Displaying items by tag: Solidia Technologies

US: Solidia Technologies has filed a patent for a new hydraulic cement consisting of Ordinary Portland Cement (OPC) and other supplementary cementitious materials (SCM) including lime, alkali hydroxides, clay minerals and over 10% synthetic pozzolan.

Solidia Technologies said, “In order to reduce global CO₂ emissions it is necessary to adopt new approaches to create a new generation of hydraulic cements. The most efficient cement kiln can produce OPC clinker with an associated emission of 816 kg of CO₂/t. Blending the ground cement clinker with SCM, which have low or zero associated production CO2 emissions, reduces the total embodied CO₂ of the final product. Using a cement with the lowest possible clinker factor for a given application is the most common industry approach to reducing the CO₂ footprint of concrete.”

Switzerland/US: LafargeHolcim has announced the extension of its partnership with Solidia Technologies to mid-2020. Cash News has reported that the partnership, which has seen a 30% reduction in LafargeHolcim’s overall CO₂ emissions since its formation in mid-2013, aims to achieve a 70% reduction in the producer’s carbon footprint.

Cement and concrete products with sustainability credentials have increased in recent years as societies start to demand decarbonisation. In spite of the recent drop in the European Union (EU) Emissions Trading Scheme (ETS) price, there has been a trend in recent years in the construction industry towards offerings with better environmental credentials. Indeed, this week’s position paper from Cembureau on a carbon border mechanism concerns directly the growth of these kinds of products within Europe. Typically, the higher profile projects have been slag cement or concrete implementations such as Hanson’s use of its Regen cement substitute in a London sewer project or David Ball Group’s Cemfree concrete in a road project also in the UK. In this short review we’ll take a selective look at a few of the so-called low carbon cement and concrete products currently available.

Table 1: Some examples of methods to reduce embodied CO₂ in cement and concrete. Note - the product examples are selective. In some cases many other products are available.

Looking at cement first, the easiest way for many producers to bring a lower carbon product to market has been to promote cements made using secondary cementitious materials (SCM) such as granulated blast furnace slag or fly ash. These types of cements have a long history, typically in specialist applications and/or in relation to ease of supply. For example, cement producers in eastern India often manufacture slag cements owing to the number of local steel plants. However, cement producers have more recently started to publicise their environmental credentials as they reduce the clinker factor of the final product. Alongside this though, in Europe especially, a number of so-called low carbon cement producers have appeared on the scene such as EcoCem and Hoffman Green Technologies. These newer producers tend to offer SCM cement products or other low carbon ones built around a grinding model. It is likely that their businesses have benefitted from tightening EU environmental legislation. How far cement producers can pivot to SCM cement products is contentious given that slag and fly ash are finite byproducts of other industries that are also under pressure to decarbonise. Although it should be noted that other SCMs such as pozzolans exist.

As will be seen below a few of the methods to reduce embodied CO₂ in cement and concrete can be used in both materials. SCMs are no exception and hold a long history in concrete usage. As mentioned above David Ball Group sells Cemfree a concrete product that contains no cement. Harsco Environmental, a minerals management company, invested US$3m into Carbicrete, a technology start-up working on a cement-free concrete, in late 2019.

Limestone calcined clay cements are the next set of products that are starting to make an appearance through the work of the Swiss-government backed LC3 project, more commercial offerings like FutureCem from Cementir and H-EVA from Hoffman Green Technologies and today’s announcement about ThyssenKrupp’s plans to fit the Kribi cement plant in Cameroon with its Polysius activated clay system. They too, like SCM cements, reduce the clinker factor of the cement. The downside is that, as in the name, the clay element needs to be calcined requiring capital investment, although LC3 make a strong case in their literature about how fast these costs can be recouped in a variety of scenarios.

Calcium silicate cements offer reduced process emissions by decreasing the lime content of the clinker lowering the amount of CO₂ released and bringing down the temperature required in the kiln to make the clinker. Solidia offers its calcium silicate cement as part of a two-part system with a CO₂ cured concrete. In the US LafargeHolcim used Solidia’s product in a commercial project in mid-2019 at a New Jersey paver and block plant. Solidia’s second core technology is using CO₂ to cure concrete and reducing water usage. They are not alone here as Canada’s CarbonCure Technologies uses CO₂ in a similar way with their technology. In their case they focus more on CO₂ mineralisation. In Germany, Schwenk Zement backed the Celitement project, which developed a hydraulic calcium hydro silicate based product that does not use CO₂ curing. Celitement has since become part of Schwenk Zement.

