Yuhua Duan

Zierler:

This is David Zierler, oral historian for the American Institute of Physics. It is December 3rd, 2020. I am so happy to be here with Dr. Yuhua Duan. Yuhua, it’s nice to meet you. Thank you for joining me today.

Duan:

Me too.

Zierler:

To start, would you please tell me your title and institutional affiliation?

Duan:

I'm a physical scientist at the National Energy Technology Laboratory under United States Department of Energy.

Zierler:

And when did you start in this position at NETL?

Duan:

I started this position from October 2005. So it is almost 15 years.

Zierler:

Fifteen years!

Duan:

Yeah. [laugh]

Zierler:

Have you been in the same position since 2005?

Duan:

Pardon me? I need to adjust the speaker volume.

Zierler:

Have you been in the same position, the same job, since 2005?

Duan:

Actually, no. First, actually, I came here as an onsite contractor, in supporting of NETL research activities. Then in 2010, I become a federal employee, directly worked with NETL.

Zierler:

I see. All right, Yuhua, let’s go back all the way to the beginning. I want to hear about your family background in China. Tell me first a little bit about your parents.

Duan:

Oh! Actually, I was growing in the countryside in China. My childhood—at that time, China was very poor. I lived in a very poor peasant family. Actually, I have two sisters and two brothers. So, our family is big. But at that time, as I kind of recall, when I was very young, we didn’t have enough food to eat. Although we were struggling for survive, my parents let me attend primary school, and middle school. During middle school, actually—because China changed, at the time, actually. Chairman Mao died, so [laugh] everything started to change. At that time, I got a chance to enroll in high school. The Chinese government had a policy that high school graduates can be selected to enroll in college by taking the yearly Nationwide College Entrance Exam, so that we, countryside kids, have opportunities or possibilities to get a high education, and fortunately, I got into the college. That’s a big jump from the countryside to the city. Because during that time, China has a strong residence restriction. If you were living in the countryside, you were not allowed to live in the city. If you went to the college or got some promotion, your residence could be changed from countryside to a city.

So normally, at that time early 1980s, I think especially for, like me, those kids from countryside, can get into the college, that’s a very, very hard things, and very proud of family, even as I remember, when I got admission for the college, at that time, I'm the only one of entire town, to get into the college. Of course, my family, especially my parents are very proud of me. I still recall when I actually attended the college, It’s my first time to watch the TV. [laugh] So especially during my primary school even middle school, we didn’t have—I didn't even see any TV or even use electricity in the countryside. We used kerosene lamp for lighting during evening. So that’s a hard time. So, once I got into the college, I have opportunity to get the education, my first major is the chemistry, not the physics.

Zierler:

It was chemistry.

Duan:

Yeah. As an undergraduate, I studied chemistry as my major. Of course, we were taking other courses, such as physics and math, because we need to use the physics, especially for the physical chemistry. Then after I graduated from the college, and I first went to another city and worked there for two years. Actually, I worked there as a teacher assistant, in Xinjiang Normal University, in the Department of Chemistry. I helped the instructor to teach physical chemistry as well as the structural chemistry. Because at that time, physical chemistry was separated with structural chemistry. Structural chemistry involves quantum mechanics stuff. Then after I worked there for two years, I passed the exams and got a chance to go to the University of Science and Technology of China for my graduate study. That’s a very good university in China.

Zierler:

Yuhua, this was for graduate school?

Duan:

Yeah, graduate school.

Zierler:

Yuhua, I want to go back a little bit to childhood.

Duan:

[laugh] Okay.

Zierler:

Were you always interested in math and science? Were you always good at math and science in primary school?

Duan:

Actually, in primary school and middle school, we were only taught two major courses: Chinese literature and the Math. Yeah, I liked math. My recall is when I was a middle schooler, I attended a contest in my home county. In China, a county is very big with huge populations. [laugh]

Zierler:

Big county.

Duan:

County under province, yeah. I won a prize, actually, as I remember. In that exam there was a big question about inequality, which we had not taught yet. Guess what, I learned by myself and I got it [laugh] right! That’s why I got the prize. And I'm the only one in that middle school to get this prize, and I got a chance to get to the city townhall to receive that prize. So actually, in China at that time, we just focused on math, physics, chemistry, especially in high school. We were told that if you are good at math, physics, and chemistry, you can go anywhere to have a job. [laugh]

Zierler:

In your family, was there anybody who was educated before you? Did your parents go to university?

