
Displaying items by tag: secondary cementitious materials
Update on low carbon cements in Indonesia
11 December 2024Suvo Strategic Minerals said this week that it had made moves towards establishing a joint-venture between a subsidiary and the Huadi Bantaeng Industry Park (HBIP). The plan is to manufacture and sell low-carbon cement and concrete products that contain nickel slag and other byproducts. This news story is noteworthy because of the location of HBIP in South Sulawesi, Indonesia.
In a release to the Australian Securities Exchange Suvo explained that HBIP is the managing company of the Bantaeng Industrial Park, where ‘significant’ quantities of nickel slag are stockpiled as part of the local nickel pig iron operations. HBIP will supply the nickel slag to the joint-venture. It will also give it access to infrastructure such as land, port facilities and utilities. Suvo subsidiary Climate Tech Cement, for its part, will supply the low carbon cement and or concrete mixtures and/or formulations. This follows the signing of a memorandum of understanding in September 2024, in which the companies agreed to process the nickel slag into geopolymer cement and precast concrete materials.
At first glance Indonesia seems like an unlikely place to market a low-carbon cement or concrete product, given the large cement production overcapacity in the country. The Indonesian Cement Association (ASI) reported a production capacity of just under 120Mt/yr in 2024 and forecast a utilisation rate of 57% in November 2024. However, the government seems serious about reaching net zero by 2060 as the country’s economy develops. The ASI updated its decarbonisation roadmap in 2024 and the draft is currently under review with the Ministry of Industry and consultants from the Bandung Institute of Technology (ITB).
In the latest roadmap, carbon capture is at least a decade away, with the first large-scale capture tentatively anticipated from 2035 onwards. Although Indonesia launched its carbon trading scheme in 2023, it is not expected to start affecting the industrial sector until the late 2020s. Instead, the short-to-medium term Scope 1 reduction methods include increasing the use of alternative fuels, reducing the clinker factor of cement and reducing and/or optimising the specific thermal energy consumption of clinker. Initiatives such as Suvo’s joint-venture in South Sulawesi tie into that middle strand. Separately, over the summer of 2024 the government and producers said that they were working together to introduce and promote the use of Portland composite cement (PCC) and Portland pozzolana cement (PPC). At this time the ASI reckoned that a complete change could cut cement sector emissions by just over a quarter. In June 2024 local media also reported that ASI members were planning to supply low-carbon cement for the Nusantara capital city project to help it realise its aims as a ‘green city.’
Semen Indonesia, the country’s largest producer, reported a clinker factor of 69% in 2023 for all of its cement products, down from 71% in 2021. Limestone was the biggest substitute followed by trass and gypsum. It is currently aiming for a clinker factor of 61% by 2030. In its Sustainability Report for 2023 it said that it was promoting the use of non-OPC (Ordinary Portland Cement) cement “...according to the needs of construction applications.” It added that non-OPC products also had a “...5 - 15% more economical price.” However, the company has not said how its current sales are split between OPC and other products.
One of the surprises at the 26th Technical Symposium & Exhibition of the ASEAN Federation of Cement Manufacturers (AFCM), that took place in Kuala Lumpur in November 2024, was the sheer amount of work that has been going on outside of Europe and North America towards decarbonising building materials. The cement associations of Indonesia, Malaysia and Thailand all presented progress and targets towards this aim at the event. Suvo Strategic Minerals’ joint-venture plans in South Sulawesi are another example of this trend.
Closing points to note about the Suvo project are firstly that it is away from Indonesia’s main cement production area in Java. Secondly, the presumption is that the low-carbon cement and concrete products manufactured by the project will either be cheaper than the competition or benefit from green procurement rules. Finally, nickel slag reserves seem insufficient to reshape the entire national cement market. Yet a general move towards using more supplementary cementitious materials could. Watch this space for more developments.
