Five decades of ammonia research and mentorship trace back to a student-built car
Left to Right: Robert Wagner, Vitaly Prikhodko, Josh Pihl, Scott Curran, Daanish Tyrewala, Brian Kaul, and Ron Graves gather at the National Transportation Research Center. Together, the group represents over 50 years of transportation research mentorship at ORNL. Credit: Carlos Jones/ORNL, U.S. Dept. of Energy
Researchers at the Department of Energy’s Oak Ridge National Laboratory are studying ammonia as a low-cost fuel for marine applications, building on work that began more than 50 years ago with a student-designed vehicle and a bold engineering question: Could a vehicle run on ammonia?
In 1972, a modified BMW Isetta powered entirely by ammonia rolled onto the National Mall in Washington, D.C. Built by University of Tennessee, Knoxville students for one of the nation’s earliest collegiate engineering competitions, the student-designed vehicle was unconventional for its time. Among the students was Ron Graves, who would later join ORNL and help shape its transportation initiatives, including efforts that helped establish the DOE’s National Transportation Research Center (NTRC), the only designated user facility focused on performing early-stage research and development in transportation technologies.
“The car ran exclusively on ammonia, no helper fuels,” Graves said. “After Washington, we drove it to the General Motors proving grounds in Detroit, where the competition was held.”
The team placed fifth overall out of 60 entries and ranked near the top in efficiency and cost, demonstrating the technical viability of the concept.
Ammonia is widely used in fertilizer and refrigeration and is one of the most produced chemicals in the world. That availability makes it attractive as a potential transportation fuel. But it burns more slowly than gasoline and requires more energy to ignite, making reliable engine performance difficult to achieve.
To address those challenges, the student team modified the engine’s ignition system, experimenting with dual spark plugs and higher compression to improve combustion stability. The hands-on work became the foundation of Graves’ 1975 American Society of Mechanical Engineers (ASME) paper, Emissions from an Ammonia-Fueled Spark Ignition Engine, which helped establish a technical baseline for future research. Five decades later, ammonia research at ORNL would again appear in the pages of ASME — this time led by a new generation of engineers.
From early experiment to enduring impact
When Graves joined ORNL, he helped cultivate a research environment grounded in engineering innovation, practical impact and a willingness to test unconventional ideas. Over time, that mindset shaped not only research programs but also the people leading them.
Robert Wagner, associate laboratory director for the Energy Science and Technology Directorate, began his career at ORNL as a postdoctoral researcher under Graves, working alongside the late Stuart Daw. Together, Graves and Daw combined high technical expectations with a focus on real-world application, an approach that continues to influence transportation research across the laboratory.
“When you step back, Ron and Stuart’s impact is massive,” Wagner said. “The ammonia car is what everyone remembers, but it’s the culture and programs that followed that really define ORNL’s transportation research.”
That lineage extends to Buildings and Transportation Science Division Director Josh Pihl and Fuel Science and Engine Technologies Research Group Leader Scott Curran, who developed their careers within programs shaped by that foundation.
For Curran, mentorship was inseparable from the science. “The culture goes back to Ron and Stuart,” he said. “It’s about teamwork, pushing each other for excellence and acting like scientists. How you interact with your colleagues, your sponsors and even your competitors matters just as much as the research itself.”
A research throughline across generations
Today, researchers at NTRC are addressing key knowledge gaps in how ammonia performs in modern engines with research led by ORNL's Daanish Tyrewala, a post-doctoral researcher. This work examines strategies to control unburned ammonia in dual-fuel engines — published 50 years after Graves’ first ASME paper on ammonia combustion.
The renewed focus reflects growing national interest in additional fuel options that can strengthen domestic energy security. As ORNL expands its portfolio of transportation energy research, the ammonia car story reflects more than a single experiment. It reflects a direct mentoring throughline across five decades of research, from Graves to Wagner to Pihl to Curran to Tyrewala. It also highlights how disciplined engineering, curiosity and mentorship can inspire innovation across generations.
UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science. — Julya Johnson