Duan:

No, no, no, no, no. Never.

Zierler:

Never.

Duan:

Until now, even the next generation of my family, there’s only one kid also went to a university last year. So, in my family, actually, in my generation and before my generation, I'm the only one who educated in college. In our next generation—except for my son, who is educated in the United States, last year my brother’s son was the only one to receive college education. So, not that much in my family. Just a few people had chance for college education.

Zierler:

Did you have to go to Hanzhong Normal College, or did you have a choice of universities you could have gone to?

Duan:

No. At that time, we don’t have a choice. Even we don’t have choice to select the university and the major. Based on the score of the nationwide College Entrance Exam, the administration officers just assigned the university and major to you. You see, at that time—

Zierler:

They just tell you, “This is what you're going to do.”

Duan:

Yeah, yeah. Because at that time early 1980s, each year, in China, there only have 270,000-300,000 students can get into the college, a very, very small number, less than 5% of high school graduates for the entire country. But now, it’s actually over eight million, over 80% of high school graduates, can get into college. Now in China, students can have choice for the college and major.

Zierler:

And your focus as an undergraduate was in chemistry?

Duan:

Yes.

Zierler:

Did you think that you were going to pursue a career in chemistry?

Duan:

Yes, at that time, because I attended the Hanzhong Normal College, now it called Shaanxi University of Technology. So, once we graduated, we were assigned a job as a high school teacher. At that time, it’s common to assign job to us and we don’t have too many choices. But when I graduated in 1985, the policy changed a little. They said I can have some—a little bit of freedom to choose where I should go. But not that much. So that’s why I got a chance went to Xinjiang Normal University. Otherwise, maybe until now I’m still a high school teacher, let’s say, in my home county high school. [laugh]

Zierler:

So at that point, graduate school was not something you were considering?

Duan:

At that time, it’s very hard to get in graduate school. In China, the graduate school was just started to form and only a small number of college students could be enrolled in. At that time, only those bigger universities had the graduate students and started to form graduate schools. Now of course, almost every university have a graduate school. [laugh] Things changed a lot in China.

Zierler:

And so I understand, the University of Science and Technology of China is a more prestigious school.

Duan:

Right.

Zierler:

This is where the best science students go for graduate school in China.

Duan:

Not only the graduate school, but also the undergraduate.

Zierler:

Undergraduate as well.

Duan:

The undergraduates are the best. Because at that time, I want to say maybe 80 percentage of the undergraduate students finally come to the U.S. In the U.S., you can find lots of professors and engineers who graduated from this university [laugh].

Zierler:

Was it your choice to focus on chemical physics for your master’s degree?

Duan:

Yes. At that time, because I worked at Xinjiang Normal University, actually I liked the structural chemistry. Now, we call it the computational chemistry, or we call it quantum chemistry. I spent lots of time studying by myself on those knowledges. That’s why when the university permitted me to take the test to get into graduate school, I selected this university and the chemical physics major. I still need to pass the test to get in. Of course, it’s harder to get into the University of Science and Technology of China. [laugh] Because it’s very competitive.

Zierler:

Yuhua, why for your PhD did you switch to condensed matter physics?

Duan:

Oh, this is [laugh] another story. Because, you see, in China, only the University of Science and Technology of China has a chemical physics department. This department is different. Firstly, for the undergraduate students, actually, they were taught lots of physics, compared with traditional chemistry major. The philosophy is that, they want to train those students as their physics is much better than those chemistry major, and their chemistry much better than those traditional physics major. So graduate study is the same. Secondly, they recruit those undergraduate students into chemical physics major, some are from chemistry background and some are from the physics background. So as a graduate student in this department, you must learn lots of physics and the chemistry.

Zierler:

And the structure in graduate school, is it like the United States, where you work with a specific graduate advisor? There’s on professor that you work under? It’s the same system?

Duan:

Yes.

Zierler:

Who was your graduate—?

Duan:

In my case, actually, my graduate advisor kept change, especially, in my Master study. Because many professors, at that time, they always come out of China to the US and European countries to learn new things. So, if this professor left, the department assigned another one to me. So actually, when I was in graduate school for my master’s degree, actually I worked with at least three or four professors, not just single one.

