partnerships that develop. Their old operations, products, skills, ways and mindsets will become less and less competitive, and opportunities to improve will become scarcer and scarcer. As Odysseus shows, there will also be winners, even when navigating such treacherous waters, even if the criteria by which they will be deemed winners is currently unclear.
There is but one certainty among this sea of uncertainty: this period will retrospectively be known as the Construction Renaissance. For leaders, investors, business developers, scientists and engineers already in the industry - and even those just entering the industry, new skills will have to be learned... and fast. These include, but are not limited to robotic construction, polymerisation of aluminosilicates and the intricacies of cryogenic carbon capture.
On the corporate side, leaders will have to build lasting industrial partnerships, identify and attract innovators and those from other industries, develop public private partnerships and assimilate incredibly diverse business cultures at speed. Our industry will define the beautiful, net-zero, connected and efficient new cities, highways and energy infrastructure of the future, and much more besides.
2 Technology and operations
After 200 years of ‘business as usual’ since Joseph Aspdin’s 1824 patent for Portland cement, we now face an urgent challenge. How can we make it without emitting CO2? The entire world is at war on CO2. As in any war, there will be casualties and new technologies will emerge. Fortunately the casualties in this case will be technologies and businesses rather than lives.
Of course, cement producers are not alone in the battle. Coal-fired power technologies that date from the 1880s are being shut down. The internal combustion engine (ICE), first commercialised in 1876, is under severe pressure from electricity and hydrogen. Even the blast furnace, the principles of which were developed more than 2000 years ago, seems destined for the history books.
While modern cement kilns are more than twice as thermally efficient as the above technologies, reaching 60-65% in ideal trim, the basics have barely changed in the five years from 2018 to 2023. There remain opportunities to improve cooler recuperation and preheater exhaust temperatures, the two main areas where heat losses are most significant. No doubt these efforts will continue for as long as there kilns that make clinker.
Grinding, of both raw meal and clinker, remains an area where major efficiency improvements could still be achieved. Those entering the industry are still astounded when a 5% ball mill grinding efficiency is quoted in their introductory training. High pressure grinding rolls and vertical mills have improved this to 10%. Does the future hold a technological leap forward in grinding efficiency?
The global cement sector has made great strides in the arena of harmful emissions - dust, NOx, SOx, dioxins and furans. Setting Best Available Technology (BAT) levels for each species undoubtedly advanced the technologies available to abate them. Now the industry is making net-zero commitments regarding CO2. The bulk of the initial work can be summed up by one word: alternative. Alternative fuels (AF), alternative raw materials (ARMs), alternative cementitious materials and additives, alternative construction and design, alternative methods of planning highways and cities, and alternative cement blends. All of these alternatives have seen different growth trajectories over the past 40+ years, with AF being the most significant. Combined, they will contribute strongly to our sector’s CO2 reduction goals.
After the ‘main course’ of ‘alternatives,’ CO2 capture and storage (CCS) is waiting as ‘dessert’. It seems that this will become an essential part of every cement company’s route to net zero. The concept is deceptively simple. Instead of being released to the atmosphere, CO2 will be captured, cleaned, concentrated and pumped underground to be stored... forever. One does not need to be an engineer to imagine the technical challenge and sheer cost of such operations. Capture, cleaning and transport will require new technologies and come with substantial energy and maintenance costs. Safe storage will require preparation, security, government regulations and leak prevention.
There are four over-arching technologies for CCS: solvents, membranes, sorbents and cryogenics. Each has sub-technologies and cement producers also have available at least three other industry specific options: LEILAC, oxy-fuel looping and calcium looping. Evaluating the options will be the most complex task the cement industry has faced in a very long time. Justifying the business cases and day-to-day operations could prove to be even harder.
In the face of the high barriers to CCS, another letter - U for utilisation - may come to the rescue. It makes commercial sense to convert the CO2 into valuable commodities - from synthetic jet fuel to carbonated drinks - to pay for its capture, processing and transport. However, CCU has its own challenges. Numerous different industries will need to align to make it feasible and ensure that CO2 is not re-released to the atmosphere ‘post-utilisation.’
3 Energy, emissions, alternative fuels / materials
The years 2018-2023 were characterised by near unprecedented energy price volatility. Coal fell from US$100/t in 2018 to US$60/t in early 2020, then soared to US$400/t in early 2022, before dropping to US$160/t at the end of 2023. Petcoke followed coal, with a variable discount in US$/GJ terms.
As we look to 2024 and beyond, the pattern of variable energy costs is likely to continue. However, traditional fuels result in the some of the highest CO2 emissions, so the writing is on the wall. While several more glamorous solutions are in development spectrum, AF is a key lever in the net-zero journey. Unfortunately, global AF progress remains agonisingly slow, increasing from a thermal substitution rate (TSR) of 7% in 2013 to just above 10% in 2022.
However, the technology exists to take this much further and faster. Europe points the way. With investments in correct alternative fuel preparation technology there will be progress. We know several drivers that governments can use to accelerate progress: Carbon pricing, either via an EU ETS-style cap-and-trade system or simple tax, increased landfill taxes, direct legislation that forces waste be used for energy recovery, fossil fuel taxes, BAT rules or simple mandates are all options. Direct solar, hydrogen and electric-to-thermal technologies will also play a part, particularly if fusion power becomes a commercial reality.
