In this episode, we share the work being done by Dr. Tim Kowalczyk at Western Washington University (WWU) in relation to Solar Thermal Fuels. We break down what this term actually means. We also go back in time and discuss Dr. Kowalcyzk’s unconventional path to physical chemistry.
Here is a short clip produced by WWU we refer to at the beginning of the interview.
Music was created by Dr. Tim Kowalczyk (video game music discussed in the interview)
Image credit: MCEC
Click Here for Transcript
>> Here we go!
[♪ Blackalicious rapping Chemical Calisthenics ♪]
♪ Neutron, proton, mass defect, lyrical oxidation, yo irrelevant
♪ Mass spectrograph, pure electron volt, atomic energy erupting
♪ As I get all open on betatron, gamma rays thermo cracking
♪ Cyclotron and any and every mic
♪ You’re on trans iridium, if you’re always uranium
♪ Molecules, spontaneous combustion, pow
♪ Law of de-fi-nite pro-por-tion, gain-ing weight
♪ I’m every element around
(Dr. Regina) Welcome to Spark science where we explore stories of human curiosity. I’m Regina Barber DeGraaff I’m here with a fellow…
(Tim) Thanks for having me Regina. My name is Tim Kowalczyk, I’m an assistant professor at the chemistry department at Western. I’m also affiliated with the institute for energy studies and the advanced materials science and engineering center AMSEC.
(Regina) I watched a short video that Western actually made of you. You were talking about the differences between the fuels most people think about and the fuels that you’re dealing with. When you’re talking about solar thermal fuels, what are you actually talking about?
(Tim) Right. The terminology is something that my field has kind of clung onto despite the fact that it’s pretty ambiguous. Solar, thermal and fuel. Let’s piece those together. So the solar thermal part refers to the fact that we’re taking energy from the sun and converting it into thermal energy ultimately. That’s like radiant energy from the sun like electromagnetic radiation into thermal energy. The interesting thing here is that we’re pressing pause on that conversion process by string the energy for some period of time in the form of a liquid or a then film fuel.
What we’re interested in here is, having something that could be a potential drop in replacement for some kind of fuel applications. We have a lot of devices and technologies that rely on flowing a liquid fuel. If you can replace the ingredients of that fuel which are typically extracted from the earth, fossil fuels, when we burn them we completely re-alter the chemical structure and release carbon dioxide which we know is contributing to anthropogenic climate change.
If we want to have a fuel that operates in a similar manner but doesn’t emit carbon dioxide, we either need to close the cycle, that’s the approach of biofuels where you are directly using CO2 from the atmosphere that are analogous to fossil fuels, so the same chemicals but not extracted from the earth, or you could do something analogous to the solar thermal fuel which is to design specific molecules that absorb light from the sun and get twist or reconfigured into a new shape which is like a strange shape.
That strange shape stores the energy from the sun. When you want to release that energy you can lease it as heat either by running the fuel over a catalyst or by gently heating it and it will release even more heat.
(Regina) So, I’m going to break down two things here. You said anthropogenic and what you mean is human right? I really liked, there’s a podcast that was on our show very briefly and it was Anthropocene or something like . . .
(Tim) Yes. Anthropocene is the new era of geological time that some geologists think we are in.
(Regina) I think that’s really interesting but the second thing I wanted to bring up is, you’re talking about, this is very new right? When people are talking about solar cells and people are talking about solar energy, they’re really talking about energy storage. So, when you’re talking about a fuel that is not the same thing, again I’ll bring up a video that we’ll link to our website and our social media. You have fuel, liquid fuel that we use for our cars, our planes, all that kind of stuff. Then we have these batteries that we have. A lot of that battery storage is not super-efficient. That’s when you’re getting a lot of energy like sun on your house solar panels. It’s good and you can put that back into the grid but actually storing that is quite difficult.
(Tim) There’s inefficiencies associated with the convergence of that energy from solar to electricity and then back to thermal. So, electrical resistive heating is not a particular efficient process. If you can instead store the solar energy and convert it directly from solar to chemical, to thermal without ever going through an electrical process or stage in the process, then that could enhance efficiency. It would be more appropriate for some applications than other. We see solar thermal fuels as being sort of part of a larger portfolio of renewable solutions. In particular, contributing in places where battery solutions alone can’t quite cut it without significant inefficiencies such as in local heating applications.
(Regina) What I want to do is I want to come back to them. I’m going to put it on pause and we’re going to come back to exactly what you are did in your lab and what does it look like and how do you use it. I ask all of my guests about kind of their background and how they got into science because I want this show to humanize scientists. I think we’re talking about these solar thermal cells, we’re talking about, you know, energy conversion and these are heavy things. You’re still a human being who was a child once. When did you start wanting to get into science?
