This is the second story in a three-part series about the Carbon Engineering Initiative underway at the University of Wyoming.
Wyoming-mined coal could be a cheap source for graphene, a material with implications for electronics, aerospace technologies and other industries and which has fascinated scientists for more than a decade.
At least that’s the hope of some researchers at the University of Wyoming who are investigating methods for “growing” graphene and other useful carbon materials from coal.
This research, led by Associate Professor of Chemical Engineering Patrick Johnson, is one facet of a much-larger effort to find alternative uses for Wyoming’s staple mineral and, in doing so, diversify the state economy.
“The thing about all these special carbon materials is they have some exceptional qualities for certain applications,” Johnson said.
“So, graphene has high (electrical) conductivity, high thermal conductivity — some of the highest conductivity of any known materials.”
The Carbon Engineering Initiative — which supports various overlapping projects across campus — aims to transform Wyoming’s extraction-based economy into one that focuses on developing and manufacturing advanced materials.
“What we’re trying to do is identify non-energy and non-fuel products that we can make from coal,” said Richard Horner, deputy director of emerging projects and technology for UW’s School of Energy Resources. “The focus, therefore, being to make new markets for Wyoming coal.”
The initiative also investigates carbon materials derived from sources other than coal, their potential applications, and the possibility of using those materials in combination with coal-based materials.
One of several projects under the initiative, Johnson’s research focuses on graphene because of its extraordinary properties and the potential it has to revolutionize various industries.
First isolated and characterized in 2004, Graphene is the strongest material ever tested — as well as being highly conductive, and is being studied in universities across the U.S.
Michael Seas, a chemical engineering master’s student working with Johnson, said graphene research is currently the most intense and competitive area of research in the world.
“Since 2004, there’s been about 10,000 publications on it — that citing a paper that was written two to three years ago,” he said. “Graphene research is extremely popular and you could look at almost any major university in the United States and they will almost certainly have one or two researchers doing graphene research.”
The Carbon Engineering Initiative looks at coal as more than just a burnable fuel source. Seas explained that coal has three main components: fixed carbon, volatile matter and inorganic ash.
“Generally, when you burn coal, you’re burning the fixed carbon and the volatile matter,” he said. “Rather than burn these things, we’re trying to extract the volatile components of coal (and) turn those into profitable thermoset plastics. And then what we’re going to be left with is this fixed carbon portion and this inorganic ash portion.”
Johnson and Seas are working on methods or routes for growing graphene from these remaining parts.
“Well, our high temperature routes actually purify that portion that’s left over and graphitizes it,” Seas said. “So, now we can extract that ash safely, collect it and then we’re left over with this graphitic material — which then can be used in all these different routes to synthesize graphene oxide, graphite (and) things like that.”
The graphene — and more carbon materials derived from coal, such as diamond nanotubes — get passed to other UW researchers who are exploring possible applications in advanced technologies.
While researchers elsewhere have been developing carbon-based electronics, they often use cleaner and more expensive feedstocks than coal, said Bill Rice, an assistant professor of physics researching applications for the carbon grown by Johnson and Seas.
“But using the dirtier source is going to be better because it’s more abundant and it’s cheaper,” Rice said. “Doing that in a cost effective manner — going from dirty coal to interesting technologically relevant electronics is the hard part.”
The projects taking place in the Rice Spectroscopy Lab address potential applications for coal-grown carbon materials — applications as varied as making cheaper touch screens and building safer airplane wings.
There is no guarantee any of these applications will lead to economic diversification, but with several projects running simultaneously, Rice said he is confident some will pan out, revealing a coal-to-technology pipeline that could one day bolster the state’s economy.
“They invested in some risky stuff and some bound-to-work stuff,” Rice said. “And so, the amount of money they invested — $2 million, which is not a lot — was able to generate a tremendous amount of research activity.”
The Carbon Engineering Initiative requires collaboration between chemical engineers, mechanical engineers, chemists, physicists to develop the coal-to-technology pipeline.
“I know the electronics and the optics,” Rice said. “I need someone else to work on the hard part of getting the coal to a good carbon source.”
Johnson and Seas are doing just that, experimenting with different routes for turning coal — a feedstock both cheap and abundant in Wyoming — into much more valuable and versatile graphene.
Much of the graphene used in research and products today is derived from mined graphite. One gram of graphene, when derived from graphite, costs more than $100.
“The goal here is can we get it from coal, which is cheap and readily available, while extracting some of the other components,” Johnson said.
The researchers plan to patent successful methods of developing graphene, which could be useful to the state’s economy even if those methods were applied to non-coal feedstocks.
“The idea would be if we were to develop the technology here, the state would get that technology and that patent, because the University of Wyoming would get that (patent),” Seas said. “You then could get those royalties if the technology is then used in the industry. But our primary focus is to see if we can do it from coal and then extend it to other systems.”