1st Global CemCCUS Conference, Exhibition and Awards 2024

Carbon capture, utilisation and sequestration for cement and lime

14 - 15 May 2024 - Oslo, Norway

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Image gallery for the Global CemCCUS Conference, Exhibition and Awards 2024 that took place on 14 - 15 May 2024 in Oslo, Norway

1st Global CemCCUS Conference, Exhibition and Awards 2024
14 - 15 May 2024 - Oslo, Norway

The inaugural Global CemCCUS Conference on carbon capture for the cement and lime industries has successfully taken place in Oslo, with 150 attendees from 31 counties, and a visit to the Brevik carbon capture plant, courtesy of Heidelberg Materials. The event will be repeated in Hamburg in May 2025.

On the day before the conference itself, industry consultant John Kline hosted a well-attended day-long ‘introduction to carbon capture’ course.

The next day, Devika Wattal of the Global Cement and Concrete Association (GCCA) started off the conference by reminding delegates of the work of the association to help the cement industry to navigate the net-zero roadmap. Devika mentioned a useful new website which is tracking existing and prospective cement industry carbon capture projects. Devika is the coordinator of the Innovandi Open Challenge, which is a project to bring forward the most promising technologies for carbon capture.

Emmanuel Brutin, policy advisor for Cembureau the European cement industry association, next spoke about the regulatory framework required for successful CCUS rollout. Four years previously, the association adopted the Cembureau 2050 Raodmap, outlining all the levers for decarbonisation in the cement industry, and Emmanuel pointed out that CCS/CCU accounts for around 35% of future cement industry carbon abatement by 2050. Cembureau also has a listing of projects underway, in Europe. Many projects are now foreseen to be operational in Europe by 2030, allowing the permanent CO₂ storage of up to 12Mt/year. However, the EU’s Industrial Carbon Management Strategy has an ambition to hike this (for all industries) to 50Mt/yr by 2030, 280Mt/year by 2040 and 450Mt/year by 2050. Emmanuel warned of a two-speed Europe, with those bordering the prime CO₂ sites of the North Sea being strongly advantaged compared to those that are more landlocked: Access to CO₂ infrastructure at reasonable costs and conditions will be critical, as will faster permitting for storage sites. The EU Innovation Fund has been critical in moving projects forward, but has been eight times oversubscribed. At least 75% of future payments by the cement sector into the EU ETS (approximately Euro80bn by 2034), should be diverted into a dedicated ‘cement fund,’ according to Emmanuel. The current framework for CCU in Europe is a major obstacle to CCU deployment in the cement industry, since after 2040 the industry will not get carbon credits for CO₂ use. 

Next Christian Preuss and Marvin Kieckhöfel of Heidelberg Materials gave a keynote presentation on HM’s approach to CCUS. The company wants to reduce its average CO₂ emissions to less than 400kg CO₂/t of cementitious by 2030, not only through using traditional levers like alternative fuels, the use of SCMs and process optimisation, but also through the pioneering use of carbon capture. ‘The published CCUS portfolio is the tip of the iceberg,’ with other projects coming. “We will capture a cumulative 10Mt of CO₂ by 2030.” To choose projects and technology, the CCUS business case must have affordable capture technology, affordable transport and storage, available subsidies and incentives, there must be government and public support, and the plant must be suitable (such as having available land, and electricity connections). “The higher-hanging fruits will become lower in the forthcoming years as technology matures and as support systems evolve.” Heidelberg Materials is investing in all known capture solutions, and expects to finally utilise a mix of approaches, depending on the situation of individual cement plants. “ETS savings are currently not sufficient to cover the cost of the CCS value chain, and the future price of carbon credits is uncertain.” The speakers reiterated the call for EU ETS payments to be allocated back to the decarbonisation of the cement industry. Marvin outlined the new EvoZero cement products - one produced and delivered from Brevik, one delivered from any European cement plant but with the Brevik capture and sequestration allocated to the product and proven using blockchain, and a zero-carbon concrete product.

Well-known cement industry expert Joe Harder of OneStone Consulting next gave an overview of cement and lime carbon capture projects worldwide. He suggested that out of humanity’s total CO₂ emissions of around 13Bnt/year, the cement industry emits around 2.6Bnt/year, and pointed out that the world is due to burst through the 1.5°C heating point in the next few years (if it hasn’t done so already). It is clear that the cement industry cannot achieve net zero without carbon capture, and Joe said that if all planned projects are built, that the cement industry is likely to be able to capture 27Mt/year by 2030. The cement industry is estimated to require up to US$900bn in capital expenditure to achieve its net zero goals by 2050. Joe identified 42 full-scale CCS/CCUS projects worldwide in the cement industry, and 10 in the lime industry.

