Technology breakthrough for direct electrification – A new climate path for the cement and steel industry?

"So far, in relation to the decarbonisation of energy-intensive industrial processes such as steel and cement, the focus has primarily been on CCS and on the development of green hydrogen and electrolysis technologies. But technological breakthroughs in direct electrification of heavy industrial processes challenge this narrative”

Technology breakthrough for direct electrification of heavy industry
challenges the CCS strategy

We are on the threshold of a number of completely new technological breakthroughs in relation to the electrification of energy-intensive production processes in industry. This also applies to a large extent in relation to steel and cement production, which for many years have otherwise been notoriously known as some of the most difficult industrial sectors to adapt to the climate (hard-to-abate sectors).

However, in recent years there have been major breakthroughs in relation to indirect electrification with the development of hydrogen-based production technologies (PtX), which open the door to a production based on renewable energy rather than fossil energy sources such as coal, oil and gas.

In addition, we are also seeing major breakthroughs for technologies that enable the direct electrification of energy-intensive industrial processes. There are thus today several companies that have promising technologies that demonstrate that the electrification of even high-temperature processes (1500-2000 degrees), which are currently necessary in the production of both steel and cement, is actually possible. In a few years, direct electrification has therefore gone from being perceived as an impossibility in relation to energy-intensive production, to being a real possibility for steel and cement production.

From several sides, there is thus today a clear expectation that production based on direct electrification can reach commercial scale within a time horizon where the technologies can have a reduction effect before 2030. See table 1.

Table 1: Technology Readiness Level list of selected projects focusing on direct electrification of steel and cement production

based on information from the companies and division into TRL levels

In several ways, this is good news for the climate. If we succeed in developing and scaling solutions that enable electricity-based production processes, we can use fossil-free electricity directly from renewable energy sources such as sun, water and wind. Direct electrification of these heavy industrial processes therefore opens the way for far-reaching, efficient and potentially cheaper climate change. It is a big step forward for the solutions that we have had so far in relation to the decarbonisation of the energy-intensive industries, as the solutions so far have not proved to be mature or effective enough, nor economically profitable. This applies to both hydrogen-based solutions, where the energy consumption is very high [1], and CCS (carbon capture and storage), which many still consider to be an absolute key technology in relation to climate change, but which has not yet proven its worth in relation to climate reduction[ 2].

Figure 1. Overview of TRL level – from 1-9 (Iowa Technology Institute [3])

FT. Technology Readiness Level (TRL), is an expression of a technology's development from research to commercialization and is placed on a scale from 1-9. TRL 1 is basic research, while levels 2-4 describe activities within technological research, 5-8 is the product development phase and level 9 is final production and marketing of the technology. There is generally a technology level of 6-7 for most direct electrification technologies, with CCS technologies currently ranking within 8-9 on the scale.

Most demonstration projects and pilot plants with direct electrification are not yet at commercial scale and have a technology readiness of 6-7 on a scale of 1-10, with CCS estimated to be on the way to 9. But the number of companies, the speed with which they win forward, and the very short time horizons that are currently planned for i relationship to scaling testifies to possible technology breakthroughs that could become a massive game changer in the way we solve the climate headaches of energy-intensive industry.

Policy recommendations: Direct electrification must be the first priority

In recent years, we have seen an increased political focus and the initiation of a number of initiatives both at home, in the EU and globally to push for decarbonisation of both steel and cement production. Among other things, the EU has launched the so-called "Net-Zero Industry Act", which aims to create better conditions for market development for low-emission technologies and support the EU's efforts to become independent of imported energy, including from Russia.

At home, several initiatives aimed at CO have also been launched₂-reductions in the energy-intensive industry – especially with massive investments and pools for CCS and on a smaller scale for PtX. See Figure 2.

Figure 2: Politically, the CCS path has been chosen

Footnotes: The category 'Direct electrification' also includes investments related to energy efficiency, conversion and electrification. In addition to the above investments, a green margin has been set aside in the Finance Act, where DKK 1,5 billion has been reserved. NOK in 2024 and 3,25 billion DKK annually from 2025-2040 for, among other things, electrification and PtX. The money from the discretion is paid out under the individual finance act.
Source: RGO (based on political agreements on climate and energy)

There is still a long way to go, both at home and at political EU level, when it comes to taking into account the technological progress of recent years, which has taken place in relation to direct electrification. This can be seen both in policy development and in the funds allocated to innovation and development within climate technologies. An example: In 2022, the Danish Energy Agency[4] estimated that only 5 percent of brick and cement production is expected to be electrified directly in 2050. In contrast, a number of research papers[5] and concrete projects point to a much greater reduction potential for direct electrification.

As long as the new technologies and progress are not taken into account, we will not get the right incentives and taxes, as well as the allocation of funds in place, to be able to seriously support and accelerate the direct electrification of the energy-intensive industries. One must therefore abandon the notion that direct electrification is not an option. Politically, electrification must be seen as a crucial part of the solution for energy-intensive industries – and as a must win in the battle to decarbonise high-energy-intensive industrial processes such as in steel and cement production.

The Council for the Green Transition therefore believes that there is a need for a rethinking of the climate policy in relation to the energy-intensive industries and the very clear commitment that CCS is the climate technology
that will bring us to the finish line.

It is therefore absolutely crucial that politically:

