Clemson University students and professors will soon help prepare turbine equipment for lower-emission electricity generation thanks to a grant from the U.S. Department of Energy .
The university was one of 11 chosen by the DOE’s Office of Fossil Energy and Carbon Management (FECM) to work on hydrogen-fueled turbines over a two-year period. Clemson was approved for $800,000, which will improve the performance of turbine materials that interact with hot gas.
Shunyu Liu , the project’s leader and an assistant professor at Clemson’s International Center for Automotive Research, said the project is expected to begin in December.
Goal of project
Ultimately, the goal of the project is to move toward fuel sources with lower emissions, Liu said.
“We will change the fuel from natural gas to hydrogen. If we use hydrogen as the fuel, then eventually we’ll achieve this final goal: To reduce and finally eliminate carbon dioxide emissions,” Liu said.
How is hydrogen produced?
Hydrogen can be produced from a variety of sources that vary in emissions levels. It’s often categorized by color – green hydrogen, or hydrogen created using renewable electricity, has no carbon dioxide emissions. Blue hydrogen, which comes from fossil fuels where carbon dioxide has been captured and stored underground, is another common type of hydrogen production. The DOE does not use the color code and obtains hydrogen from “diverse sources,” provided they meet federal standards .
A low-carbon emissions source
Hydrogen is often championed as a low-carbon emissions source because combustion primarily emits water vapor and warm air instead of carbon dioxide. It can also be mixed with natural gas, which creates opportunities for a transition to alternative fuel.
But using hydrogen isn’t as simple as just replacing natural gas, primarily made up of methane. Hydrogen burns hotter than natural gas, meaning that the equipment needs to withstand harsher temperatures.
Focus on thermal barrier coatings
Clemson’s project will focus on thermal barrier coatings for hot gas path components. Essentially, they’ll work to strengthen a coating system that protects metal surfaces in the turbine from extremely hot gasses.
Thermal barrier coatings (TBCs) consist of several layers: a ceramic top coat, thermally grown oxide (TGO), a bond coat, and a substrate layer. Clemson will develop and advance the bond coat portion of the TBC.
Those improved bond coats will:
- Improve oxidation resistance
- Withstand higher temperatures
- Help protect the material from water vapor
Temperatures in the turbine are higher because the adiabatic flame temperature , or the temperature a flame can reach without losing heat, is higher for hydrogen than it is for natural gas. Hydrogen’s adiabatic flame point is about 500 degrees Fahrenheit higher than natural gas, which can make the metal much hotter.
Less carbon dioxide is goal
FECM Division Director Robert Schrecengost said that while less carbon dioxide is the goal, it can provide additional stress on the turbine material.
“Another complication with hydrogen is you get more water vapor formed because it's all hydrogen. Methane has carbon and hydrogen, so some goes to water vapor, and some goes to CO2. Well, this all goes to water vapor. Water vapor can attack thermal barrier coatings in these turbines,” Schrecengost said. “They can delaminate and come off and no longer protect the turbine blades from these temperatures. This is looking specifically at bond coats that can handle the higher moisture contents and can stay and keep the thermal barrier coatings in place for the blade so that they don't experience the higher temperatures from the combustion and suffer damage as a result.”
Steam from the combustion process can also cause oxidation , which can corrode or damage the metal.
“We need to provide a sufficient oxygen to burn this hydrogen,” Liu said. “So in this way, the material also needs to have very, very good oxidation resistance.”
Team will design new bond coats
Liu and her team will design the new bond coats and manufacture them. Then, they’ll test the whole thermal barrier coating system with the new bond coats.
“The bond code is only a section of this entire system,” she said.
They’ll test the bond coats and TBCs in a lab with controlled temperatures, gasses and steam. Then, they’ll work with GE Vernova to test the TBCs in an industrial burner rig chamber in Greenville.
Finally, they’ll develop a data-driven training model to accelerate the technology transition and material development.
How long will process take?
The whole process will take two years. At the end of the two years, the universities will present their research, which focuses on different aspects of turbine improvement.
“We're all trying to contribute in little, small ways to being able to combust hydrogen at the higher temperatures. It’s a crowdsource,” he said. “It's not an organized group project, but we're trying to identify multiple solutions to a problem that then manufacturers can pick and choose what best works in their equipment.”
Program helps train people for workforce
The University Turbine Systems Research (UTSR) program has existed for two decades, Schrecengost said. It focuses on different improvements that can be made to turbines, but it also helps train people for the workforce.
“The biggest benefit of this program has always been the ability to connect grad students with company and commercially relevant problems and train people to be in the industry,” he said, adding that many of the designers for companies like GE and Siemens have come through the program.
Liu said Clemson’s project will include a post-doctoral fellow, two Ph.D. students and short-term interns. She said she will also create opportunities to train minority students.
Researchers will participate in monthly project updates with the FECM team.
More information about Clemson’s project, as well as projects from the other 10 universities , can be found on the DOE website.
Sarah Swetlik covers climate change and environmental issues in South Carolina's Upstate for The Greenville News. Her position is funded by The GreenSouth Foundation . Reach her via email at sswetlik@gannett.com or on X at @sarahgswetlik.
This article originally appeared on Greenville News: Clemson chosen for Department of Energy grant to improve hydrogen-fueled turbines
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