Zhiwei Gu of CMBI/Sinoma next gave an update on carbon capture in the Chinese cement industry. Chinese clinker production peaked in 2013-4, with consolidation and rationalisation in the years since, and with utilisation rates sinking from around 80% in 2010 to around 60% in 2023. Process emissions account for 60% of emissions, indirect emissions around 5% and energy activities around 35%. The theoretical CO₂ sequestration capacity in China is estimated at 1.2-4.1trillion tonnes, in both onshore and offshore basins. There are a number of CCUS demonstration projects in the Chinese cement industry, and although capture costs are relatively high, at Euro40-80/t, they are still lower than the international average. Amines and pressure swing adsorption are the key technologies under consideration for carbon capture in China. Gu said that Chinese government support for CC is currently in the form of policy support, with no specific financial policies yet in place. He gave details of ‘the world’s first cement kiln flue gas carbon capture system,’ at the Bai Ma Shan cement plant of Anhui Conch, near Wuhu, Anhui province. Zhiwei Gu forecast that China will progressively test, develop and commercialise carbon capture technology in the coming years. He forecast a capture cost of Euro20-40/t by 2050.

Ben Lee of Energy Aspects then gave a much-anticipated presentation on future EU ETS carbon emissions pricing trends. The days of permits at Euro20/t are long gone: the EU’s default policy is to completely decarbonise industry by around 2040, with the elimination of free allocations by 2034 as the carbon border adjustment mechanism (CBAM) is phased in. Despite the global financial crisis, falls in demand due to Covid, and the inflation/interest rate crisis of the last couple of years in Europe, the European cement industry still has CO₂ emissions of above 100Mt. Industrial weakness and lower demand for permits has hit the price of permits, but activity is likely to start to rise from 2025. Ben mapped out the likely future supply and demand of emissions permits, pointing out that the market is currently balanced, but will tighten again from 2026, and there will be very little surplus in permits by the end of the decade. Speculators have flooded into the market, but starting in May 2023 have flipped from taking long positions in the market to now shorting the market, helping to push prices down.

At the start of the next session, on technical aspects of cement industry carbon capture, Stéphane Poellaer of Alterline outlined the process optimisation steps that are required as a prerequisite. Firstly, the kiln must be stabilised, and the process and all equipment must have very high reliability (while also using a very high proportion of alternative fuels). The exhaust gas volume must be decreased since this impacts on the capex and opex of post-combustion technologies. The CO₂ concentration in the exhaust gas must be maximised, and acid gases and specific pollutants (SOx, NOx, VOCs etc) must be minimised. He gave many specific examples of how producers can practically improve production (whether they plan to introduce carbon capture or not). “Do not envisage CCUS if your kiln stops 150 times per year - fix the main problems first!”

Simon Knitter of IKN GmbH then gave a rundown on some carbon capture  technology options. The company has historically been known as a manufacturer of coolers, but now does so much more, including pyro projects and now CCUS. IKN has been involved, progressively, with the early Cemcap projects, Cleanker, and Leilac projects, and now is researching Oxyfuel. Simon clearly explained the calcium looping concept, and gave details of the Cleanker project demonstrator in Italy, which showed that it would be suitable for green-field or retrofitting, and which would work with many fuel types. The Leilac concept allows indirect heating of the limestone and hence the collection of high-CO₂ exhaust gases. Oxyfuel has a high capture potential for CO₂, at relatively low cost. Fuel is burned in pure oxygen, excluding ambient air and its high nitrogen burden, allowing high CO₂ concentrations in the flue gas. Many Oxyfuel concepts are being developed at the moment, all of them seeking to eliminate false air, but potentially using separate ambient air circuits, such as cooler-grinding circuits, or preheater-cooler-grinding-circuits. New sealing technologies are required to address the false air problem, for example beyond the use of flexible skirting or graphite blocks for kiln sealing. IKN can increasingly help customers in many areas of the CCUS sector.

David Jayant of FLSmidth next spoke about how to tailor cement production for CCUS. The company’s new OneCal in-house modelling software can analyse multiple scenarios to optimise production, and to prepare the plant for carbon capture. FLS trialled Oxyfuel combustion back in 2010, but then shelved the technology, since it appeared to be before the curve. However, David said, Oxyfuel with post-combustion cryogenics-capture and calcium looping (CaL) is now recognised as the most economical approach, but is at a technological readiness level (TRL) that is too low at the moment. David gave an outline of different approaches to decarbonisation, including 'Newcement,' full and partial Oxyfuel projects, cryogenics-capture approaches, clay calcination, pyro-optimisation and the use of the FuelFlex pyrolyser.