Zierler:

And was your graduate study more focused on experimentation or on theory?

Duan:

On theory.

Zierler:

It was on theory?

Duan:

Yeah, but I worked closely with those experimental guys who do the experimental work. I helped them to explain their findings by theoretical modeling.

Zierler:

What was your dissertation research? What was the topic for your thesis?

Duan:

The thesis for my master’s degree, let me recall, it was on quantum chemistry. I focused on modeling molecules adsorption on the surfaces of metal and their oxides.

Zierler:

And was your intention in getting the PhD that you would become a university professor? Did you think you would enter into industry? What were your goals after graduate school?

Duan:

Normally, at that time, we never thought about the industry.—Because you know, in China, there is a big organization, called Chinese Academy of Sciences. Under there, that have many institutes that can cover all the disciplines. So, I wanted either to be a professor, or to be a researcher at one of those institutes.

Zierler:

Yuhua, what did you do after graduate school? What was your next opportunity?

Duan:

When I got my master’s degree in the end of 1989, at that time, China had—a lot of things happened. So, at that time, actually, it’s harder for me even to find a PhD program and advisor. With the help of my Master Degree’s advisors, I contacted with professor T.S. Kê who was a Chinese physicist renowned for his contributions in internal friction, anelasticity, solid state physics and metallurgy. He was very famous, especially during 1940-1950s. Because he was also an adjunct professor at University of Science and Technology of China. Then I contacted with him. He said it’s possible for me to be his PhD student. But still I needed to take enrollment exams, and of course, an interview. [laugh] Finally, he let me be his PhD student. I'm also proud of being his student and worked with him. Actually—my PhD work is mainly focused on experiments. I did lots of measurements on internal friction of grain-boundary of metals. Although I did some molecular dynamics simulations to explain my findings, most of my PhD work was on experimental measurements. When I graduated, actually, in the Spring of 1993, Prof. Kê was 80 years old. Just before his birthday, I was graduated. [laugh]

Zierler:

Is the same system in China like the United States where you have a postdoctoral position?

Duan:

Yes, more or less the same. Because at that time, when I got my PhD, in China most of high-ranking universities started to have postdoc positions. The funding was directly from the Chinese Ministry of Education.

Zierler:

And this was at Fudan University?

Duan:

Yeah, Fudan University.

Zierler:

And that’s where you focused more on surface physics?

Duan:

Right. At that time, of course, my research was on computational side, instead of measurement side. I switched back to do the modeling work. One of my advisors, prof. Xide Xie, was also very famous on surface science, you may know. She graduated from MIT, and she was also famous in China, not just in the scientific community but also in the Chinese government. She served one term president of the Fudan University and the chairman of Shanghai People’s Political Consultative Conference. She was very nice, actually.

Zierler:

Yuhua, at some point, you realized that perhaps you would pursue research outside of China.

Duan:

Right. There was two reasons. One reason is that I saw at Fudan University, even as the same postdocs, the persons with oversea experience were treated differently and had better living environments (bigger apartment) and higher income over those who didn’t have such experience, like me. Another reason was that I saw many professors went out of China very often. They tried to bring some new things back, such as new ideas, new research directions. It was kind of opened my eye. That’s why I thought—“Oh, maybe it’s time for me also go abroad to see the other world.” [laugh]

Zierler:

What was your next opportunity? You went to Switzerland next.

Duan:

No. First, I went to the Brazil.

Zierler:

Oh, right, you went to Brazil!

Duan:

[laugh] First I went to Brazil. Because at the same time, I communicated with the professor in Switzerland. He said it’s possible he will give me a position, but he’s not so sure. So, I got an offer from Brazil first and decided to go there.

Zierler:

Yuhua, was this your first time leaving China? Had you traveled abroad before?

Duan:

[laugh] Yeah, yeah. That was my first time leaving China and taking airplane.

Zierler:

Yuhua, how was your Portuguese?

Duan:

Portuguese? I forgot all of them.

Zierler:

[laugh]

Duan:

Actually, when I was in Rio de Janeiro, I attended a Portuguese class and learned some very basic Portuguese for everyday use, but [laugh] I forgot all of them now.

Zierler:

Did you have a fun time in Rio de Janeiro?

