Displaying items by tag: Cambridge Electric Cement

UK: A steel and cement co-recycling process developed at the University of Cambridge has received US$2.9m in seed funding. Cambridge Electric Cement is utilising slag produced during the steelmaking process, which uses electric arc furnaces instead of blast furnaces, as clinker for cement. The researchers are conducting a US$8.4m trial called Cement 2 Zero to test the production process, aiming to produce 110t of recycled cement during the two-year program.

UK: The Cement 2 Zero project has successfully concluded its first trial melt of recovered cement paste in an electric arc furnace at the Materials Processing Institute’s Teesside campus. The project uses the paste as flux for electric steel recycling. Cambridge Electric Cement (CEC) has demonstrated that the ‘slag’ from this process can be ground into fine clinker that, when mixed with gypsum and supplementary cementitious materials (SCMs), produces net zero CO₂ cement. The Cement 2 Zero project to produce CEC’s cement at an industrial scale launched in March 2023, with US$7.85m in funding from UK Research and Innovation. Tarmac will grind the clinker from the project’s trial melts for testing in order to obtain certification and specification as a usable cement product.

UK: Legal & General Capital, an alternative investment arm of financial services company Legal & General, has invested around US$15.5m in Cambridge Electric Cement (CEC) and other companies as part of its strategy to decarbonise the residential sector. It is also investing in Hometree and SunRoof, as well as increasing its existing investment in Sero Technologies.

CEC is developing process to create net zero-CO₂ cement product using recycled concrete paste. It launched a two-year industrial trial of its Cement 2 Zero project in February 2023.

Cement 2 Zero (C2Z) has officially launched in the UK this week. The project is an industrial scale pilot of the Cambridge Electric Cement (CEC) process. The Materials Processing Institute will lead on this stage with two-year funding of around Euro7m provided by UK Research and Innovation (UKRI). Partners include the University of Cambridge, Atkins, Balfour Beatty, Brewster Brothers, Celsa Group, Day Aggregates and Tarmac.

CEC’s method uses recycled concrete paste in place of lime-flux in steel recycling. Slag is formed as the steel melts and this is then used in place of clinker to make more cement. This way of making cement cuts out the decarbonisation of limestone step from conventional clinker production. If renewably-sourced electricity is used to power the heating and grinding parts of manufacture, then cement production in this way could potentially cut out most of its CO₂ emissions. The first phase of trial melts by C2Z will be conducted by the Materials Processing Institute using a 250kg induction furnace and this will be scaled up to 6t in an electric arc furnace (EAF). Later, industrial scale melts will be tested in Celsa Steel's EAF in Cardiff, Wales.

CEC is taking a similar approach to HeidelbergCement with its research into using recycled concrete paste. However, HeidelbergCement says it is using the paste to help capture CO₂ in an enforced carbonation step it is testing at cement plants. It too though wants to create a secondary cementitious material (SCM) afterwards. There are also links here to construction and demolition waste and electric cement kilns as covered by Global Cement Weekly previously. The latter is different with regards to what CEC is doing because it is recycling concrete waste to produce an SCM (slag) rather than using an electrically powered kiln to make clinker from limestone. Coolbrook, VTT and the like have had to build electric kilns effectively from scratch or adapt technology from elsewhere for their approaches whilst CEC appears to be about to use existing EAFs in its industrial scale pilot.

Figure 1: Projection of how the Cambridge Electric Cement production process could be used at scale in the UK. Source: UK FIRES. Click to view larger version.

CEC’s forecast of how its process could be used at scale in the UK can be seen above in Figure 1. If the majority of the country’s steel scrap was recycled in this fashion each year then 2.4Mt/yr of CEC cement could be produced. This would represent a quarter of the c10Mt of cement sales reported by the MPA in 2021. Assuming the EAFs were powered by renewables then this could reduce the cement sector’s CO₂ emissions significantly. Although it would still leave the industry looking for other decarbonisation routes for the other three-quarters of cement demand.

C2Z and CEC offer a novel spin on cement production by recycling concrete waste, using an electrical heating step and dodging the process emissions associated with normal ordinary Portland cement (OPC) clinker production. If it did progress to a commercial stage then it would see a continued relationship between steel and cement producers. Currently this is mainly centered around iron and steel slag usage as a SCM. One point of interest here would be how much higher levels of steel recycling and a process like CEC being used regularly would affect existing slag usage as an SCM. It doesn’t look like CEC could solve the cement sector’s CO₂ emission problem all on its own but it could certainly make a difference if it progressed to a commercial stage. As ever with cement sector decarbonisation there appear to be a range of options available to producers.

UK: Cambridge Electric Cement (CEC) has launched the two-year trial of its Cement 2 Zero project, aimed at scaling up production of its net zero-CO₂, demolition waste-based alternative cement. It aims to produce 20t of the material for use in a low-impact construction project. CEC’s method, developed at the University of Cambridge, is based on the conversion of demolition waste into a slag-forming material within a steel furnace.

Developer Julian Allwood said “By combining steel and cement recycling in a single process powered by renewable electricity, we could supplement the global supply of the basic construction materials to support the infrastructure of a zero emissions world and to enable economic development where it is most needed.”