Welcome everyone to 100 Climate Conversations. Thank you so much for joining us. Today is number 45 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, which is climate change. And we are recording live today in the Boiler Hall of the Powerhouse Museum. Before it was home to the museum, this was the Ultimo Power Station. It was built in 1899 and it supplied coal powered electricity to Sydney’s tram system into the 1960s. In the context of this architectural artifact, we are now shifting our focus forward to the innovations of the net zero revolution here tomorrow. Yiradhumarang mudyi, Rae Johnston youwin nahdee, Wiradjuri yinhaa baladoo. Hello friends, my name is Rae Johnston. I’m a Wiradjuri woman. I was born and raised on Dharug and Gundungurra country and that’s where I have responsibilities to community and Country. And it is an honour today to be here with you on the unceded land of the Gadigal. And I wish to pay my deepest respects to their Elders, past and present, for the sacrifices that they have made so that we can be here today. Now, as we begin today’s conversation, it is important to remember and to acknowledge and also to respect that the world’s first scientists and technologists and engineers are the First Nations peoples of this very continent, from the world’s oldest continuing cultures. And that’s despite all attempts to erase them. Now, in my everyday work, I am a STEM journalist and a broadcaster, and I have the opportunity to talk to a lot of different people that are using science and technology to help the planet. And today, sitting beside me is one of those people I have Rose Amal, who I am very much looking forward to chatting with today. Rose Amal is a Scientia Professor at the University of New South Wales School of Chemical Engineering, where she is co-director of the ARC Training Center for the Global Hydrogen Economy. Now, Rose is a chemical engineer who is recognised as a pioneer and a leading authority in the fields of fine particle technology, photocatalysis and also functional nanomaterials. And her research focuses on designing nanomaterials for solar and chemical energy conversion applications. We are so thrilled to have you joining us today. Welcome. Thank you.

Thank you Rae.

Now. Let’s start at the beginning, shall we? When you were growing up in Indonesia, what drove your passion for science in those early days?

Well, I liked mathematics and physics and chemistry in school, and I was always fascinated in terms of how science actually explains a lot of what we see in nature. So, that’s the reason that I am really passionate about that. And actually, only recently I found out because my brother was telling me, when I was telling him about my work, about harnessing solar energy and converting the chemical energy, that we can bottle it and export it to other countries. And he said to me when I was little, I’d ask him whether we can catch sunlight and then bottle it up and use it at nighttime. So, perhaps subconsciously when I was little, because of some of the blackouts happening in my town, I always had that passion to sort of see how I can harness solar energy and use it and store it.

So, was there anything in particular from your upbringing you think, that instilled a desire for your research to reflect sustainability?

Yeah, I guess that was probably during my undergraduate year because, you know, chemical engineering – as a chemical engineer, you will produce chemicals and you will produce waste and what are we going to do with [that] waste. We cannot just dispose of it in the environment. So, how can we do it sustainably? How we can develop a process that will be able to make sure that the waste is minimised, and the waste is also treated before we discharge it to the environment? So, those are the things that sort of drove me to the research that looked into water treatment, air pollution control, and now moving into sustainable energy.

I can imagine that your career path could have taken lots of different directions. So, was it really that sustainable part that sparked something in you? Does it excite you to work on these kinds of projects?

Yes. You know, one of the things that we always sort of see is that, okay, we made this process. A lot of the things that we do is to meet our needs now. But sustainability is about future generations. How do we meet the needs of all of us now, but ensure our future generations still have the capability to meet their needs?

Let’s talk about chemical engineering. Let’s start at the beginning, though, by asking what is chemical engineering and what sort of industries do chemical engineers work in? What problems are they trying to solve?

Right. So, chemical engineering is an engineering field that deals with, I would say, the design and operation of chemical plants. They convert the raw materials to useful products in large quantities, I have to stress, large quantities to meet society’s needs. For example, to produce ammonia, which we use as fertilizers to feed our populations, and those processes [are] actually known as the Haber-Bosch process. So, we have a chemist that develops the synthesis method to convert air – nitrogen in air – and hydrogen to make ammonia. But then the chemical engineers take that process to make it in large quantities so that we can feed [the] 7.8 billion populations that we have now. And those are the things that we are doing. And also, the same thing with other applications, like looking at antibiotics. Penicillin, for example, we know that Alexander Fleming is the one who invented penicillin, but then it’s the chemical engineers that produce it in large quantities so that were really able to go to those wounded soldiers in World War Two, those are the kind of things that chemical engineers do. And we are sometimes also known as the universal engineers, what that means is that we work in almost every sector that has to do with chemicals. We work in food production, we work in water treatment, we work in pharmaceuticals, we work in fuel and energy. And also, we sometimes work in aerospace as well. So, anything that is to do with chemicals, chemical engineers have some role to play.