Duan:

Yes, actually that’s.. In Rio de Janeiro, the life is very interesting. Because the institute I worked is just located very close to Copacabana Beach, I think, maybe just less than two miles away.

Zierler:

Very beautiful.

Duan:

Yes, it is very beautiful. However, the weather is very hot. [laugh] I remembered, one time I saw the temperature is 42 °C outside.

Zierler:

Celsius.

Duan:

Yeah

Zierler:

That was a very short visit, though. You were there for less than a year in 1995.

Duan:

Right. I just stayed in there for about nine months. Then I went to Basel.

Zierler:

And then you went to Switzerland.

Duan:

Yes, I went to Basel University. Actually, I worked in the Institute of Physical Chemistry. I came back to the chemistry! [laugh]

Zierler:

You keep coming back to chemistry.

Duan:

Yeah.

Zierler:

What was your research at the University of Basel in Switzerland? What were you working on there?

Duan:

Actually, I worked on two things. One thing is to perform experimental measurements of TOF, TPES, PMIS and TPIPECO spectra of gases. Another project is theoretical analysis these spectra based on ab initio molecular orbital calculations. So actually, I did two things there.

Zierler:

And then of course you came to the University of Minnesota. How did that opportunity become available to you?

Duan:

Oh yeah, in Switzerland, the professor told me I only can work for him a couple years. Then someone told me, “You should think about the United States.” I said, “Okay!” Then I saw the advertisements, and I applied several places. Finally, Professor Woods Halley of University of Minnesota, he offered me a position. Then I came here the U.S., in the Fall of 1997.

Zierler:

And was this a faculty position? Was it another postdoctoral position? What was your title?

Duan:

No, my title is called research associate. It’s a little bit different from the postdoc position, but similar. Because at the university, you know, sometimes there are a little bit difference between the postdoc or research associate or research assistant professor kind of title. But those positions are still depending on funding. So, if there is funding, I can work on it. If I don’t have funding, [laugh] I must leave.

Zierler:

And then from your first—

Duan:

So, I worked there for almost eight years.

Zierler:

And your first position there was with the School of Physics and Astronomy?

Duan:

Yes.

Zierler:

And then from there, you moved onto the Chemical Engineering and Materials Science Department.

Duan:

Yes. Actually, in the School of Physics and Astronomy, I worked there with Professor Woods Halley for almost six years. My main job, I was doing modeling on the polymer electrolyte for the battery applications. That project was supported by DOE, of course, for three years, and then we renewed it for another three years. And so, I worked on it for almost six years. At that time period, actually, Professor Halley let me take some graduate courses. That’s why I also enrolled in the graduate school of the University of Minnesota. I got a master’s degree in computer engineering. Of course, I spent lots of my own time to work on it.

Zierler:

Was getting the degree in computer engineering, was that very important for your research? You needed that degree?

Duan:

Yeah, of course it’s very helpful, because my focus was on the high-performance computing, which was highly related with my research as we needed coding in efficient way. It’s very important to have strong computer programming skills, so that we can develop our software package more efficiently. This is one focus. And finally, I got this degree—I’m also proud of it because this is my first degree obtained out of China.

Zierler:

And then what was your research when you switched over to the Chemical Engineering and Materials Science Department?

Duan:

Oh. That time, my research actually focused on—the protein interaction. You may know the protein-protein interaction is different than something just like a—if you think about the spaghetti, if two pieces of spaghetti put it together, they may penetrate and twist together. However, when two proteins coming together, they just touch to each other, and never penetrate with each other. So, my main job was to predict—if two proteins were put together, what’s their final configurations. Based on docking scheme, DFT and MD simulations, as well as machine-learning techniques, we developed the algorithm as well as software to predict the protein structures. Such algorithm also could be used to predict the protein-DNA and DNA-DNA interactions.

Zierler:

And then from there, you had yet another research associate position at Minnesota, in the Department of Animal Science.

Duan:

Yeah. [laugh] That’s interesting, because at that time, my funding in chemical engineering department was almost ended, so another professor from animal science department, he offered me a position because I worked on the biologic system and had background on biochemistry and statistics, and I also learned how to do the simulation on the biologic system. So that professor Da Yang offered me this position to let me work on—genetics! Mainly focused on developing computational tools and statistical analysis methods to detect and map candidate genes and quantitative trait loci (QTL) with complex inheritance modes. Because I just worked on this project several months, so I don’t have too much to say. As I remember the goals of such software package were to test the overall QTL effect and individual QTL effects including additive, dominance, imprinting, and sex-influenced QTL effect under the F-2 design.