Reassessing the CCS effort – and the current political consensus that CCS is the best and absolutely necessary solution for the decarbonisation of energy-intensive industries. Despite many years of development and large sums of investment, CCS is still an immature and pre-commercial technology, where the climate effect and the time horizon [6], in relation to technology maturation, are still very uncertain. Therefore, the Green Transition Denmark recommends that a temporary pause be taken, during which an independent and critical analysis is made of whether the expectations for CO₂-catch and storage in Denmark holds. Before the state opens new bidding rounds and directly supports CO₂-the capture technology, an independent body – such as e.g. The Climate Council - get time and resources to make a more thorough investigation of the prerequisites.
Earmarks public funds for research, development and scaling of electricity-based production technologies and energy storage technologies. There is a need to set aside public kroner for research and development within direct electrification – this will benefit Danish production companies, including the cement industry in relation to climate reductions, but it could also be a leverage to be able to strengthen Danish companies' opportunities on a global market, where electrification technologies are gaining momentum.
Introduces CO₂- tax on cement production. There is a need for the government here to revisit the agreement on the green tax reform, including the decision to introduce a CO₂- charge. Here it is important that CO₂-the tax is phased in and increases faster than what is planned now. Where the so-called mineralogical processes – including cement production – must be included, so that they are also required to pay for the CO₂, they emit (in addition to the quotas they pay/have to pay via the EU's quota system). This will give the cement industry a clearer incentive to reduce CO₂- the discharge, and it will also make good sense from a socio-economic point of view. The economic sages have calculated [7], "that the concluded agreement on green tax reform for industry and beyond entails additional socio-economic costs in 2030 of approx. DKK 1,7 billion annually compared to a uniform CO₂-taxation that achieves the same reductions.”
Ensures a large enough supply of renewable energy for production in energy-intensive industries that are based on electricity. Production based on renewable energy sources - and including electrification solutions and possibly hydrogen, will require much more speed in the roll-out of renewable energy, both on land and at sea, if the supply is to be able to keep up with the demand for green electricity. In the EU, things are going too slowly – and this also applies here at home, where the roll-out of renewable energy has largely stagnated in recent years, and where the path to a quadrupling of electricity from solar and wind on land by 2030 seems somewhat unclear [8] . In the last five years, only an extra 1,4 GW of solar and wind energy has been installed on land. The government's new renewable energy plan in no way indicates how it will be realized, and therefore a new and clear plan with clear priorities and deadlines for renewable energy is needed. There seems to be a particular lack of tangible financial incentives for the municipalities to take on a task that often meets local resistance. Today, municipal politicians largely only make a fuss out of such projects - without being able to argue with noticeable improvements to the municipal economy. Part of this is also to ensure investments in the expansion of the energy infrastructure, which must support the conversion of the energy grid.
Uses public procurement as a driver. As it stands today, the public sector is not subject to green requirements in relation to purchases [9] – this also applies to construction and facilities, where they make bulk purchases of steel and cement. If green requirements are introduced as part of public tenders, the climate footprint of the public sector can be reduced. At the same time, it is made much more attractive for companies to invest and develop green solutions, as the public sector, qua its economic muscles, is an attractive customer.
Places itself in the ambitious field in relation to the EU's climate and industrial policy. It is important that Denmark puts greater pressure on the EU in relation to ambitious legislation that can further promote electrification. This applies both in relation to setting up renewable energy, but also investment and legislation, which can create a better incentive for companies to invest in the development of technologies that enable direct electrification.

The energy-intensive industry: Large and growing climate footprint

Steel and cement are today two of the biggest climate headaches both here at home, in the EU and globally. Cement is one of the most used materials in the world and accounts for approx. 8 percent of the global and 4 percent of the EU's CO₂-emissions. The steel industry today accounts for approx. 5 percent of the EU's CO₂-discharge. Worldwide, the consumption of steel is estimated to make up between 7-11 percent of the global climate footprint.

Both steel and cement are materials that are used on a large scale both for construction and construction and for the production of, for example, cars and wind turbines, where there are currently no obvious and perfectly good alternatives. These are materials that our society is deeply dependent on, both in relation to mobility and infrastructure and the green transition. See Figure 3.

Figure 3: Steel is included as an important component across society (ING, 2023 [12 ])

There is therefore not much to suggest that our dependence and consumption of steel and cement will decrease in the coming years. On the contrary. Forecasts show that demand for both materials is expected to increase towards 2050. Global cement production is expected to increase by almost 50 percent from the current level of 4,2 to 6,2 billion. ton per year in 2050 [10]. The demand for steel is expected to increase by 30 percent in 2050 compared to 2022 [11].

This will potentially have large and negative consequences for global CO₂-emission, if new technologies and methods are not developed and implemented to produce both steel and cement with a much smaller impact on the climate as a result.

Energy-intensive production

A major reason for the high climate footprint of both cement and steel is that today's production process is extremely energy-intensive. Production takes place in so-called high-temperature ovens, which are heated by adding large amounts of fossil energy. For example, Aalborg Portland's so-called rotary kiln 87 is today heated up to 1.500 degrees when it has to produce cement clinker [13].

Especially for cement, there is also a further major climate challenge in the use, specifically of limestone (chalk), which is today the primary raw material for the production of cement. The chemical formula for lime is CaCO₃. When the lime is heated, CO is released₂, and today it makes up around 50-55 percent [14] of CO₂- the discharge from cement production when it has to be converted into so-called cement clinker.

In steel production, the process in which iron ore is converted into pig iron today requires coal-fired blast furnaces that burn at up to +1.100 degrees [15]. In addition, there is the process from iron to steel, where in a new high-temperature process oxygen must be added to reduce the carbon content and thus be able to obtain the desired steel alloy. It is also a chemical process which in itself emits a small amount of CO₂ as a waste product.

Both at home, in the EU and globally, the high-temperature processes, in both the production of cement and steel, are still deeply dependent on fossil energy sources – including coal, oil and natural gas and a smaller proportion of biomass. For example, Aalborg Portland's rotary kiln is heated primarily with petroleum coke and coal and to a lesser extent natural gas and biogas. See Figure 4. On a global level, it is more than 70 percent [16] of the steel that is produced today, which is produced with coal as an energy source. The rest is produced based on scrap metal in an electric melting process. And every time you produce one tonne of steel based on virgin materials, up to two tonnes of CO are released overall through the process₂.

Figure 4: Aalborg Portland's energy consumption for cement production, (Aalborg Portland, 2022 [21])

"Every time one tonne of steel is produced, up to two tonnes of CO2 is emitted"

If you look at CO₂-the emission per ton of cement, emitted (including energy consumption and calcination process) on average, according to the International Energy Agency (IEA)[17], 600 kg of CO₂. In research article l from the scientific magazine Joule, which has looked at the climate footprint of cement production at the manufacturers Cemex, Heidelberg Cement and LafargeHolcim, thus also shows that 561-622 kg of CO are emitted₂ per tons of cement produced, with minor differences related to the materials used to make the cement, the type of cement kiln and the use of different types of fossil fuels [18].

An estimate from the IEA [19] thus shows that steel and cement, together with chemicals, are globally responsible for more than half of the total industrial energy consumption. According to an analysis by the United Nations Economic Commission for Europe (UNECE) and the Economic Commission for Western Asia (ECWA), steel and cement also account for 52 percent [20] of the direct CO2 emissions from the industrial sector on a global level.

The transition is too slow

Generally speaking, things are going far too slowly here at home, in the EU and in the rest of the world when it comes to climate reductions in both the cement and steel industries. In their calculations of how different industries are in relation to climate change, the IEA thus assesses both steel and cement production to be "not on track".

According to the IEA [22], the total CO₂-emissions from the iron and steel sector have thus not decreased over recent years. On the contrary, emissions from the steel industry have increased globally. The primary reason for this is that in recent years we have seen significant increases in demand for steel. But when you look at the energy intensity in relation to steel production, there have also been only minor reductions over recent years.