So, what opportunities would you say chemical engineering has to contribute to a net zero world? It seems like chemical engineering is everywhere, really. So, what opportunities are there?

Well, one of the key roles is to make sure that our chemical industry and our – we call it a hard-to-abate industries, like steel and aluminum – we are able to make sure that the carbon that still needs to be discharged will be able to be treated or recycled back and used [to] make other products as well. So, I see that as one of the key roles of chemical engineers is to meet net zero. And chemical engineers because they design and plan and they operate plans, they also need to know how to be able to design in such a way to prevent waste, for example, and minimise waste. In the chemical industry now, most of the raw materials that we use are actually from fossil fuels, they’re fossil fuel based. So, we’re using fossil fuels like petroleum. And then we make the some of the hydrocarbons, which become the building blocks for consumer products. So, if we’re going to shy away from fossil fuels, then we need to really look at alternatives. What are the alternative carbon [sources] that we can have in order to make those raw materials for consumer products? And one of the ways is to look at extracting the CO2 from air or CO2 from the emissions from industry, and then recycle it back using renewable energy to make the chemicals to make the raw materials for the consumer products. So, I see chemical engineers will play a big role in order to meet the net zero targets that many governments have already pledged.

Absolutely. So, a lot of your work is driven by the process of catalysation. Could you take us back to high school chemistry please, just for a moment here and tell us what is a catalyst exactly?

A catalyst is a substance that you put into the chemical reactions so that you can speed up the rate. And for chemical reactions to occur, normally, you have this so-called activation energy, you have a barrier, a big barrier for the chemical reactions to occur. So, the catalyst is actually reducing the barrier so that the chemical reaction can proceed swiftly. In that way you will make sure that the rate is fast so, it’s active and also the catalyst can help to selectively drive the chemical reaction to the products you want. So, the catalyst will also minimise the waste because if you’re not selectively making that product, you’re making a lot of other byproducts that you need to purify or you need to discharge to the environment. The beauty of the catalyst is also that you put in the chemical reactions so you can use it again and again. So, although it’s changed, it will return back to the original state so you can reuse it and the type of catalyst that you need to choose, you need to make sure that it’s also stable, because in industry you do not want it to change it every day. You want to be able to use it for years. So, that’s one of the ways we are choosing catalysts, we’re looking at if it’s active, if it’s selective and also if it’s stable.

So, your research, it focuses on harnessing solar energy to produce chemicals and fuels. You are a world leader in photocatalysis and that is the process of using light as a catalyst to drive those chemical reactions. What drew you to specialise in photo catalysis?

Well, we have abundant sun energy, right? And it is free. In fact, 2 hours of sunlight is actually enough to power the world for a year. So, electrical engineers are very good already in terms of harnessing solar energy to make electricity. And of course, this is one way we want to keep on pursuing. But as chemical engineers, we also see that we can harness the sun’s energy and use it as a chemical energy or storing in chemical energy and use it in order to power our chemical reactions. In that way, we sort of look at it in a sense of not just using the electrons, but also using it for making molecules and chemicals as well. And also, chemicals and molecules can be stored for [a] much longer time. Because with electrons, you can either use it [immediately] or you have to use batteries to store it. And storage of batteries is limited in terms of time and capacity. So, there are many different ways that we can use the sun’s energy.

Now, you are the head of the Particles and Catalysis Research Group at the University of New South Wales. One of the projects that you’re working on there is SHINE 2.0, which is demonstrating how sustainable chemical processes can close the carbon loop. Firstly, what is the carbon loop?