Monaca McNall and co-authors from WL Gore then gave details of how to optimise gas pre-treatment for carbon capture using Gore filtration products. “This is the decade to develop CCUS technology,” stated Monaca, and she mentioned the requirements for a filtration solution: it needs to avoid particulate contamination, avoid solvent degradation, minimise corrosion, have economic regeneration and have a low pressure drop. Among a variety of Gore solutions, including DeNOx filtration, low drag bags, liquid filtration, Gore mercury filtration and Turbine Filters, Monaca focussed on bag house solutions. Gore low drag filter bags may be used as a ‘polishing’ solution after a normal bag house, since the bags use a unique membrane structure which is ideally suited to fine particulate matter, and which does not need a filter cake to work well. Initially the pressure drop might be higher than equivalent clean bags, but because the fibres in the low drag bags are so fine, they do not tend to become contaminated and blinded, so that over time, the low drag bags maintain a steady, lower pressure drop. Gore also offers catalytic filter bags for DeNOx, which, when combined with SCR, will fully clean the gas prior to carbon capture.

Lukas Biyikli of Siemens Energy Global then spoke about the importance of compressor selection and how they can drive project economics and plant concepts. Above a certain temperature and pressure - the so-called critical point (for CO₂, 31.3°C and 73.8 bar), a fluid is in the supercritical phase, meaning it has properties of a liquid and a gas. Supercritical CO₂ has the density of a liquid (slightly lighter than a liquid, but much heavier than a gas) and the viscosity and compressibility of gas (slightly less than a gas, but much higher than a liquid). The most efficient state of CO₂ for pipeline transport is as a dense-phase liquid without risk of phase change, which corresponds to a lower pressure drop along the pipeline per unit mass of CO₂ when compared to the transportation of the CO₂ as a gas or as a two-phase combination of both liquid and gas. Gaseous transport in pipelines is not economical due to the high volume of the gas, low density and high-pressure losses; Liquid CO₂ requires insulated pipelines. Lukas stated that for a heavy gas like CO₂, a centrifugal compressor is favoured over a reciprocating compressor. However, for CO₂ pipeline compressors, reciprocating compressors are typically chosen, since they can process much lower flow rates if required. Single-shaft compressors are typically not the most cost-effective technology, since the entire casing needs to be designed for the maximum discharge pressure. On the other hand, internally geared compressors allow for intercooling after each stage, since each stage is within its own volute casing, which leads to significant power reduction. All of the compressor solutions can be split into modular container-sized portions. Siemens is working to combine centrifugal and reciprocating compressors in a single design.

Awards dinner

At the end of the first day of the conference, delegates visited the Norwegian armed forces flight museum during which the inaugural Global CemCCUS Awards were presented, based on global voting. Holcim was awarded the ‘Global CemCCUS company of the year,’ while the Brevik carbon capture unit was awarded ‘project of the year.' Aker Carbon Capture won the award for innovation of the year, and thyssenkrupp Polysius won for ‘supplier of the year.’ The award for Global CemCCUS ‘personality of the year’ went to Dr Dominic Von Achten, CEO of Heidelberg Materials.

Second day

On the second day of the conference, Monika Nikolaisen of Aker Carbon Capture spoke about heat integration solutions. Around 4.1GJ/t of CO₂ captured is required for carbon capture using monoethyl amine (MEA), the industry benchmark amine. Energy recovery from the heat energy produced by the amine system is critical to reduce energy consumption, and Monika stated that heat pumps are well suited to this application. Waste heat recovery from the rest of the cement pyro system will further reduce overall electrical requirements for the plant.

Madison Savilow of Carbon Upcycling focussed on clinker substitution and carbon capture, pointing out that SCMs are starting to become scarce in some markets. Carbon Upcycling uses industrial byproducts, including fly ashes, steel slags, clays and natural pozzolans, which are then subject to ‘mechanically assisted chemical exfoliation,’ (MACE), increasing their surface area and boosting reactivity. They are then combined with low-concentration CO₂ to produce carbon-captured CO₂ cements, with up to 60% reduced carbon emissions and with up to 40% strength increase. The system is fully electric, with no fossil fuels used, and has been used commercially for more than three years already. Madison suggested that the cost of ‘sequestration’ using this process is US$50/t of CO₂, compared to perhaps US$100/t for carbon capture and sequestration, or US$1200/t for direct air capture (DAC).

Cato Christiansen of Capsol Technologies next looked at high-pressure hot potassium carbonate-based (HPC) carbon capture. The CapsolEoP (end of pipe) solution is for large-scale carbon capture. The inorganic solvent is non-degradable, is non-volatile and is environmentally-benign, and the technology has been proven in over 700 plants worldwide since the 1950s. The system traditionally requires the use of compressors, requiring high electrical use. However, adding in an expander (basically a reverse compressor) and heat exchanger can extract energy from the compressed gas, reducing electricity consumption by 60% and avoiding the need for any additional heat. Cato suggested that the system has an energy requirement of 0.6Gj/t of CO₂ captured, versus 2.5-3.5Gj/t with MEA amines, depending on the CO₂ concentration in the flue gas.