The IEA [23] also estimates that the emissions for cement production have remained stable over the last five years, with a small (1 percent) increase in 2022, and the IEA thus also points out that the cement industry, in line with the steel industry, is also far from up in gear when it comes to annual reduction rates. The required rate of reduction is estimated to be 4 percent per year until 2030 in order to be in line with the net-zero scenario in 2050.

This also applies here at home

If you look here at home and at Aalborg Portland [24], there is also a long way to go in terms of realizing reductions in the climate footprint to the extent that is needed if the Aalborg cement producer is to be able to stay within the reduction targets, which are in the Danish climate act – and reduces at a pace that is necessary for net zero by 2045.

Fortunately, the cement manufacturer has reduced its CO₂- emissions in scope 1 from 2.341.966 tonnes in 2020 to 1.981.746 in 2022. In the same period, the energy intensity has improved from 958 to 868 KG PER TCE (tonnes of coal equivalents) - partly because they have integrated more biogas as an energy source in the production. They have also reduced the amount of white cement produced, which emits significantly more than traditional gray cement. However, the cement giant's scope 3 emissions have increased in the same period – by 240.000 tonnes of CO₂ from 2021-2022 (there is no data for scope 3 in 2020). If you look at Aalborg Portland's climate plan towards 2030, the cement producer expects to obtain the most climate reductions from CCS going forward. They have a concrete objective of reducing their climate footprint, so that they emit a maximum of 600.000 tonnes of CO₂ per year in 2030 – of this, they estimate that 1 million tons of the required reductions must come from CCS. See case about Aalborg Portland.

Case: Aalborg Portland – can biogas and CCS climate-proof production?

Aalborg Portland is Denmark's largest and only cement producer - and Denmark's absolute most CO₂-dischargeable company, as they account for as much as 4,5 percent of Denmark's total discharge. Therefore, seen in the light of the increasing climate requirements both in Denmark and in the EU, there is a natural pressure on the Aalborg company in relation to finding ways to achieve significant climate reductions within the coming years. Currently, 50 percent of Aalborg Portland's emissions in Scope 1 come from the consumption of fossil fuels and 50 percent of the emissions from lime production.

Last year, Aalborg Portland presented a roadmap for a net zero target in 2050. Towards 2030, the concrete climate reduction target for the cement producer is 1,6 million tonnes of CO₂. The cement group has set a ceiling on CO₂-the emission of a maximum of 600.000 tonnes in 2030, regardless of activity level, and this corresponds to a reduction of 73 percent compared to the emission in 2021.

In relation to their 2030 ambition, it is currently planned that part of the reductions must come from new, more climate-friendly types of cement and a transition to a production that is based to a greater extent on alternative fuels. In relation to new products from the cement manufacturer, they have launched Aalborg Solid and Futurecem, which respectively emit 20 and 30 percent less than traditional gray cement [25].

In relation to alternative fuels, Aalborg Portland aims to replace conventional fossil fuels such as petroleum coke and coal for heating the rotary kilns. The transition to alternative fuels will take place in stages, first from petroleum coke and coal to natural gases, then to biomass and finally to biogas. There are currently no plans for Aalborg Portland in relation to direct electrification of their production.

They are far from the only cement or steel producer to bet on bioenergy. Among others, the steel producers, German Stahl-Holding-Saar and Spanish Rio Tinto, today, as a clear part of their decarbonisation strategies, have to switch from coal to bio-based energy. Although it immediately opens for CO₂-reductions, it is, however, a reduction path with very large limitations. Bioenergy is indeed a very limited resource, and according to the European Energy Agency (EEA)[26], there will be a great need to begin to prioritize much more sharply in relation to who gets access to it.

The EU [27] thus also does not assess that there will be sufficient bioenergy available to be able to supply enough for a bio-based production of steel within the union's borders. Therefore, there is a need for other scalable solutions in the conversion of steel and cement.

The largest part of the reductions will be obtained by Aalborg Portland via CO2 capture, which according to their current reduction plan must deliver a CO2 reduction of 1 million. tonnes per year in 2030. See figure 5. Aalborg Portland has so far initiated two CCUS pilot projects (carbon capture utilization storage) and in 2022 completed their first pilot project to capture CO2 in collaboration with, among others, DTU with support from the Innovation Fund. In 2023, they launched the so-called ConsenCUS project, which is a "collaboration with a number of research institutions and companies from several parts of Europe, on a pilot plant for CO2 capture. The purpose of the project is to test a new electricity-based capture technology within CCUS, which can potentially halve the energy consumption for CO2 capture and ensure better utilization of the collected CO2."

Figure 5: CO2 capture is a crucial part of Aalborg Portland's 2030 strategy (Aalborg Portland, 2022 [28])

The ConsenCUS plant is to replace Aalborg Portland's first pilot plant for CO2 capture. The plant, which it is hoped can capture up to 2,4 tonnes of CO2 per day, is scheduled to be put into operation at the end of 2023 and must be tested at Aalborg Portland until March 2024.

However, there are also a number of caveats here, which must be taken into account when it comes to the realism of that objective. So far, CCS on cement production is still only on a pilot scale, and in the tests and pilot plants that have been so far, there have been a number of challenges in terms of efficiency, energy consumption and costs. The chemical processes in the calcination process also mean that CO₂'one in the flue gases is very impure and therefore difficult to capture.
See text box 1.

Text Box 1: CCS is not yet at scale

Many pilot projects with CCS for cement and steel production

Today there are many CCS pilot projects and demonstration projects on the drawing board around the globe, but there are still no well-functioning and economically sustainable projects for CO₂- capture on a larger scale within the energy-intensive industries such as cement and steel. In the cement industry, there are several plants under way, but we still need to see a large and scalable project that is also financially connected. There is a small plant at a cement factory in San Antonio, Texas that captures between 30-50.000 tons of CO₂ tonnes/year. ArcelorMittal has opened a CO₂-capture plant at an iron and steel plant in Belgium (Steelanol), where it is hoped to be able to capture 125.000 tons of CO₂ per year, but it is still not fully operational. Norwegian Heidelberg cement has been trying for several years to get a capture plant up and running at their Norcem cement factory in Porsgrunn. However, there have been major delays and cost increases on what has been launched as the world's first large-scale plant with CO₂-trapping in the cement industry. The Norcem Brevik plant, which has cost over DKK 4 billion. Norwegian kroner (or just over 3,2 billion Danish kroner) must capture 0,4 million tons of CO₂ per year. Danish FL Smidth is also involved in the plant, which is scheduled to run at full scale from 2025.
It is not yet known whether it will succeed.

Land gains on the way

Both large and international companies in cement and steel production and a number of smaller startups have in recent years put decarbonisation on the agenda and initiated several innovation initiatives and demonstration projects. There are several that focus on CCUS projects, but there is also increasing attention and more and more projects that focus on electrification – including both direct and indirect electrification (hydrogen). See text box 2.