Okay, I mentioned earlier that because in [the] chemical industry you will always produce some sort of carbon, or carbon dioxide. And that’s the reason that we always [say] that we want to meet the net zero target – the net zero carbon target, not the zero carbon [target]. Meaning that we will always still produce some CO2 in some of the processes. So, closing the carbon loop means that we recycle the CO2 back. So, we generate the carbon, but then we close the loop, so we do not omit the carbon dioxide into the atmosphere. We recycle it back. And with the SHINE project, what we are doing there is to sort of demonstrate, I would say, is the future of chemical engineering. It’s looking at using carbon dioxide that could be coming from air – because we still need to lower the concentration of carbon dioxide in the atmosphere. And so, we are using the sun energy, which could be the heat of the sun and the light of the sun, in order to activate a catalyst to convert the CO2 (carbon dioxide) and water to something that is useful. So, in the SHINE project we have carbon dioxide, we have water, we have a solar collector which can heat up the photo-reactors, and we have a catalyst in [the photoreactor]. In the SHINE project, we have a solar panel which will drive the electrolyzer to split water to hydrogen. So, now we have hydrogen that is produced from solar and water, and then we have the carbon dioxide coming in which is going to the photo reactors that’s heated up by the solar collector and the carbon dioxide, the hydrogen, will then form methane or methanol. And those are the raw materials that [we] use as building blocks for a lot of consumer products. So, methanol and methane, it used to be that you needed to get it from fossil fuels – from cracking the fossil fuels. So, instead of using fossil fuels, cracking from fossil fuels to produce those raw materials – or even methanol and methane can be used as chemical and fuels, we are using CO2, carbon dioxide that is from emissions, or from direct captures, and water and the sun’s energy in order to really close that carbon loop to produce something that is of value. But using CO2, I think that would be the ultimate, well, it’s probably the holy grail to be able to use the waste and reduce the concentrations of the carbon dioxide in the atmosphere. Currently, the concentration of carbon dioxide in most atmospheres is 417 ppm and in order to really meet the net zero, we will need to also reduce the concentration of the carbon dioxide in the atmosphere.

Now you are the program lead for the hydrogen production at the Hydrogen Energy Research Center. Can you tell us why you are focusing on hydrogen as an energy source and where do you see it fitting in in the overall renewable energy landscape?

So, hydrogen has a lot of potential, [even though] it is the tiniest molecule. Because when it’s combusted, it’s used, it doesn’t produce any carbon. Because when you combust hydrogen, it produces water. And so, I see hydrogen as a carrier that [can] actually bring renewable energy to the sectors that you cannot directly electrify, such as chemical industry, for example. So, you can produce hydrogen using renewable energy and these molecules then can be used in industry. Either used for chemical production or also [it] can be used as a fuel cell to generate electricity later on. And with hydrogen as well, it can be used [for] storing renewable energies like sunlight or wind energies as well, because it can store longer, much longer compared to batteries. Hydrogen [can be] stored for weeks or months or for years and whenever you need to use it, you can just use it and power fuel cells as well. So, there’s a lot of range of applications that we can use hydrogen for and therefore that is the reason that a lot of people turn to hydrogen and look at the potential of using it. And for example, Australia, we also have our national hydrogen strategy written up in 2019 because we see the potential of using these molecules in order to meet the net zero targets.

So, tell me about hard-to-abate sectors and how hydrogen can help address issues of those sectors. What does that mean?

Hard-to-abate industries means those are the industries that you cannot really use the renewable energy directly. Say, for example, airplanes, right. Currently there is no battery technology that we will be able to use in order to power commercial airplanes.

Solar powered planes are very small.

Yes. So, that’s the reason we see something like hydrogen [as] being able to help us in order to make sustainable aviation fuels. So, hydrogen can be used in order to convert CO2 and make E-kerosenes. So, looking at using the electrons from the renewable energy indirectly electrifying the airplane because you’re using that energy and the electrons to make the hydrogen and sustainable aviation fuel is one of them. Steel is another one, because currently in the steel industry we use a lot of coke and coal in order to reduce the iron ore to make iron metal. So, hydrogen again could be used in terms of those processes rather than using coke and coal, using fossil fuels. We’re going to use hydrogen because those are the ones that, again, you cannot use the renewable energy, the electrons from the renewable energy directly for those processes as well.

So, as we hear more about hydrogen, there’s almost like a rainbow of colors being used to describe it. Could you tell us a bit about the difference between grey and green and blue hydrogen, for example?

Well, scientifically, hydrogen is only one, one kind. So, hydrogen, you’ve got two hydrogen atoms that share electrons and are bonded by covalent bonds. But because now we’re going to use hydrogen to decarbonise and to meet the net zero target, so we need to be very careful of how the hydrogen is actually produced. And so, as you mentioned, the rainbow colours of hydrogen, brown hydrogen is sort of hydrogen that they consider as produced by brown coal.

