As COP26 swings into action I’m talking to Ian Riley, CEO of the World Cement Association. I recorded this conversation just before the association held its annual conference last month. Recognising that the industry is a major contributor to global emissions, the conference had a clear focus on emissions reduction. Sessions included Key Challenges in Decarbonising Hard to Abate Industry, CCS (Carbon Capture and Storage) and the Cement Industry - Where we are and what’s needed for net zero, and presentations on financing the transition and on low carbon concrete. There was an interesting short video from Dr Paula Carey of Carbon8 who explained how carbonation can incorporate emissions into rock and effectively sequester them for all time.

Here’s what I discussed with Ian Riley.


Ian Riley is the CEO of the World Cement Association. Ian welcome to the Sustainable Futures Report.

Thank you, Anthony. Pleasure to be here.

The World Cement Association, a relatively new organization, tell me, what's your purpose? What's your role? What percentage of the world industry do you represent?

So we were found in 2006 and we have three main objectives. So the first one is to give a voice to the industry and to the industry participants. So not just the big companies who can probably manage on their own, but also the smaller producers around the world. But secondly, we try to help our members to improve their operating performance, to reduce their carbon footprint, to improve their energy efficiency, and ultimately, to reduce their costs. And then thirdly, we help accelerate the decarbonisation of the cement and concrete industry. And perhaps we can talk a bit about that in the course of the podcast today.

Well, I think we will because of course, the carbon footprint of the industry is very significant. It's, I believe, two and a half Giga tonnes per annum, which is about 7% of global CO2 emissions. So anything you can do will have quite a significant effect. What steps are you taking in this direction?

So let me put these in a bit of context so that people can understand where the industry is, and then subsequently what we're trying to do about it. So the industry recognized 20 years ago, that emissions and particularly CO2, although not only CO2, were a problem for the industry. So this reduction in CO2 emissions is something that the industry has been working on for at least 20 years, over 20 years now. And in that period of time, the emissions per tonne have come down by about 23%, 24%. So there has been some progress there, but clearly not enough to get us to net zero. Now, the challenge with cement is that a large portion about two thirds of the emission comes from the raw materials. So the raw material is primarily limestone. When that's put into a kiln and it breaks down into CO2 and calcium oxide, so you inevitably get that CO2 emission just in the nature of the process. The remaining third is the energy use primarily the fuel. And so when we've looked at how we can reduce the emissions, we've looked at three leavers traditionally. So the first is energy efficiency, and with energy efficiency, of course, assuming you don't have to spend a lot of capex, then energy efficiency will save you money as well as reducing your carbon footprint. Secondly is fuel switching. And again this has been done partly to save money, partly to reduce the carbon footprint. So, this is generally switching away from coal and towards waste derived fuels or in some cases biomass. So, the impact of that is, is in reducing the carbon of the fuel but it's also in some cases performing which was a useful service to the municipalities who need to dispose of their waste in some way and burning it in a cement kiln is a safe and fairly cheap way of doing that. And then the third way is to reduce the portion of cement that is coming from clinker. So, clinker is the product that is made in the kiln, and then cement is ground clinker with gypsum and also supplementary cementitious material. So the standard cement is just the clinker in the gypsum, but the blended cement which you use more and more these days, incorporates other materials, particularly fly ash and slag, which obviously are waste products from other industrial processes. And so by using these other segmentations else we can bring down the proportion of clinker used, which, you know, is where most of the CO2 is generate. So that's kind of the picture with cement. And when we look…

So before you go forward, can I just ask you about emissions? Are you looking in any way at carbon capture and storage in your process?

Yes. So if we go forward, I'll touch on that. 


There is some work that has been done to date. I think he would probably characterize it as, perhaps it's a bit more in the pilot stage, but it's, you know, early stages, and all of the work to date has received considerable government funding from primarily in Europe and North America. And the issue, with carbon capture, and storage is cost. But let's come back to that in a second. So going forward, from today, we can probably reduce the carbon footprint by perhaps a third with the traditional leavers. And that will leave us two thirds that we need to do something else with. Right? 


