combustion technologies for producing electricity, solid
oxide fuel cell and turbine technologies, materials for
ultrasupercritical boilers, and technologies for recovering rare
earth elements from coal and its byproducts.
NETL is the U.S. Department of Energy’s only national lab
dedicated to fossil energy research. Its mission is to discover,
integrate and mature technology solutions to enhance the nation’s energy foundation and protect the environment for future
generations. For more than 100 years, the organization has been
building its expertise in coal, natural gas and oil technologies.
A new initiative
Nearly three years ago, NETL started developing innovative
ideas for creating commercially viable technologies that use
domestic coal as a manufacturing feedstock. In response, it
launched its Manufacturing High-Value Carbon Products
from Domestic Coal Initiative, which sets the vision and tone
for research activities in this program.
NETL’s Christopher Matranga, who works in the organization’s Materials Engineering and Manufacturing directorate,
explained the goals and opportunities that drive the initiative.
“Manufacturing high-value carbon materials from coal
would create new revenue streams for the industry and estab-
lish manufacturing technologies with reduced costs and energy
consumption.” he said. “At NETL, we are focusing on using
coal to make carbon nanomaterials, such as graphene, which
can be used directly, or which can be used as an additive in
composites and coatings to improve performance.”
While carbon nanomaterials first made a splash in the 1980s
with the discovery of the C60 fullerene, they have not been
widely utilized since, said Matranga.
“Despite decades of promising research, carbon nanomate-
rials still do not enjoy widespread commercialization, in part
due to their excessive cost and limited supply,” he said. “These
commercialization barriers partially arise from the cost of the
petroleum- and natural gas-based feedstocks used, as well as
the complicated vapor phase growth process commonly used
to make carbon nanomaterials.”
Coal offers unique opportunities to bring down the costs of
carbon nanomaterials and to increase their availability for use
in innovative products. Coal is generally far cheaper per ton of
carbon than the petroleum, natural gas, or graphite feedstocks
used to make carbon nanomaterials. Additionally, the processes
for turning coal into graphene-type nanomaterials are simple,
inexpensive, and closely related to classical coal processing
technologies, which suggests they are scalable. As such, a major
goal of NETL’s initiative is working to address cost and supply
issues that prevent commercialization.
If successful, coal-based manufacturing has the potential to
drive new economic opportunities for jobs, products and markets. Coal feedstocks at $30 to $60 per ton could be converted,
through NETL’s innovative manufacturing processes, into carbon products selling for much more. For example, carbon fiber
and structural composites can cost $140,000 per ton, specialty
3D printing materials can cost $700,000 per ton, and graphene
nanomaterials can cost more than $100,000,000 per ton.
“One of the really exciting aspects of this research is that
coal-based manufacturing can be applied to so many products
that previously were not part of the coal value chain—textiles,
pigments, paints, cosmetics, specialty plastics, and more. So, the
range of applications is incredibly broad,” Matranga said.
Matranga and his research team have met with notable success. A big accomplishment came in the form of a tiny dot—a
graphene quantum dot. Graphene quantum dots are small
fluorescent nanoparticles with sheet-like structures that are one
carbon atom thick and a few hundred atoms in diameter. The
unique size of these materials imparts amazing optical and electronic properties to these coal-based derivatives. The chemical
composition and small size of these graphene quantum dots also
helps them to bond with composite materials, interact with the
composite, and impart unique properties to the composite.
In the energy field, graphene quantum dots are useful in
applications such as catalysis, electronics, light emitting diodes
(LEDs), and sensors because of their optical and electronic
22 R&DMagazine FEBRUAR Y 2019 www.rd ag.com
“One of the really exciting aspects
of this research is that coal-based
manufacturing can be applied to so
many products that previously were
not part of the coal value chain—
textiles, pigments, paints, cosmetics,
specialty plastics, and more”.