So it’s dirty hydrogen?

It’s dirty hydrogen. So, you’ve got a lot of CO2 that’s coming out from that. There’s another one called grey hydrogen, if you’re using natural gas in order to – using [the] steam methane reforming process to make the hydrogen. Again, there’s a lot of CO2 coming out. With blue hydrogen, its actually the brown and the grey hydrogen but the CO2 that is produced during the production of hydrogen is captured and installed or utilised. So, that becomes blue because the carbon is not emitted anymore to the atmosphere. In fact, when we’re talking about the carbon dioxide emitted, it’s roughly about 900 million tonnes of carbon dioxide that is actually now produced or emitted in the atmosphere when we produce hydrogen because currently hydrogen is actually produced by coal gasification and steam methane reforming. So, that’s the reason that we need to really clean up this process as well and make this process more sustainable. Green hydrogen is the hydrogen produced using the electrolyzer to split the water from – the water splits to become hydrogen and oxygen. And the green hydrogen is when you split the water, you need electricity. Then the electricity has to come from renewable energy, [it] has to come from either solar, wind or hydropower. If you’re using electrolyzer to split water making hydrogen, but the electricity is coming from coal or from gas, it doesn’t count as green.

It’s brown, then, isn’t it?

Yes, it’s still brown –

I’m getting it.

Because the source of the power is still the dirty fuels. So, that’s the different colors of hydrogen.

So, hydrogen coming from Shine 2.0 would be green.

It would be green because we’re using the solar panels to split the water to make the hydrogen.

Fantastic. I’ve got my head around that now. So, how much hydrogen is being used around the world currently and how much of that would be green hydrogen?

So, currently there’s about 94 million tonnes in 2021, 94 million tonnes is actually produced. And the majority is – I would say that 99 per cent of it is produced by either the coal or the gas, as well. There’s a very limited amount that is produced by the renewable energy and electrolyzer. And so that’s one of the things that if we’re going to really start to produce hydrogen or use hydrogen, we need to start to make sure that the hydrogen we produce for the chemical industry – because most of the hydrogen currently is mainly used for ammonia production or for oil refineries and those are the things that we need to start to make green first.

Do you think that green hydrogen will end up being the most used type of hydrogen in the future?

In the future, probably by 2050, yes. But by 2030, because there are a few targets – like by 2030, we wanted to cut our emissions by 50 per cent. I would say that probably a combination of blue hydrogen and green hydrogen. So, the Shine project will be good because the project looks at the carbon dioxide that’s emitted. If we’re going to still use fossil fuels to make hydrogen, there’s carbon dioxide that is emitted, [and it] can be utilised and make the raw materials for hydrocarbons for the chemical industry. So, making that hydrogen become blue.

What changes need to happen within the industry now to convert more to green hydrogen?

Currently the limiting factor is the cost, and the cost is because the electricity cost is still high and also the electrolyzer cost is still high. So, I guess in order to make it more feasible we need to make the electrolyzer sort of more efficient as well. Efficiency will then make the cost lower. And I guess also productions at scale, because a lot of times most of those technologies, if you produce at scale, then the cost will come down. So, [to] be able to really improve the performance of the electrolyzer – and this is one of the things that we are working on as well is to look at how to improve the electrolyzer performance by developing better catalysts, more efficient catalysts, and also cheaper catalysts. Because some of the electrolyzers are using platinum as the catalyst.

Platinum is expensive.

It’s expensive. So, that’s the reason that our work is trying [to] look at reducing the loading. And some of the project that we’re doing is using 20 times less of the platinum in the electrolysis system and still [getting] the same performance or using other metals like nickel and iron, which [are] more abundant and cheaper as well. So, those are the things that I guess that we still need to do more in terms of the research and scale up to make sure that we can really produce that green hydrogen at scale.

Do you see this as an opportunity for Australia? Do you think that we will be exporting hydrogen and green hydrogen specifically in the future?