And the ‘something’ else at the moment is a question mark. So from a technology standpoint, the most advanced is the CCS, but it's also very expensive. So is that really the best way of doing it? -then, it's a bit of a question mark. There are a lot of new technologies that look at carbon capture and usage are primarily usage in building materials, so in aggregates or in concrete, that look as if they have good potential and probably lower costs, but they haven't been scaled yet. So you know, they have a question mark over there, commercial feasibility. And indeed, you know, whether the technology will work at scale.

Right, doing some background reading, I've come across carbon injection, or other CO2 injection into the mix as concrete is prepared. And apparently, that is a method of sequestrating carbon dioxide, because it reacts and produces calcium carbonate and is inert and therefore is locked up forever. It might work against your members, because apparently, if you use CO2 in this way, you need less cement. What's the story on that?

So in this particular technology you're describing is an example of one of the technologies I was talking about. This one, which I think you're talking about carbon cures technologies, is one of the more advanced they have - I think - now 400 radio stations around the world that's using this technology and it absorbs a little CO2 in that concrete making process, and it forms these nanoparticles of calcium carbonate, that act as cementitious material and allow the proportion of cement to be reduced. And so you sequester a little CO2 in the concrete and you save a little by reducing the cement portion. So, I think, we will put the categories of the technology into three main categories around the concrete. So, there are technologies that absorb the CO2 into the concrete. There is a company called ‘Solidia’ and it's been around for perhaps 10 or 12 years that is producing or that has a technology, which it licenses to cement producers to produce a slightly different type of clinker, and this is then turned into concrete using a direct carbonation method. So by sitting the concrete blocks in CO2 chambers, and this absorbs CO2 during the concrete curing process, so this has an overall impact to reducing the CO2 by about 70%. This is a standard process, but is really limited in the applications that it can serve to precast applications and currently without reinforcement, because there's some questions to the long term impact of that method of concrete curing on the reinforcing steel, whether it corrodes that. So there's trials being done at the moment to see whether or not that's the case. But obviously, when you're trying to judge things over a long period of time, the tests also take a long period of time. And then we have CarbonBuilt,  ( which has started more recently and has a similar kind of approach with a slightly different chemistry. So that's one kind of approach is absorbing the CO2 into the concrete directly. Another kind of approach is to use more of the supplementary cementitious materials, replacing clinker. And in that area, there's a couple of significant step forward. One is a cement which is called LC3, which stands for Limestone Calcined Clay Cement. So this is a blend of clinker with calcined clay and limestone, using about 50% of clinker and giving similar strength properties to a cement that's made with 90%, 95% clinker. So that's a pretty significant opportunity, and just beginning to have commercial acceptance. It's also possible to have an LC2, which the concrete makers can use - so without the clinker portion - and then the concrete makers can blend the LC2 with the ordinary cement. So there's some flexibility on how to deploy that solution. And there's also a number of companies who are looking at how they can improve the quality of supplementary cementitious materials, partly so that you can use more of that and less clinker, and partly so that you can use more of the resource that is currently not used today. So if you were to ask somebody for a zero carbon cement today, then they will give you probably something that contains slag and fly ash, and all the slides on fly ash with the right quality is largely being used today anyway. So although you might have zero carbon concrete, you're really using somebody else's. It's a bit like when you say, - well, I want to have renewable energy, unless you expand the total amount of renewable energy somebody else is using, you know, more coal, or more fossil fuel.

So technologies that allow poor quality fly ash to be used, or other cementitious materials we use, you know, expand the total amount available, and therefore are contributing to the overall reduction in the carbon footprint. And then the third technology is synthetic aggregates. Most aggregates of calcium carbonate are limestone, and if you take a calcium carbonate, it's over 40% CO2. So if you take CO2 plus calcium oxide, you can make a synthetic aggregate, and that has a very significant negative carbon footprint. So if you then use that to make concrete, you end up with a negative carbon footprint concrete, so something that's a sink, rather than a metre of CO2.

Right! Well, if you're going to introduce these technologies, I'm sure that you're going to need to make capital expenditure. And I think there are two sides to that. The first, of course, is how that affects your competitivity in the market. And the second is given that you're a world organization, and you work in developing countries, as well as in developed countries, these different countries are going to have different capacity for adopting these new technologies. So how is that going to work in the future?