Nic Renard of Ardent next spoke about the use of membranes for carbon dioxide capture. He suggested that membranes have the advantages of reduced energy consumption, no chemical use and no steel use. Nic gave examples of membranes working long-term in industrial applications, and also debunked the suggestion that membranes need high pressures to operate: the Ardent OptiPerm membrane can successfully operate at 1-4 bar. Nic gave an assessment of capture economics with membranes, using realistic (almost pessimistic) assumptions, for a membrane and cryogenics system producing 99.99% pure CO₂ with 90% capture. He suggested a cost of US$101/t of CO₂ captured (US$110/t of CO₂ avoided), with capex of US$118m. He suggested that the use of membranes has lower exposure to utility cost variability, and a lower cost of CO₂ avoided, compared to using MEA amines.

Stratos Stavrakakis from Nuada, a company named after an ancient Irish king whose name means ‘capture,’ explained about his company’s metal-organic frameworks (MOF), which can be used to capture carbon dioxide at low energy intensity of 0.7Gj/t of CO₂ captured. “Essentially, this is vacuuming CO₂ from industrial emissions,” stated Stratos, with the MOFs being regenerated simply by applying a vacuum once they are saturated. Nuada is at the pilot stage (1t/d) today, but aims to build a 50t/d demo project in the UK by 2025.

Aaron Lyons of Carbon8 spoke about his company’s process to react cement kiln bypass dust (CBD) with CO₂ to produce artificial aggregates. Aaron suggested that the value of all carbon markets worldwide is already worth US$850bn/year, already covering 70% of the world’s GDP. “Data is going to be vitally important to carbon capture, to provide full third party verification of valuable credits.”

Tom Hills of Leilac was next up and he gave an update on progress. The technology is a combined calciner and carbon capture system in the form of a hollow tube surrounded by a furnace: heat is radiated into the inner calciner tube releasing CO₂ from the limestone feed, and producing a high CO₂ exhaust gas. The single-tube LEILAC 1 plant was built in Lixhe in Belgium in 2019 with a CO₂ capture capacity of 25kt/y. The four-tube LEILAC 2 plant will be built at the Ennigerloh plant in Germany, will have a capacity of 100kt/year and will capture 20% of the plant’s unavoidable process emissions. The plant is due for completion in 2025 and will also examine the possibility of using alternative fuels. Tom suggested that the LEILAC 2 plant can avoid process emissions at a cost of Euro33/t of CO₂. The approach captures around 90% of process CO₂ generated in the pyroprocess, but it does not capture combustion-related emissions. An additional carbon capture process might be added to capture the remainder of the CO₂ from the system. “There is enough waste heat in a Leilac-enabled plant to drive a post-combustion capture plant which captures the final CO₂,” he concluded. The capex is Euro120m for a 1.2Mt/year cement plant.

John Kline of Kline Consulting next gave delegates an idea of the real total cost of cement industry CCUS. In a nutshell, the cost of a carbon capture plant for a cement plant will cost the same as building another cement plant! Cost is a function of the gas quality and flow, as well as heat consumption, fuel type, elevation and false air, as well as the operational costs of the particular carbon capture technology chosen. Thorough cleaning of the gas is required prior to carbon capture, and this is potentially a very costly procedure. John gave an idea of projected costs for a carbon capture project, warning to pay no attention to the absolute numbers but to note the percentages of the project cost for each of the cost categories, which would be transferable to other projects. The bottom line for the project, before inflation was taken into account, was more than half a billion dollars. John also showed a bewildering array of different specifications for gas that would be allowed into different pipelines - with the limits being tough (and expensive) to attain (for example having less than 10ppm oxygen). A recent VDZ study suggests that around 4500km of new CO₂ pipelines will be required for the German cement industry by 2035, at a cost of Euro14bn. Additionally, Europe has a finite amount of geological storage space - and the easiest and cheapest sinks will be used first, so that sequestration costs will mount through time.

Robert Jutson of Griffin Capital gave the penultimate presentation at the conference, looking at project finance. Rob suggested that industry and regulators are involved in a massive game of ‘chicken,’ to work out who has the liabilities for CO₂ capture and sequestration at the end of the day. He suggested that the objective for participants is to reduce their balance sheet risk to as low as possible, and specialised project finance is one means to achieve this objective. One problem is that the risks involved are not well known, and nor are the pricing levers for sequestration sinks. He pointed out the difference between the cost of CO₂ avoidance (perhaps Euro40 - 120/t of CO₂) and the cost of EU ETS carbon emissions permits (varying between Euro50-100/t historically, but at unknown levels in the future). Long term, a reliable floor price needs to be established, above the ‘best’ cost of carbon capture. However, growth in emissions from countries that will not abate emissions in the next 50 years will swamp all carbon capture efforts in the developed world.Despite this, he concluded, “time is of the essence.”

