TAMEST Member Profile: Joan Frances Brennecke, Ph.D. (NAE), The University of Texas at Austin

TAMEST Member and 2025 Hill Prize in Engineering Recipient Joan Frances Brennecke, Ph.D. (NAE), The University of Texas at Austin, is a leading figure in chemical engineering. She is known for her groundbreaking work developing environmentally friendly solvents and processes.

Raised in Victoria, Texas, she says it was her father’s career in chemical engineering that sparked her passion for science and chemistry. A true trailblazer in her own right, Dr. Brennecke was one of the first female faculty members in the College of Engineering when she started at The University of Norte Dame in 1989 and one of only two on faculty to be elected to the National Academy of Engineering in 2012. After spending 28 years at Notre Dame, Dr. Brennecke was recruited back to Texas in 2017 by UT Austin, where she currently serves as The Cockrell Family Chair in Engineering #16 in the McKetta Department of Chemical Engineering.

Dr. Brennecke’s research has made significant strides in studying supercritical fluids and ionic liquids, focusing on their potential for sustainable chemical separations and reactions. In 2025, she received the Hill Prize in Engineering alongside Co-PI and TAMEST Member Benny Freeman, Ph.D. (NAE), The University of Texas at Austin, for developing advanced, stable, energy-efficient membrane technology to separate olefins from paraffins.

She will soon serve on the 2026 Hill Prizes’ Engineering Subcommittee to help select next year’s recipient. She has previously served on the TAMEST Edith and Peter O’Donnell Awards selection committee and Hill Prizes inaugural committee. TAMEST connected with Dr. Brennecke about her commitment to research and education, her time volunteering for TAMEST and her dedication to mentoring the next generation of engineers.

Please tell us a little about yourself and your work. 

I went to high school in Victoria, Texas and was an undergraduate in Chemical Engineering at UT Austin. My dad, who had a tremendous influence on my decision to pursue chemical engineering, was also a Ph.D. chemical engineer. He worked most of his career at Alcoa.

After I got my B.S. at UT Austin, I went to the University of Illinois at Urbana-Champaign (UIUC) and got my M.S. and Ph.D. working to understand the molecular structure in supercritical fluid solutions.

From UIUC I started a faculty position in Chemical Engineering at The University of Notre Dame in 1989. Another woman was hired in Civil Engineering the same year; we were the first female faculty in the entire College of Engineering! I spent 28 years at Notre Dame and then had the opportunity to move back to UT Austin eight years ago.

Your research interests include the development of more environmentally friendly solvents and processes. How did you find this field of study? 

As I mentioned, my Ph.D. thesis involved studying supercritical fluid solutions. When I started at Notre Dame, I focused on the solvent effect on reactions in supercritical fluids (SCFs). Supercritical (SC) carbon dioxide (CO₂) is a popular supercritical fluid because it is nontoxic and nonflammable.

The use of SC CO₂ as a solvent in a process does not require making or releasing CO₂ into the atmosphere so it is generally considered a more environmentally friendly solvent than common volatile organic solvents. For instance, SC CO₂ is used in the decaffeination of coffee. So, my interest in SCFs is how I got interested in the development of more environmentally friendly solvents and processes.

In 1998, I was at a meeting in Sante Fe, New Mexico, to give a presentation on separation of metals with SCFs. At the meeting, there was a professor from Northern Ireland (Dr. Ken Seddon) talking (enthusiastically) about ionic liquids. I had not previously heard of these materials. They are simply salts that, unlike normal table salt (NaCl), have very low melting points, so that many of them are actually liquid at room temperature (even without any water present).

A friend of mine, Dr. Eric Beckman (University of Pittsburgh), and I were sitting in the back and we decided to do something combining SCFs and ionic liquids (ILs). His group made an IL and we dissolved naphthalene (old-fashioned mothballs) in the IL and extracted it out with SC CO₂. It got published in Nature (Lynnette A. Blanchard, Dan Hancu, Eric J. Beckman and Joan F. Brennecke, “Green Processing Using Ionic Liquids and CO₂,” Nature, 399, 1999, p. 28-29) and totally changed the direction of my research.