Zierler:

Yuhua, I would like to ask on the personal side, at what point did you know that you would make a life for yourself in the United States? That you were not going to go back to China and have a career there?

Duan:

When I left University of Minnesota to come here in Pittsburgh, at that time in 2005, I think—at that time, there were two reasons, I think, why I accepted this offer because this was a permanent job. This give me a possibility to stay in the U.S. Another thing is that actually I have a son. He at that time, already got in primary school. He got educated from kindergarten and primary school in the U.S. So, at that time, if I brought him back to China, maybe—there was not going to be time for him to catch up with those Chinese kids. Because in China, the education system, especially the primary school middle school and high school, is very different from the U.S. So, I think these are two main reasons why I thought to make a life here in the US.

Zierler:

What was your work status? Were you at the University of Minnesota on a visa?

Duan:

Yeah. First on visa. Then, I applied for a Green Card. Actually, when I tried to move here in Pittsburgh, I got the Green Card, which is another reason.

Zierler:

You knew eventually, though, that to be a federal employee at NETL, that you would have to apply for citizenship at some point.

Duan:

Right. That’s why in 2009, I got the U.S. citizenship.

Zierler:

Oh, wow.

Duan:

That’s why I can become the federal employee. Otherwise, I cannot. [laugh]

Zierler:

Yuhua, how did the opportunity at NETL become available to you? How did that work out?

Duan:

Initially, when I applied this position—actually this was not a research position at the very beginning as advertised. Because at that time NETL and the University of Pittsburgh planned to start a computational lab, and that means they wanted to have computer clusters, at that time—not a supercomputer yet. They wanted to build that lab and wanted a guy who had a background on computational chemistry and has skills in computer or computer engineer. Because at that time, they wanted me to in charge of those hardware and software. Initially this position was opening that way. But [laugh] when I joined in the NETL team as an onsite contractor, they changed their plan and did not finally build such joint computational chemistry lab. So, I was told, “Okay, that means you’re doing research.” [laugh] Hence, I finally continued doing research.

The first research work assigned to me was to simulate the microwave sintering by finite element approach. Because you may know using the traditional heat method and the microwave—the results are different. Not just the efficiency issue, but the micro-structure difference: to get the different texture. We wanted to know what caused such difference. I used the finite element approaches which was implement in COMSOL Multiphysics packages. As you know the microwave, actually, is just electromagnetic wave. So electrical and magnetic fields played the role. However, at that time, in the early version of COMSOL software, for sintering modeling only the electrical field was included, the magnetic field was ignored. Hence, I added that part in there. Because depends on the material, for some materials, actually, the magnetic field is very important, clearly more important than the electrical field, depending on if the material is magnetic, of course. If not, of course, the electrical field play a dominant role. At the end, our simulated results explained the experimental findings very well. Then, after that project, we started to work on the climate change. I started to work on CO₂ capture to fight climate change.

Zierler:

Yuhua, what was the project on carbon capture? What were you working on with regard to carbon capture?

Duan:

Oh, the carbon capture—if we want to capture CO2, we first need to have the material which can absorb CO₂. So, my main project—my main research work is just to develop a theoretical methodology to screen materials to find good CO₂ sorbents. As you may know, the computational modeling has another beauty functionality—we can design or synthesize new materials. After applied my methodology, I can predict or synthesize candidates of CO₂ sorbents for the experimental validation. Actually, I have been working on this project for around ten years. I have lots of publications in this area. [laugh]

Zierler:

What have been some of the successes or findings of this research on carbon capture?

Duan:

Yeah, actually my methods is very effective with high-performance. That means the high throughput. So, my work actually attract a lot of attention. Lots of researchers from inside and outside of the U.S., they wanted to collaborate with me. They provided me their experimental results, and I can help them to identify those capture properties and mechanisms through calculations. Even at our lab, actually, I explored lots of materials, and provided promising candidate materials to our experimentalists to test. Some of them were successful and some of them were not. Because I found there are some materials, from computational point of view, are very good at for CO₂ capture, but there may have some other issues prohibit them to be used as CO₂ sorbents practically. I focus on the solid materials for chemical reaction with CO₂. Those kinds of research are actually very interesting.