Read a review of the 26th Technical Symposium & Exhibition of the ASEAN Federation of Cement Manufacturers (AFCM) in the forthcoming January 2024 issue of Global Cement Magazine
Ban ‘green’ cement!
05 June 2024The Indonesian government emphasised its intention this week to use ‘green’ cement in the construction of its new capital city Nusantara in Borneo. However, this begs the question: what exactly is ‘green’ cement?
In this case, Mohammad Zainal Fatah, the secretary general of the Ministry of Public Works and Public Housing, told state media that his department was “seeking to encourage the supply of domestic-industry-based material resources and construction equipment, which can support sustainable infrastructure development principles." The ministry is working with state-owned cement producers such as Semen Indonesia (SIG) to ensure the provision of sustainable cement and related products. SIG was selected as a supplier for the project in late 2022 and, as of February 2024, has reportedly provided 400,000t of cement from its plants at Balikpapan and Samarinda.
This is admirable stuff. However, the timing of the announcement is curious given that both the head and deputy head of the Nusantara Capital City Authority resigned this week forcing the government to reassure investors that the project was still on. Cue some swift discussion about ‘green’ cement! Previously it was hoped that the first phase of the US$34bn project could be inaugurated on the country’s independence day in August 2024 with civil servants scheduled to start relocating to the site in the autumn.
SIG sells a number of ‘green’ blended cement products and some of these have received Green Label Cement certification from the Green Product Council Indonesia. The group says that these products have contributed up to a 38% drop in CO2 emissions compared to Ordinary Portland Cement (OPC). This compares to the group’s clinker factor reduction rate of 69% and its Scope 1 emissions intensity reduction of 17% to 585kg/CO2/t of cement in 2023 compared to 2010 levels.
Along similar lines, the Alliance for Low-Carbon Cement & Concrete (ALCCC) in Belgium also announced this week that it had released a new policy roadmap aimed at achieving net zero emissions by 2040. Amongst its recommendations were a focus on the standards for cement and concrete to promote low-carbon products and encouragement to create lead markets to develop demand for them.
Crucially, the ALCCC uses low-carbon cement in place of ‘green’ cement and this makes its definition clearer. ‘Green’ cement is a marketing term intended to associate cement with environmentalism. Yet there is no accepted definition describing how these products are more sustainable than, say, OPC. For example, a so-called ‘green’ cement could use 100% clinker manufactured with no CO2 emissions-abatement, but it might be sustainable in other ways such as saving water. For the purposes of this article we’ll assume that ‘green’ cement means a low-carbon one. To further add to the confusion, ‘green’ concrete can be made using OPC in various ways but that’s beyond the scope of this piece. Clearly the world could do with some universal definitions.
US-based research and consulting company Global Efficiency Intelligence came to the same conclusion when it published its ‘What are Green Cement and Concrete?’ report in December 2023. It decided that - despite there being plenty of standards, protocols, and initiatives - there is no general agreement on the definition of ‘green’ cement or concrete. Its emissions intensity for cement summary table can be viewed below. It demonstrates the massive range of emissions intensity between the various standards. It is worth noting here that the description the Indonesian government may have been using for ‘green’ cement could already meet SIG’s Scope 1 emissions intensity reduction for its cement in 2023 depending on the standard being used.
Standard / Initiative / Policy Name | Emissions intensity target (t/CO2 per tonne cement) |
Climate Bonds Initiative | 0.437 & 0.58 |
IEA and IDDI | 0.04 – 0.125 |
First Movers Coalition | 0.184 |
U.S. General Services Administration IRA Requirement | 0.751 |
New York (USA) Buy Clean | 0.411 |
Table 1: Emissions intensity definition for cement as stated by standards, protocols, initiatives, and policies with stated numerical quantity targets. Source: Global Efficiency Intelligence.