Anders Peterson of Heidelberg Materials gave the final presentation, which was an introduction to the carbon capture project at the Brevik plant, to be visited by delegates the next day. Anders pointed out the long gestation of the project, starting in 2014. At Brevik, captured CO₂ will be loaded onto ships, which will take it to the Northern Lights hub, after which it will be pumped out to sinks below the North Sea for permanent geological storage. At Brevik, the CO₂ is stored in insulated tanks. One of the first things to be built at the plant at the beginning of the project was a pier, to allow very large process equipment to be shipped to the plant. Extensive piling was undertaken, prior to the first of nine WHR units being delivered. Enormous absorber and desorber units were delivered and lifted into position by very large cranes, along with the CO₂ storage tanks. As of the date of the conference, the plant is around 80% complete. Anders detailed a number of valuable takeaway lessons learned. Primarily, there was a disjoint between expectations in the cement (low cost/practical) and petrochemicals (low/no risk, high cost) industries. This presentation and ‘lessons learned’ takeaways alone could save potential cement industry developers millions of Euros.

Fileld trip and farewells

The day, after the conference, many delegates took a long journey to the Brevik cement plant for a field trip, using a specially-chartered local ferry boat in order to give delegates the best view of the plant being built. On a beautiful day, everybody enjoyed the tremendous views of the impressive plant and gave hearty thanks to the hosts of the visit, Heidelberg Materials.

At the end of the conference delegates gathered together for a farewell reception and the award of the conference prizes. Following voting by delegates, Lukas Biyikli from Siemens Energy Global was awarded third prize for his presentation on compressor selection for carbon capture. In second place was Madison Savilow of Carbon Upcycling with her paper on carbon capture and sequestration in artificial aggregates. However, the winner of the prize for the best presentation was Anders Petersen, with his ‘warts and all’ account of the building of the new Brevik carbon capture unit.

Delegates very strongly praised the conference for its excellent presentations, for its outstanding networking opportunities, and for the friendly conference organisation. After voting by delegates, the second Global CemCCUS conference will take place in Hamburg, Germany, in May 2025. 

4th Global FutureCem Conference on cement industry decarbonisation
6 - 7 December 2023 - Brussels, Belgium

The 4th Global FutureCem Conference on cement industry decarbonisation has taken place in Brussels, with delegates from around the world. The majority of delegates felt that their companies would substantially reduce their carbon emissions as a result of attending the event.

Ioannis Retsoulis of the Joint Research Center of the European Commission gave an opening overview of the current status of the Industrial Emissions Directive (IED). As Inoannis says, "The IED is currently being revised, including more effective legislation, which will boost green innovation and increase decarbonisation. He furthermore elaborated on the INCITE (INnovation Centre for Industrial Transformation and Emissions) concept. INCITE as an innovation centre, having a global vision, aims to be the central point of reference for identifying and evaluating the environmental performance of emerging technologies in Europe and beyond. Early technology front-runners will be rewarded with more lenient permitting, whilst outputs from INCITE can encourage financing of emerging environmental technologies and foster competitiveness. He emphasized that working hand in hand with the cement industry and all relevant stakeholders is important in order to unlock INCITE's full potential, and that a launch event for INCITE is provisionally planned in Spring 2024 in Seville, Spain."

Chris Erickson of Climate Earth spoke about the use of automatically-created Environmental Product Declarations (EPDs), for both cement and concrete. EPDs are 3rd party verified international standardised reports used to report assured environmental performance about products in particular product categories such as cement, or concrete, allowing comparisons between products. The information that is gathered for EPDs is put into a database, allowing ‘instant’ generation of machine-readable EPDs for cement blends and concrete mixes. In Europe, the same data can be used to create country-specific EPDs, since requirements across the EU vary from country to country. The cost of each EPD is also much reduced.

Dan Maleski of Redshaw Advisors outlined how the new CBAM scheme in the EU and how it affects the European (and global) cement industry. Dan presented a slew of forecasts for the cost of emitting a tonne of CO₂ in the EU, suggesting that it will be Euro150 in 2030, and Euro225 by 2035. CBAM will impose a carbon price on imported goods, considering their embedded carbon, akin to the EU ETS (and with the same cost). He pointed out that the CBAM scheme is exceptionally bureaucratically cumbersome. The transition period started in October 2023, to allow industry to learn how to use the scheme. Full compliance will start in December 2025. Non-compliance may eventually result in revocation of importation rights. The phase-in of the CBAM scheme will be synchronous with the phase-out of free allocations under the EU ETS. Dan said that importers of clinker and cement will find their margins under pressure. However, countries can establish their own ETS schemes, pay their carbon taxes to their own country exchequer and import into the EU CBAM tax- free. There may eventually be a CBAM export rebate, depending upon the stance of the WTO.

