A Concrete Solution to Sequestering Carbon: An Interview with CarbiCrete
Did you know that concrete is responsible for about 8% of global carbon dioxide emissions, more than double those from aviation.
On this week’s podcast, Chris Stern the Chief Executive Officer and Co-Founder at CarbiCrete introduces a made-in-Canada solution for addressing part of concrete’s greenhouse gas problem. His company has developed a carbon-negative technology for producing precast concrete. The precast market makes up about 30 percent of the total market for concrete.
Here are some of the questions that Jackie and Peter asked Chris Stern: How much concrete does the world use each year? How are carbon dioxide emissions created in the production of traditional concrete and how can they be reduced? How is CarbiCrete’s product made? How is CarbiCrete’s product carbon-negative? Do you receive carbon credits for removing emissions? How long has it taken to develop your concrete process so far? Are customers concerned about the durability when new concrete mixes and processes are introduced?
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Episode 175 transcript
Disclosure:
The information and opinions presented in this ARC Energy Ideas podcast are provided for informational purposes only and are subject to the disclaimer link in the show notes.
Announcer:
This is the Arc Energy Ideas Podcast with Peter Tertzakian and Jackie Forrest. Exploring trends that influence the energy business.
Jackie Forrest:
Welcome to the Arc Energy Ideas Podcast. I’m Jackie Forrest.
Peter Tertzakian:
And I’m Peter Tertzakian. Well, welcome back and I’m back from my European vacation. And Jackie, I love going to Europe dominantly for the art and the architecture, and of course the history that’s associated with the art and the architecture. And every time I stand in front of some of these historic buildings, whether there are things like the Roman Pantheon or whether it’s cathedrals and things, I’m just amazed and staggered by the ability to build these grand structures with materials, and they didn’t even have modern trains and things. It’s just quite staggering.
And then of course the materials themselves are really quite amazing. Take concrete, for example, which was, I think it dates back to the fourth century BC but was refined and in Italy where I was, I spent a couple weeks, they figured out how to mix the concrete mix with volcanic ash and strengthen it and so on. And it’s just really quite amazing. But as we fast forward to today, and the subject of today, which we are going to talk about concrete, is of course that the mixing of concrete and the processes does liberate a lot of carbon dioxide, greenhouse gases. And so, the mix has to be changed yet again. And that’s what we want to talk about, isn’t it?
Jackie Forrest:
Yeah, I mean, concrete is responsible for about 8% of global carbon emissions, more than double those from flying. You may be surprised to know. If you think flying in airplanes is where we’re getting all our emissions from, but concrete’s fairly significant. And as you say, we build these buildings and they last for many years, but every year we build quite a few more buildings. In Canada, it’s a little bit less. According to the government of Canada’s website, 1.5% of Canada’s greenhouse gas emissions were from concrete. That’s probably because we have a lot of other industrial output compared to a lot of other countries that makes that percentage smaller. So, we’re really interested today to learn a bit more about how the emissions from concrete can change and what the constraints and barriers are to doing that. And so, we are very happy to welcome our guest, Chris Stern, CEO and co-founder of Carbicrete, which provides concrete solutions for carbon dioxide. Welcome, Chris.
Chris Stern:
Oh, thank you very much. Jackie and Peter, very happy to be here.
Jackie Forrest:
Well, Chris, maybe tell us a little bit about yourself and a bit about Carbicrete. We’ll get into more details later on in the podcast, but just a quick thumbnail for everyone.
Chris Stern:
Yeah, great. Well, I’m a degreed engineer but didn’t practice up until now. I’ve been mostly in business development and sales and first half of my career I was selling capital equipment and then I got into the solar power industry in 2005. Ended up starting a company in residential solar, which we sold to NRG Energy in 2014. This is my second startup and Carbicrete is a technology that was invented at McGill, my alma mater. And we started the company in 2016 and here we are today with 40 people.
Peter Tertzakian:
Wow, that’s really impressive. So yeah, I mean for our audience, you’re speaking to us from Montreal where you’re from.
Chris Stern:
Exactly. Yes.
Peter Tertzakian:
Right. Okay. Well give us a sense of how much concrete is consumed annually in the world and maybe also add to that the basic dynamics or the process of making concrete. What is concrete? So how much is consumed and what it is.
Chris Stern:
Yeah, so there’s about 30 gigatons. So that’s 30 billion tons of concrete made every year. China, for example, makes enough concrete to build 2000 Pentagons, the US building, if you’ve ever seen it’s immense and they make enough to make 2000 of them. There’s two tons of concrete made for every person that walks the planet every day.
