Episode 054 | May 1, 2023 | 27:52
Guest: Skage Hem
Published: May 1, 2023
Duration: 27:52
Description
Join Joachim Almdal from Green Innovation Group as he talks with Skage Hem, Geologist at Alumichem, about the complexity of cement production and its role in global CO2 emissions.
Learn how to reduce emissions from cement production, what clients in the healthcare industry should do to reduce emissions, and how a system change and mindset shift are needed to address financing for CO2 emissions.
Get valuable insights on how to make a green transition!
Enjoy!
Full transcript
About this transcript
This transcript was automatically generated and may contain inaccuracies, typos, or mistranslations. Episodes recorded before 2024 were transcribed by an on-site model and may have a higher error rate. The content reflects the original conversation to the best of our ability. For the authoritative version, please listen to the audio episode.
You could probably have a scenario where if the buildings used half as much cement and the cement contained half as much limestone, then we would be down to 25% and that would go far. The CO2 emission is clearly the big one. So if they can solve, crack that knot, it will be a huge step forward and the technologies to crack half the knot is available.
Hello, Joachim from Green Innovation Group here, still working on making the healthcare sector sustainable. Today we are talking about cement and why are we talking about cement on a healthcare podcast? Because most healthcare happens in buildings and most buildings are built with cement. Cement is a huge CO2 emitter — one of the largest globally. So I invited Skage onto the podcast. Skage has a PhD in geology and is the former head of R&D from FLSmidth, a company that produces cement equipment. We take a deep dive into how cement is made, why it’s so CO2-emitting, and what can be done to change it.
Skage, welcome to the Sustainable Healthcare Podcast. You are not from the healthcare industry but you are very knowledgeable about a lot of the components that go into making a modern healthcare system. Today we’re going to talk about cement and you have a PhD in geology and you worked as Senior Vice President, head of R&D for FLSmidth, a large cement equipment manufacturer.
Cement, this little bit dull gray material, is immensely complex. It has typically 20-25 different components at least that influence how it crystallizes, how it hardens and how you have to produce it. And then you have to make this material in very large amounts very cheaply. As a scientist that was a fantastic challenge in the beginning. It was important to take these raw materials that come from nature that are heterogeneous and complex and produce a simple homogeneous product that has very uniform properties so that when you build buildings out of it you know what you get. Everything is very regulated — there are both standards and legislation so the products have to be of a very specific quality.
Why are we talking about cement in a Sustainable Healthcare Podcast? First of all, there’s a huge amount of building mass involved in the healthcare industry. Most of healthcare is done inside, whether that is the small office of a general practitioner or a large super hospital or the factories of pharmaceutical companies. Most of these buildings are built in cement. CO2-wise it’s quite costly to produce cement. Some of our listeners have asked: could we do something about this? They see it in Scope 3 — the emissions are coming way before it reaches the pharmaceutical company or the hospital.
Cement is like a 2000-year-old material. It has very attractive properties. It’s simple to make — you can make it in your garden if you can make a fire that gets up to 1000 degrees. The Romans did that and made cement that lasted for thousands of years — very high quality stuff. The challenge is that the primary component, the strength-giving component, is a calcium silicate made from lime — chalk which you burn at high temperature. The lime consists of calcium and CO3. From limestone, when you heat it up it turns into calcium oxide and CO2, and that CO2 then has to go somewhere. Traditionally it was just released into the atmosphere, and for every ton of cement you made, you emitted roughly one ton of CO2 plus the energy cost. So it’s not only that you need a lot of heat to make it, it’s also that you are releasing CO2 from the limestone itself.
It hardens fast, so it’s very flexible. You can manipulate it so that it can harden in different environments. You can store it easily. There’s no material that competes with it that is available in large amounts because it hardens in atmospheric conditions. Just mixing it up, waiting for an hour, you have a hard surface. When you put the tiles on your bathroom floor, what you use there is actually a very specialized cement, which is very effective. The properties are: it can be stored easily, it is easy to mix on site and prepare, and it hardens with very high strength and very predictable properties. This means it has been a very successful material; most buildings are built of it. Everybody is trained to use cement.
Roughly what amount of global CO2 emissions are coming from cement? It depends on how you calculate it, but I’d say at least 4% and maybe as high as 10%. I think maybe 6-7%, something like that. So we are actually more than the whole healthcare industry, which is 4-5%. Enough that it would be one of the largest countries in the world if you just took the cement industry and made it into a country.
Is there any hope for CO2-neutral cement? I think both substitution with other materials (like wood) is clearly one strategy. But also if you go from the technology chemical side, you can substitute up to 50% of the limestone. It requires changes in the industry, it requires investments, but you can. You can use calcined clay to a large extent. There are Danish start-ups that have developed this, and FLSmidth also offers these kinds of solutions. So 50% of the emissions of the cement can be taken out. It’s not easy. The most sustainable building is often the building that we don’t need to build.
A lot of cement is being used in countries that are still building up their infrastructure. There is a curve — when you have GDP per capita versus cement and steel consumption, this is like a curve that has a steep incline and then plateaus. China, Africa, India are on this steep incline. The richer your population gets, the higher GDP, the more you consume of cement and steel, and then it plateaus. China has maybe plateaued. The consumption of cement and steel in a country like Denmark or in Europe is not that high, but in China, India and Africa it’s growing fast.
For our clients in the healthcare industry where this comes into their world — the company has grown so it needs a new factory or new office space, or some healthcare system is building a new hospital. I would try to choose solutions that use less cement and try to create demand for cement types that have less CO2. At least it would start creating a push, saying this is the entire CO2 footprint of the project, and break it down into bits and pieces. That could create a competitive edge around low-emission cement so that producers could see a market for it.
The supply chain: cement factories have access to raw material, they own the rights to mine limestone and clay and sand, which are the principal components. They build the factory close to the stuff because it’s heavy. Cement plants are usually 200-300 km apart because transport expense becomes too big a competitive factor. Then concrete producers buy the cement and mix it. Concrete is when you take cement and add sand and gravel and water. The cement is the white powder that gives strength to the material. Two-thirds of the material is actually not cement.
How long does a cement building stand? It can stand forever essentially. There will be a millimetre of the surface of the cement building. If there are no cracks, not much will happen. But if there are microfractures and cracks, CO2 from the air will start reacting with it. So it will actually start tying up carbon dioxide again. It goes slowly but I’ve seen rates of maybe one millimetre per 20 years.
Besides CO2, are there other negative environmental aspects? NOx emissions from the fuel. But I think that’s fairly controlled with filters and ammonia systems. You also have some ecosystem impact when gathering raw materials. The footprint of a cement plant is maybe half a square kilometre to a square kilometre. You do have dust, so it will be bad in that area but it’s relatively confined. The CO2 emission is clearly the big one.
The technologies to crack half the nut are available. So that’s the positive news. It just needs to be implemented. Unfortunately that is the story for most areas of the green transition. We have almost all the technology we need. It’s an implementation issue, a financing issue, a system change, mindset change issue, much more than we need some fancy technological breakthrough. We need to use the tools that we have. These companies are in a competitive environment and somehow the change has to start happening. So it’s one of those places where we need to price those CO2 emissions so that they become a sound part of the economic framework. Thank you so much Skage for coming in and making us more knowledgeable about cement.