Zierler:

Did you work at all on carbon storage? In other words, it’s one research challenge to capture the carbon. It’s another challenge to store the carbon. Did you work on carbon storage at all?

Duan:

No, I don’t work on the CO₂ storage. To storage CO₂, we must first capture them. Maybe you remember—at the very beginning, we didn’t call it storage; we called it sequestration, carbon capture and sequestration. Because the amount of the emitted CO₂ is huge, we only can use about maybe less than 5% percentage. We must find some places to store CO₂ permanently, right? So here, in the U.S. we already identified several sites, where geologically can sequestrate the CO₂ underground. At that time, that’s why we called it sequestration instead of storage. Then later, especially during recent years, the terminology we often use is storage and utilization. Because even the CO₂ amount is huge, we still need to find a way to use them.

However, the question is the CO₂ utilization is still very limited. One big usage is for the oil recovery. In the oil well, use CO₂ to push the oil come to surface. If you really want to use CO₂ as a compound to make other useful chemicals, there is a huge energy requirement. Because as we know, CO₂ is almost at its lowest energy stage of carbon. If we want to use it, we need to break the C-O bond again with huge energy input. So, if we don’t use other energy type as our resource, it doesn’t make any sense to convert CO₂ into other chemicals. Because you burn the coal, get the energy and release CO₂. Now you use such energy (electricity) to dissociate the CO₂ again. This doesn't make any sense. However, if we can have the nuclear power, or the renewable power as our energy source, we can convert CO₂ into other compounds, useful and valuable compounds. This is called CO₂ utilization.

Zierler:

Yuhua, have you always understood carbon capture and sequestration as a part of the solution to fix climate change? Was it always understood to be a tool in the battle to stop the carbon emissions in climate change?

Duan:

Yes, we believe in that. The reason is that we have the data to prove that CO₂ is the main emission caused climate change. The trend, you can see that the CO₂ concentration in the air increases very high and causes lots of problem. So, we must find a way to solve this environmental issue. Few years ago, I saw a set of comparison pictures in Pittsburgh downtown. One set were taking during early 1960s, I remember, it looked very, very bad with air pollution. Another set was taken in recent year at the same place. They looked very beautiful with sunshine and blue sky because of environmental improvement due to steel industry vanished in Pittsburgh. Comparing these pictures together, you can see—it’s totally different.

Zierler:

It’s better?

Duan:

The environment—yeah, much, much better, due to less CO₂ emission. Not just better, [laugh] I think such change is very important. We must fight the climate change, and keep the air clean, not just for us, also for next generations. So, it’s very important for us to prevent our environments. So that’s why our mission—one of our lab missions is to protect the environment for future generations. Because our lab is under fossil energy office, we must face how to utilize the fossil energy in a smarter way, and eliminate those environmental issues.

Zierler:

Yuhua, what has been some of your work in developing sensor materials?

Duan:

Oh, sensor materials is another interesting topic. We need sensors in almost all aspects. Everywhere, we can find some kinds of sensors. Generally speaking, sensor mechanism is very simple—if there is a difference, we can use that difference as a sensor. But for me, in our research, we just focus on the optical sensor. Use the materials’ optical properties as a sensor. So, we focus on the high temperature gas sensor development. As I said, we have sensor almost everywhere. However, those materials just work under room temperature. But under extreme conditions, we don’t have enough sensor materials. At high temperature or high pressure or a corrosive situation, we must have materials as sensors.

So, what we are doing, actually—we work on the theoretical modeling, but we also have experimental partners. We develop the high-temperature sensor, especially can be used in solid oxide fuel cell technology. What we are doing, actually, we are trying to calculate those materials to see if they are suitable for sensors at high temperature. Of course, that material must be stable at that high temperature, is the first property. And another property we want to check—if the properties of material at the room temperature,—how those properties are changed when the temperature goes up. So, this is our main job. We try to calculate those properties, especially the electronic and magnetic as well as the optical properties, versus temperature change. Based on this, we still need to develop a methodology first to find good materials which can be used as sensor under extreme conditions. Another part is to design some new materials. Those material may not exist yet. Once we design them out, we can let experimentalists to synthesize and test them.