Peter Tertzakian:
Whoa.
Jackie Forrest:
Wow.
Chris Stern:
Every year, sorry. And so, the process of making concrete is you take cement, water and aggregate and mix it all together and then it sets. Where the greenhouse gas emissions come from are the manufacturing of cement. Roughly half the emissions come from burning fossil fuels or old tires or other things like that to heat up the kilns to get to the right temperature. And then the other half comes from…You’re starting off with limestone, so calcium carbonate, CaCO3, and when you burn it, you tear off the CO2 and that becomes calcium oxide, which is what we know as cement.
Peter Tertzakian:
Making cement is a very energy intense combustion-based process because you have to heat the CaCO3, calcium carbonate, to these high temperatures. Is that where the bulk of the emissions are or is actually-
Chris Stern:
No, it’s half and half. So, it’s half because of a chemical equation. And then the other half is from burning stuff. There are processes that are being explored now to do it with different energy sources, but there’s like thousands of cement plants that are operating today, burning stuff.
Peter Tertzakian:
Is it dominantly natural gas that they used or is it-
Chris Stern:
It’s gas, it’s fossil fuels effectively.
Peter Tertzakian:
Yeah.
Chris Stern:
Greening in the cement industry in their perspective is using old tires that actually is greening their industry according to them, but so it’s burning whatever they can get their hands on.
Jackie Forrest:
Well, and one of the challenges is the energy part, maybe you could substitute, but this chemical reaction, you can’t get rid of that with the existing process unless you do something different. But hey, before we get onto that, I wanted to talk about, so what are the options? There’s obviously an option to do it differently. Are there options that are being looked at, for example, substituting the use of concrete using more wood or recycling more concrete? Are there other options outside of a new process to reduce the emissions? That’s incredible, two tons of concrete per person on the planet.
Chris Stern:
Yeah, I mean look, in Canada, we do a lot of buildings with wood, what used to be difficult in the past, they now make 12 story buildings out of wood. The problem with buildings made out of wood is that they can burn down very easily and quickly. So that’s a bit of a challenge for the industry. The other ways you can make concrete, you can capture the carbon from the cement plant, which is very expensive, but you can capture the CO2 coming off the smokestacks. Those are some of the ways to mitigate the carbon footprint of the cement industry.
Peter Tertzakian:
Are the emissions, the CO2 emissions fairly pure to capture? I mean you said it’s difficult to capture, is it because it’s not so pure in the flux?
Chris Stern:
Yeah, precisely. In terms of flux gas, it’s fairly concentrated compared to a natural gas fire, electricity plant, which is like 8% of CO2, a cement plant, it’s about 30%. So, it’s more pure than other things, but still, it’s difficult to clean.
Jackie Forrest:
All right. We’re going to get into Carbicrete Solution, but in general, are there different kind of categories of new processes that are being developed? Because if it’s hard to capture CO2, you may have to just do it differently and is there options for that?
Chris Stern:
Yeah, that’s precisely it. I mean, you’re looking to make calcium oxide, so there’s many different ways to do that. And there’s a lot of new startups that are looking at making calcium oxide, either growing it using sea water, there’s other process steps to make it. But all these are sort of at TRL four, so they’re just in the lab stage at this point. Whereas our process is we’re using previously enjoyed materials from the steel making industry and combining that with carbon dioxide to make Carbicrete.
Jackie Forrest:
Okay. Well let’s talk about Carbicrete then. Just describe in a little bit more detail your process. Normal cement. What’s the feed stock for that? And you’re using something different?
Chris Stern:
The feed stock for cement is limestone and that’s what they’re burning to make cement. From our process, we’re actually taking an industrial byproduct of the steel making industry. It’s called steel slag, and it’s about 15% by weight of steel making is actually slag. You need to make it in order to make good steel. So, it’s not necessarily a bad thing, but you have to do something with it afterwards. A lot of steel slag is ending up in landfill or there’s some other uses for it underneath roads. But typically, there’s not a lot of use for steel slag. So, we take steel slag, we combine it with some other aggregated like rock or sand, mix it with water, make a product like a concrete block or a paving stone or retaining wall. And then we actually put into a curing chamber where we subject it to carbon dioxide, CO2 ends up reacting with the steel slag and it makes a calcium carbonate effectively a limestone.
Peter Tertzakian:
So, you’re describing a process that not only can be a net carbon negative process is what you’re saying?
Chris Stern:
Absolutely. The fact remains is that we’re replacing cement a hundred percent. So, there’s no emissions associated with steel slag because it’s associated with the steel making operation to make it carbon negative, we’re actually taking carbon dioxide and putting it into the steel slag.
