Even as a kindergartener, Caleb Moellenhoff said he wanted to become an engineer — a dream sparked by the inspiration of his father, an electrical engineer. That early curiosity didn’t fade and led him to Missouri S&T, where he earned a bachelor’s degree in chemical engineering last year.  

Now, Moellenhoff is a Ph.D. student in chemical and biological engineering at Princeton University and working in the Maravelias Lab, which focuses on analyzing and improving chemical processes for sustainable energy applications. 

“It’s been a good experience. People come here from all over, and it’s been great getting to meet my classmates and learn about their backgrounds,” Moellenhoff says. “There’s a lot of shared experience among those coming from chemical engineering programs, but also interesting differences in how various schools emphasize different aspects of the field.” 

While at S&T, Moellenhoff was in the Kummer Vanguard Scholars program and participated in Opportunities for Undergraduate Research Experiences (OURE).  

Through the Kummer Vanguard Scholars program, Moellenhoff joined the student-mentorship program and met with a graduate student mentor during his junior year, which helped him gain different perspectives on graduate school and a career in research. He was encouraged to present his work from OURE at the annual Undergraduate Research Conference. 

“Gaining the experience presenting research in a variety of settings developed my communication skills and drove me to a better understanding of the motivation for biofuels research,” he says. “For me, the Kummer Vanguard Scholars program was what you wanted to make it. I knew I wanted to do graduate school, so I made the program all about undergraduate research.” 

Moellenhoff’s undergraduate research was directed by Dr. Joseph Smith, a professor in the Linda and Bipin Doshi Department of Chemical and Biochemical Engineering, which focused on improving biomass-to-fuels processes for the development of sustainable energy technology.  

For his first project with Smith, he worked with former graduate student Dr. Shyam Paudel and focused on improving biodiesel production processes. He drew design plans for the proposed modular biorefinery, created a simulation for the process and even got practice writing grants for the research. 

“I don’t think writing grants is common for undergraduate research,” he says. “That was definitely helpful for me as I sharpened my writing skills and experienced the excitement and agonizing difficulty of the world of research.” 

Moellenhoff’s other undergraduate research project with Smith required working with former graduate student Dr. Hasan Al-Abedi. The project focused on pyrolysis, a process where an organic feedstock is heated in the absence of oxygen which breaks the material down into oil, gas and char components. The resulting pyrolysis oil can be upgraded to produce fuel. Smith’s research group studied blending feedstocks such as biomass, waste plastic, oil shale and coal for pyrolysis to improve the quality of the pyrolysis oil. 

“It’s a hard process to model because the mixture of complex feedstocks results in the possibility of many unknown chemical reactions within a vast array of organic molecules and unknown metal catalysts,” Moellenhoff says.  “But I think it was very helpful to have that push to try to answer a research question. That’s why when graduate schools are looking for students; they want to see that you’ve tried undergraduate research because it teaches you that it’s not easy. Most of the time, research teaches you how little you know, and that’s making a step in the right direction.” 

As a new member of Dr. Christos Maravelias’ research group at Princeton, Moellenhoff is learning to use and develop process systems engineering tools to study biofuel production technologies. 

“We’re formulating optimization models to study lignocellulosic biorefineries producing biofuels and biochemicals,” Moellenhoff says.  

A lignocellulosic biorefinery is a facility that processes lignocellulosic biomass, which are plant-based materials to produce biofuels, biochemicals and other products. The goal of the refineries is to replace petroleum-based products with sustainable alternatives. 

“The work will involve collaborating with experimental researchers who are developing new technologies,” he says. “We’re working to first show how these technologies can be integrated in a biorefinery and then calculate economic and environmental impact metrics for these production strategies.” 

Moellenhoff says the need for clean energy is one of the world’s biggest problems, and the benefits of a reduced reliance on fossil fuels are numerous. 

“Of course, climate change is the big one, but also national security, public health and so many other things,” Moellenhoff says. “There is a good reason behind doing this research.” 

Moellenhoff considers himself a “traditional engineer,” and finds the research interesting because of its various applications. 

“I like theory, but to me, it has to have a purpose,” he says. “It’s exciting to think that the process I’m modeling and analyzing on the computer is a step away from being designed and commercialized to provide energy, reduced emissions and increased economic opportunity.” 

Moellenhoff has advice for incoming students at S&T: plan toward your future. 

“If you can figure out what you want to do, knowing your direction allows you to plan better,” he says. “My advice to anyone considering graduate school, industry or different subfields is to pursue something that will help you decide if it’s the right path or give you valuable experience to guide you in that direction.” 

While he didn’t go directly into an industry role, Moellenhoff says the education he received at S&T has helped him approach problems from multiple perspectives. 

“I’m definitely grateful for S&T and the strong foundation it provides in preparing engineers for industry, something not every school offers,” Moellenhoff says. “Even though I didn’t go directly into industry, that background still has been valuable.” 

About Missouri S&T 

Missouri University of Science and Technology (Missouri S&T) is a STEM-focused research university of over 7,000 students located in Rolla, Missouri. Part of the four-campus University of Missouri System, Missouri S&T offers over 100 degrees in 40 areas of study and is among the nation’s top public universities for salary impact, according to the Wall Street Journal. For more information about Missouri S&T, visit  www.mst.edu.