Research may fuel new energy sources
by Lynn Nystrom, Liz Crumbley, and Sherry Bithell
Energy crunch. No, it's not a trendy, granola-laden snack, although that might be a more familiar interpretation for Americans who haven't heard the term--which refers to the higher prices and occasional unavailability of energy--bandied about so frequently since the mid '70s. However, questions about the current and future supply of energy have made headlines all year, due in part to the California power outages, the debate over drilling for oil in the Arctic, and the renewed focus on nuclear power in the United States.
Here at Virginia Tech, faculty members recently have received visibility in the media and federal grant money for their work in two areas of alternative energy research. Their work, underway at the university today, just may prove to be a vital part of the energy wave of the future.
Improving coal usage at home, abroad
U.S. exportation of coal--the country's second most-used source of energy, with 87.5 quadrillions of BTUs used in 1998--has declined over the past decade. In 1992, the U.S. sold 102 million tons of coal valued at $4.2 billion to overseas markets, but by 1999, the export level had fallen to a record low of 57 million tons valued at only $2.1 billion.
This loss in market share can be attributed, in part, to Australian coal producers who have "improved their productivity through technology development," says Roe-Hoan Yoon, Virginia Tech professor of mining and minerals engineering. "Other competitors from the European Union countries are heavily subsidized by their governments, thus limiting opportunities for U.S. coal in Western Europe," adds Yoon, who believes the U.S. can rely on more of its own assets.
||Roe-Hoan Yoon, professor of mining and minerals engineering, is working on improving coal production and separation technologies.
Virginia Tech now has the opportunity to address the country's reliance on imported energy needs by means of a $3-million grant, to be shared with West Virginia University, from the U.S. Department of Energy (DOE) to establish a Center for Advanced Separation Technologies (CAST). Researchers believe they can help the mining industry increase the production of coal and improve the efficiency of producing minerals in an environmentally acceptable manner by developing advanced separation technologies.
Yoon, the director of CAST, explains that improved separation technologies--which generally account for 40 to
70 percent of the capital and operating costs of the many
industries--would increase the usage of coal. Improving
separation efficiencies and reducing technological barriers, he says,
"should result in energy savings, minimize pollution, create new
markets, and increase the rate of returns on investment."
Although various separation processes are currently used
in the mining industry, they need improvement, particularly
for processing fine particles. "The advanced separation
technologies to be developed at CAST can be used to recover the coal
that currently sits in refuse ponds due to the high processing cost.
At the same time, these refuse ponds will be cleaned-up,
minimizing the environmental impact of mining," says Yoon, who also
hopes to see these technologies exported to China and India,
where much of the mined coal is burned without cleaning. "This
would help increase the combustion efficiency and thereby reduce
the global sulfur dioxide emissions."
Another DOE grant has provided Virginia Tech
researchers with $7.9 million to demonstrate the commercial potential
of new coal production techniques they have developed.
Although companies have mined coal on a large scale since the
Industrial Revolution, they still must discard a significant portion of
the coal fines--waste generated during mining--due to the
difficulty in cleaning and handling.
The DOE, which estimates that more than 2.5 billion discarded tons of fine coal sit in various impoundments around the country, will test two different processes that may solve this major environmental problem. The technologies, developed by minerals engineers at Virginia Tech, will be tested at four locations, including one of the largest coal preparation plants in the U.S., owned by CONSOL Energy.
ME Professors Michael Von Spakovsky (left), and Mike Ellis (second from right) work with students on a fuel cell stack.
"Our dewatering technology allows coal companies
to recover coal from waste products. We kill two birds with
one stone. The process recovers valuable coal from waste and, at
the same time, eliminates fine coal impoundments that are
a significant environmental concern," says Yoon. "The
technology we developed here can help companies reduce the costs
of producing coal and thereby help increase the use of coal."
Processing fine coal is the most difficult and costly part
of producing the solid fuel, Yoon says. Impurities such as sulfur
and other mineral matter are removed from the coal by washing it
in water. However, the cost of separating water from the fine
coal particles made during processing is too high.
Consequently, many coal producers are forced to discard the fines to
impoundments and recover only the coarse coal. Virginia Tech's
new technologies will now allow coal companies to remove the
water from fine coal efficiently and to recover high-quality solid
fuels from the waste streams.