(Tim) So, I was not particularly the kind of childlike explorer, the scientist by the sort of stereotypical break things and see what happens and go chasing around insects. That stereotype doesn’t describe me very well. My childhood was, in terms of the interests that I engaged in, my childhood was a mixture of video games and music mostly. [Laughing.]
(Regina) There is a lot of science in just those two things that you’re talking about.
(Tim) Yes. So video game music composition was a career choice that I very seriously considered before realizing how small the pool of potential jobs in that area is.
(Regina) Really, did you make any video game music?
(Tim) Oh yeah. Uh hu. I love that stuff.
(Regina) I need to hear this later. So, you’re into video games which is, I mean, I was too as a kid. But I think that this idea of being really curious and problem solving, I did a lot of RPG games where you solve a lot of puzzles and go on a journey. That kind of stuff. I think music in itself kind of has a foundation of being a scientist, in my mind. You’re putting staff together, you’re composing things, you’re asking why this sounds this way or does this, you know.
(Tim) I was all about this music theory and ear training. Those two aspects just, yeah, love that stuff.
(Regina) What happened? How did you get into chemistry?
(Tim) I was really interested in sort of music theory and ear training and jazz and all of those kind of things. I was also thinking that I wanted to keep myself kind of competitive for stem related careers because it seemed like a more viable direction in terms of the job market.
(Regina) So like science was your like, plan B?
(Tim) I don’t know if it was a plan B. I think I kind of went to college undecided about whether I wanted to pursue science and math exclusively or do something that was at the interface of math, science and music.
(Regina) So, you get a math degree, did you also get a physics degree? You said you took upper division physics. Or was that just part of your chemistry?
(Tim) Right. So I got a chemistry and math degree. I was just taking all of my sort of open holes in my schedule I was filling with the intermediate mechanics and ENM and ultimately just for kicks taking the galaxies and cosmology class which was one of the most fun classes to take as an undergrad.
(Regina) not all physics majors take those right? You’re a chemist that probably knows more about astronomy than most physicists. You’re kind of like a physical chemist. So you leave there, you still love me music but you go off to grad school because you think that’s what you’re supposed to do.
(Tim). Well, let’s dig into that a bit. The decision to go into grad school was not as, sort of, I guess I don’t feel like I was stepping into the void as much as it may appear. At the end of sophomore year, I started applying to REU programs. It’s a national foundation program where undergraduates at institutions across the country can go to conduct summer research experiences at other universities.
(Regina) you get in assuming to one of these REUs and it helps solidify, like, I want to be a scientist.
(Tim) A couple things there. I was very fortunate to get accepted to a program that had a couple of theoretical chemists on the team. Diageo Troya and Daniel Crawford at Virginia Tech. I did a second REU the year after I would say rather than solidifying my passion for computational chemistry, it solidified my hesitance and distaste over experimental chemistry. [Laughing]
(Regina) The second one.
(Tim) The second one.
(Regina) Got it.
(Tim) There was a lab explosion in my second to last week of post doc. I left a sealed vessel under heat. I was the only person in the room. When I realized that there may be a problem in the hood next to me. I managed to diagnose the fact that I couldn’t fix the problem and left the room. As I was leaving it exploded and all of the glass in the room was shattered. That was the effective end of my experimental chemistry.
(Regina) do you think that your hesitation for experimental chemistry was because of the trauma from the explosion a little bit? [Laughing]
(Tim) I had already decided earlier in the REU that theory and competition was the direction that I wanted to go.
(Regina) I think that’s an important lesson I think if there’s any students listening to this podcast or our show to not assume that every single event or every single experience you’ve had has to be 100% awesome. If it isn’t then you’re not a scientist. I think that a lot of my students fall into that problem. They way, “well I didn’t really like this class so I shouldn’t be a major in this major.” Just because you didn’t like that one class in the ten classes doesn’t mean you don’t belong here or you don’t get this material.
(Tim) That’s right. If I hadn’t sort of given up and switched over to say strictly math or math and physics rather than taking the organic chemistry sequence, I never would have found an interest in theoretical chemistry. Ultimately how light interacts with matter, which is the crux of what I do now.
(Regina) Yeah. The thing that’s really important, it’s really important to know what you don’t like.
(Tim) The lesson that I hope anyone that might be listening is that be a student or earlier stage science interested individual hearing about my experience with a lab explosion, I hope the other thing you take from it is to ask lots of questions. I’m not sure in that situation if there was really an opportunity or an easy opportunity to ask, “what’s going on in this hood next to me?” If you do see something that is unsupervised that looks unsafe, it’s totally reasonable to go find someone who knows what’s going on with that set up and ask. They might be thanking you for having caught something.
