Here we are again. Welcome, everyone to 100 Climate Conversations. Thank you for joining us. Before we go any further, I’d like to acknowledge the Traditional Custodians of the ancestral homelands upon which we meet today the Gadigal people of the Eora Nation. We respect their Elders, past, present and future and recognise their continuous connection to Country.

Today’s number 56 of 100 conversations happening every Friday. The series presents 100 visionary Australians that are taking positive action to respond to the most critical issue of our time, climate change. We are recording live here in the Boiler Hall of the Powerhouse museum. Before it was home to the museum, it was the Ultimo Power Station. Built in 1899, it supplied coal powered electricity to Sydney’s transit system into the 1960s. In the context of this architectural artefact we shift our focus forward to the innovations of the net zero revolution.

My name is Pat Abboud. I have been working on climate conversations over the past year and we are here today recording the podcast as well with today’s wonderful guest sitting next to me, Torben Daeneke. Dr Torben Daeneke is a pioneering chemical engineer focussed on creating pathways for direct carbon capture that could be used to revolutionise polluting industries. He lectures and leads the research team at RMIT University’s School of Chemical and Environmental Engineering, exploring the chemistry of liquid metals, nano enabled electronics and photovoltaics. We are so thrilled to have you join us today. Please make him feel very welcome.

You are an inorganic chemist? Can you tell us what that is? What is inorganic chemistry?

We’re looking at chemistry. Essentially, there’s two main branches of chemistry. One of them is inorganic chemistry. The other one, of course, the organic chemistry. So, organic chemistry deals with anything that has mostly carbon and hydrogen in it, and that would be anything that is biological usually. Organic chemistry also includes all of the petrochemicals or anything that’s made from oil or plastics and so on. That’s all-organic chemistry. What we are doing is we’re looking at all of the other atoms in the periodic table. So, inorganic chemistry works with metals, oxygen, nitrogen and all of these other elements, while organic chemistry mainly focuses on carbon and hydrogen. So, they’ve got two elements we’ve got the rest.

You knew at a very young age that you wanted to be a chemist, which I find really extraordinary because, you know, as a teenager you don’t really – most people don’t really know what they want to do. You had a really clear pathway.

Yes.

What was it that sort of triggered that thought for you as a teenager to say, ‘I want to be a chemist?’

There were two things. So, the main one was when I was a young kid, I was a massive nerd and I used to play a lot of video games. And in the video games I was playing, you had to invest into research to get to the next level. And that sort of taught me from a young age that science is important for us to progress. And that was even before I was a teenager. So, I don’t know, as an eight-year-old, nine-year-old, I was playing these video games. And then when I was growing up in the early 90s, climate change became a big issue. And there were – all over the news there were discussions about the Kyoto Protocol and the fact that global warming is happening and that we should do something about it. So, that’s where I sort of got the passion to do research and focus it on environmental issues, on climate change in general, sort of energy, climate change, pollution, so on.

Your choice to study chemistry was driven by a desire to make a positive impact on the environment, as you’ve said, and we’ll get into your specific work in a moment. But where can inorganic chemistry create opportunities for solutions on climate change and sustainability?

So, inorganic chemistry these days is used for everything. So, the fundamental concepts that are exploited in batteries for your electric car or for your energy storage at home, that’s all inorganic chemistry. So, that’s one big aspect of it. Then making photovoltaics, so your solar panels on your roof. That’s inorganic chemistry to make those. Making, in our case here, we’re developing technologies to take CO2 and turn it into useful products. And that’s all done via inorganic chemistry. So, inorganic chemistry touches everything and it’s very important for the solution or for getting towards a solution for climate change, I believe.

You specialise in liquid metals. What are liquid metals and what excites you about them?

Whenever I talk about liquid metals, most people think about two things first, and they sort of freak out and they either think about mercury, which of course is toxic and it’s a well-known liquid metal. You don’t want to work with that. Or they think about the Terminator movie, and we’re not going to make killer robots either. So, we’re going to be looking at other liquid metals, elements that are liquids at room temperature or close to room temperature. Why are we so excited about working with liquid metals? It is because it’s one of those really unexplored areas in chemistry.

