New NGV Storage Material Technologies to Lower Cost of Light-Duty Vehicles
10/03/12 Des Plaines, IL
Gas Technology Institute (GTI), a leading research and development organization serving energy and environmental markets, was recently awarded two new cutting-edge research projects by the U.S. Department of Energy (DOE) through its Advanced Research Projects Agency-Energy (ARPA-E). The ARPA-E grants are very selective and designed to fund highly transformative technologies.
GTI will serve as lead research organization for projects focused on the development of new adsorbed natural gas (ANG) technologies for use in light-duty vehicles, for which it received $2.375 million in awards.
With natural gas prices at an all time low, compressed natural gas (CNG) technologies can take advantage of clean natural gas to displace higher-cost fuels. The economic and environmental benefits of natural gas vehicles (NGVs) are being increasingly recognized, but the first-cost entry into using them is preventing more widespread adoption. The development of innovative, low-cost natural gas storage technologies and methods to lower pressure in vehicle tanks will help overcome market barriers to increased NGV use.
The projects are part of DOE's new program, titled Methane Opportunities for Vehicular Energy (MOVE), which aims to engineer lightweight, affordable, natural gas tanks for passenger cars and develop natural gas compressors that can efficiently fuel a natural gas vehicle at home. Current NGV technology requires tanks that can withstand pressures up to 3600 psi which represent added cost and weight for an NGV compared to gasoline and diesel vehicles.
To help overcome these challenges, GTI plans to develop a low-pressure adsorbent material to be used in a gas storage tank specifically designed for natural gas vehicles. Low-pressure gas tanks represent significant potential for lowering not only the cost of NGVs, but also the cost of fueling by reducing the need to compress the gas.
GTI received a $1.5 million grant for work they will do to advance gas storage using adsorbed natural gas (ANG) technology, which enables the installation of more flexible and lighter storage systems. With ANG technology, natural gas is adsorbed by a porous adsorbent material at relatively low pressures, enabling a volumetric efficiency increase of more than 25% compared with traditional CNG storage cylinders. The gas-storing materials, known as metal organic framework (MOF) adsorbents, hold natural gas the way a sponge holds liquids.
GTI researchers will work to identify a new adsorbent material that could be used along with a conformable storage tank for light-duty vehicles. GTI will partner with Northwestern University, NuMat Technologies, a Northwestern start-up company, and Westport Innovations, Inc. to identify materials with the best characteristics. The team will characterize methane uptake capacities for these new materials as well as develop new computational models and synthesis routes. This approach will enable researchers to rapidly identify high-potential, low-cost alternatives.
"We'll produce a small quantity of the material in our laboratory and conduct characterization testing—to determine how well the material adsorbs natural gas, how easily it releases it, what temperatures and pressures it displays when doing so, and how tolerant it is of contaminants," says Ted Barnes, GTI Senior Project Manager, who will lead the project. "We hope to have an opportunity to follow-up our research with a demonstration of the material on a full-sized vehicle."
GTI also received a grant of $875,000 for development of a unique low-pressure natural gas storage technology using an adsorbent with thin tailored shell to dramatically reduce the storage pressure while driving down cost. GTI's innovative shell acts like nano-valves that can be opened and closed on demand to enable vehicle refueling, driving, or storage.
"The thin film coating would act as a 'liquid valve' with adsorbents," says Dr. Shiguang Li, Principal Engineer, who will lead the project. "It would be applied to adsorbents so that, at a given temperature, the coating is impervious to methane when transferred across it—and, at an increased temperature, it can be opened up and allow methane to flow across."
The research is aimed at the development of engineered adsorbents with high energy densities and storage pressures lower than ARPA-E targets. A lower storage pressure can lower requirements for wall thickness, translating to a lighter storage tank, facilitating the use of natural gas use in transportation. Other team members include the University of Louisville and University of South Carolina.
About Gas Technology Institute (GTI)
GTI is a leading research, development and training organization that has been addressing the nation's energy and environmental challenges by developing technology-based solutions for consumers, industry, and government for more than 70 years.