Solidia isn’t the only company looking at two complementary technologies along the cement-concrete production chain. A number of companies are looking at recycling concrete and demolition waste. Generally this splits into coarse waste that is used as an aggregate substitute in concrete and fine waste that is used to make cement. LafargeHolcim has Evopact for the coarse waste and Susteno for the fine. HeidelbergCement has EcoCrete for the coarse and is researching the use of fines. Closing the loop for heavy building material producers definitely seems like the way to go at the moment and this view is reinforced by the involvement of the two largest multinational producers.

Of the rest of the other low carbon cement methods detailed in table 1 these cover other non-Ordinary Portland Cement (OPC) such as geopolymer and calcium sulphoaluminate cements. The former are a type of alkali activated binder and generally lack common standards. The latter are similar to slag cements in that they are established specialist products with lower CO₂ emissions than OPC.

With concrete when trying to make a low carbon product the first choice is whether to choose a low-carbon cement as the binder or even not to use cement at all in the case of Regen or Cemfree. From here the next step is to simply use less cement in a concrete mixture. There are a number of ways to do this from optimising aggregate gradation, following performance specifications more closely, using strength tests like maturity methods and generally adhering to quality control protocols better to deliver more consistency. Read the Mineral Production Association (MPA) publication Specifying Sustainable Concrete for more detail on this. Using concrete admixtures can also help make concrete more sustainable by improving quality and performance at construction sites through the use of plasticisers and accelerators, by decreasing embodied carbon through the use of water reducers and by improving the whole life performance of concretes. The use of locally-sourced aggregates is also worth noting here since it can reduce associated transport CO₂ emissions.

More novel methods of reducing embodied CO₂ emissions in concrete include the use of geopolymer concrete in the case of Zeobond Group’s E-Crete or adding graphene as Concrene does. Like geopolymer cements, geopolymer concretes are relatively new and lack common standards. Products like Concrene, meanwhile, remain currently at the startup level. Finally, if all else fails, offsetting the CO₂ released by a cement or concrete product is always an option. This is what Cemex has done with its Vertua Ultra Zero product. The first 70% reduction in embodied CO₂ is gained through the use of geopolymer cement. Then the remaining 30% reduction is achieved through a carbon offsetting scheme via a carbon neutral certification verified by the Carbon Trust.

As can be seen, a variety of methods exist for cement and concrete producers to reduce the embodied CO₂ of their products and call them ‘low-carbon.’ For the moment most remain in the ‘novelty section’ but as legislators promote and specifiers look for sustainable construction they continue to become more mainstream. What has been interesting to note from this short study is that some companies are looking at multiple solutions along the production and supply chain whilst others are concentrating on single ones. The companies looking at multiple methods range from the biggest building material producers like LafargeHolcim and HeidelbergCement to smaller newer ones like Solidia and Hoffman Green Technologies. Also of note is that many of these products have existed already in various forms for a long time like SCM cements and concretes or the many ways concretes can be made more sustainable through much simpler ways such as changing aggregate sourcing or working more efficiently. In many cases once markets receive sufficient stimulus it seems likely that low carbon cement and concrete products will proliferate.

Global Cement is researching a market report on low carbon cement and concrete. If readers have any comments to make please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.

US: Solidia Technologies has partnered with Xpansic CBL Holding Group (XCHG) to develop data technology products for precise measurement of CO₂ emissions and water usage in cement production. “Digital Feedstock enables industrial consumers to seamlessly connect sustainability ambitions with procurement decisions, wholly disrupting the way the cement industry meets consumer demand for accountability,” said Solidia Technologies CEO Tom Schuler.

Solidia Technologies produces reduced-CO₂ concrete with lower-energy cement and water-free CO₂ curing.

US: Solidia Technologies has appointed Jules Kortenhorst to its board of directors. Kortenhorst is currently the chief executive officer (CEO) of the Rocky Mountain Institute (RMI). Prior to this he was the founding CEO of the European Climate Foundation (ECF) and he also served as a member of the Dutch parliament for the Christian Democratic Party.

Kortenhorst was the CEO for International Operations of ClientLogic Corporation and he worked for almost 10 years for Royal Dutch Shell, including managing director at Shell Bulgaria. He began his career as an analyst at McKinsey & Co.

He currently serves on the Energy Transition Commission and is the co-chair of the WEF Global Future Council on Energy. He also is a non-executive board member of the Energy Web Foundation and an advisory board member of Land Life Company. He holds an MBA from Harvard and a Master’s in Economics from Erasmus University, Netherlands.