Peter Tertzakian:
So, the steel slag that is a byproduct of the steel industry. Where would it go normally?
Chris Stern:
Into landfill or it’s used as road base. So, try and think of it as a hard mineral. So, like rock, effectively.
Peter Tertzakian:
Okay. So, you have to take it and transport it by truck to the concrete plant. And so how easy is it to retrofit existing concrete plants with your process?
Chris Stern:
Yeah, that’s a great question. I mean, most of the plant remains the same. The only thing that changes is the curing system. So, if you have a 30-million-dollar concrete plant, you might use one sixth or one seventh of that change over the curing system in order to use our process. It’s using the same mixers, the same block formation components, the same automation. Everything else is the same except for the curing system.
Peter Tertzakian:
Okay. So how many other people are doing this in? Who are your competitors?
Chris Stern:
There’s a couple of competitors that do other types of cementitious materials. Nobody else is doing the technology as we have it. We have wide patent coverage for the technology. There’s a handful of other companies that are using different types of materials to get to the same end result.
Jackie Forrest:
Now, is it unique, this idea that your carbon negative so that I guess that means that there must be some energy and using the mixers and everything, but you’re absorbing more CO2 than you’re using in the energy for creating the concrete?
Chris Stern:
Yes, we’ve done several lifecycle analyses of the whole process from cradle to gate of the process and we’re net negative.
Jackie Forrest:
And is that unique? Are there other types of concrete processes that achieve that? Because I sometimes see carbon neutral advertised.
Chris Stern:
Yeah, there’s low carbon net technologies and there’s…I’m not aware of any carbon neutral ones, but there’s no carbon negative ones. There might be some that are being spoken about right now that are far off in the future. They’re the lab at this point.
Jackie Forrest:
It’s probably worth clarifying that your process today is being used to create blocks and pavers and products where you form them into something and then you could put them in a curing chamber. How big is that market relative to the whole market for concrete?
Chris Stern:
The precast market is about 30% of the concrete making market. This subset, which is dry cast, is nearly 10% of the entire concrete market. So, it’s huge. There’s no way we will reach the end of that because it’s the sheer size of it.
Peter Tertzakian:
I want to take you back to the process and something, the feed stock for your process is, one of the feed stocks is CO2. And so, to what extent are you using combusted CO2 from some other process versus sometimes it’s cheaper to manufacture CO2 and use CO2?
Chris Stern:
So, I mean, look, we’re operating in Quebec right now at our pilot plant in which is about an hour away from Montreal. We get our carbon dioxide from a biogenetic source. It’s from an ethanol fermentation plant. So, nothing’s being burnt to make this carbon dioxide.
Peter Tertzakian:
So, then that brings about the next question, which relates to carbon credits. So, given that your carbon negative, are you generating and selling credits or how does that work in the carbon market?
Chris Stern:
On a contractual basis, part of our licensing agreement is that we hold onto those carbon credits. The abatement credits are worth something, which is the replacing of cement by a non-CO2 related material. So, the steel slag, but the removal credits are worth quite a bit more, actually hundreds of dollars per ton.
Jackie Forrest:
And are you selling those, I know you’re in Quebec and you guys have a cap and trade there where you have, I think you’re aligned with California. Are you selling into that market or is it more voluntary markets where you’re achieving that type of price for your carbon credits?
Chris Stern:
Yeah, it’s the voluntary markets because their frontier credits, people really want these because mineralization is literally the best way to get rid of CO2. The lifetime is more than a hundred thousand years compared to a tree which is less than a hundred.
Jackie Forrest:
What are frontier credits? Could you just clarify that?
Chris Stern:
So, it’s the beginning of the industry. So, they want to support this part of the industry so that it grows and that it becomes normal or more normal I should say, than other types such as planting trees or other types of carbon removal.
Jackie Forrest:
Because the voluntary market is much lower than that, typically not nearly a hundred dollars, but there are certain buyers out there that say, I want to support these new technologies.
Chris Stern:
So, Shopify, Stripe and Microsoft and a few others got together, and they created something called the Frontier Fund. It’s nearly a billion dollars and its purpose is to do just that, to support companies like ours with outsized purchases for the carbon credits.
Peter Tertzakian:
So, the CO2 input you’re getting, basically, credits for as you get into arrangements with the ethanol plant where you get the CO2 from the steel slag. So, the steel makers would’ve otherwise thrown this into the landfill. Do they now charge you for the steel slag or how does that work? Do you buy the steel slag, or they give it to you, or say come and take it away?
