Utilizing copper foil, glass containers and a standard family microwave oven, College of Wyoming researchers have demonstrated that pulverized coal powder will be transformed into higher-value nano-graphite.
The invention is one other step ahead within the effort to seek out different makes use of for Wyoming’s Powder River Basin coal, at a time when demand for coal to generate electrical energy is declining resulting from considerations about local weather change.
In a paper revealed within the journal Nano-Buildings & Nano-Objects, the UW researchers report that they created an surroundings in a microwave oven to efficiently convert uncooked coal powder into nano-graphite, which is used as a lubricant and in gadgets starting from hearth extinguishers to lithium ion batteries. This “one-step technique with metal-assisted microwave therapy” is a brand new method that might signify a easy and comparatively cheap coal-conversion know-how.
“This technique offers a brand new path to convert considerable carbon sources to high-value supplies with ecological and financial advantages,” wrote the analysis group, led by Affiliate Professor TeYu Chien, in UW’s Division of Physics and Astronomy.
Others concerned within the undertaking have been Professor Jinke Tang, within the Division of Physics and Astronomy; Affiliate Professor Brian Leonard, within the Division of Chemistry; Professor Maohong Fan, within the Division of Petroleum Engineering and the College of Power Assets; graduate college students Rabindra Dulal, of Nepal, Joann Hilman, of Laramie, Chris Masi, of Syracuse, N.Y., and Teneil Schumacher, of Buffalo; and postdoctoral researchers Gaurab Rimal, of Nepal, and Bang Xu, of China.
Whereas earlier analysis has proven that microwaves can be utilized to scale back the moisture content material of coal and take away sulfur and different minerals, most such strategies require particular chemical pretreatment of the coal. Of their experiment, the UW researchers merely floor uncooked Powder River Basin coal into powder.
That powder was then positioned on copper foil and sealed in glass containers with a gasoline combination of argon and hydrogen, earlier than being positioned in a microwave oven. A traditional microwave oven was chosen due to comfort and since it offered the specified ranges of radiation.
“By reducing the copper foil right into a fork form, the sparks have been induced by the microwave radiation, producing a particularly excessive temperature of greater than 1,800 levels Fahrenheit inside a couple of seconds,” says Masi, lead writer of the paper. “This is the reason you shouldn’t place a steel fork inside a microwave oven.”
The sparks brought on by the microwaves generated the excessive temperatures needed to remodel the coal powder into polycrystalline graphite, with the copper foil and hydrogen gasoline additionally contributing to the method.
Whereas the experiment included microwave durations starting from 3 to 45 minutes, the optimum length was discovered to be quarter-hour.
The researchers say this new technique of coal conversion might be refined and carried out at a bigger scale to yield each a better high quality and amount of nano-graphite supplies.
“Finite graphite reserves and environmental considerations for the graphite extraction procedures make this technique of changing coal to graphite an ideal different supply of graphite manufacturing,” the scientists wrote.
Reference: “Changing uncooked coal powder into polycrystalline nano-graphite by metal-assisted microwave therapy” by Christoffer A. Masi, Teneil A. Schumacher, Joann Hilman, Rabindra Dulal, Gaurab Rimal, Bang Xu, Brian Leonard, Jinke Tang, Maohong Fan and TeYu Chien, 5 January 2021, Nano-Buildings & Nano-Objects.