Professor Johann Plank of the Technical University of Munich next spoke on decarbonisation strategies of the cement and concrete industries. Each year mankind releases 41Bt of CO₂, although the biosphere absorbs 13Bt, and the oceans 10Bt, leaving 18Bt of additional CO₂ in the atmosphere, which should be eliminated to achieve climate net zero. The cement industry should be aiming at an average of not more than 455kg CO₂/t cement in order to ‘do its bit.’ Decarbonisation of limestone produces around 65% of emissions from ‘traditionally-produced’ OPC, fuels provide 20% and grinding produces another 15%. Oxyfuel firing uses near pure O2, and allows easier CO₂ capture. Carbon capture can be achieved using amine scrubbing (‘the BASF process’), which can be made more efficient by using catalysts to reduce the splitting or cleaning temperature of the amines; by using membrane technology; by using cryogenics and by other means. The Leilac process of indirect limestone heating and decarbonisation can also be used to create a CO₂ rich exhaust stream (see also below). Captured carbon dioxide may be injected into offshore reservoirs in the form of a supercritical liquid. Around 200 CCS projects are already in operation, with more than 40 under construction, while Norway, the USA and Canada are very active in this area. Prof Plank pointed out that normal oilwell cements are not resistant to supercritical CO₂, and new cements will be required to cap these CO₂ injection wells. Johann reminded delegates that the global warming potential of concrete - even made with OPC - is relatively low, perhaps 310kg CO₂ per cubic meter. If it is made with blended cements, using slag , activated clays and ash, then concrete can even be made ‘net zero.’ Alkali activators (Na₂SO₄, Na₂CO₃, Na₂SiO₂, NaOH) may be needed to improve early strength in slag-based cements, while superplasticisers may be required with low water-to-binder ratios to allow workability. New activators and admixtures are currently being developed for the new low-clinker binder systems. He pointed out that LC3 cement (with 50% clinker) and a 550 - 600kg/t CO₂ emission is not climate neutral and the use of superplasticers and accelerators may be required to achieve on-site workability. In China, the clinker factor is around 70%,with the remainder generally being slag and/or limestone, while huge programmes are underway to use mining tailings and ash as supplementary cementitious materials (SCMs). The Chinese cement industry has a production capacity of over 2Bt, but demand in 2024 is expected to be only around 1Bt (leading to a 'saving' of perhaps 800Mt of CO₂ emissions compared to previous years).

Fabrice Fayola, CEO of Surschiste and president of ECOBA, the European coal combustion products association, spoke about the position of ash in Europe. 123Mt of ash is used each year in Europe, even while the production of coal combustion products (CCPs) is steadily decreasing. Many countries are now using ash from stockpiles, particularly in countries that now have no fresh CCP production. A variety of EU standards allow the use of ash in cement and concrete, and fly ash is now covered by EPDs, typically with 50 - 100kg CO₂/t of embedded emissions.

Lawrie Evans of EmCem Ltd next stated that the last thing that the cement industry needs right now is clinker. The clinker factor in Europe was 0.95 until around 1970, at which point it reduced over a couple of decades to around 0.7, using SCMs. Globally, it has next to no possibility of reducing to its target of 0.45 by 2030. Lawrie pointed out that significant strength gains can be gained by optimising the particle size distribution. Additionally, cement particles over 32microns are effectively unreactive (and the CO₂ emitted during their production was for no cementitious effect), since articles only hydrate to a depth of around 5 microns - and even particles larger than 10 microns have unreacted cement cores. He suggested that intergrinding of limestone with clinker results in under-ground (and under-reactive) coarser clinker particles. Limestone should be separately ground from clinker in order to optimise clinker performance. He said that it was time for cement to be environmentally rated - like refrigerators or homes - on a simple F to A scale.

Niall O’Hare from Ecocem next spoke about high-filler low-water cements. CCUS on its own will not be enough to decarbonise the cement industry, due to both technical and economic issues. Ecocem’s ACT cement is composed of 50% limestone filler, 30% SCMs and only 20% clinker, which has a carbon footprint of 180kg CO₂/cement. The company has optimised particle size distribution and has used additive technology to improve or surpass the workability of traditional cements. Around 330kg of ACT is used for each cubic meter of concrete, with performance equal to traditional cement.

Mathieu Pépin of Stepan Europe next spoke about how to unlock the power of graphene using aqueous fluid suspensions. Graphene adds mechanical strength, reduces water permeability and adds sulphate resistance to concrete. However, graphene is an insoluble fine powder and it is difficult to disperse in aqueous mixtures. Stepan has a patent-pending suspension system that allows temperature-stable high aqueous concentrations of graphene, with a user-friendly viscosity and which is stable for up to six months. Just a 0.01% loading of graphene can significantly improve concrete performance, requiring only a 0.003% wt/wt addition of the Stepan suspension additive.

Jagabandhu Kole of JSW Cement gave the final presentation on the first day, on durable low carbon cement (DLCC) with only 5% clinker. JSW’s mix uses 80 - 85% GGBFS, 10 - 15% anhydrous gypsum and 5% OPC clinker, along with some additives. Performance of DLCC is reduced compared to PPC and PSC, but is still higher than required for the particular concrete grade. DLCC has low water and chloride ion permeability, making it well-suited for marine environments. Dr Kole stated that cement demand in India is increasing at around 12% per year: JSW Cement has a target of becoming ‘close to net-zero’ by 2070.