Well, Australia has plenty of renewable energy, plenty of sunshine and [we] also have plenty of wind energy as well. And I see that there’s great potential. In fact, that the World Energy Council identified Australia as [having] the potential as the giant for exporting hydrogen. One of the problems exporting hydrogen is that hydrogen is very light. So, you need to compress it, or you need to liquefy it if you wanted to export the hydrogen and transport it. I see that there’s a lot of potential that we can use the hydrogen to produce some other products, for example, ammonia [which] I mentioned, because globally we require 150 million tonnes of ammonia. So, we can really use the green hydrogen to make green ammonia and export that as well. Or we can also export our steel, green steel, for example. So, there’s a lot of opportunities that we can use the [derivatives] of hydrogen in order to export it, not necessarily just the hydrogen. Yes, definitely hydrogen is one of the products, but I would say that we probably have opportunity to produce – I call it power to X. So, renewable power [for] different sorts of products. Hydrogen, green hydrogen, green ammonia, maybe green methanol as well, because green methanol also can be used in terms of shipping fuel and also sustainable aviation fuel, which I mentioned earlier.

So, storing energy is something that’s becoming more important with the growing uptake of renewable energy technologies. And lithium-ion batteries are the most common solution for this at the moment. Now, the research center posits hydrogen as another method of storage. Could you talk a little bit about why?

So, lithium ion [batteries] currently, their energy density is about 200-250 watt hour per kilogram. And so, the prediction is that maybe you can go up to about 400 watt hour per kilogram. So, for electric vehicles, that’s fine [for a] passengers’ car that you just drive for a short distance, but if you want to [go] a long-haul distance, you cannot because the battery needs to be charged again. So, that’s why you need a sort of a – for example, the fuel cells will be advantageous for those kinds of applications as well. And also, for heavy machinery as well, if you wanted to use renewable power, you can’t really use the battery because the energy density is not enough. So again, something like fuel cells will be the one that you can use. So, heavy trucks in mining, for example. And when we’re talking about sustainable and renewable energy, we need to make sure that also those industries like mining, it also will become sustainable, becoming green and clean, because all the minerals that required to make solar panels, to make the electrolyzers, to make the wind turbines they also has to be clean, or has to be green so that we can claim that whatever the energy that we actually use is really green as well. So, the way I see that the hydrogen will be used in terms of those type of applications as well as sort of hydrogen fuel cells for the heavy trucks, the machinery to replace some of the fossil fuels or diesels that currently they use a lot in mining.

You’ve supervised 73 PhD. students. This is an absolutely huge achievement. And one of the things that you’ve said that you enjoy most about your job is teaching your students and seeing their confidence grow. So, how important is having supportive teachers and nurturing those long lasting and impactful careers for the STEM industry?

Well, I think I had a very good example when I was a student and also probably a young engineer, a young academic, because I’m sort of blessed with I call them the giants, which always lend their broad shoulders so that I can stand [on] to see further. And so, I always in my career sort of see whether I can help anybody, can mentor and sponsor the young ones so that they can stand on my shoulders to see further as well. I think this is very important because I always believe that I can only do so much [as an] individual. But if I can inspire even just 10 people, 10 students, and each of them can inspire 10 others to work on something sustainable, to really make this world a better place for everybody to live in, then this is a domino effect and that sort of will spread. And I think that’s the reason that I was already passionate, that yes, I’m passionate about my research, sustainable research, but I’m more passionate in terms of transferring my knowledge, transferring my skills, and also inspiring them.

Seeing all of those different projects and PhDs coming out of the works, you must see a broad range of different solutions being presented for climate change. How important do you think it is for researchers and innovators to collaborate on this?

It is critical, Rae. It is critical to have collaboration. It’s not just one profession. We need electrical engineers in order to give us the green cheap electrons, and we need the chemical engineers to use the electrons to make the molecules. We need the mechanical engineering to build the machinery, and we need the economist to be able to tell us whether that’s economical. We need the social scientists to sort of see how [it] impacts with society as well. So, we do need the whole range of things and for example, in the training centers that I’m co-directing, we actually cover all ranges. We have the technology side looking at hydrogen production and hydrogen safety. We have the value chain and business model, which we have the economist helping us to look at the economic feasibility study. We also have the social scientist to see the impact of these technologies to the community. So, when we build the electrolyzers in the remote areas, what is the impact? How can we really bring the community together and know how valuable those projects are [to] us as well. So, I think collaboration is the key to success.

Fantastic. Well, Rose, thank you so much for spending time with me today. It’s been wonderful speaking with you.

Thank you for having me, Rae. Thank you.

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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.