In the EU and in the USA, several companies are in full swing developing and testing new ways of production that can enable the direct electrification of cement and steel production. This applies both in relation to production processes, which currently takes place at high temperatures and in relation to new types of raw materials, which enable less energy-intensive production processes (production at lower temperatures is less energy-intensive) and thus can contribute to reducing emissions. This applies, among other things, to the development of alternatives to lime in the production of cement clinker. See cases page 15-19.

Finnish-Dutch startup Coolbrook has developed a technology for electrified kilns for cement production that can reach over 1700 degrees. The electrified ovens are powered directly from renewable energy sources and thus avoid the use of coal and gas. Among other things, they have partnered with the Mexican cement producer Cemex to scale their technology. They expect that the technology will be ready for commercialization on an industrial scale in 2024. In relation to reduction potential, the assessment is that the electric kilns can reduce cement production's CO₂-discharge by 45 percent.

Text box 2: Hydrogen – indirect electrification, but not without challenges

Several large steel and cement producers are investing large sums in these years in the development of hydrogen-based production as an alternative to coal and other fossil energy sources. Among other things, the Swedish steel producer SSAB has an ambition to be able to produce what they themselves call "fossil-free steel" and has established a so-called Hybritt pilot warehouse, which stores hydrogen produced by electrolysis based on renewable energy. The hydrogen must be used for the direct reduction of the iron ore, which removes the oxygen from the iron ore, instead of CO₂- heavy coke. SSAB plans to launch its first commercial “fossil-free” steel in 2026. ArcelorMittal, the world's largest producer of steel, is another example. They produce 88 million tonnes of steel/year – a production which today is based on coal and methane gas. ArcelorMittal has entered into an agreement with the German electricity supplier RWE to establish offshore wind and hydrogen facilities, which will be the primary part of the energy input for their German steel production. They want to establish a pilot plant with 70 MW in 2026. They also reached an agreement with the Spanish government back in 2021 – and received 1 million euros in public support – to switch to hydrogen-based steel production at their factory in the Spanish city of Gijón . According to AncelorMittal, this will be able to reduce CO₂-the emission by 4.8 million tonnes until 2025.

Another completely new concept is American Sublime Systems, which has developed a new method to produce cement via an electrolysis process based on electricity instead of fossil or other fuels and with the possibility of using less CO₂-containing raw materials other than lime. Sublime System's technology thus potentially eliminates both the use of fossil energy for heating and CO₂- the discharge from the traditional calcination process of lime. If calcium from raw materials other than lime is used, they can completely avoid the process emissions of CO₂. But Sublime's new process can also use lime, where the CO₂, which is discharged, can be tapped off at 10 bar pressure and room temperatures, and thus easily sent on to a CO₂- warehouse. Thus, the potential CO₂-reduction of 100 percent.

Similarly, we see examples within steel production. Among others, the American startup Electra, which will produce steel at 60 degrees through a chemical process. It opens the way for the production of iron completely without fossil energy in the process, where iron is separated from the iron ore, which accounts for 90 percent of the emissions from the production of steel.

The American startup Boston Metal's technology also replaces the use of fossil fuels with energy from renewable energy sources through an electrolysis process in the production of steel. Their technology further opens up the possibility of going directly from the process of extracting iron from the iron ore to casting steel – because their production process eliminates the need for additional chemistry and refining to turn iron into steel. They expect to be able to go to market with a commercial product in 2026.

In addition, more CO has been used over many years₂- friendly production of new steel products based on recycled steel. Here, electricity is used as the primary energy source rather than coal. That process emits 70 percent less [29] than the production of virgin steel – and the reduction potential is greater if the electricity comes from solar and wind in the future.

The transition from fossil fuels to an indirect electrification through hydrogen can be an important step in the right direction to reduce CO₂- the emissions in the energy-intensive industry – including cement and steel production.

But it is not always as good a climate solution as direct electrification. The production of hydrogen is primarily very energy intensive. This is because the electrolysis process, where renewable energy is converted into green hydrogen, is an inefficient process with very large energy losses during the process. One third [30] of the energy used is lost. This also makes the process very expensive in terms of financial terms. With a direct electrification of the production, there is not the same energy loss, as the energy can be utilized to the full. The same amount of energy is therefore better utilized in direct electrification.

In addition, it is not certain that the hydrogen is really climate friendly. 99 percent of the world's hydrogen production is produced today with fossil fuels. There is therefore a risk that the production of hydrogen will not contribute to the decarbonisation of the energy-intensive industries if not enough renewable energy is developed to produce green hydrogen. In other words, indirect electrification is not particularly energy or climate efficient compared to direct electrification. In addition, there is a risk of leakage [31] and the release of hydrogen has a warming greenhouse gas effect, and this simultaneously requires increased safety, as hydrogen is flammable and explosive. A study [32] published in Nature estimates warming to be more than 11 times as harmful to the climate as CO₂ seen over 100 years. Other studies [33] have shown that hydrogen over 20 years can be between 19-38 times more harmful than CO₂.

An often-advanced argument for choosing hydrogen rather than choosing direct electrification is that it is not possible to achieve high-temperature heat without combustion. However, changes to processes and technological breakthroughs in the area mean that some processes can probably take place at significantly lower temperatures. But even for temperatures above 1.500 degrees it may be possible to electrify directly, as long as there is a stable electricity supply. See cases page 14-18.

With the current development and progress in the direct electrification of heavy industry – including cement and steel production – care should therefore be taken in introducing hydrogen, as investments in infrastructure and production equipment can lock the industry into indirect electrification and thus delay a more efficient direct electrification . Over the coming years, there are potentially good opportunities for the vast majority – if not for virtually all – industrial companies to electrify directly and thus reduce the need for hydrogen.

Great potential for direct electrification

For many years, direct electrification has not been considered a real possible way to go for cement and steel production in particular. There are a large number of analyzes and reports which uncover the potential for electrifying energy-intensive industrial processes. But the vast majority of those reports primarily look at the potential for electrification of heating and indirect electrification – with hydrogen. The focus on indirect rather than direct electrification must be seen in the light of the fact that many of the technologies that enable direct electrification are new and still at pilot project level.

But the direct electrification of energy-intensive industries may now be facing a breakthrough. See text box 3. The potential is great. It shows, the research paper "The CO₂ reduction potential for the European industry via direct electrification of heat supply (Power-to-heat)” [34], which emphasizes the possibility of direct electrification of heavy industry in the EU. The paper includes both known and new technologies and, based on these, it is assessed how far we can get on the path to electrification (direct electrification) - including a particular focus on cement, steel and chemicals, which "are the most challenging to electrify." Thus, their calculations do not include indirect electrification through hydrogen. Their estimates indicate that, based on known and new (immature and unsafe) technologies, it may be possible to electrify a total of up to 60 percent of the energy consumption in the production process of chemicals, steel and cement respectively. See Figure 6. This is in sharp contrast to the Danish Energy Agency's assessments from 2022 [35], where only 5 percent of brick and cement production is expected to be directly electrified in 2050.