At the end of the first day of the conference, delegates enjoyed a convivial dinner and a fun ‘pub quiz.’

Second Day

Commencing the second day of the conference, Dirk Schlemper of INFORM GmbH outlined how AI can reduce costs and CO₂ emissions from building materials logistics. He pointed out that a 300km round trip for a cement truck will produce around 560kg of CO₂ - as much as a tonne of cement. This offers a juicy target for optimisation. Efficient logistics can also help to gain points towards sustainability certifications. Electric vehicles add further complications (range, recharging time, charging infrastructure, temperatures and elevation profiles) to logistics calculations, but the software can cope - easily.

Koen Coppenholle, CEO of Cembureau, pointed out that the new ‘big idea’ for the EU, after its single market project of the last 40 years, is the EU ‘Green Deal.’ Part of that is the CBAM, as well as a new Innovation Fund. Cembureau’s Road Map outlines many levers (‘The 5C approach’) for decarbonisation, and Koen said that all levers will be needed - with CCS making up perhaps 40% of the solution. “Long term investment cycles (30 - 35 years) mean that 2050 is practically just around the corner.” The lack of renewable energy and inadequate planning for the future will leave the EU uncompetitive and unprepared for an electrified future, with demand for electricity doubled or tripled. The biogenic component of alternative fuels is becoming more important, since biomass is zero-rated for CO₂ emissions - contrary to fossil-based AF. The Net Zero Industry Act, NZIA, will regulate the CCS industry in the EU, while giving long-term certainty to sector participants. The Innovation Fund is primarily for demonstration-level projects at technological readiness levels (TRL) 7 - 8, with cement sector projects well represented. The permanence or otherwise of the ‘use’ part of CCUS is being actively debated at the moment - for example mineralisation would be permanent, but would manufacture of a plastic be permanent sequestration of cement industry CO₂?

Luc Rudowski from thyssenkrupp Polysius and Hendrik Möller of Schwenk Zement next spoke about a new approach to valorisation of clay through mechano-chemistry. Luc stated that calcined clays are becoming a reality throughout the world, particularly in west Africa, since clinker imports are expensive. The tkP mechano-chemically activated (‘meca’) clay approach goes beyond grinding, although grinding is the first step during the ‘Rittinger stage,’ where the lower size limit is reached. The second step is an aggregation and activation stage where crystal structures are broken down: the higher the level of amorphisation, the higher the level of energy imparted and stored in the meca-clay. The third step is an (re-)agglomeration stage and the fourth stage is the application stage, with particle disintegration and hydration. In the second stage, which is the start of mechano-chemical activation, the tkP ‘Booster mill’ or Charger - a dry agitated bead milling technology - is used to maximise the surface energy of the clays, using the minimum electrical energy input. The electrical consumption of the process is higher than for normal calcined clay (450kWh/t vs 66kWh/t) , but the thermal input is lower (174kWh/t vs 609kWh/t), giving a modestly lower energy consumption on average (624kWh/t vs 675kWh/t), but with 70% lower thermal CO₂ emissions. The strength of mortars formed from meca-clays is higher than for clinker - even with clays with low kaolinite content of only around 5%. The meca-clays produced have more rounded morphologies, which aid in mortar and concrete workability, while reducing water demand. Due to the low processing temperatures, even calcareous clays will not produce CO₂ emissions. A demo-scale plant will be build at the Schwenk Allmendingen plant.

Pierre Landgraf from the Technical University Freiberg next spoke on mechanical comminution and electrodynamic fragmentation of concrete rubble in the UpCement project. The aim of the project was to separate hardened cement paste from old concrete rubble, and to reactivate the recovered paste at low temperatures. Jaw, cone and impact crushers are used for comminution, followed by electrodynamic fragmentation (EDF). An electric current is passed through a water tank containing ground rubble - the current preferentially passes around constituent particles in the concrete and disaggregates the concrete at the grain boundaries. With finer comminution and separation, the fraction of cement paste in the samples increases. Pierre concluded that further investigations must continue.

Tom Hills from Leilac Ltd came to the podium to give delegates an update on developments at the company, after the installation of the original Leilac 1 project at the Lixhe plant in Belgium, which had a single tube. The four-tube single module Leilac 2 installation in Hannover has a carbon capture capacity of 100,000t/year. Leilac uses an externally-heated tube down which the raw materials are dropped. The tube radiates heat into the raw materials, which are thus calcined. The process gas is then nearly-pure (98%) CO₂ which can subsequently be captured. The Leilac vessel would replace the preheater and precalciner in a traditional plant. In the future, more four-tube modules would be added to scale processing capacity. The Leilac 2 project is exploring the use of solid alternative fuel, and also uses vent and tertiary air streams. Tom suggested that the cost of the process will be around Euro33/t of CO₂ avoided, with capital cost for a 2.4Mt unit at around Euro100m. 70% of the cost of using Leilac are capital repayments and the operation of the CO₂ purification and compression unit. Fuel costs are reduced compared to a traditional process, and maintenance is modest. Electricity or zero-carbon fuels are options for the future, for higher avoidance rates. Post-combustion capture (PCC) fuel CO₂ capture may be achieved with amines, with the process powered using waste heat from the cement plant, bringing the cost for CO₂ avoidance to Euro39/t CO₂. Tom suggested that one large Leilac plant would need to be built every week from now until 2050 to fully decarbonise the world’s cement industry. Leilac Ltd is also exploring direct air capture (DAC) options.