"The costs of implementing the new technologies are
low," Yoon says, "and their commercial application will not
entail environmental problems." His prediction of a low cost
for implementation is based on case studies performed by
his research center during the Phase I portion of this work,
also funded by the DOE. One study showed that a Virginia
coal company could increase its revenue by $4.6 million a year
using the new technology by removing only one half of the water
left in the fine coal.
Fuel cells: The future of energy?
General Motors (GM) announced in August that it plans
to produce fuel cell systems that can be used as power supplies
in homes and small businesses within three years. GM hopes
to have fuel-cell-powered vehicles on the market by 2010.
Widespread commercialization of fuel cells could be
the energy wave of the future, and Virginia Tech researchers
associated with two centers are playing a part in bringing this
technology into everyday use: the Energy Management Institute
(EMI), directed by mechanical engineering (ME) professor Michael
von Spakovsky, and the Virginia Tech Center for Automotive
Fuel Cell Systems, a Graduate Automotive Technology
Education (GATE) center established by a DOE grant and directed by
Doug Nelson of ME.
A fuel cell is a site for an electro-chemical reaction
that combines hydrogen and oxygen to result in the release of
water, electric energy, and heat. To produce enough power to be
useful, fuel cells are combined in stacks. Depending on power density,
a 20-kilowatt stack may contain more than 100 cells but be
only about the size of a couple of breadboxes placed end-to-end.
The first fuel cell was built in 1839 by Sir William Grove,
an amateur scientist in Wales. "The fuel cell was invented
before the internal combustion engine," von Spakovsky says,
"but engines quickly began to dominate because at the time they were easier
and cheaper to produce, maintain, and operate." Unlike internal
combustion engines, fuel cells emit significantly
less carbon dioxide and other air pollutants during energy production. Fuel cells
also have tremendous potential as high-efficiency power supplies. During
the internal combustion process, for example, 20 to 30 percent of the
power production potential of the fuel is lost. The electro-chemical process in a fuel cell avoids this loss
by converting the potential in the fuel directly into electricity.
Despite these advantages, fuel cells are in short supply.
So far, they have been custom-made because no company
has invested the capital needed to build mass production
facilities, making cost a major drawback to widespread commercial use.
In addition, fuel cell technology needs fine-tuning. "To improve
fuel cells, we must develop new materials, as well as tools to
analyze, predict, optimize, and integrate their design and operation,"
von Spakovsky remarks. "That's where the research is needed,
and that's what we're working on at Virginia Tech."
Currently, the GATE center is funding research on
computer modeling of fuel cell systems to help achieve high efficiency
for vehicle use. "Fuel cells can go from low power to high power in
a short time if their air and fuel supplies, cooling systems, and
air humidity are controlled correctly," Nelson says. GATE
associates also are figuring out the best methods of providing fuel
for vehicle fuel cell systems. "One of the major research issues
for automotive fuel cell use is compressed gas hydrogen storage
and conversion," Nelson says. "Right now, it takes about 10
gallons worth of space in compressed gas hydrogen fuel to equal
the energy in about one gallon of gasoline." Directed
Technologies, Inc. (DTI), a product development company based in
Arlington, Va., is sponsoring a project through the GATE center to
develop a better conversion and storage method. DTI employee
Frank Lomax (M.S. mechanical engineering '96; Ph.D. '01) is
developing an "off-board reformer" to convert natural gas into
hydrogen to power vehicles with fuel cell systems, which could
allow vehicles to fill up at a service station.
As part of its $85.7-million, cleaner-energy science
and technology initiative, the DOE has also given $2 million to
a Virginia Tech group led by chemistry professor James
McGrath to develop the next generation of polymer electrolyte
membranes, membrane electrode assemblies, and related
fuel-cell material systems. In addition, McGrath's group will partner
with one of 17 organizations that received DOE grants as part of
the initiative, International Fuel Cells of South Windsor,
Conn., which received $7.5 million to develop fuel-cell
materials capable of operating at high temperatures. McGrath's group
will receive $500,000 over three years to work with the company
on this research.