Yeah, so I think there's two main drivers for adopting the technologies that go beyond cost saving. So a lot of the work that's been done so far, has reduced the carbon footprint, and at the same time, reduced the cost of making cement. Now, if you want to go to something that reduces the carbon footprint and increases the cost of cement, then you get into, you know, the question of who's going to pay for that. And because cement price is very low relative to the amount of CO2 that's emitted, it becomes immediately an issue of competitiveness. And indeed, in the future, how each cement company decarbonizes, is going to be very fundamental to their competitive situation. But coming back to your question, so I think there are two key drivers and the first one is a carbon price. Now, we could say that in Europe, we've had a carbon price for some time, but actually, because of the free allocation system, the cement industry in Europe is only just now starting to have to buy carbon credits. So the impact of letting the past has been, let's say marginal. If we might have multiple, say, margins - I did a podcast on this particular topic about a year ago and actually, the picture was even worse than that. But anyway, let's be polite and say marginal. But in the future, that will start to have an effect because the allowances are being scaled down and eventually, the plan is to move to a border adjustment mechanism rather than a freelance mechanism. So once you have this price on carbon, then you have an incentive, currently, what 50 euros a tonne, or 60 euros a tonne to reduce your carbon footprint. Now, that's not really enough to pay for carbon capture and storage, but it may be enough to pay for some of these new technologies, these alternative technologies. And perhaps we can come back to that one, because I think it's quite a very interesting stage at the moment. The other mechanism is that we start to see asset owners. So property developers in the UK Network Rail, in the US, San Francisco Airport that would be example, who are asking for zero embedded carbon in their buildings, or are looking for zero, embedded carbon in the buildings and are therefore very interested in zero carbon or low carbon concretes. So in California, in particular, you see, a lot of the tech companies have this kind of ambition, you know, they've said they wanted to be net zero. So when they build new offices, they also want to reduce the embedded carbon in the office buildings. So I think this is one of the driving forces. And I think we'll see more of this in Europe and North America, with customers saying ‘We want our buildings to be lower carbon.’ So obviously, there are looking at alternative ways of doing that and alternative materials. So I think we'll see more buildings using wood. But if you look at what concrete is used for, then replacing it with orders is only going to be a portion of the demand, probably quite a small portion of the demand, where that's irrelevant or a possible replacement. So for the rest of it, we really have to find ways of decarbonizing. And yeah, as I say, the technologies that are being developed now look encouraging, but are still at early stage.

Well, the Paris agreement has set challenges for all of us, and particularly big challenges for your industry. Are you optimistic?

I think when I look at the cement industry and the concrete industry and the things that are being done, then it's possible to be quite optimistic that we will actually achieve this net zero goal. But when you reflect on the overall macro situation, so not worrying about a specific industry, but just looking at the total, you know, it's very sobering to see how little progress we've made so far. If you look at the primary energy mix, I think in the last 20 years, we've gone from 91% fossil fuel to 89% fossil fuel, while tripling the usage. So if you look at these macro pictures, you can see, it's really a huge challenge. But I think when I look at the cement and concrete industry, and the potential we have, then I can be optimistic, so I shall have to leave it to others to be optimistic about the rest of the economy.

And thank you very much for sharing your thoughts with the Sustainable Futures Report.

Thank you. It's a pleasure to speak to you Anthony.

Ian Riley of the World Cement Association. (

Thank you for listening to this Wednesday Interview from the Sustainable Futures Report. There will be a regular episode of this podcast on Friday, and as you would expect we'll be mainly talking about the opening of the COP 26 conference in Glasgow. Next Wednesday there'll be another interview and this time I’m talking to a man who has a new angle on solar power.

As you know, the Sustainable Futures Report comes to you without advertising, sponsorship or subsidies, but I do appreciate the support of my patrons who pay a small monthly amount to cover my costs of research, transcriptions and hosting. If you’d like to join them at you’d be more than welcome.

I’m Anthony Day.

Until Friday.

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