Part of the problem here is that there is a language gap between the simple definition of a cement that is less CO2 emissions-intensive than OPC and the technical definitions used in the specifications and standards. Simply describing a cement product as ‘green’ can potentially cover anything that is slightly better than OPC down to a bona-fide net-zero product. Added to this is pressure from the manufacturers of new and existing cement products that use less or no OPC for regulators to move to performance-based standards to replace existing prescriptive standards, because it makes it easier for their products to be used. For more on this issue see Global Cement Weekly #606. Cement associations such as Cembureau and the Global Cement and Concrete Association (GCCA) have also called in their respective net zero roadmaps for changes to the standards system to promote low-carbon cement and concrete products.
The answer to what is ‘green’ cement is whatever the promoters want it to be. So, it might be helpful if the use of the word ‘green’ were banned in connection to any marketing activity related to cement products. Everyone could then adopt some kind of universal grading system using simpler language. One approach might be to copy the colour-coding scheme used by hydrogen to describe how it is made. One could use yellow for limestone blends, silver for slag, orange for clay, black for OPC made with carbon capture and so on… but not green! Another route might be to mandate the use of the carbon labels that some cement producers have used for at least a decade. Or something like the alphabet energy rating system used in the UK and EU for electrical appliances could be used. It’s too much to hope for a global system but simpler systems in the main markets would make it much easier to determine what exactly is ‘green’ cement.
CemVision to supply low carbon cement to LKAB
26 December 2023Sweden: CemVision has announced its first commercial agreement to sell its low carbon cement. Pilot deliveries are scheduled to begin in March 2024 to LKAB. Further commercial agreements are planned over the next four years. CemVision produces its Re-ment product using industrial residual products such as those from the steel and mining sectors instead of limestone.
Anders Lundgren, Chief Sustainability Officer for Business Area Special Products at LKAB, said “The letter of intent include the pilot deliveries and trial use of CemVision’s products in our concrete production, and intent to source from their future full-scale production, which presents a potential to further enhance the circularity and to decarbonise our supply of cement and addressing our emissions in the supply chain.”
Solidia Technologies ignites pilot line at San Antonio headquarters
01 November 2023US: Solidia Technologies has commenced production of its mineralised CO2-based supplementary cementitious material (SCM) at a pilot line at its headquarters in San Antonio, Texas. The pilot line increases the company’s production capacity of the SCM by a factor of 25.
Solidia Technologies senior director of strategy and business development Pradeep Ghosh said "With the dramatic increase in production capacity that the new pilot line brings, we are now shipping significant quantities of Solidia SCM to ready-mix concrete producers, transport agencies and contractors to qualify and trial our material."
Canada/UK: Carbon Upcycling has raised US$26m in a Series A funding round. The clean tech company says that the funding will support its construction of planned carbon capture systems at CRH's Mississauga cement plant in Canada and Cemex UK's Rugby cement plant in the UK. Carbon Upcycling’s technology injects captured CO2 into industrial byproducts and minerals to produce supplementary cementitious materials. BDC Capital and Climate Investment led the funding round, with strategic investments from Cemex Ventures, CRH and Oxy Low Carbon Ventures.
Carbon Upcycling chief executive officer Apoorv Sinha said "Closing this round is a major milestone on the road to becoming the most impactful carbon tech company of this decade.” He continued “Over the next year, our mission is to demonstrate our technology's versatility, scalability and operational elegance. Significant, cost-effective decarbonisation potential in the cement industry is possible without a green premium.”
Mexico-based Cemex first invested in Carbon Upcycling via its venture capital unit Cemex Ventures in February 2022. Its said “Cemex is committed to supporting decarbonisation for the built environment, and our follow-on investment in Carbon Upcycling demonstrates such ambition. Carbon Upcycling provides a scalable solution that effectively reduces the carbon footprint of cement. Increasing the supply and use of cementitious materials aligns with Cemex’s goals of reducing CO2 emissions and becoming fully net-zero by 2050”
The collaboration between Carbon Upcycling and Cemex dates to early 2020, and work towards a commercial-scale plant at the Rugby cement plant commenced in June 2022. The project will target a capture capacity of 1600t/yr, and has secured US$2.96m in government funding from UK Research and Innovation. Cemex says that it will subsequently roll out further CO2 mitigation projects in partnership with Carbon Upcycling at cement plants across Europe, the Middle East and Africa, Mexico and the US.