Since ILs are salts, there are very strong interactions between the cations and the anions. As a result, they have incredibly low vapor pressures. Therefore, they are liquids that do not evaporate, so they cannot contribute to fugitive emissions (which is a big problem for normal volatile organic solvents). In this respect, they also have the potential to be more environmentally friendly solvents. For the last 25 years, we have focused on the design and development of ILs for a wide variety of chemical separations, ranging from post-combustion CO₂ capture to olefin/paraffin separations.

What makes you most passionate about your work? 

The thing that makes me passionate about my research is educating graduate students.

Teaching grad students how to do research and discover new knowledge is what I enjoy most.

Grad students come in with widely varying knowledge and experience. Watching them learn how to develop and test hypotheses and gain confidence and ability is so incredibly fulfilling.

This year, you received the 2025 Hill Prize in Engineering to “develop advanced, stable and energy-efficient membrane technology to separate olefins (such as ethylene and propylene) from paraffins, a process crucial in many industries including petrochemicals.” What will this prize do to help further your research? 

We made the scientific discovery of olefin/paraffin separation membranes that were stable to reducing agents (like H₂) as part of a National Science Foundation Engineering Research Center called CISTAR (Center for Innovative and Strategic Transformation of Alkane Resources) based on supported ionic liquid membranes.

We subsequently translated that discovery to polymeric membranes. What we plan to do with the Hill Prize is move this scientific discovery to a practical, commercially relevant membrane module.

The key is to develop a thin film composite membrane where the active membrane material is a very thin (< 1 micron) layer on top of a porous support that provides mechanical structure.

In 2012, you were elected to the National Academy of Engineering (NAE) and became a member of TAMEST in 2017 when you were recruited to Texas. What was your reaction to finding out about your election?

Being elected to the NAE was really amazing. At the time, I was at The University of Notre Dame. Only one other person had ever been elected to the NAE while at Notre Dame. Moreover, in Chemical Engineering (Section 3 of NAE), there had only been a handful of women previously elected.

The best part was that my dad, who passed away in May 2012, was still around to celebrate this milestone with me when the announcement was made in February 2012. Of course, it was great to get elected to TAMEST in 2017 when I moved back to Texas!

You have previously served as a member and chair of the O’Donnell Awards subcommittee and the inaugural Hill Prizes subcommittee. Why do you volunteer your time to help further such TAMEST programs? 

Many people think of the National Academy of Engineering (NAE) and TAMEST as honorific societies. That is completely wrong. The NAE (and TAMEST) are all about SERVICE. Receiving recognition by one’s peers carries with it a responsibility to help other researchers and promote the next generation of researchers.

The O’Donnell Awards are absolutely phenomenal. They recognize, celebrate and encourage the best and the brightest of mid-career researchers in Texas. I can’t express how honored I have been to be able to participate in the selection of those amazing individuals.

Therefore, of course, I agreed to be on the inaugural Hill Prize engineering subcommittee. But once I realized that my research with TAMEST Member and Professor Benny Freeman, Ph.D. (NAE) on olefin/paraffin separations might be a potential candidate for the Hill Prize, I said I wanted to be off the committee so that I could apply!

Now that we’ve won it, I’m more than happy to be back on the Hill Prizes engineering subcommittee for next year!

You received your B.S. in Chemical Engineering at UT Austin but left to receive your M.A. and Ph.D. training in Illinois. What about UT Austin and Texas made you return to pursue your research here?  

Growing up in Texas, I learned that anything is possible. Everything in Texas is bigger, including our dreams.

My dreams. I was born in Texas, and I am definitely a Texan at heart, in terms of believing that anything is possible. So, it was fantastic being able to come back to Texas and The University of Texas at Austin.

Of course, I can point to fantastic collaborators and fantastic facilities at UT Austin. But in the end, it is coming home to a place and a belief in being able to do anything you want to do.

What does being a member of TAMEST mean to you?

TAMEST is fantastic because it is members of the National Academy of Engineering (NAE), National Academy of Sciences (NAS) and National Academy of Medicine (NAM). I’ve been very active in the NAE on the national scale, but that is just for engineers.

TAMEST brings together the most distinguished scholars in our state in all areas of science, engineering, medicine and technology, which is a really unique opportunity.

Is there anything else you’d like to add? 

I just want to say that it has been a real honor to be associated with TAMEST in every way – serving on award committees, coming to the TAMEST meetings and winning the Hill Prize!