So, potentially what you’re saying is there are a whole number of solutions that could be alive in liquid metals that we’ve never thought about. You are working with gallium at the moment. What is gallium?

Gallium is – well, it’s a metallic element that is not used for much. At the moment the main use for gallium is in semiconductors, where gallium is reacted with nitrogen to make gallium nitride, and that’s the basis of all white light LEDs. So, if you’ve got LEDs back at home, you’ve got a very tiny disc of gallium nitride in there that is used to essentially make light. That’s the main use for it.

And why gallium? Like what are the specific properties or potentials that exist within gallium that we don’t know about?

Well, it melts at 30 degrees celsius. So, on a hot day in Sydney, gallium would be just natively liquid. So, liquid state is easily accessible. Then gallium is relatively safe. It’s not toxic, it is stable. It’s for all purposes, it’s very similar to aluminium in a way from a chemical point of view. So, it just has a very low melting point and that’s why we like working with it. It’s stable, it’s easy to work with and it doesn’t kill you.

That’s handy. Let’s talk a little bit about carbon capture technologies. You and a team at RMIT University are working on carbon capture technology at the moment, which can help decarbonise difficult to abate industries. Firstly, can you tell us what decarbonisation is? And why is that your end game? Why is that the goal?

So, decarbonisation is generally used as a term to refer to essentially the process of stopping our society to emit CO2. So, at the moment if you look at our society and what we produce in a given year, carbon dioxide is actually the second largest product of all human activity. So, the number one product is clean water. So, we use a lot of clean water. The second one is CO2 afterwards is like cement and plastics and all of this stuff. But essentially, if you make a huge amount of CO2 each year and the CO2, of course, is slowly destroying the planet because of global heating and we need to do something about it. So, decarbonisation basically is overall the overarching process of stopping us from emitting CO2. Now, there are many ways of doing it. So, the easiest way is to just stop burning coal. Yes. So, we are on the way towards that.

I think globally where we are now relying more and more on renewable energies, wind energy, photovoltaics and so on, and we definitely need to do that. But there are some processes that we as a society really need that we can’t decarbonise. And one of the big ones is cement manufacturing. But then there’s also steel manufacturing and other similar processes and they still account for a fair bit of CO2 emissions, and we need to do something about that. And the reason why we can’t decarbonise, for example, cement manufacturing, is that we take limestone, we need to heat it up to then turn it into quick lime. And in that process, just the way the chemistry works, CO2 is emitted. So, it doesn’t come from the burning of fossil fuel to heat up the furnace. It actually comes from the limestone where it emits the CO2, and we need to do something about that as well. So, what we want to develop here are processes and technologies that can directly capture that CO2 from the processing and then turn it into something that can be useful. Or in the worst case, it can just be stored. So, we remove it from the atmosphere.

How far away are you from achieving that?

We are actually doing it on small scales in the lab so we can now take carbon dioxide and turn it into solid carbon. So, we’re literally taking CO2 and turning it back into coal.

It’s small scale now, but it potentially can be large scale.

It can be big, yes.

What are the hard to abate or difficult to decarbonise industries that you’re tackling? You mentioned that, you know, cement, steel, etc. shifting those minds, is difficult.

Actually we talk to a lot of people from these industries, so they are very, very keen to do something about it. So, a good way to think about it is a person that runs a cement factory. Yes, they want to make cement, but they also have a family. They want to have a future for their kids. So, they actually – when I talk to them, they actually really care about solutions. In the end, it’s not a challenge to necessarily to turn their minds, I guess. It’s to find a way to work together with them to then build the solutions together.

There are two iterations of the technology, the first of which is an electrochemical process. What was this first iteration in more detail and what were the learnings that you took from it?