Chris Stern:
It depends because in some cases you’ve got small bits, so less than a few millimeters in diameter. And this, there’s a tipping fee because it’s useless when it’s larger chunks, when it looks like gravel, it’s about five bucks a ton because they can sell it into a company making a road. It can be used as the base.
Jackie Forrest:
Now it must be really heavy to move this around. I don’t even know, but something called steel a? Seems heavy. Is that a constraint to your process that the transportation costs for that heavy material or just concrete face that
Chris Stern:
It’s like you’re transporting rocks around, so you want to make it within a certain amount of kilometers from where the source is? So, part of our economics are within 200, 250 kilometers away, the concrete plant should exist from the steel.
Peter Tertzakian:
So, if we were in an ideal situation where we could reinvent society and the economy, we would put a steel plant right beside a concrete plant.
Chris Stern:
Oh yeah, exactly. We’re even talking to some steel companies in India and elsewhere saying they want to get into concrete making and they want to put a concrete plant right next to their plant. They’ve got CO2 from the steel making industry, but from the steel making operations, they’ve got the slag, and we can create a whole new business model for them.
Jackie Forrest:
Now Chris, you said 30% of the market is precast, and of that 10% is sort of what you’re going after. Is there a way that your process could be applied to the traditional poured concretes, or do you think it’s not applicable?
Chris Stern:
It is applicable. I mean, we’re working on a flexible curing system together with McGill that you can bring to a site. So, it’s a transportable curing system, but we’re really focused on precast because it’s, look, the market’s so huge by the time we get to ready mix we’ll be years away.
Jackie Forrest:
Now, one barrier for new types of concrete I understand is the adoption or people accepting the product, the existing thing has worked, and people build things like bridges and buildings, and they want them to last for a hundred years. Or Peter you just talked about in Europe, thousands of years in some cases, and they’re not sure that these new types of mixes are going to be as durable or as good. Can you talk a little bit about what it takes to get people, consumers, but regulators too, to certify your products?
Chris Stern:
Yeah, I mean, we’re working with the NRC in Canada. A lot of the products don’t need any certifications, so like paving stones and retaining walls. It’s only the instructional applications for concrete blocks for institutional installations where you should have some sort of a… People should follow the process steps that we defined with the NRC. But outside of that, I mean as long as we meet the actual performance-based standards, then you can use them. And to be quite frank, the end material is the same as concrete. Once you add the CO2 with the calcium oxide, you’re creating limestone.
Peter Tertzakian:
Maybe talk about your business model. Is Carbicrete setting up concrete plants or are you licensing your technology to concrete companies or some hybrid version of that? What’s your business model?
Chris Stern:
Yeah, we’re licensing the technology in the case of mom and pops, and we can help them finance the changeover for their curing systems. But in larger companies like Fortune 50 building products companies, they can leverage their balance sheet to actually do the changeovers. It’s a licensing-based model.
Peter Tertzakian:
Okay. So, what are the next steps then for Carbicrete given where you’re at?
Chris Stern:
We’re getting through phase two, our pilot right now, it’s actually going to be turned on next week. That’s very exciting for us. So, we’re going to be producing about 2,400 blocks a day by the end of this year. And then we’re going to build out that plant over the course of the next couple months. And then we’re going to be talking to many different customers. So, we’ve got projects in Quebec and Ontario, as well as in France as well as the UK.
Jackie Forrest:
So, Chris, for everything you’ve told me, your solution is a part of the solution. So, your technology could address the precast market, which potentially could be 30% of the whole market, but what about the rest of the market? Is there solutions for that?
Chris Stern:
Yeah, there’s new ways to make cement. So, there’s a bunch of startups that are looking to make cement using different process steps that don’t involve burning limestone. That’s one way to solve it, and that’s years away. The other process that could be applied to the cement industry, if you don’t change how, you make cement, is to capture the carbon dioxide as it comes off the flux stack.
Peter Tertzakian:
So, like a CCS type solution, carbon capture, which is probably essential if the concrete cement or cement slash concrete industry is going to achieve these aggressive targets by 2030 and beyond all the way to net zero by 2050.
Chris Stern:
Precisely, precisely. It needs to be all hands-on deck.
Jackie Forrest:
So, Chris, you’ve mentioned that you’re working with McGill University and that you had gone there in the past. Can you tell us a little bit about the story of how the technology was developed and how McGill was involved with that?