Update on cement and concrete standards
03 May 2023Betolar has called today for a global performance-based standard to replace existing prescriptive standards. Riku Kytömäki, the head of Betolar, argued at the London-based Concrete Expo that the lack of a performance-based standard is holding back the use of low-carbon materials from replacing cement in concrete production. He said “the current regulations across the markets are restricting the use of circular materials allowed in concrete buildings.” Betolar produces Geoprime, an additive designed for use in cement-free concrete production with ash and ground granulated blast furnace slag (GGBFS). This gives the company a financial reason to want standards to change, as it will potentially allow it to sell more of its product. However, as the company points out, “there is a huge need for new alternatives.” The world needs around 4Bnt/yr of cement but there is only 300Mt/yr of slag available.
Building materials producers and related companies wanting to change rules and standards in response to new trends is a common refrain. For instance, the increased use of alternative fuels by the cement sector has prompted all sorts of regulatory changes. However, rather than simply asking for amendments to the existing ways of doing things, Betolar is advocating for more wholesale change. It isn’t alone. Also this week the ASTM in the US announced that it is writing a specification to include a wider range of secondary cementitious materials (SCM). In addition, many of the interviews Global Cement Magazine has conducted with companies developing and marketing new types of cement and concrete in recent years have said similar things. Examples include the use of graphene, carbon nanotubes or sequestering CO2 into industrial by-products to create novel secondary cementitious materials (SCM).
Prescriptive versus performance-based approaches to buildings and building materials tie into wider design philosophies about construction. The prescriptive approach provides detailed descriptions of regulations, methods and components, such as cement and concrete standards. With respect to concrete standards, this might mean setting mandatory SCM and cement proportions, determining allowable water content, certain types of aggregate to be used and so on. The performance approach focuses on the end results, although it can be just as codified and standardised as the prescriptive route. For concrete, for example, this means that performance is measured by standard test methods with defined acceptance criteria stated in the contract documents with no restrictions on the parameters of concrete mixture proportions.
For cement and concrete standards the prescriptive approach dominated in Europe and North America in the 20th century. However, this began to change in the US in 2002 when the National Ready Mixed Concrete Association (NRMCA) started working on its roadmap towards its Prescription to Performance (P2P) initiative. The key aim of the scheme was to shift the emphasis from prescribing (or indeed proscribing) the ingredients and their proportions in a concrete mixture to an emphasis on the performance properties of the combined materials. A decade later in the mid-2010s it found during a progress review that about half of the sample of project specifications studied were classified as ‘prescriptive.’ The biggest prescriptive restriction was on the quantity of SCMs set by specification writers. These were often percentages required in certain circumstances, such as freezing and thawing cycles, but imposed on all usage.
The current bout of interest in performance-based standards appears to be driven by the growing demand for cement and concrete products to lower their clinker factor by using higher amounts of SCMs. A far wider range of SCM-based products are being developed and coming to market and then encountering regulatory burden. These new material manufacturers are meeting up with the sustainability lobby, which also has an interest in decarbonising building materials. In 2022, for example, the Belgium-based Environmental Coalition on Standards (ECOS) started pushing for performance-based standards for cement. In a statement it said that, “it is commonly accepted that prescriptive specifications are convenient, but that this convenience is obtained at the expense of (eco-) innovation and decarbonisation.” It added that the switch to performance-based standards would also strengthen the European internal market for construction products as part of the Construction Products Regulation (CPR). It noted the ASTM standards for hydraulic cements (ASTM C-1157), that were developed in the 1990s in the US, and more recent developments in the field in Latin America.