So this is now about four or five years ago; we went into the lab and by that time we had already done a lot of work with liquid metals and studied sort of what happens on their surfaces and so on. Then in that very first process, we essentially took our liquid metal alloy and we wanted to see if it can be used to turn carbon dioxide into useful products. And there is a big research field out there where people use electricity essentially to drive chemical reactions, and that’s called electrochemistry.

So, how long would it take to say, to collect, you know, a kilo of carbon?

Oh, forever. That’s a problem with electrochemistry. Well, at least with our process in electrochemistry. But in that process, we took our liquid metal, put it into a solution that contained a lot of carbon dioxide. So, it’s a lot like sparkling water. It was very similar to sparkling water. And then you just have a little drop of liquid metal in there and you just apply electricity to it. And when we’re doing this after some time, we could start to see the solution to turn brown. When we looked at the product that’s being formed, it was basically little carbon flecks. So, we got very excited about it because at that point in time we were probably the first people that turned CO2 into solid carbon in an electrochemical process. And there’s a lot of reasons why that’s very challenging. But at that point in time, we were making tiny, tiny amounts. So, if you would let this run for maybe a day or two, you would end up with a few coffee grains worth of carbon.

The second iteration of the technology you’ve just described was developed after a very serendipitous meeting between yourself and chemical engineer Dr Ken Chang. Can you talk us through the current process you’re using?

So, the second iteration is an iteration where we essentially split up two components of the chemical reaction. In our first iteration, we try to do everything at once. So, we’ve got our liquid metal, we’ve got the carbon dioxide. They react together to make carbon, and then we apply electricity to basically run the cycles continuously. Now, in our second iteration, we take our liquid metal and we just react it with the CO2 first. And now we’ve got a very different reaction there. We literally have a big bucket of liquid metal, and we just flush CO2 through it. And it turns out that this reaction between CO2 and the liquid metal is very fast, happens in split seconds, and they start to make large amounts of carbon at that case.

But now during that process, we also form a by-product, which is metal oxide. And now this metal oxide needs to be turned back into liquid metal. And it sounds quite complicated, but essentially metal oxide is what we would mine in the first place as well. So, the technology to turn a metal oxide into a metal that already exists, so we’ve already developed it. That’s essentially how we are already making the metal in the first place.

So, now we split up these two processes so that we first do the reaction between carbon dioxide and metal, which can now be done on a much larger scale, much faster. And then once our metal is all used up, we take it and we turn it back into the liquid metal, which we already know how to do. We already now work on much larger scale. So, as I said, with the first iteration, we made little coffee grains of carbon. Now we’re making large amounts of – can have a handful of carbon already now after a day or two, and now it’s just about upscaling. So, I think this can be scaled. We’re now working towards that with industry partners, and we are now at that point where we’ve got to do the technical aspect of sizing it, designing the equipment and basically building a bigger machine that can do the job.

So, what are you doing with this carbon that you’re producing?

Well, ideally you want it to be useful if you go through the efforts, and this is an energy intensive process. So, you’ve got to use renewable energy. Probably build a solar farm somewhere, to drive this process at scale. If you go through all of that effort, you ideally want to use this as a product. The material that you’re producing, the carbon flakes, they can likely be turned into a product that I just mentioned before, graphene or graphene-like materials. So, it might actually become useful in energy storage for making batteries. It could also be directly put into the cement, for example, to make the cement stronger. So, there’s a lot of research out there that shows that if you take carbon flakes and you put them into cement, it actually makes the cement better. So, what we want to do is we want to take the CO2 that is being produced in cement manufacturing, turn into carbon flex and take the carbon flex, put them back into the cement so you get better buildings that way.

And on that, though, is there a danger when you use it in products like concrete, that the carbon will be unlocked again later in the lifecycle of the product?

Not really, because what happens at the end of building, you know, in the end, unfortunately, I guess to a degree the building gets demolished and it might end up, you know, maybe it gets re utilised once or twice more, but ultimately in the end it will likely at some point end up in landfill. But what this means is that the carbon that you’re producing ultimately ends up back underneath the ground and that’s where you want it to be. So, the carbon we are producing, we want it to be used ideally as much as possible, but at the very end in 100, 150 years, 200 years, whatever, and we can’t use the product anymore. We want it actually to end up underground. So, this is something you want to end up in landfill. So, it puts the coal back underneath the earth.