Text box 3: Breakthrough for the electrification of high-energy industrial processes
extends beyond cement and steel

Outside the steel and cement industries, but within other types of energy-intensive industries, electrification is also advancing rapidly. One example is the chemical industry, where there is also a growing focus on the electrification of production processes, which can replace fossil fuels with renewable energy sources. It is something among other Danes Haldor Topsøe focus on.

Another example is the production of mineral wool, where Danish Rockwool has succeeded in electrifying the rock melting process, which takes place at a very high temperature of over 1.000°C. At Rockwool's factory in Norway, they have replaced the traditional "cup ovens", heated with fossil or biogenic fuels, with an electrically heated process.

Progress is also being made in the production of aluminium, which for many years has already been based on electricity as an energy source through the so-called Hall-Heroult electrolysis process. However, a large part of the electricity for the production of aluminum today comes from fossil energy sources, because the industry has no longer been able to find cheap hydropower resources. There are places, for example in the Nordic region, where hydro energy is used instead of special coal in production. Furthermore, as it appears today, carbon anodes are primarily used in the process that releases CO₂ , as part of the electrolysis process in the production of virgin aluminum (the electrical energy flowing through an anode is what makes aluminum melting possible). Several companies are currently switching to inert anodes. IEA estimates that it is used in around 7 percent of the total aluminum production and points out that it is a significant step in the climate change of aluminum production. Companies that have projects underway with the implementation of inert anodes therefore also expect large reductions in the use of inert anodes. Among other points Eurometaux on a reduction potential of 50 percent in relation to aluminum's overall climate footprint in production.

Figure 6: Great electrification potential with new technologies (IOP science, 2020 [37])

Specifically for cement, CO is assessed₂- the reduction potential for production's total climate footprint by direct electrification, to be 31 percent. A large part of the emissions comes from the process of converting lime into cement clinker, which, according to the researchers, will require either CCS or alternative raw materials for lime.

The report may underestimate other ways to reduce emissions from cement production – including the use of calcined clay and fly ash as a substitute for limestone. It has shown its potential in relation to reductions in CO₂- the emissions in cement production and which several companies including FLSmidth and Heidelberg are testing in various innovation projects. Heidelberg estimates that there is a reduction potential of 40 percent [36] of the total CO₂- emissions from cement production by replacing cement clinker with calcined clay.

In addition, a material such as limestone fired clay can be produced at only 800°C, a temperature that can be achieved with electric rotary kilns or flash burners that can be powered by renewable energy. For steel, the research article points out that a scenario where we base production on scrap metal rather than virgin materials (iron ore), which can be produced with electricity, would be able to reduce energy consumption from this sector by 70 percent and CO₂- the emission by 74 percent.

The question, however, is how far the use of scrap metal can go, especially in a scenario where the demand for steel increases. According to the European Steel Association [38], today +60 projects within the EU are underway with a technology readiness of at least 7 out of 9, which are expected to be able to produce commercial-scale steel with far less CO₂footprint by 2030, based on both indirect and direct electrification. See figure 7.

ESA's estimates indicate that, overall, they have a reduction potential of 81.5 million tonnes per year from 2030. This corresponds to reducing the total CO₂-footprint from steel with a third in the EU.

Figure 7: Several electrification projects underway in the EU's steel industry (Source: Eurofor, 2023 [39])

Barriers: CCS, finance, deployment of RE and scale

Although there is a lot in several of the new technologies and innovations within the electrification of cement and steel production, which are positive, and which at first glance appear to have great climate potential, as it appears today, there is still a a number of barriers that stand in the way of scaling and commercialisation.

One of the biggest barriers in relation to the electrification of both steel and cement is a very large focus on CSS. This applies both from the political side and to players in both the steel and cement industries.

It has been the opinion for many years that CO₂-catch and storage is an absolutely decisive tool in relation to both industries' climate change. Back in 2021, the IEA [40] thus also estimated that CCUS facilities/technology must be established on more than 53 percent of global steel production in 2050 if we are to stay within the net-zero target. That is why large sums of money have been invested in CCS in recent years, both at home and in many other countries. In Denmark alone, DKK 38 billion has been set aside. DKK to CCS over the next 15 years. For comparison, 1,25 billion has been set aside so far. DKK to PtX, which is also considered a crucial building block in the decarbonized energy system of the future. See text box 4.

Box 4: Political preference for CCS

Both at home and in the EU, large sums of money have been earmarked in recent years for the development of technologies and efforts that can reduce the climate footprint of the energy-intensive industry.

Until now, a majority in the Danish Parliament, in a series of broad political settlements since 2020, has set aside DKK 38,7 billion. DKK to CO₂-catch, -storage and -use, and it is hoped to be able to capture 3,2 million tons of CO₂in 2030. In the spring, Ørsted received just over DKK 8 billion. DKK for a large CO₂-capture facility, and on 20 September a broad settlement was reached at Christiansborg to hold two bidding rounds in 2024 and 2025, where they will give DKK 26,8 billion. DKK to capture 34 million tons of CO₂ over fifteen years. It is expected to be able to realize a total of 3,2 million tonnes of CO₂ reductions in 2030.

For comparison, in relation to hydrogen, which is another politically popular investment area, 1,25 billion has been set aside. DKK with the so-called Agreement on the development and promotion of hydrogen and green fuels, from 2022. The ambition here is that Denmark should aim to build 4-6 GW of electrolysis capacity in 2030.

The government mentions in many places that the investment in CCS is due to the fact that there are no alternative ways to minimize emissions from "difficult" sectors such as heavy industry, agriculture and sea and air transport. Many international analyses, e.g. under the auspices of IPCCi and IEA, has had the same approach. To that extent, it is commendable that the government and the Folketing also address the climate challenges for "difficult" sectors. But as described in this note, the assumption that CCS is the only or best solution hardly holds true for cement and steel production

With the large sums that are planned to flow towards CCS projects over the coming years, there will naturally be fewer funds for other types of climate solutions. Another significant barrier is finances and costs associated with the conversion to electrified production. The development of and the transition to new production technologies that can enable electrification is a costly affair – which requires both capital for risky pilot plants, up front investments for building new facilities, new production chains and, as it appears today, will also come with higher operational costs. A study from 2020, made at the behest of ITRA - Energy-intensive industries - challenges and opportunities in energy transition [41], thus estimates that the conversion to a CO₂-neutral economy will "result in price increases of 2-11 percent in the most energy-intensive sectors such as refineries, cement, fertilizers and iron and steel." An analysis in relation to additional costs for green steel in Sweden [42] estimates that switching from coal to hydrogen "under current conditions and Swedish electricity prices will add around 10% to the price of a ton of unfinished steel" - and that's without additional capital costs associated with rebuilding and redesigning production facilities. It may be more cost effective to go the direct electrification route as the energy efficiency of hydrogen is still a cost challenge. Coolbrook, which has developed a direct electrification technology for the production of steel, thus also estimates that their technology will be between 30-60 percent cheaper than hydrogen-based steel production.