Chris Stern:
Yeah, that’s a great question. So, my business partner, Mehrdad Mahoutian who was starting his PhD in 2012, and he wanted to find a material that would replace Portland Cement in concrete. And so, he tried many different products and things, and he discovered that steel slag could be used as a binding agent within concrete. He also determined that you could react it with carbon dioxide, make it gain strength. So that started in 2012. I met him in 2015 and we spent a year discussing how to bring it out of McGill and start a company. And by 2016 we actually started the company. It was really a process to follow.
Jackie Forrest:
Well, and it’s interesting just how long it takes to develop new technologies. The idea was sort of in at lab or just as an idea in someone’s head in 2012, and here we are 10 years later and you’re still at a fairly early stage in terms of rolling this out. So, I think it’s a lesson in terms of it does take a long time to develop these technologies, to scale them up, to get the funding and to get to where you are today, which, how much concrete are you producing today? It’s still fairly small, right? Relative to where you might be in…
Chris Stern:
It’s small because yeah, we’re just in the second phase of our pilot, but we’re doing a scale by the end of this year. But from there, it’s going to fan out and we’ll be able to expand in a parallel fashion.
Peter Tertzakian:
The next step is to get consumer buy-in the construction companies, builders, et cetera, saying, “Yeah, okay, I will use this new product over what I have used for decades, century, if not millennia.” If should go back to Roman times. So how are the consumers reacting to this? Are they anxious to see this kind of thing? Or are they…
Chris Stern:
We have phone calls all the time from internet streaming companies that you all watch, to the phones that you use, asking us how can we get our hands on this, to big GCs, general contractors, widespread inquiries into our technology.
Peter Tertzakian:
And the big question, maybe the biggest question is it cost competitive with existing concrete technology?
Chris Stern:
The materials are actually less than cost because you’re not burning stuff, you’re taking an unusable product, just grinding it. So, in terms of cost competitive, yeah, it’s absolutely cost competitive. In some cases, it’s lower cost if you have a greenfield plant. So, if you build a cement based concrete plant next to a Carbicrete plant, ours will actually be less expensive to build and operate. Furthermore, our technology provides that the concrete is ready within 24 hours. You can ship it and use it within 24 hours as compared to a cement-based concrete, which takes 28 days to get the full strength. Which is why when you drive by these concrete yards, they’re huge. We don’t need those huge yards because we can ship right from that machine.
Peter Tertzakian:
Right. Okay. And then finally, understanding this whole thing, if everybody starts using the Carbicrete process, is there enough steel slag to satisfy the demand that’s needed, or is the price of steel slag going to go through the roof?
Chris Stern:
That might happen and [inaudible 00:23:0g economics might take place. I hope it does, but there’s 250 million tons of steel slack created every year, so that’s good enough for up to two gigatons of carbon negative concrete.
Jackie Forrest:
And then one other clarifying question. You talked about the fact that the construction companies and the different technology companies are folding you up and wanting this product. Why is that? Is that because the environmental attributes?
Chris Stern:
Absolutely. That’s a hundred percent the reason. Like they’re trying to green the building industry, and you can’t do it by just taking a little bit of carbon out of concrete because that’s window dressing. So, if you get to negative emissions, that gets them very excited.
Jackie Forrest:
All right. So, what I talked earlier about the fact that people are a little concerned by using these products because are they going to have the longevity of some of the existing products? I guess for the market that you are attracting that isn’t such a concern and they’re happy to use them right away. There isn’t really a lot of pushback from consumers.
Chris Stern:
Yeah, they’re pushing for us. Literally all these large companies are contacting us and saying, how can we get your product?
Jackie Forrest:
Well, it’s a great place to be.
Peter Tertzakian:
I think that was very insightful. It’s interesting to talk about other heavy emitting industries beyond oil and gas and how they are modifying their processes to achieve emission reduction, meaningful emission reduction going forward. And your process obviously has consequences to the future consumption of traditional fuel. So, it’s very important to understand these trends from just energy supply, demand balance, perspective as well.
Chris Stern:
It’s absolutely very interesting. And just a further note, Jackie mentioned the airline industry responsible for 4% of gas emissions. Guess what? Light vehicle is 6%. And look at, you’ve got a trillion-dollar company making cars to tackle a 6% problem.
Peter Tertzakian:
Well, Chris Stern, CEO and co-founder of Carbicrete, thanks very much for joining us. Jackie will put the website link on our site and anyone who has more interest in the company can go check it out.
Jackie Forrest:
Yeah. Thank you, Chris.
Chris Stern:
Thanks very much.
Jackie Forrest:
And thanks to our listeners, if you enjoyed this podcast, please rate us on the app that you listen to and tell someone else about us.
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