Jerome Friler next gave details of a proposed fully-decarbonised cement plant using hydrogen, in Mauritania. Several large infrastructure projects are planned in the vicinity of Nouadibhou, requiring large quantities of cement. A new plant is planned, but lenders were not interested - until the plans were modified for it to become a fully decarbonised plant. The plant will produce LC3 cement, using green hydrogen produced using solar and wind electricity from a nearby 100MW wind farm, and a to-be-built 55MW solar farm. The green H₂ plant will produce at a rate of 23t/day, which can be fed to a turbine to produce electricity for wind and solar-free days. The plant will be fired using imported alternative fuels. The price of cement in Mauritania is currently $160/t, and the plant will reduce expensive imports. The plan is to create synthetic methanol with any captured CO₂.

Victor Smith from CM Biomass gave an overview of the global wood pellet market and its potential benefits for the cement industry. Major inflows of wood pellets into Europe occur from the US (8Mt/y), Canada (1.7Mt/y), southeast Asia (1.1Mt/y) and other sources including South America (0.7Mt/y). German cement industry coal use is the equivalent of the use of 5Mt of wood pellets, so that there is a huge potential market for biomass-based pellets. In fact, other types of biomass are available apart from wood, including cashew shells, palm kernel shells, bagasse pellets, olive pits, straw pellets, sunflower husk pellets and coconut pellets, with a variety of net calorific values and ash contents, sourced from around the world. Victor suggested that the use of wood pellets saves around 90% of the CO₂ emissions compared to coal, after calculating processing and shipping emissions.

In the first of a trio of papers on CCUS, Nicolas Renard from CMS spoke about carbon capture economics with membranes. “We can’t build a nuclear power plant just in order to drive a carbon capture system,” was a comment from one industrial sector, with a strong message coming from others that low energy carbon capture is a must. Membranes selectively allow CO₂ to pass through, with relatively low pressure loss, and have been used for this purpose for decades already, for transformer oil degassing, for olefins paraffin separation, and for CO₂ removal from natural gas. The solution from CMS is modular and containerised, and the membranes are chemically resistant. Nic suggested that a realistic estimate of cost would be Euro85/t of CO₂ captured, delivering pipeline-transport-quality carbon dioxide at a cost ‘at least 25% better than MEA (amine capture).’ The costs of capture would reduce with electricity at less than $0.06/kWh.

Thomas Lamare, previously of Holcim and now with Chovet, spoke on the ins and outs of integrating a full-scale carbon capture unit in an existing cement plant. In general, electricity demand for carbon capture will be much higher than for ‘plain’ cement production. Thomas gave the example of an installation of a carbon capture system at a Lhoist lime plant in France. He concluded that the technological challenges have largely been surmounted, but that the economics may still be against widespread adoption, today at least. Every plant will be unique, and sequestration will not always be possible. In this case, there will be a 50km pipeline to Dunkerque, from where the CO₂ can be further transported for sequestration.

Xavier d’Hubert of XDH-energy gave a final round-up of the challenges and opportunities that CCUS offers to the cement industry. He pointed out that the production process must first of all be fully optimised. Once optimised, other options can be used to reduce the embodied carbon in the produced cement, such as alternative fuels, the use of slag and other SCMs, and the use of renewable electrification, prior to considering CO₂ capture. He reiterated that the energy requirement for an amine-based CC scheme will be colossal, and that WHR may supply a portion of that energy. Gas streams into carbon capture units, independent of the capture technology, will be required to be clean, dust-free, dry, and cool. Achieving this is not free. Ceramic catalytic filters (‘candles’) might be an option for gas conditioning in the future. Adsorption (using MOFs), absorption (for example using amines), cryogenics and membranes are distinct carbon capture options, but hybrid systems are also possible. Future technology choices are under active consideration by many cement producers and other industry sectors.

Delegates voted for their favourite presentations at the end of the conference: Niall O’hare from Ecocem was third, Johann Plank from TU Munich was runner-up, and Luc Rudowski from thyssenkrupp Polysius and Hendrik Möller of Schwenk Zement were in first place with their paper on meca-clays. Delegates strongly praised the 4th Global FutureCem Conference for its smooth organisation, excellent networking opportunities and for its technical content.