It is worth pointing out that the prescriptive route does have its advantages. Using a prescriptive system is easier for less-experienced practitioners or generalists as it sets a minimum standard, even if it is over-engineered. Responsibility is shared out among the supply chain under a performance-based system for the quality of concrete. Under a prescriptive system, the supplier or contractor can be held responsible for quality control issues. For the performance approach this has to be specifically defined, although systems are in place to help. Making it harder via ‘red tape’ for new products to enter a market may stifle innovation but it also gives these new products far more time to be tested rigorously.
The whole prescriptive-performance standards issue opens up the wider implications of decarbonising construction materials. Where once there was a relatively small number of different types of cement and concrete now there are potentially hundreds, each looking for market share. Whether this situation will be the same in a decade’s time remains to be seen. A few common SCM-based cement and concrete products and formulations may predominate. For now, the future seems wide open and bigger changes, such as the global performance-based standards Betolar is advocating, may be required to support this. Considering the massive variation between countries and states, even within the US and the European Union, let alone the rest of the world, this seems ambitious. But it is not impossible!
Betolar calls for a global performance-based standard to support low-carbon building materials
03 May 2023UK: Riku Kytömäki, the chief executive officer of Betolar, has called for a global performance-based standard to replace the current building requirements that restrict the use of new low-carbon materials to replace cement in concrete production. He made the comments at the London Concrete Expo. Kytömäki argued that current standards state that concrete manufacturers must use a certain percentage of cement to strengthen the finished product. Betolar’s product Geoprime is an additive designed for use in cement-free concrete production with ash and ground granulated blast furnace slag (GGBFS). However, “ageing” standards rule out the use of these kinds of products such as this despite their sustainability advantages.
Kytömäki said “It is time for global concrete industry to step up their sustainability efforts. New material innovation is available. It is cost-effective and helps to meet stricter durability requirements. However, the current regulations across the markets are restricting the use of circular materials allowed in concrete buildings.” He added that his company’s product Geoprime, “does not require large investments, but there is regulation to be developed quickly so that new solutions and materials can be used."
Betolar says it has analysed over 200 side-streams other than slag and fly ash, providing flexibility to process locally available side-streams. It added that there are also significant CO2 savings to be found in logistics when manufacturing processes take place near the source of the industrial side-streams.
Canada: The Cement Association of Canada (CAC), with its members and partners in the concrete sector, has released Concrete Zero, an action plan to help the local cement and concrete sector reach net-zero CO2 emissions by 2050. The five priority areas it is focusing on include: eliminating the use of coal and petroleum coke as fuel sources for clinker production; reducing the volume of clinker used to produce cement; increasing the use of supplementary cementitious materials; working towards building carbon capture, utilisation and storage capacity; and advocating for performance-based codes, standards and specifications, procurement policies and increased material efficiency in construction. Targets include reaching a 100% fuel mix from non-fossil-based sources by 2050. The latest plant follows the goal of achieving a 40% emissions reduction by 2030 as part of its Roadmap to Net-Zero Carbon Concrete by 2050.
Adam Auer, the president and chief executive officer of CAC, said “Our net-zero action plan is ambitious and cannot be achieved by industry action alone. Working with government, industry, and partners in the design, architecture, and construction industry will be essential for success. Canada’s cement and concrete industry are committed to doing our part to help Canada build a better, cleaner future. Working together, we can deliver Concrete Zero.”
US: ASTM International’s concrete and concrete aggregates committee (C09) is developing a proposed standard specification for a broad range of supplementary cementitious materials (SCM). Larry Sutter, an ASTM International member and the principal engineer at Sutter Engineering, commented that this performance specification (WK70466) will ease the adoption of new materials used for SCMs as established sources become less available.