There is also a long history of alternative raw materials being used in the cement industry. The emphasis has moved towards raw materials that contain calcium without the associated CO2. Waste slags and construction waste are high on the agenda. Steel slags now appear to be the leader in this field, particularly since the number of electric arc furnaces is set to increase as blast furnace numbers decline. The use of steel slags as a kiln feed also takes advantage of its free lime content, which has prevented its significant use as a supplementary cementitious material (SCM) due to expansion issues. Relatively high levels of chromium VI in clinker made using steel slag could be a limiting factor, but greater use is still likely to be around the corner.
When adding SCMs to ground clinker, ground granulated blast furnace slags (GGBFS) has been the industry preference for more than 50 years. GGBFS use has risen since 2018 as low-CO2 products have gained prominence. Over the same time-frame, there has been a spectacular rise in the value of GGBFS, reaching parity with CEM I in Europe. However, the supply is threatened by the phasing out of blast furnaces. The decline of GGBFS volumes seems inevitable, with the only uncertainty being the speed of the decline.
Fly ash, the second most important SCM, also has many useful properties, but quality issues, especially residual carbon content, and geographical and seasonal supply-demand mismatches have held it back. Even the most optimistic estimate suggests that less than 25% of the fly ash produced globally has been utilised in cement and concrete, with billions of tonnes having been landfilled. As with blast furnaces, the future of coal-fired power stations is one of steady decline. However, improvements in ash beneficiation have made recovery and treatment commercially viable, opening up vast legacy deposits. The US, France and the UK are leading the trend. Others will follow.
Natural pozzolans, mainly volcanic ash, have been used in cement recipes for millennia, albeit usually where deposits offer consistent high-quality material. As with fly ash deposits, technologies are helping to iron out inconsistencies and open up previously unusable reserves.
However, the greatest centre of attention in the rest of the 2020s - and beyond - will be artificial pozzolans. Clays with kaolin, montmorillonite and illite have long been known to be activated via thermal treatment, but only kaolin / metakaolin has been targeted as a high value artificial pozzolan. Brazil has led the way as the only user of significant quantities of calcined clays, largely thanks to its national standards. However, there is now huge research into artificial pozzolans from a variety of players, many of which have been covered in these pages.
Could steel slags also have a part to play in plugging the cementitious gap? The technical challenge certainly is high due to its variable activity, variable expansion issues and the aforementioned chromium content. However, with billions of tonnes of steel slag available in dumps, the prize is highly significant. Without doubt there will be a proliferation of technology in development studies to promote steel slags in the SCM value chain.
Finally, cement grinding remains a critical area for development in order to fully optimise the use of SCMs. There is a growing belief that delivering cements that offer full hydration and strength development must be pursued.
4 Products
Since their inception, cement standards have largely concerned cement ‘recipes,’ that, unfortunately, do not necessarily optimise clinker usage. Recent modification of the EN 197 standards in Europe has only added further recipes. In the US, ASTM C1157 is probably the most well-developed example of a performance-based standard for cement. It has existed since 1992 but remains in competition with recipe-based standards such as ASTM C150. The question of changes from existing recipe-based standards to performance-based standards in other countries / regions remains open, with many who are engaged in the production of novel blends keen to draw attention to their cause. It will become a more pressing need as new cement formulations reach maturity.
There are many new cementitious solutions emerging to challenge the status quo. All offer the opportunity to reduce the CO2 footprint of cement to varying degrees. The current leader is perhaps geopolymer cement. First patented in Germany in 1908, there were two significant incursions into the Portland cement market in the 20th Century. The first was Purdocement in 1950s Belgium, although it did not remain in the market for long. Pyrament emerged in the 1980s in the US but failed to hit significant volumes due to its high cost and a conservative market.
Over the past 10 years, geopolymers - based on either calcined clays or GGBFS / fly ash - have been relaunched into a far more receptive market. Many companies have launched their own brands, but volume growth is slow – still hindered by cost, insufficient standards and conservatism within the construction industry, as well as some performance considerations. However, we argue that none of these constitutes a fatal blow. Greater pressure from further start-ups should push the product to market.
There are many other formulations of cementitious products in various stages of development. These include magnesia-based cements, calcium sulphoaluminate, calcium aluminate and Belite-Ye’elimite ferrite. There are many other less well known technologies emerging in the wings too. Watch this space.
5 Conclusion
To quote D H Lawrence...“Everyone dreams: but not equally. Those who dream by night in the dusty recesses of their minds, wake up in the day to find it was vanity. But the dreamers of the day are dangerous people, for they may act their dreams with open eyes, to make it possible.”
The industry leaders today are already pushing their organisations to meet growing construction demand with the net-zero solutions of the future. To do this, a complete change in the industry is unfolding in front of our eyes through new types of customers, partnerships, technologies, innovation hubs and myriad other ‘stars.’ These must all align to help us navigate on our odyssey towards building more - and better - with less. Together we have the tools to avoid both Scylla and Charybdis!
Gregory Bernstein
Gregory Bernstein has worked for Holcim for more than 30 years. He met Lawrie Evans in the UK in the early 1990s, before taking on process, project, strategy, well cement and business development roles in the UK, Europe and the US.
Lawrie Evans
Lawrie Evans founded EmCem Ltd, a UK-based cement consultancy, in 2014. He previously worked for more than 40 years at Italcementi, Heracles Cement and Blue Circle in the UK, Greece, the US and Italy across optimisation, management, operations and chemical engineering.