Zierler:

In what ways has quantum information science been useful in energy-related research?

Duan:

This is another interesting growing area. It has been from 2018, I believe, since the national quantum initiative act was signed into law, the quantum information science grows very rapidly. Because especially the quantum computer is different from our CMOS computers that we are using daily. The quantum computer may become to commercialize, maybe within about five to ten years or longer. Generally, the quantum computer has advantage on speed up over traditional computer. So that’s why we've tried to learn what quantum computer can do for us. Another aspect is that quantum information science, actually, has mainly four areas: One is quantum computer & computing, of course, another three are the quantum networking, quantum communication, and quantum sensor. Quantum sensor may let us do sensing remotely. We are working on this area, just started from last year actually. NETL already has developed optical fiber network. That’s a classical sensor system. We are trying to add quantum part to have a quantum-classical hybrid sensor system. Such sensor system can be used for the cybersecurity application in infrastructure, such as checking leaks in pipeline. So, we just started such research. I think this is a very new direction and is very, very important. Since the national quantum initiative act was issued, from last year, lots of funding were released to support QIS area.

Zierler:

Yuhua, you believe that quantum information and quantum computing will be very important for energy research and energy efficiency in the future.

Duan:

Yes. That’s why we did a literature review on the current status of the quantum information science and application to the energy sector. In Nov. 2019, NETL held a Fossil Energy Workshop on Quantum Information Science (QIS) & Technology. This was the first time to bring QIS experts and Energy experts together to identify future areas on QIS for energy application.

Zierler:

Yuhua, what have been some of your research in non-carbon energy sources, such as nuclear reactors and solar cells?

Duan:

Oh! [laugh] since 2017, I started a new project on tritium production. Actually, this project is supported by NNSA and managed by PNNL. As we know the deuterium and tritium, two isotopes of hydrogen have, for decades, been considered the fuels for the first generation of fusion reactors. Deuterium is presence in the oceans with high abundance. Tritium is radioactive, decaying with a half-life of 12.3 years. In fact, the natural tritium abundance is only around 3.5 kg. Therefore, we must find ways to produce tritium. In NNSA tritium science project, we use Tritium-Producing Burnable Absorber Rods (TPBARs) in nuclear reactor to produce tritium. My research focus on exploring the tritium formation and diffusion mechanism in TPBARs by first-principles study. I think if we can solve the fusion problem, that means we use the tritium and deuterium to produce huge amount of energy without environmental issue. So, what I'm doing actually—as a team work, we help other partners to explore the mechanisms of tritium formation and diffusion in TPBARs, because we work on theoretical modeling.

Zierler:

Yuhua, I’d like to ask, since you were both a contractor at NETL and then a federal employee, in that transition, as a federal employee, do you have more flexibility in the kinds of research projects you take on?

Duan:

Yes. Generally speaking, as a federal employee, each year, I can propose something, some new ideas and tasks. Of course, they are still associated with NETL missions. But as a contractor, normally I was just assigned tasks to work on. Recently, the contractors are allowed to propose new concepts each year, but not that much. Normally from my experience, federal employee has more flexibility than the contractors.

Zierler:

Yuhua, given that your research has delved into so many different areas that have different applications—possibly military, possibly medicinal, possibly physics, chemistry, all of these different areas—what are the most important government agencies outside of NETL that you have collaborated with, such as other national laboratories, or the NIH, or the FDA? What are some government agencies that are very important for you as a partner or a collaborator for your research?

Duan:

I collaborate with scientists of Pacific Northwest National Lab (PNNL). That’s DOE’s another national lab. And I also collaborate with several—mainly professors at universities, within the U.S. or outside of the U.S. I also built collaboration with scientists in Mexico and in China. But last year, we terminated the collaboration with scientists from Chinese Academy of Sciences.

Zierler:

Because you worked in an American university and then of course at NETL, an American national laboratory, I wonder if you can reflect on the quality of the instrumentation that you have available to you at NETL?

Duan:

So actually, my work just focus on theoretical modeling. So, the only equipment I need actually is just a supercomputer. NETL has a very, very good supercomputer called Joule 2.0. When it was built couple years ago, as the world rankings, it was within top 50. As I know it will be updated to Joule 3.0 soon. So, our computational resource is very good, and I can use as much computer time as I can. This supercomputer is just for us to use. NETL Joule 2.0 doesn’t provide the service to those outside of NETL. So, our computer resource is very, very sufficient.