(Regina) Right. We’re going to take a quick break. When we come back we’re going to get into where the story goes next.
Welcome back to Spark Science where we’re talking to Dr. Kowalczyk. We’re talking about solar thermal fuel and we’re also talking about how light interacts with matter. That’s what he’s doing for his research. We wanted to start out with the solar thermal fuels and what does that mean? When I think of fuel, I think of my car, I think of putting the fuel in. It somehow gets used up. It burns and I don’t have that fuel any more right?
(Regina) When you’re talking about this fuel dealing with solar energy and being reusable, what are you meaning by that?
(Tim) So this fuel, instead of being made by these hydrocarbons which are sort of these complex molecules of carbon and hydrogen, when you burn that traditional fossil fuel, you’re literally breaking up the bonds in that molecule and rearranging them together with oxygen molecules from the air to form carbon dioxide, C02, as well as water, H2o.
Most of what should be coming out of your exhaust should be carbon and H2o. There’s going to be some other miner products in there that we try to mitigate and minimize with your catalatic converter so we’re not dumping a lot of other pollutants into the atmosphere. You’re mostly completely chemically converting your liquid hydrocarbon fuel into these two, well this gas, carbon dioxide and then water which is likely in a vapor form as it’s being combusted and then condenses and comes out as a liquid. That’s the conversion process that happens in a usual traditional fuel.
In this solar thermal fuel concept, now instead of typical hydro carbons we have customized molecules that are very good at twisting when they absorb energy from the sun. One way to think about the fuel is you can almost think about it as a property that is more battery like in the sense that if you take a beaker of this stuff and you put it out in the sunlight, the molecules are going to adopt this stronger twisted state. It’s kind of like a charged state. There’s no electrical charge here. It just means that they’ve gained energy.
(Regina) So, they just have potential energy. They’ve stored that energy.
(Tim) Right. It’s like pushing a ball up a hill.
(Regina) Right. So you have this fuel and instead of having combustion and instead of burning it you’re running it through . . .
(Tim) The goal is to have it release this heat energy but you can get the ball rolling with an initial amount of heat added. If you think about the charged state of the molecule as if it’s like a ball on a hill that’s trapped at some higher elevation, and you need to get it over some ridge for it to roll all the way down and release all of the energy. So you can get it over the edge with a little bit of gentle heating. Once it’s over the ridge then it will just roll down to the bottom. So, gently heating is one way to release that energy. That could be a self-propagating thing where some of the energy that’s released by the first million molecules goes on to provide the heat for the next 10 million molecules to get them over the edge and release that energy.
(Regina) So it has some sort of reservoir and now it’s useful, we put it back in our giant vats in Arizona and we do this all over again.
(Tim) That’s right.
(Regina) Well this is super interesting. So how far in this process has anyone come?
(Tim) This idea, the general concept of it, is definitely not new. The earliest ideations in the literature on this topic go back half a century. There are strained molecules that folks have recognized are potential candidates for strong chemical energy in these strand bonds for a long time. A couple examples are anthrasine. It’s a potential component of fossil fuel mixtures. It can be found in crude oil.
It’s a molecule that can dimerize, meaning two individual molecules will come and stick together when they absorb light. That’s a temporarily stable state that stores energy and could release that energy as heat later on. That’s an early concept of this kind of fuel. What we’re trying to do, again our group is aetherian [sp?] competition group. At this stage we don’t make these molecules in the lab. If we got to the stage where we wanted to make some of these in the lab we would probably be recruiting collaborators to help us with that.
The main goal for us is to develop a screening protocol, so like a virtual high throughput screening protocell where we can use the computer to try to predict what chemical changes to basic or sort of base line solar thermal fuel structures, could improve the various metrics that we are trying to improve to make a good solar fuel. For example, the energy density, the reverse isomerization barrier, that is how long do they last.
(Regina) You’re explaining kind of this theoretical version of this problem right? You’re still kind of in the process of kind of thinking it through and figuring out what molecules will work. Is there any of the groups across the world that have gone kind of further where they have actually produced a fuel?
(Tim) So, there are some examples specifically norbornadiene derivative that have been studied for this purpose.
(Regina) These are the molecules you were talking about before.
(Tim) Right. One of the sets. So right, norbornadiene itself absorbs in the UV but you can perform chemical substitutions that red shift the absorption. This makes them absorb in the visible. There’s a particular group based in Denmark that has made significant progress in identifying these derivatives. We have actually rely pretty heavily on their experimental work as a benchmark for our bigger goal here, a scheme that allows us to identify alternative scaffolds for alternative solar thermal fuels. We have the small number of photo switches that exist as default scaffolds that we’re trying to expand that base from which to work.
