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Decarbonizing the Quicklime & Cement Industry – Electrification vs. Standard Carbon Capture


SaltX:s Corey Blackman, Ph.D. in Energy and Environmental Technology, on how new technology must be implemented to heavily reduce one of the biggest emitters in the world, the cement and quicklime industries.

Why have we chosen to tackle emissions from quicklime and cement production?

Corey Blackman: Well, if we don’t tackle the emissions from quicklime and cement industries, we won’t be able to meet our climate targets. So they account for about 8% of global CO2 emissions. So just by tackling these two specific industries could be huge wins for decarbonization and also our climate goals. 

Why are cement and quicklime industries such large emitters?

Corey Blackman: Well, for the first part, they’re massive industries, so they use all over the world. Quicklime is used in steel making, in pulp and paper, used in water purification and cement, which is part of concrete, and concrete is the second most used substance on Earth. When I talk about massive in terms of cement production, we’re talking about 130 tons of cement produced every second globally. So this is the main part. Another part of it is that CO2 is a byproduct of the quick-lime production process or the cement production process. So for every ton of cement that’s produced, about 600 kilos of that is transformed directly into CO2. And this is an intrinsic part of the process. You can’t have cement without this actual process going on. And so it’s a byproduct of the cement production process. And this means that cement produces unavoidable CO2. 

Why won’t electrification alone save us?

Corey Blackman: Well, in many industries they’re going towards electrification, which makes sense. So in many cases we can replace fossil fuels with low carbon or renewable electricity. And this is very important in many different industries to be able to go in that direction. However, it doesn’t tackle the entire problem, especially when it comes to the production of cement and quick-lime. We do need to heat up the limestone to these quite high temperatures, and that is typically done with some form of fossil fuel. So we typically burn some sort of oil or coal or natural gas in order to do that. And so this accounts for about 200 to 300 kilos of CO2 for every ton of cement that’s produced. However, as I mentioned before, we have just by this heating up and breaking down of the limestone, we produce an additional 600 kilos of CO2 for every ton of cement that’s produced. So this means that if we are going to tackle the cement industry using electrification, this means that we will only tackle about 30% of the problem because only 30% of the emissions actually comes from burning fossil fuels. The rest of the emissions come from the actual breakdown of the limestone. So it’s very critical that there’s some sort of capture process for this CO2, and this can be done either using our EAC or by CCS. 

What is CCS?

Corey Blackman: So CCS stands for Carbon Capture and Storage, and this is a process or method or technology that’s used in order to basically extract or to suck CO2 out of a gas stream. And this can be from a factory or a power plant or something like that. So CCS has been in the news recently for good and for bad. In many cases, it’s seen as a process or a method or way of fossil fuel industries to be able to continue business as usual. And this is an okay stance. But however, when it comes to cement and quicklime industries, we have to be able to take care or handle the CO2 that’s produced by just the process itself. So this is why it’s important. And CCS could be one of these possibilities in order to do this. However, one should take into consideration that using the typical CCS technologies, it is also energy intensive. So this has to be considered when utilizing it for these industries. 

How do we do things differently with our EAC technology?

Corey Blackman: So the SaltX EAC technology, which stands for Electric Arc Calciner, is basically more of a separation technology rather than a carbon capture and storage technology. So we took it from a more from a first principles approach rather than when it comes to CCS, which basically tries to separate out the CO2 from a mixture of gases. What we said is what happens if we only have CO2 gas in our system? So what we’ve done is that we take the limestone, we put it into an airtight chamber, we heat it up to quite high temperatures using renewable electricity. And that way, when we do the separation of the limestone decomposes into the quicklime and the CO2, we get the CO2 in gas form and we get the quicklime in the solid as solid particles. So it’s quite easy to separate the solid and this gas. So what we get from our EAC is a pure stream of CO2 that we can take directly towards storage. And so this makes it a lot easier to separate. So you use a lot less energy for this separation process versus like a CCS process where you need to separate out gas particles from other gas particles. So this makes it the EAC technology a lot less energy intensive compared to typical CCS systems. 

Why is EAC suitable for these industries? 

Corey Blackman: So since these quicklime cement industries need to actually tackle this unavoidable CO2, the EAC is a good way of doing that because it can significantly reduce the amount of energy that’s needed. In order to do that, it’s much easier to do the separation method or let’s say, less energy intensive to do the separation method. But also we produce a lower volume of CO2. So this means that you on one side, you can reduce the amount of energy that’s used on the other side, you actually don’t have as much CO2 to manage and to handle and to have to store at the end of the day. So it’s a cost reduction on both ends.

What kind of adjustments are needed to implement this technology?

Corey Blackman: Yeah, that’s a good question. And the engineering answer is it depends because a lot of it depends on the availability of low carbon electricity, and the increased demand in electricity for the system. So that needs to be one thing that’s important for the application of this technology. But also in case of retrofitting, we need to also adapt the system to attach our EAC to the overall system. And in many cases, you can actually reuse a lot of the components. And so this attachment is relatively similar to what you would do in a CCS process. The other thing is that if you’re looking at a new build, so a completely different, completely new system, this opens up some other possibilities that I think are kind of unique to the EAC, especially being able to co-locate the plant with existing renewable energy sources, or a place where you can actually store the CO2 opens up a lot of different possibilities there, or even to have smaller distributed plants that are actually quite close to local resources, and to also local energy sources in order to be able to minimize the impact of this cement production. So there are lots of different ways of doing this implementation. And we have been exploring all these different aspects at SaltX.

How are you planning to decarbonize these sectors?

Corey Blackman: So we at SaltX, the main goal for us is to rapidly scale this technology. This is why we’re working with some of the biggest players in the cement and quicklime industries in order to be able to scale the technology. So just quite recently commissioned the 2MW system, and this is going to be a precursor to an 8MW commercial system, which is going to be part of our industrialization strategy where we’re going to be going towards more modularized solutions, which will be key in rapidly deploying this technology. 

Are there other potential application areas for this technology?

Corey Blackman: So yes, there are different ways of implementing the technology. And for us, what is going to be key, let’s say the fundamentals of the implementation is, are you producing a solid or a powdered material that needs to be heated to 500 plus degrees Celsius? So that’s the, let’s say the general. This is interesting for, let’s say, production of aluminum, for magnesium, in direct air catcher systems, in lithium production. And there’s so many different opportunities here. But for us, one of the key is that we can tackle these high impact industries where we can actually help to decarbonize them with our technology. 

What is needed to accelerate the decarbonization of these industries?

Corey Blackman: Yeah, so that’s a really good question because from our perspective, we need to have these carbon pricing signals. So it is right now it’s too cheap to just release CO2 into the atmosphere. So there needs to be some sort of incentive for us not to do that and for us to actually store the CO2. And then talking about storage, then we need to have the facilities to store large amounts of CO2. So a lot of investment, a lot of work in technologies needs to go into that as well. So we see that as a very critical factor. And then we also need to be investing more in these decarbonization technologies so that we can move it quickly. So I think that there needs to be more of a sense of urgency for the development of these technologies and for moving towards this carbon free future.