As it stands today, the financial framework is not sufficiently ambitious to ensure the necessary financial incentives that can pave the way for the necessary investments in the transition to electrified production. The ITRA study estimates that there is still a far greater need for investment in the EU than what is made available today, among other things with reference to the fact that the EU's allowance prices are not high enough in relation to promoting decarbonisation to a sufficient extent and pace, among other things of steel and cement. It is also a barrier to a large extent here at home, where it has been politically decided that the cement industry and other mineralogical processes must have a lower CO₂- tax than other sectors. In relation to steel, a large part of Denmark's consumption is imported from countries outside the EU, which do not have quota regulation or a climate tax. Therefore, the climate footprint is not reflected in the price - and there are no financial incentives to opt for greener solutions. With the introduction of CBAM, however, the EU is tightening up the quota regulation of steel and cement, which will in future make it more expensive to import steel and cement from countries without climate regulations. This can make investments in green solutions, including electrification, more attractive. See text box 5.

Text box 5: CBAM

The risk of leakage has been high on the climate agenda for many years. It has filled in relation to CO₂- tax, quotas and ensuring fair international competition.

The EU's answer to this is the so-called Climate Border Adjustment Mechanism - CBAM - which is supposed to prevent a distortion of competition between European producers, who increasingly have to pay for their CO₂- emissions and producers in countries outside the EU that are not equivalent, or are required to pay climate quotas, and can therefore sell equivalent goods with a lower price tag.

This is particularly true of the climate-heavy industries in the EU, which are particularly sensitive to international competition:

Cement
Iron and steel
Aluminium
Artificial fertilizers
Electricity

With CBAM, which is being tested right now and is expected to be introduced from 2026, goods from outside the EU within the particularly climate-heavy industries will thus be charged a cost that corresponds to the EU's quotas when they have to be sold on the European market.

Another challenge is that today there is not enough speed in the roll-out of renewable energy to ensure that there are sufficient terawatts to be able to ensure a green production of energy-intensive materials. Among other things, the research paper "The CO₂ reduction potential for the European industry via direct electrification of heat supply (Power-to-heat)” [43] that electrification of the steel industry in Europe will require 2-3 times more electricity than what the industry uses today (1786-2313 THW). In comparison, the total production of electricity in 2021 in the EU was 2785 TWh – of which only 32 percent was from renewable energy sources. See Figure 8.

Figure 8: Production of electricity, EU, 1990-2021, ThW (Eurostat [44])

As it appears today, both here at home and in the EU, politically, however, we are far from having secured a roll-out of RE, which can supply enough for the electrification of energy-intensive industries at the level that, among other things, steel and cement production will require. Therefore, today we also see several of the large cement and steel producers entering into PPA agreements with renewable energy providers as a step towards being able to secure green power for production themselves. One example is the steel producer ArcelorMittal, which has an ambition to replace coal with green hydrogen at its German production facility. As part of this, they have signed a so-called "memorandum of understanding" with RWE, which is one of Germany's largest producers of electricity, to work together to develop, build and operate offshore wind farms and hydrogen plants that will supply the renewable energy and green hydrogen, required to produce low-emission steel in Germany. Another example [45] is the Swiss cement producer, Holcim, and German steel producer, Salzgitter, both of which have entered into a PPA with the Spanish energy company, Iberdrolas, to purchase electricity from their 476 MW Baltic Eagle offshore wind farm, which is currently under construction off the island of Rügen in northern Germany. This type of initiative by the companies themselves are important steps on the way to ensuring a greater supply of RE, but they do not change the fact that there is a need for a drastic scale-up both in volume and pace in relation to the expansion of RE and the infrastructure that is necessary to ensure enough power for energy-intensive production processes such as steel and cement.

In addition, despite positive results in both steel and cement, it is still technologies and innovations that need to prove their effect on a large scale. There are thus individual products on the market, but there is no commercial scale yet. If you look at Sublime in the USA, for example, they still only have a very small scale of production and expect the first full-scale factory to be ready in 2028.

Denmark's cement and steel industry

Denmark has one large cement producer, Aalborg Portland, which produces 2.363.000 tonnes of cement each year. In other words, it is Aalborg Portland that alone constitutes Danish cement production. However, there is a large concrete value chain with a number of large and small players to which Aalborg Portland supplies cement. FLSmidth is also involved in cement projects and supplies technology for production, but does not have cement production itself today. In addition, there are startups, such as CemGreen, which also work to reduce the CO2 footprint from cement production.

Denmark does not currently have a steel production, but imports large quantities of steel, among other things from Sweden, Germany and previously also on a large scale from Russia. Denmark today has only one major steel rolling mill, NLMK DanSteel, which is owned by the Belgian investment fund, Sogepa, and the Russian rich man, Vladimir Lisin. NLMK DanSteel is located in Frederiksværk and produces hot-rolled structural steel sheets for construction/construction, bridge building, the wind industry (onshore/offshore), offshore oil and gas, shipbuilding, boilers and pressure vessels as well as transport. In addition, smaller companies, such as Give Steel and Grædstrup Stål, which also produce steel products.

Cases: Innovations show new paths to decarbonisation

Across the EU and in the US, there are today a number of examples of new technologies and innovation projects that demonstrate new opportunities for decarbonisation of energy-intensive production of both cement and steel. These are solutions which together open up alternative routes to CCS for both cement and steel production – and which have the potential to be scaled up towards 2030.

EcoClay^TM – an electrified alternative to the CO₂-heavy calcination process

The cement group, FLSmidth, has teamed up with the Technological Institute, the Technical University of Denmark – DTU, the energy storage company, Rondo Energy, as well as the cement producers, French VICAT, and Colombian, Cementos Argos, in the so-called EcoClay^TM-project. The project, which runs from 2022-2026 and is partly financed by the Danish Energy Agency's Energy Technology Development and Demonstration Programme, EUDP, aims to reduce CO₂- emissions from cement production by up to 50 percent.