US: OGCI Climate Investments has made in an investment in Solidia Technologies to support the adoption of Solidia’s patented cement and concrete technology using CO₂.

The Oil and Gas Climate Initiative (OGCI) is a chief executive officer (CEO) led initiative of 10 oil and gas companies that collaborate on action to lead the industry response to climate change. OGCI Climate Investments, its investment arm, supports the development, deployment and scale up of new technologies that are intended to reduce greenhouse gas emissions.

“We believe that Solidia Technologies’ product and process can provide a step change in lowering the greenhouse gas and water footprint of the cement and concrete industry,” said OGCI Climate Investments CEO Pratima Rangarajan.

Solidia Cement is a non-hydraulic cement composed primarily of low-lime-containing calcium silicate phases, such as wollastonite and pseudowollastonite (CaO·SiO₂) and rankinite (3CaO·2SiO₂). The setting and hardening characteristics of Solidia Cement are derived from a reaction between CO₂ and the calcium silicates. The company uses a patented process called reactive hydrothermal liquid phase densification (rHLPD) to do this. Solidia Cement is intended to be a sustainable replacement for Ordinary Portland Cement (OPC). It uses the same manufacturing process, equipment and raw materials used by the cement industry while consuming less energy and generating less greenhouse gases.

World: Lafarge has signed an agreement with Solidia Technologies to sell its low-carbon cement and CO₂-cured concrete worldwide. Under the terms of this agreement, Lafarge will have the right to commercialise the process that reduces the carbon footprint of the end-to-end process by up to 70%. The commercial launch will initially take place in some key markets in North America and in Europe for the manufacturing of concrete elements such as paving stones, roof tiles and concrete blocks.

Solidia has developed a new binder made from similar raw materials to Ordinary Portland Cement and produced in a traditional rotary kiln. It is produced at lower temperatures and through a different chemical reaction that generates less CO₂. Used afterwards in the manufacture of precast concrete, Solidia Cement hardens through the addition and absorption of CO₂ in a patented curing process that reduces the overall carbon footprint by up to 70%. Produced at traditional precast concrete manufacturing facilities, Solidia Concrete reaches full strength in less than 24 hours.

Lafarge has worked with Solidia Technologies since 2013 to industrialise this technology. In April 2014, a joint group of Lafarge and Solidia scientists confirmed the reduced carbon footprint and commercial viability of Solidia cement during a full-scale trial at Lafarge's Whitehall cement plant in the US. The cement produced has subsequently been used by a variety of pre-cast customers in North America and Europe to further validate Solidia's curing technology and to produce blocks, pavers and roof tiles for commercial testing. In December 2014, Lafarge invested in Solidia Technologies and joined Solidia's Board of Directors.

US: Solidia Technologies has reported the chemical properties, manufacture and performance qualities of a sustainable cement that can reduce the carbon footprint of cement and concrete products by up to 70%.

Solidia Cement™is made from the same raw materials and equipment as OPC, but is adaptable to a wide variety of cement formulations and production methods, offering a sustainable and performance-enhancing alternative.

Solidia Cement clinker is produced at 1200°C, approximately 250°C lower than OPC clinker. The cement is a non-hydraulic material that is composed primarily of low-lime-containing calcium silicate phases such as wollastonite / pseudowollastonite (CaO.SiO₂) and rankinite (3CaO.2SiO₂). The setting and hardening characteristics are derived from the reaction between CO₂ and the calcium silicates. During the carbonation process, calcite (CaCO₃) and silica (SiO₂) form and are responsible for the concrete strength development.

Concrete products produced with Solidia Cement are manufactured using the same mixing and forming processes as OPC-based concrete and sequester up to 300kg of CO₂/t of cement. The reduced CO₂ emissions, combined with the ability of the cement to sequester CO₂ during concrete curing, renders a CO₂ footprint (associated with both the manufacturing and use) that is reduced by up to 70%.

"For over 50 years, scientists have tried to cure concrete with CO₂ knowing the resulting product would be stronger and more stable. Solidia Technologies is the first to make this commercially viable. Our current focus is testing additional applications with an even wider variety of concrete formulations and manufacture methods to facilitate adoption across the globe," said Solidia Chief Technology Officer Nicholas DeCristofaro, who co-authored the paper with principal scientist Sada Sahu.

Solidia Concrete™will be explored in a companion paper that is due to be released in January 2014.