Is the technology easily integrated and accessible?

So, at the moment we are designing and upscaling it. So, the technology, we believe will work, it’s more about the financial viability and so on, which is in the next step. So, there [are] two aspects to innovation. So first of all, you’ve got to make a product that works, and then you’ve got to figure out a process that works, I guess, in this case. And then in the end, you need to work together with industry and essentially find a way to make it worth their while. Otherwise, you struggle to get it adapted.

So, you’ve mentioned a couple of times that you are working with industry, but what does that actually look like in terms of getting to the goal of making it happen?

Well, there’s many aspects of it that are very important. One aspect that’s very important is that I’m a chemist. I work in the lab. I can imagine what that problem looks like. I can imagine what the gases look like that they’re producing out in their smokestacks. But they can actually tell me what they’re doing. They can tell me what they need. They can tell me what they’re producing. So, I really need to get that information directly from the industry partner, because without that information, I might design a process that doesn’t work. So, that’s the first thing. And the second thing is we need some capital to basically design and build these processes.

So, you need them to feed information back to you so you can push the research forward.

Into the right direction. But also, I need know their capital and investments to develop something together. So, this is a real partnership, both financially and intellectually.

And are you seeing that uptake? Is that happening?

There is a huge interest on the industry side globally for these types of technologies. So, at the moment, I would say every couple of weeks or so there’s a potential industry partner that wants to have a chat to us and says, ‘Hey, are you guys ready? We want to have your technology, how can we help?’ So, they’re very keen on making this happening.

How do these processes you’re describing differ to other carbon capture technologies that are being developed around the world? Because this is the thing, as you said, we want to sequester carbon, get carbon back. And there’s so many different industries that are looking at this, which is fantastic. How does your process differ?

So, there’s a lot of different approaches. One of the key ones that has been trialled around the globe a lot is to essentially take the carbon dioxide and just pump it underground. That one has been trialled in very large, very expensive sort of experiments and up to now unfortunately, I mean it would be beautiful if this would work, but up to now I think all of these trials have failed. The main issue is that if you pump the CO2 underground, you basically cross your fingers and you say hopefully it stays down there for thousands of years and that does not necessarily work.

So, your carbon capture technologies are a more permanent form of locking up the carbon?

Yes, because we basically turn the CO2 into something solid. Into basically coal and coal is stable is that’s why we can mine it, we can ship it, we can transport from A to B. So, if you turn the CO2 back into something solid worst-case scenario, if you don’t have a use for it, you just put it underground. You just stored somewhere.

Devil’s advocate here, does this sort of technology give industry a sort of free pass to continue business as usual and continue to burn fossil fuels?

Definitely not, because the best way to reduce CO2 emissions is to just stop burning fossil fuels. Also, the most economic way of dealing with this at scale anyway, the best way is to transition anything that can be decarbonised or can just be replaced by renewable energies. The best way is to simply do that. Our process is quite energy intensive. So, basically if you are taking carbon dioxide and you want to turn it back into coal, you have to put a large amount of energy into these chemicals to go from A to B. And this is really something you want to avoid if you can.

So, our technology is going to become very useful for processes where you will emit CO2 from just the way the chemistry works. So, that’s cement manufacturing and so on. We’re targeting that very specifically. We’re not talking about making a coal fired power station and then bolting our sort of technology at the smokestacks there because it just wouldn’t make sense from an economic point of view there, because the energy that the power station will be producing will then be consumed to take the CO2 and turn it back into carbon.

So, I think it’s helpful to have a sort of sense of scale. You’ve given us that. But in terms of timeframe, like how long have you been developing this technology?