Specifically tested and developed in Ecoclay^TM- project the possibility of replacing lime with clay in cement production - and electrifying the calcination process of the clay. Replacing lime with clay enables less calcination of lime, which emits large amounts of CO₂. Electrification replaces the use of fossil energy, such as coal and natural gas, and enables the use of electricity based on CO₂-free sun and wind. By replacing lime with clay and electrifying the process, a reduction of 35-50% of CO is thus expected₂- the discharge per tons of cement.

In recent years, there has been an increasing focus from several manufacturers and in research on fired clay as a partial replacement for cement in concrete. In trials conducted by FLSmidth, with a new clay calcination system that can produce a highly reactive clay, it has thus been shown to be possible to replace up to 30 percent of the lime content for cement production with clay.

Clay can be incorporated into the production of cement on existing cement plant equipment by modifying rotary kilns (traditional Portland cement manufacturing equipment) to use a slower and longer heating process. Furthermore, as part of the project, the Technological Institute will try to develop a scalable method to burn the clay particles using electricity rather than using fossil energy such as coal and natural gas.

Calcined clay can potentially also be produced using flash calcination, a new technology to activate materials more quickly and efficiently, and fired clay can be combined with crushed limestone to offer an efficient alternative to clinker with less CO₂-imprint. Since limestone fired clay cement can be produced at a much lower temperature, it can be electrified, which significantly reduces emissions.

Scalability, time horizon and price
EcoClay^TM the partnership expects to have the first full-scale commercial production of electric clay calcination ready by the end of 2025.

Boston Metal – new electrolysis process

The American startup Boston Metals has since 2013 tested the production of steel via direct electrification based on an electrolysis process. Today, by far most steelmaking starts in the blast furnace, by reacting coke (a coal-derived material), which is almost pure carbon, at high temperatures with iron ore, a mixture of iron oxides and other minerals. The reaction draws out the oxygen and leaves behind liquid iron, while releasing oxygen and carbon dioxide. Boston Molten Oxide Electrolysis (MOE) is a new technology that originates from MIT (Massachusetts Institute of Technology) and has been developed, among other things, in collaboration with NASA.

The new process replaces the coal with an electrochemical process that uses electricity to heat the iron ore and then create chemical compounds that can separate the iron oxides from other minerals in the iron ore. See Figure 9. The result is a pure liquid metal of high purity, which therefore does not need to be further refined or purified, but can be sent directly to the foundry and converted into steel and iron products. It allows for the production of steel, which is more efficient, has lower costs than traditional methods and will also not emit CO₂ – provided that the energy source for the electrolysis process is green.

Figure 9: New electricity-based process for the production of steel (Boston Metal, [46] )

In addition to the production of iron and steel, the technology can also be used on a number of other metals – including titanium and beryllium or rare earth metals.

A significant advantage of the technology from Boston Metal is that it is modular and scalable - the outlet is the way in which a large part of aluminum production has been electrified, where production capacity can be added when relevant. This results in far lower upfront start-up costs than if you, as a steel producer, have to invest in a full-scale new plant.

Boston metal has demonstration projects in the USA and in Brazil – in the USA the focus is on steel and in Brazil on the extraction of rare metals. Boston Metal is scheduled to introduce high-value metals produced with their MOE technology in 2024, and they expect to be able to deliver commercial scale on their production of steel from 2026.

Scalability, time horizon and price
A commercial-scale demonstration project in 2026. With their current pilot system and ongoing construction of another demonstration system in Brazil, Boston Metals' technology is placed at level 6 on the TRL scale.

German Salzgitter – bet on hydrogen

The German steel producer Salzgitter today has a declared ambition to be able to produce green steel in 2033 – with a reduction in CO₂- the emissions from steel production amounting to 95 percent. In concrete terms, this will mean that the German steel producer will be able to deliver 1,9 million tons of green steel per year in 2033, potentially reducing Germany's national CO₂- emissions by around 1 percent.

Salzgitter will realize that objective by switching their production of steel from being mainly based on coal to being based on green hydrogen via an electrolysis process – so that hydrogen generated by renewable energy will replace the carbon that is needed until now for smelting iron ore . According to their own plan, the German steel producer will begin to rebuild and convert parts of their steel production plant from 2025, and according to the company itself, this will pave the way for a 30 percent CO₂-reduction in 2026.

Salzgitter launched their so-called Salco program back in 2015, which includes a number of different initiatives, research efforts, pilot projects and partnerships.

Among other things, they have erected 7 wind turbines, which can deliver a total of 30 megawatts at their head office in Salzgitter. They have a specific focus on the development and improvement of electrolysis technology - with the aim of improving the energy efficiency of high-temperature electrolysers (HTE), which is a challenge in relation to making green hydrogen a commercial alternative to fossil energy sources . Among other things, Salzgitter has invested in an electrolysis plant, which uses steam from industrial waste heat from steel production. In addition, they have initiated a project that looks at resource and energy improvements throughout the value chain. Here, among other things, they are investigating whether biogenic materials can be used as a substitute for coal and natural gas, in order to adjust the necessary carbon content in steel. They are also looking at more efficient use of water, as large amounts of water are needed in the production of green steel for, among other things, electrolysis, which is why there will be gains to be made by being able to recirculate water to a greater extent.

The total costs for the conversion of Salzgitter's production plant as well as the installation of wind turbines and electrolysis plants are estimated to be 50 million euros. Among other things, the steel producer has received almost 1 billion euros in state aid from the German government.

Scalability, time horizon and price
The first large-scale phase of electrolysis-based production is planned to be operational at the Salzgitter production plant from 2026 and is expected to provide a CO₂-reduction of 30 percent. In 2033, Salzgitter expects that their entire steel production will be based on hydrogen rather than fossil fuels.

Electra: Steel production at 60 degrees

The American startup Electra has developed an electrochemical refining process that can convert iron ore into iron and from there into steel, using only renewable electricity. By far most production of steel today is based on large blast furnaces, where coke (coal) is used as an energy source to transform iron ore into pure iron at 1400-1500 degrees. Electra's chemical process, in which the iron ore is immersed in acid via an electrolysis process in water, enables a production process in which the iron ore is remelted into iron at 60 degrees - thereby avoiding the high-temperature process in coal furnaces. After the chemical process, the iron can be converted into steel using electric arc furnaces, which are already used today on a large scale in the steel industry to remelt recycled steel into new products.

According to Electra's own estimates, their technology thus enables the production of iron completely without fossil energy in the process of extracting iron from the iron ore, which accounts for 90 percent of the emissions from the production of steel.

Electra's process is, in terms of low temperature of 60 degrees, far less energy-intensive than traditional steel production. In addition, the process is very flexible, as you can turn it on and off in relation to the supply of energy. Therefore, Electra's technology also has the potential to be a stabilizer for the energy grid in a future where sun and wind are the primary sources.