Other fuel cell research at Tech includes:
- ME assistant professor Mike Ellis' work with the American Society
of Heating, Refrigerating, and Air Conditioning Engineers to develop
a guide that will help building designers assess opportunities for using fuel
cell systems in buildings. Ellis is also working with von Spakovsky
and faculty in the College of Architecture and Urban Studies to develop a system to supply heat,
cooling, hot water, and power for a residence.
- Another DTI-funded project focusing on designing low-cost collector plates, which form the mechanical structure of the stacks and conduct electricity, for fuel cell stacks. "When some company starts trying to mass produce fuel cell stacks, it will need an inexpensive method of producing collector plates," explains Nelson.
- The design and construction of a fuel cell test stand by former student Mark Davis (M.S. mechanical engineer '02), Ellis, and an undergraduate design team advised by von Spakovsky. For example, the stand will enable McGrath's group to test the effects of advances in material developments on fuel cell performance.
Von Spakovsky believes that fuel cells are the most promising energy device for the 21st century. "Fuel cells have the potential to solve immediate energy problems, to be one of the primary solutions to the problems of making fossil fuels less costly to the environment, and to increase the efficient use of these fuels," he says, but he cautions that there are no "silver bullets" to complex energy problems. "Fuel cells won't be the only solution--they will play a major role in combination with other energy production developments."
He adds that the interdisciplinary nature of fuel cell
research at Virginia Tech is one of the program's great strengths.
"This group brings an extraordinary range of interests and skills to
the advancement of this technology. We have the opportunity
to become the premier university in fuel cell research."
Tapping alternate resources
|Solar panels on the roof of Whittemore Hall provide data to the CEAGE.
Given Virginia Tech's broad base of experts, it should come as no surprise that the university has several irons in
the fire when it comes to alternate energy research. Examples of other ongoing projects include:
Solar energy. The Center for Energy and the Global Environment (CEAGE) is participating in the Virginia Million Solar Roofs project, part of the commonwealth's new State Partnerships in the DOE Million Solar Roofs Initiative. Virginia has committed to installing 500 solar energy systems on buildings throughout the state by the year 2010. To help meet that goal, the CEAGE has combined its resources with the Photovoltaics for Virginia Working Group, an organization created by the Department of Mines, Minerals, and Energy to facilitate the installation of photovoltaics (PV) systems, which convert light energy into electricity. The purpose of the Million Solar Roofs project is to help sustain revenues and jobs created by PV manufacturers in the state while promoting innovative ways to address Virginia's energy needs and environmental challenges. The center's research is being conducted on the roof of Whittemore Hall, which sports solar energy panels. A web page about the project is currently under construction; the URL will be www.solar.vt.edu.
Biofuels. University research on biofuels--growing crops that can be harvested for energy through burning or other conversion methods--has been funded by the DOE through Oak Ridge National Laboratory since 1985. David Parrish, professor of crop and soil environmental sciences, is currently conducting research on which species might be most effective in providing biofuels and how best to manage that crop. Currently, several institutions working with Oak Ridge on biofuels research are focusing on switchgrass, a plant native to much of the U.S. that fares well in poor growing conditions, such as drought and steep land, allowing it be planted on potentially tens of millions of acres that are unsuitable for other crops. The university has focused on finding ways to successfully establish switchgrass and how to manage the crop for long-term productivity. For more information, go to http://bioenergy.ornl.gov/bfdpmain.html or contact Parrish
Geothermal energy. As part of its outreach program,
the Department of Geological Sciences issues reports on
two homes in Blacksburg that are heated and cooled using
geothermal energy via groundwater heat pumps, a process
called "GeoExchange." Because temperatures four-to-six-feet
below ground don't change much throughout the year, a
buried, closed loop of pipe can circulate constant-temperature
water into a house and back out again. In the winter, this
process allows a compressor to heat the water and circulate that
heat through the house. In summer, the system reverses,
pulling heat from the house into the water and pumping the
water outside, where the heat is dissipated into the earth. Not
only does the GeoExchange system not burn fossil fuels, but it
has proven to be several times more efficient than the
most efficient conventional system.
The department has also created a web site to post
its research on basic temperature and heat-flow data, creating
the most complete geothermal data base in the eastern U.S.
from New Jersey to Georgia. Professor emeritus John
Costain continues to update the site. For more information on
the GeoExchange system or to access the department's
geothermal data, go to http://geothermal.geol.vt.edu.