So, we’ve been working on it for about four or five years now, but we’re now in that process where we believe we want to now rapidly scale it up so we know it works and we are sort of ironing out the last kinks of this technology, but we are really looking towards upscaling it now and our goal is in about three years’ time, maybe four years’ time, we want to have sort of a container sized system. So, right now we’ve got a shoebox and we want to go big towards about a container sized system. And that container size system will be able to then do CO2 conversion on a reasonable scale. So, then you probably look at many kilograms a day, maybe tonnes a day, and we can then start to do a few trials, takes this container, put it next to a cement factory, see how it all works. If it works well then, we can either have multiple containers stacked side by side that will then produce carbon, or we might just build an even bigger version of it.

On that, as uptake for renewable energy increases, is this sort of technology an interim solution to just get us to where there are no emissions from fossil fuels?

This, what we are developing right now, will help us hopefully to get there. But there will always be a need for a solution to deal with CO2 emissions. Again, from processes like cement that emit CO2 inherently. No matter what, we will have to come up with some solutions for these processes. Also, I believe we’re probably already at a point where maybe in 50 years’ time, maybe in 100 years’ time, we have to go actively out there and take the CO2 that we have already emitted, take it out of the atmosphere and remove it. We will have to do that at some point.

There are already quite large facilities out in Switzerland and I think in Iceland is another one, where companies are filtering out CO2 from the atmosphere and they are right now taking that CO2 and try to sell it off for like beverages and so on. So, they basically take it to carbonate your beer and your Coca-Cola and so on. That’s not going to be a permanent solution because once you drink your Coca-Cola, you will actually burp out the CO2 again. So, it ends up back into –

It’s a cycle.

It’s a cycle, yes. But what will happen in the future is that that CO2 needs to be stored and utilised permanently. So, there are very large facilities already operating that take CO2 out of the atmosphere, concentrating it up, and then what we do with the CO2 afterwards –

So, they’re taking it from the air directly.

Yes, they’re already doing it.

How?

Very large fans that take air and put them through very carefully designed materials that act a bit like a sieve. So, they literally sieve out the carbon dioxide from air.

That’s extraordinary.

Yes, science is cool.

Science is very cool. You’re very cool. You’ve also turned your attention to some other issues in hard to abate industries that we’ve just been discussing. Tell us why ammonia has your interest and the potential positive impact that could have on reducing emissions. Firstly, just what is ammonia for people that don’t really understand that.

So ammonia, I think most people might know it from, you know, cleaning products. So, ammonia is – it’s a molecule that contains one nitrogen atom and three hydrogen atoms. Ammonia is at the moment used mostly not for cleaning products, but actually to make artificial fertiliser. So, fertiliser is required to essentially provide plants with nitrogen so that they can grow. Unfortunately, nature is not that good at activating nitrogen or making nitrogen available for some plants. So, about a 100, 120 years ago, chemists came up with ways to make ammonia and synthesise ammonia.

So, fossil fuels?

At the moment they use fossil fuels, but basically, it’s a process where hydrogen is combined with nitrogen to make these ammonia molecules and that then is turned into fertiliser and without artificial fertiliser, planet Earth would only be able to sustain about maybe 1 billion, maybe 2 billion people. So, chances are that we are all alive here because 120 years ago somebody invented ammonia synthesis and that allowed us to make artificial fertiliser. So, fertiliser is very important.

Who knew that that terrible smelling thing in cleaning products is actually helping to keep us alive?

Yes, exactly. So, it feeds the planet. And now the problem is the ammonia synthesis, it is hugely energy intensive. Just the process of making ammonia globally causes about 1.4 per cent of the global CO2 emissions. And for reference point, that’s actually more than Australia as a whole nation does. So, we have to find better ways of making ammonia full stop.

But now the other aspect of this is also that ammonia contains a lot of hydrogen, so we can actually use ammonia as essentially a vessel to carry hydrogen from A to B. So, people are now talking about – people might have heard about a hydrogen economy, but the next step afterwards is the ammonia economy, where we take hydrogen, turn it to ammonia, because ammonia is just really easy to transport from A to B, much easier than hydrogen. The future might look like that where you have a big solar farm, you could produce hydrogen using electrolysis and then you take that hydrogen and turn it into ammonia. Some of that ammonia is used to make fertiliser which is great, you know, growing tomatoes, fantastic. And then the rest of the ammonia might be then shipped to, I don’t know, Japan, Europe wherever they need energy, and this would be a good way to export sunshine from Australia to Japan.