(Regina) So this fuel that has the UV red shifted fuel, that does exist, it has been used, it’s been in some sort of device to get it going?
(Tim). Yes. There is another group in the US that works on azobenzene derivatives which is another type of photo switch. They have done some proof of concept creation of a solar thermal fuel that in thin film form and can be used for local heating so they can measure the released heat energy and estimate the energy efficiency of that full solar of heat release conversion process.
(Regina) When you say the thin film form, I’m going to keep asking these questions. Actually you said this earlier. What do you mean by that? We kind of walked through how you would use a fuel, but how would you use a thin film?
(Tim) Right. So, in the case of a thin film, you would deposit a thin film as several molecular layers of the solar thermal fuel and kind of a basically solid state form on top of the surface. Then you would place that film and the backing that it’s on in light so it can charge up. Then that film itself could be either heated or collocated with a catalyst to release the energy.
(Regina) Now I think I want to take a break. Let’s take a break, we’ve been talking about these fuels. When you say thin film I think of like a battery but not quiet. We want to go from that idea to the solar energy that we’re used to, the idea of panels and the other research you do.
(Regina) Welcome back to Spark Science where we are talking about solar energy in various forms. In fuel form, in thin film form, in battery and solar panel form with Dr. Kowalczyk we’re really talking about this idea of fuel versus battery. On the break we talked about it being harder to pin down. It’s not as black and white as you’d think.
(Tim) Right. Both words are like useful for introducing the concept of how this solar thermal fuel works but neither of them is sort of precisely accurate. At least based on our usual context for the words like fuel and battery.
(Regina) We were talking in the break, which was really important, which is how this energy is being created and how to do it efficiently and how someone might use it.
(Tim) That’s right. So the work that we have been discussing has a strong application bend to it but at the end of the day it’s fundamental physical chemistry research with a competition in theory specialization.
(Regina) Can you tell us more about your other projects?
(Tim). Sure. We’re interested in organic materials broadly. These solar thermal fuels are one category of that. The other kind of photoactive or light absorbing organic materials we’re interested in are the kinds that can absorb light and then use it to convert the light energy into electricity. If you think about converting light energy into electricity, the first think you may think of is a solar panel. Solar panels take some light and convert it into electricity.
Most of the solar panels that we see around us are made of silicone. It’s a great material for that, it’s very affordable, it has some advantages to it. But it has some disadvantages too that other materials don’t necessarily suffer from. For example, silicon solar panels are very brittle. That requires particular limits, certain use cases, I can’t wear a whole bunch of silicon solar panels on my clothing and walk around like that. I could but it would be awkward and inconvenient.
(Regina) It would be like one use.
(Tim) Right. [Laughing] so being able to identify alternative materials that could have improved properties like flexibility, improved durability perhaps, improved recyclability, to be safer or lower energy intensity to produce, there are a variety of metrics by which we could develop materials that would be more ideal materials for solar to electricity energy conversion.
(Regina) What do you mean by safer?
(Tim) Well, I mean the various components that go into the different kinds of solar cells that are available.
(Regina) Like the toxic components.
(Tim) Right. For example, maybe not so much for silicon but there’s going to be safety hazards there as well. The one that really jumps to mind would be CIGS solar cells. It’s a more expensive solar cell design, a multi-junction solar cell. Some of the elements that go into those solar cells are toxic.
(Regina) If you need to get rid of it or make it having the . . . OK.
(Tim) It would be nice if we could make solar cells out of organic materials, some of which can be toxic but you can try to optimize to make them minimally environmentally harmful. Ideally more recyclable and lower energy intensity to produce. That’s another big one. The kinds of material that my group is looking at right now in this area, a type of material called covalent organic framework. This is a relatively new class of organic materials. It’s only been around for about a decade.
They are made of organic materials that assemble and can be stacked on top of one another and their porous so they have many holes. The thing about them to us is that, they have a structure that in principle could support a doubling of the light to electricity conversion. Like an increase of 200% of the efficiency through a process called singlet vision. The idea is that a single high energy photon can result in two electrons moving through your external circuit instead of one.
(Tim) So, we’re trying to see if we can optimize again the same kind of strategy of exploring chemical substations that can optimize that light energy to electricity process.
(Regina) all of that is super interesting and it’s really, I want to say, would you say it’s on the forefront of a lot of the solar work? We do have energy institute.