Zierler:

Is there an example of research that you're doing where you need computational power even beyond what’s available today?

Duan:

Yeah, definitely. Even in our calculations, if I perform a DFT calculation, I only can handle a system which contains less than one thousand atoms. There are two main reasons. One is the limitation of the memory capacity of the computer, and another one is the speed. Currently, the fastest supercomputer is just up to 100 or 200 petaflops. To realize the exascale calculations, there is about one or two orders away to go. This is just still for the classical computer. However, if the quantum computer become available, there may be a bigger jump on the speed-up.

Zierler:

Yuhua, for the last part of our discussion, I want to ask you a few broad questions. So the first is, how do you see your research fitting into the overall mission of NETL?

Duan:

Yeah, I see that. My research projects are just directly associated with each NETL Field Work Proposal (FWP). For example, our Solar oxide fuel cell (SOFC) task is under the SOFC FWP, our sensor projects associate with Sensor & Control FWP. So, my research activities, all of them are associated with NETL FWPs, that means directly support the NETL mission.

Zierler:

Yuhua, on the political side of things, you've been at NETL since 2005, and that means you've been there for many different presidential administrations—the Bush administration, then the Obama administration, then the Trump administration, and now coming into the Biden administration. Because these different presidents and therefore their secretaries of energy have different ideas about the role of fossil fuels in the overall national energy plan, and given that the NETL is the national laboratory that focuses most squarely on these issues, I wonder if those political differences, Republican versus Democrat—if you feel those differences at your level. If it filters down from national policy to the Department of Energy to the NETL? If you can reflect back on all of these years, all of these different presidential administrations, if the research or the mission has changed at all with regard to who was in the White House at the time.

Duan:

Yeah, it’s true, actually. I can feel those changes. [laugh] Under each different administration, actually, our focus shifted. Not a total change, but some shifts. For example, previously in the Obama administration, we focused on CO₂ capture, on the clean energy, on renewable energy, etc. We spent lots of efforts on developing renewable energies. So, after that, actually, during Trump administration, we switched back to focus on coal, and not that much on environmental issues. We still work on some of these research areas, such as CO₂ capture and storage and utilization. Last year, or this year actually, we just talked about restarting that hydrogen economics. As I remembered hydrogen industry actually was a hot topic during the Bush administration, But I don’t know next year if we will really work on the hydrogen. I'm not so sure yet. But the CO₂ capture and utilization I think is still alive! [laugh] Because this is an important issue not just for the science itself, but also affect everyone. Because we only have one Earth, we must take care of it.

Zierler:

Yuhua, on a similar note, even though there might be some political differences with regard to understanding climate change, we can all agree that NETL and the research that happens there is crucial for climate change research.

Duan:

Yes, you are right, Dave.

Zierler:

What do you see long-term as the most significant contributions from your career and from NETL generally that will contribute most positively and powerfully to controlling carbon emissions and mitigating climate change?

Duan:

For CO₂ capture and storage, actually, our lab led such effort. There are lots of guidelines, benchmarks, and funding opportunities come out of our lab. For example, for post-combustion CO₂ capture, we want to capture 90 percentage of CO₂ with cost in electricity no more than 30 percentage. Then with new technology developed, we increase—instead of 30%, we increase to 20%. [laugh]Because NETL is under the DOE fossil energy office, our focus is on the fossil energy related, especially on coal and the natural gas. So, we must have a clear solution—to use them, but in an environmentally friendly way, by reducing the CO₂ emission into the air.

Zierler:

Yuhua, for my last question, for your career, what are you most excited about in your research looking to the future?

Duan:

For me, I think I like this job, and I want to see if I can use my wisdom to establish some important accomplishments. For example, recently you may know, there is a report listed top worldwide scientists. My name was listed in the top two percentage of scientists worldwide. So, I'm a little bit proud of what I've done here so far.

Zierler:

Yuhua, it has been a great pleasure spending this time with you. Thank you so much for answering all of my questions and for giving me [laugh] a greater understanding of all of the excellent work that happens at NETL.

Duan:

Thanks.