Their chemical process also enables the use of low quality iron ore (iron ore with 30-35 percent iron content), without further refining processes. According to Electra, this will help to ensure that their technology will not increase the costs of steel production - especially in a future where the demand for iron ore with a high iron content (+60 percent) is expected to be in short supply.

Electra raised, in 2022, 85 million US dollars in investments from, among others, Breakthrough Energy Ventures (Bill Gates' climate investment fund), Nucore, the USA's largest steel producer, and Amazon for the construction of a larger test facility, which will be completed in 2023 in Boulder, USA. However, they are only betting on full-scale commercialization from 2026 and towards 2030.

Scalability, time horizon and price
The current ambition for Electra is full-scale commercialization from 2026 and towards 2030. They do not expect increased production costs compared to traditional fossil-based production. Electra expects to scale up their technology from a laboratory production to having a pilot system ready by the end of 2023. With the new pilot system, the technology moves to level 5-6 on the TRL scale.

Coolbrook

The Finnish-Dutch company, CoolBrook, has developed a technology that can potentially heat industrial ovens to +1700 degrees with electricity from renewable energy sources. Coolbrook's technology – the so-called RotoDynamic Heater – thus opens up the possibility that coal and gas can be supplanted as the otherwise perennial primary energy sources in high-temperature processes, such as in steel and cement production. According to Coolbrook, there is no CO₂-emission associated with their technology process, and they thus assess that it has the potential to reduce global CO₂-emissions with over 2 billion t/year – equivalent to 30 percent of total global CO₂- emissions from industry and 7 percent of global CO₂-udledninger.

Developed in collaboration with Oxford, Cambridge and Ghent universities, Neste Engineering and Mitsubishi Heavy Industries, Coolbrook's technology is based on turbine technology that harnesses electricity and rotational kinetic energy to produce the extreme heat required for many heavy industrial processes. It enables the electrification of industrial processes, where it has otherwise proved difficult to reach over 500-600 degrees in production processes.

Coolbrook's technology has shown positive results from test and demonstration projects in recent years, but has not yet been tested on a full commercial scale. According to Coolbrook, their technology can be mounted directly on existing industrial facilities – which greatly reduces the time perspective and costs for a conversion from fossil-based to renewable energy. The next step is thus to implement the technology on commercial production facilities, where Coolbrook has, among other things, announced partnerships with both cement and steel producers, including UltraTech Cement Limited, CEMEX and ArcelorMittal, to implement and test the technology on concrete large-scale industrial facilities. The demonstration projects are expected to be operational in 2024, with a full commercial rollout of the technology starting from 2025.

Scalability, time horizon and price
First large-scale demonstration projects are expected to be operational in 2024. From 2025, Coolbrook expects their technology to be ready for commercial deployment. Coolbrook's [47] own estimates in relation to the costs of their technology indicate that their technology will be 30-60 percent lower than the operational costs if production were to be based on green hydrogen. Based on the above, Coolbrook is placed at level 7 on the TRL scale.

Sublime Systems – USA 

The American company, Sublime Systems, has developed a new method to produce cement via an electricity-based electrolysis process. It can thereby use electricity, based on sun and wind, instead of fossil energy. Furthermore, it can use other calcium sources than the CO₂-heavy lime, which is today the main raw material for the production of cement.

Cement production today is tied to a process that results in large amounts of CO emissions₂ – by two primary processes: Partly from the heating of limestone using primarily fossil fuels. Partly the chemical process that occurs when limestone (CaCO3) is heated to high temperatures, which splits the lime into CaO and CO₂ – where CO₂'one has traditionally been derived. CO₂'one from traditional cement production is mixed with various contaminants and diluted, making it complicated to capture.

Sublime Systems has developed a new production technology that potentially eliminates both emission sources. They use electrochemical processes to extract calcium, which is one of the basic components of cement. This technology can thus be powered by electricity from the sun and wind. The process also makes it possible to use different raw materials with a calcium content that is not bound to carbonate – CO3. In this way, they can completely avoid the process emissions of CO₂ from the raw material.

In addition, Sublime's platform can also use the abundant and cheap limestone for cement. All that CO₂, produced during the conversion process of lime, can be tapped at 10 bar and room temperature, making it easy and cheap to transport to a CO₂- warehouse. There is thus no need for expensive and energy-intensive CCS plants. Production takes place at room temperature.

According to the company, the energy consumption of the new process at the current stage of development corresponds to traditional cement production without CCS plants. The most widespread CCS technology, with the use of amine washing of flue gas, increases energy consumption by up to 50 percent. Contrary to traditional cement production, the new process has no emissions of dust, NOx or heavy metals.

Sublime's process can be run entirely based on renewable electricity from the sun and wind. The electrolysis process can also be run up and down, thereby making use of periods of cheap electricity. This means that it can be included as a flexible electricity consumption – as hydrogen production is expected to do in a future electricity system based on fluctuating sun and wind. Sublime's cement has just been ASTM certified, which means that the quality and performance characteristics are at least equivalent to traditional Portland cement. There is a lot of interest in Sublime's technology, and last year the company raised US$40 million from investors, including a large sum from Siam, the largest cement producer in Southeast Asia.

Scalability, time horizon and price
The process is definitely in the experimental stage. Sublime currently has a plant that produces 100 tonnes of cement per year – new cement factories often have an annual capacity of around 1 million. tons. But they will use 40 million. US dollars to build a demonstration plant, which will reach 25.000 tons/year, and they expect to scale up to 1 million. tonnes already in 2028. So far, the technology is placed at TRL level 6.

The price of cement in the first plants is expected to be slightly higher than traditional cement production without CCS and without payment for CO₂-discharges. Keeping expectations in relation to scaling, the expectation from Sublime itself [48] is that the new process potentially delivers cement significantly cheaper than traditional cement plants that are equipped with CCS.

About the report

The report was published in January 2024 and was prepared by senior analyst at the Green Transition Denmark, Anna Fenger Schefte.

Jens Dahlstrøm Iversen, senior advisor in energy and climate, and Erik Tang, senior consultant, are responsible for policy.

Thomas Jørgensen and Andele Simunovic have contributed research.

Layout by Isabella Rosenberg Jørgensen.

The note is financed by the European Climate Foundationn.

Contact

Anna Fenger Schefte, Senior Analyst
anna@rgo.dk
Tel. 5194 7932

Jens Dahlstrøm Iversen, senior advisor
jens@rgo.dk
Tel. 3318 1932

Green Transition Denmark is an independent non-profit environmental organization that has advised on the green transformation for more than three decades. Like a green solution tank we will deliver concrete, realizable and ambitious solutions that can accelerate the transition to an absolutely sustainable society.

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