(Tim) Right. We do have the institute for energy studies, which I would argue, laying a new framework for what truly interdisciplinary energy education looks will like. We do have pockets of research leadership in different corners, aspects of energy science technology as well as policies. We have a significant energy economics crew. In terms of how the work that we do connects with the broader community. There’s connections at Western but our direct collaborators on the single vision efforts and photoactive covalent frameworks are actually international.
We have a collaborator in Japan, Advances Institute of Science and Technology outside of Kanazawa who synthesizes, pairs these covalent organic framework materials. They have a strong interest in electroactive covalent organic frameworks and we’re interested in helping them add the photo part to it. So, adding the light and using that light to drive the electrical activity that they’re interested in studying in covalent organic frameworks.
(Regina) That’s awesome. All of the stuff you do is kind of, I don’t want to call it futuristic but I think 10 years ago it would have been called futuristic and some people would call it that now. When I think of futuristic kind of science I think of sci-fi. I think of how our science has been portrayed in popular culture. Can you think of, in your mind, how your science has been portrayed in books or TV or movies that has been really good or really done poorly?
(Tim) It’s interesting because I think using light for energy conversion, I think science fiction has, maybe it’s my lack of exposure because I’m not particularly a huge science fiction junky, but I don’t really see those kinds of technologies exploited creatively in ways they could. If anything I think the real life has kind of leap frogged what I’ve seen in sci-fi. I’m thinking in particular about our new cell phone screens. They’re made of organic light emitting diodes. It’s basically an organic photovoltaic running in reverse if you want to kind of condense it into a single sentence.
Those concepts you can imagine kind of extrapolating that to organic or bio-powered devices in a sci-fi context. I’m sure things like this are out there but I have not seen it to the extent that you would expect. The closest thing I can think of is the over utilization of bioluminescence in Avatar for example.
(Regina) Right. I never saw that movie which is crazy because I see everything. I agree, it hasn’t really been, what’s really been utilized in sci-fi is like holograms right? Manipulating light itself but not utilizing light for energy.
(Tim) Surely, this concept has been used in sci-fi. I’m not exactly sure where but the concept of a Dyson sphere, this concept that you could surround, as a species needs to consume more and more and utilize more and more energy it eventually uses the resources available on its home planet so it manufactures guess what? Conventional silicon solar panels that it wraps around its local star to provide energy.
(Regina) Star Trek has gone wild with that.
(Tim) It’s extremely imaginative but at the same time there’s something kind of vanilla about the materials that are used. [Laughing.] But materials, there’s something kind of vanilla about materials in general that makes it difficult to get more creative about it. I’m sure there’s folks who have proposed . . .
(Regina) That’s what they had at the time right? Richard Dyson [sp?] who proposed this, who’s son was on this show. He’s a writer and lives in Bellingham here if you didn’t know that.
(Tim) I didn’t know that. Wow.
(Regina) Yeah. Well that’s what they had at the time right? It is a creative idea but you’re right. The materials, how the energy is actually taken from your local star and put in the Dyson sphere and somehow converted to energy, that itself is a dated thing.
(Tim) To some extent, yeah.
(Regina) Is there anything that I have not asked that you would like to share about your work or anything else that came to your mind?
(Tim) Well, if you’re interested in pursuing a STEM interest, whether it’s for career purposes or your own general enjoyment, you may find inspiration or a determination to keep going through things that don’t seem directly related at all.
(Regina) Some of those connections aren’t going to be obvious until you break them down.
(Regina) Thank you. Thank you for talking to me. I’ve learned a lot about a lot of chemistry which I have avoided my whole life.
(Tim) [Laughing] Thanks for having me. I really appreciate it.
(Regina) Thanks for listening to spark science. If you missed any of this show go to our website sparksciencenow.com. If there’s a science idea you’re curious about send us a message on twitter or facebook @sparksciencenow. Spark Science is produced in collaboration with KMRE and Western Washington University. Today’s episode was recorded at the Video Services Studio at Western Washington University at Bellingham Washington. Our producer is Regina Barber DeGraaff. Our audio engineers are Natalie Moore, Andra Nordin and Tory Highly [sp?]. Our theme music is Chemical Calisthenics by Blackalicious and Escape Theme and Abandoned Base by our guest today, Tim Kowalczyk.
[♪ Blackalicious rapping Chemical Calisthenics ♪]
♪ Lead, gold, tin, iron, platinum, zinc, when I rap you think
♪ Iodine nitrate activate
♪ Red geranium, the only difference is I transmit sound
♪ Balance was unbalanced then you add a little talent in
♪ Careful, careful with those ingredients
♪ They could explode and blow up if you drop them
♪ And they hit the ground
[End of podcast]