Sutter said “For a variety of reasons, historic sources of SCMs, like coal fly ash from electric power generation, are in short supply and new materials are emerging.” He added, “These new materials do not fall under existing specifications, leading to the need for new specifications. Rather than writing a new specification for every emerging material, we are writing a performance specification that can be used to cover the full range of them.”
Sutter noted that concrete made with SCMs can be less costly, more durable and more sustainable than ordinary Portland cement. New specifications will allow these new materials into more construction projects. This effort relates to the United Nations Sustainable Development Goal #7 on clean and affordable energy.
Update on fly ash in the US, April 2023
26 April 2023Heidelberg Materials announced a US acquisition at the same time as the ongoing IEEE/IAS-PCA Cement Conference in Dallas, Texas this week. It has entered into a purchase agreement to acquire The SEFA Group, a fly ash recycling company based in Lexington, South Carolina. Its operations include five beneficiation plants, five utility partners, 20 locations and over 500 employees. It supplies fly ash to over 800 ready-mixed concrete plants in 13 states. It processes around 1Mt/yr of ash from storage ponds using its proprietary thermal beneficiation process. No value for the acquisition was disclosed.
The proposition for a heavy building materials manufacturer of securing a supply of fly ash is an attractive one. Fly ash can improve the performance of concrete, reduce its cost by lowering the amount of ordinary Portland cement (OPC) required and decrease the associated carbon footprint. It can also be use to make blended cement products. Heidelberg Materials and its US-subsidiary Lehigh Hanson could have various options here including using this new supply of fly ash internally, selling it on to other companies or licensing the beneficiation technology. Heidelberg Materials’ global sustainability report in 2021 reported that just under 9% of its cement-type portfolio comprised pozzolana or fly ash cements.
Graph 1: Coal combustion product production and use, 1991 – 2021. Source: ACAA.
Data from the American Coal Ash Association (ACAA) shows in Graph 1 that coal combustion products (CCP) production have declined in the last decade as the proportion used has steadily risen. In its annual production and use survey, the ACAA revealed that the use of harvested ash continued to grow in 2021 and that it constituted around 10% of the volume of ash recycled from current power plant operation. Thomas H Adams, the executive director of the ACAA, said “The rapidly increasing utilisation of harvested CCP shows that beneficial use markets are adapting to the decline in coal-fuelled electricity generation in the US. New logistics and technology strategies are being deployed to ensure these valuable resources remain available for safe and productive use.” Separately, the ACAA reported that coal-fuelled power stations represented about 50% of the country’s electricity demand in the mid-2010s compared to 20 – 25% in 2021 despite base-load remaining the same. It forecast that fly ash production was likely to remain fairly constant to around 2040 but that harvesting would help to cut the gap between supply and demand in some regional markets. It said that over 2Bnt of coal ash was in disposal. However, no indication of how recoverable this was given although it did note the higher cost of beneficiation. Work on updating specifications was ongoing to suit current circumstances.
As with the slag market, this presents a dilemma for cement and concrete producers that want to become more sustainable. They want to use more by-products from other carbon-intensive heavy industries – such as coal-fired power stations and steel plants – but these industries themselves are also trying to become more sustainable and are producing less secondary cementitious materials. Heidelberg Materials’ interest in a fly ash beneficiation company makes sense because it secures a bigger portion of a dwindling resource from the direct operations and opens up the possibility of selling the beneficiation technology to others. It is also worth mentioning that other fly ash thermal beneficiation processes are available. For example, Charah Solutions installed its MP618 technology at its Sulphur terminal in Louisiana in early 2019.
The general fly ash market in the US looks set to track the level of coal-fired power generation for the foreseeable future. Yet the proportion of CCPs being used continues to rise. In this context focusing on harvesting may be starting to make more financial sense. Charah Solutions’s new unit in 2019 and SEFA Group’s new units in 2020 and 2021 seem to support this view. Heidelberg Materials’ acquisition of SEFA Group may be further confirmation of this.