Asphaltene, a by-product of crude oil production, is a potential waste material. Rice University scientists are determined to find it by turning the carbon-rich resource into useful graphene.
Muhammad Rahman, assistant research professor of materials science and nanoengineering, uses Rice’s unique Joule-flash heating process to instantly convert asphaltene into turbine graphene (loosely aligned) and mix it into composites for thermoplastic and 3D printing applications.
The process makes good use of materials that have been incinerated for reuse as fuel or disposed of in tailings ponds and landfills. Using at least some of the world’s reserves of more than 1 trillion barrels of asphalt as a feedstock for graphene would also be good for the environment.
“Asphaltene is a huge headache for the oil industry, and I think there will be a lot of interest in this,” said Rahman, who described the process as a sustainable and scalable way to reduce carbon emissions from burning asphaltene.
Abd al-Rahman is a similar lead author of the paper in Science advances It was co-led by Rice chemist James Tour, whose lab developed Joule flash heating, materials scientist Puclel Agyan and Md Golam Kibria, assistant professor of chemical and petroleum engineering at the University of Calgary, Canada.
Asphaltene contains 70% to 80% carbon already. Rice’s lab combines it with about 20% carbon black to add conductivity and flashes it with an electric shock, turning it into graphene in less than a second. Other elements in the starting materials, including hydrogen, nitrogen, oxygen, and sulfur, are vented as gases.
“We try to keep the carbon black content as low as possible because we want to maximize the utilization of the asphaltene,” Rahman said.
“The government is pressuring the petroleum industries to take care of this,” said Rice graduate student and co-author MASR Saadi. “There are billions of barrels of asphalt available, so we started working on this project mainly to see if we could make carbon fibers. That led us to think maybe we should try making graphene by heating flash joules.”
Confirming that the Tour process works just as well on asphalt as it did on various other raw materials, including plastics, e-waste, tyres, coal fly ash, and even car parts, the researchers set out to make things with graphene.
Al-Saadi, who works with Rahman and Agyan, mixed graphene into compounds, then into polymer inks intended for 3-D printers. “We improved the rheology of the ink to show that it is printable,” he said, noting that the inks contain no more than 10% mixed graphene. He said that mechanical tests of the printed objects are coming.
Rice graduate student Paul Advincula, a member of the Trekking Lab, and a co-author on the research. Co-authors are Rice graduate students MD Chagdol Hok Thakur and Ali Khater, Jacob Beckham and Mingyi Lu, Asha Zinke and postdoctoral researcher Soumyabrata Roy; Shabab Saad research fellow, graduate student Ali Shayesteh Zaraati, graduate student Sharif Kabria Nabil, and postdoctoral assistant Muhammad Abdullah Al-Bari from the University of Calgary. Sravani Bheemasetti graduate student and Venkataramana Gadhamshetty, Associate Professor, South Dakota School of Mines and Technology and their 2D Materials Center for Biofilm Engineering Science and Technology; and research assistant Yuen Cheng and Anirudh Vashiseth, associate professor of mechanical engineering at the University of Washington.
This research was funded by the Alberta Innovates for Carbon Fiber Grand Challenge, the Air Force Office of Scientific Research (FA9550-19-1-0296), the US Army Corps of Engineers (W912HZ-21-2-0050) and the Army National. Science Foundation (1849206, 1920954).