Wow. So, this is happening?

This will likely be part of the future where ammonia is already being produced on large scales and we are now looking at finding less polluting ways to produce the ammonia in the first place. Because at the moment the process that we’re using has been invented 140 years ago, something like that, 120 years ago. And since then, the technology has not improved that much. So, we really need to come up with new ways of making ammonia. And it’s again, an area where we feel liquid metals can actually make a big difference.

Well, you’ve sold me on liquid metals and clearly, you know, there is a lot there that we haven’t tapped into, and the research work you’re doing is incredibly important. Are there other issues that you’d like to investigate using liquid metals?

Look, I personally – I think that liquid metals are super cool, so and there’s so many unknowns. So, it’s also very rewarding to study them because whatever we are doing right now, chances are nobody has done it before. So, it’s a very exciting field at the moment. So, we’re looking at making ammonia, we’re looking at turning CO2 into useful products, solids, but also other products. And we also are trying to make hydrogen and so on. So, basically all of the work that we’re doing is sort of centred around liquid metals right now, but we are also utilising them to make sort of molecules or do chemical reactions that are environmentally relevant, I guess.

Another big aspect of our work that we’re doing at the moment is – but it’s very different actually – is we’re using liquid metals to grow semiconductors and I think you mentioned that in your introduction as well, where we discovered that you can take a liquid metal and if you expose it to air, it will actually grows these very, very thin layers of materials on the surface. And we discovered that you can actually peel these layers off, and these layers turn out to be excellent semiconductors. It’s, again, one of these sort of chance discoveries that we made just playing with liquid metal. Allowing it to roll over surfaces and we figured out like, oh, it’s leaving behind like these little smudges and this little trails. First, we thought, that is quite annoying, making a mess, essentially.

But then after some time we started to look into these smudges more carefully. Turned out that these are these super, super thin layers of metal oxides that turn out to be very good semiconductors. So, we can now use these to make electronics. So, we should be able to make flexible electronics, bendable electronics, even transparent electronics that operate quite well. So, fast switching little transistors and sensors as well. And the important thing here is that the processing of making these semiconductors ultimately might be much less polluting. So right now, making silicon-based electronics again, very energy intensive, but also there’s a lot of very nasty chemicals that are used on the way there. So, our process might be less polluting overall. So, that’s another big aspect that we’re playing around.

It sounds like you’re consistently working short-term, long-term projects going all the time. What are you putting everything into right in this moment?

Well, at the moment, everything we’re doing is liquid metal. So, that’s sort of the overarching field that we’re working on. And we just want to understand these fluids because as I said, I think it’s one of those sorts of liquids that has been understudied. So, for the last few hundred years, we’ve been working with conventional solvents. So, that’s your water, your, you know, ethanol’s, alcohol’s. We know how to use them, we use them every day. Then maybe for the last 30 odd years or so, we’ve been looking at ionic liquids. So, these are molten salt and so on and there’s a lot of applications for that. But liquid metals is another category that nobody has looked at properly yet. So, I just feel that they have so much to offer, and I want to be one of those people that figures out what that could be.

Well, thank you for doing the extraordinary work you are doing. Please join me in thanking Torben Daeneke. To follow the program online you can subscribe wherever you get your podcasts. And visit the 100 Climate Conversations exhibition or join us for a live recording, go to 100climateconversations.com.

This is a significant new project for the museum and the records of these conversations will form a new climate change archive preserved for future generations in the Powerhouse collection of over 500,000 objects that tell the stories of our time. It is particularly important to First Nations peoples to preserve conversations like this, building on the oral histories and traditions of passing down our knowledges, sciences and innovations which we know allowed our Countries to thrive for tens of thousands of years.