Bioprocessing engineer turns agricultural residue into energy storage material
It’s about transforming corn stover, dried distillers grain solids (DDGS) and even native grasses into a product more than 1,000 times more valuable—graphene.
The pyrolysis process turns plant materials into bio-oil and biochar, according to assistant professor Zhengrong Gu of the South Dakota State University agricultural and biosystems engineering department. When the bio-oil is further processed, it becomes biofuel.
Gu is converting biochar, a charcoal-like material, into graphene which can be used in place of expensive, activated carbon to coat the electrodes of energy storage devices—supercapacitors.
Small engines use start-up and run capacitors, Gu explained, but supercapacitors have more rapid charge and discharge rates as well as a higher energy storage capacity. Unlike conventional batteries, supercapacitors can withstand low temperatures.
To manufacture these storage devices, the United States now imports most of its activated carbon from Asia—including Japan, Thailand and China. “We can use these abundant agricultural materials as biofuel to reduce our dependence on petroleum and, at the same time, generate good active carbon to export,” Gu said.
Increasing product value
Gu estimated that approximately 2.2 pounds of graphene is worth at least $1,000. A pound of DDGS costs 7.5 to 9 cents and converts to approximately 7 ounces of graphene.
“That’s the increased value of the product,” Gu said. “We can convert agricultural residue to a high-value product that is easy to ship.”
Once the DDGS or corn stover is transformed to biochar, Gu mixes chemical called a catalyst with the biochar and heats the mixture to 1,292 degrees Fahrenheit for one hour to make porous graphene.
“It’s a one-step process,” he said. He estimated production costs, including feedstock, at about $1.36 for a pound of graphene.
Using the native grass big blue stem as the feedstock, Gu said, “we save more on feedstock.”
In addition, Gu hopes to adapt a new plasma processing technique developed at SDSU that reduces the processing time to five minutes and the temperature to 302 degrees Fahrenheit to convert biochar to graphene.
That could result in a significant cost savings, he added.
Optimizing material properties
Though Gu’s processing method generates graphene with the properties needed to capture and discharge electricity, he admitted, “We don’t know how the reaction happens.”
Through a $775,155 grant from the National Science Foundation along with $332,210 in university matching funds, Gu and a team of SDSU researchers studying carbon materials and biofuel technologies have purchased a transmission electron microscope will help advance this and other projects campuswide. The instrument should arrive this spring.
“We can find out how the process happens and learn how to change the parameters to improve the end product,” Gu said.
With the microscope, he and his team can determine the internal material structure and how the morphology changes its energy storage properties much like doctors use a CT scan to examine the human body, Gu explained. They can also find out whether biochar from one type of feedstock produces better graphene than another.
About South Dakota State University
Founded in 1881, South Dakota State University is the state’s Morrill Act land-grant institution as well as its largest, most comprehensive school of higher education. SDSU confers degrees from eight different colleges representing more than 175 majors, minors and specializations. The institution also offers 32 master’s degree programs, 15 Ph.D. and two professional programs. The work of the university is carried out on a residential campus in Brookings, at sites in Sioux Falls, Pierre and Rapid City, and through Cooperative Extension offices and Agricultural Experiment Station research sites across the state.
Christie Delfanian | newswise
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine