20. HIGH PERFORMANCE
MATERIALS FOR LONG TERM FOSSIL ENERGY APPLICATIONS
New materials, ideas, and concepts are required to
significantly improve performance and reduce the costs of existing fossil
systems or to enable the development of new systems and capabilities.
The Fossil Energy Materials Program conducts research and development on
high-performance materials for longer-term fossil energy applications, including
gas separations and storage. The
program is concerned with operation in the hostile conditions created when
fossil fuels are converted to energy. These
conditions include high temperatures, elevated pressures, and corrosive
environments (reducing conditions, gaseous alkali). Grant
applications are sought only for the following subtopics:
a. Surface Modification of Alloys for Ultrasupercritical
Coal-Fired Boilers—The implementation
of ultrasupercritical boilers will require materials with high-temperature creep
properties and high-temperature oxidation and corrosion resistance.
New ferritic, austenitic, and nickel-based alloys have been designed to
meet the creep resistance demands, but the high operating temperature poses the
risk of accelerated material degradation in various harsh environments.
In a coal-fired boiler, there are oxidizing and corroding environments
that range from simple gas attack to the deposition microclimates of complex
nature. The gases can be oxidizing,
such as mixtures of O2 and
SO2/SO3, or a more complex
mixture including aggressive gaseous compounds such as H2S,
HCl, COS, CS2,
CO, and methyl mercaptan. These
later gaseous compounds are usually generated during the substoichiometric
combustion of coals when modified combustion systems are implemented for NOx emissions
control. Similarly, the
substoichiometric combustion process generates unburned carbon and pyritic
particulate that, based on the hydrodynamics of the fireball, may end up
deposited on heat transfer surfaces. The
deposits can generate various local reducing environments, ranging from
carbonaceous to sulfidizing, and even low-melting eutectics that act as a flux
on the metal surface.
Surface modification techniques could provide an
alternative to otherwise costly nickel-based materials.
The science of thermal spray has evolved in the last 15 years with the
implementation of techniques, such as High Velocity OxyFuel (HVOF), that have
improved the quality of the applied coatings.
Other emerging techniques include cold spray technology, which when
combined with nano-size powders can provide flexibility and economic advantages,
and weld overlay and chromizing technologies, which are used to ensure that
pressure parts are adequately protected from the operating environment.
Grant applications are sought to develop new surface modification
techniques, or to optimize the techniques mentioned above, for the protection of
high temperature alloys used in ultrasupercritical coal-fired boilers.
Questions -
contact Richard Read (richard.read@netl.doe.gov)
b. Sealing Technology for Gas Separation Devices—One
of the enabling technologies required for high efficiency, low emissions
fossil energy conversion is the development of sealing materials for
hermetically joining the inorganic membranes used in high temperature gas
separation to the underlying support structure of the separation device. Ceramic
membranes, which have operating temperatures between 250 and 1000ºC, are
attracting increasing attention because of their technological importance in
high temperature gas separation and membrane reactor processes.
However, in order to fully exploit the unique properties of these
advanced ceramics, the ceramic membranes must be sealed to a dense ceramic or a
metal support structure. Commonly
used seals are not suitable for these applications because their heat resistance
is ineffective above 400ºC. Therefore,
grant applications are sought to develop inorganic materials with high melting
points that can be used for sealing the ceramic membranes at high temperatures
(greater than 600ºC). For good
sealing results, the seals must be tailored to obtain suitable wettability,
viscosity, chemical inertness, thermal expansibility, and bonding strength.
The sealing of these ceramic membranes should achieve a success rate of
nearly 100% if correct sealing procedures were adopted.
In addition, materials need to be developed for joining
ceramic and metal parts in newly developed hydrogen gas separation membranes
which operate at high temperatures. This
high temperature 'glue' will replace materials used at lower temperature.
The work should focus on new strategies and materials and evaluating the
strength and chemical properties of the latter.
Questions -
contact Richard Dunst
(dunst@netl.doe.gov)
c. Computational Tools for Materials Development—Novel
materials that can withstand high temperatures and extreme environments,
as well as those needed for the separation and storage of hydrogen are dominant
themes in materials development for efficient energy systems.
For the former, basic requirements are elevated melting temperatures,
high oxidation and corrosion resistance, the ability to resist creep, and high
toughness, and encompass some of the most challenging problems in materials
science. Computer simulation to
study the structure, properties, and processing of materials on the atomic scale
is needed to speed the advancement of innovative strategies that would replace
traditional, trial-and-error experimental methods which are costly and
time-consuming. A wide range of
computer modeling tools, ranging from highly accurate quantum mechanics
(electronic structure) methods to simple interatomic potentials, could be
brought to bear on addressing critical materials needs.
In gas separation and storage systems, there is a need to
use computer simulations for the development of novel membranes for gas
separations, especially hydrogen separation from coal-derived gases.
Novel membranes could include: micro-engineered
membranes, nano-composite membranes, inorganic membranes, and those needed for
membrane reactors. Theory, modeling,
and simulation will enable (1) understanding the physics and chemistry of
hydrogen interactions at the appropriate size scale and (2) the ability to
simulate, predict, and design materials performance for separation and storage.
An effective way to accelerate research in this field is to
use advances in materials simulations and high performance computing and
communications to guide experiments. This synergy between experiment and
advanced materials modeling will significantly enhance the synthesis of novel
high-temperature materials. Grant
applications are sought for the development of computational tools and
simulations that will reliably predict properties of materials for fossil energy
systems in advance of fabrication. The
research should only address materials of interest to fossil energy conversion
systems.
Questions -
contact Patricia Rawls
(patricia.rawls@netl.doe.gov)
References:
Subtopic
a: Surface
Modification of Alloys for Ultrasupercritical Coal-Fired Boilers
1.
Stringer, J., “Coatings in the
Electric Supply Industry: Past,
Present and Opportunities for the Future,” Surface and Coatings Technology,
108-109: 1-9, 1998. (ISSN:
0257-8972)
2.
Pint, B. A., et al., “Defining
Failure Criteria for Extended Lifetime Metallic Coatings,” 2002.
(Full text available at: http://www.netl.doe.gov/publications/proceedings/02/materials/Pint%20Fossil%20Paper.pdf)
3.
Pint, B. A., et al., “High
Temperature Oxidation Performance of Aluminide Coatings,” 2003.
(Full text available at: http://www.ornl.gov/sci/fossil/Publications/ANNUAL-2003/ORNL-2B.pdf)
4.
Zhang, Y., et al., “Interdiffusion
Behavior in Aluminide Coatings for Power Generation Applications,”
2003. (Full text available at:
http://www.netl.doe.gov/publications/proceedings/03/materials/manuscripts/Zhang_m.pdf)
Subtopic
b: Sealing
Technology for Gas Separation Devices
5.
Weil, K. S., et al., “Development of Brazing Technology for Use
in High Temperature Gas Separation Equipment,” Proceedings of 17th Annual
Conference on Fossil Energy Materials, Baltimore, MD, April 23, 2003. (Full
text available at: http://www.netl.doe.gov/publications/proceedings/03/materials/Weil.pdf)
6.
Ritland M. A. and Readey, D. W.,
“Processing and Properties of Al2O3-Cu Composites,”
Proceedings of the 1993 TMS (The Minerals, Metals and Materials Society) Fall
Meeting: Processing and Fabrication
of Advanced Materials III, pp. 3-13, TMS, August 1994.
(ISBN: 0873392310)
7.
Ritland, M. A., et al., “Method for
Sealing and/or Joining an End of a Ceramic Filter,” June 2001.
(
8.
Hardy, J. S., et al., “Joining Mixed
Conducting Oxides Using an Air-Fired Electrically Conductive Braze,” Journal
of the Electrochemical Society, 151(8): J43-J49, 2004.
(ISSN: 0013-4651)
Subtopic
c: Computational
Tools for Materials Development
9.
Chan, K. S. and Davidson, D. L.
“Improving the Fracture Toughness of Constituent Phases and Nb-Based In-Situ
Composites by a Computational Alloy Design Approach,” Metallurgical
and Materials Transactions A, 34A: 833–1849, 2003.
(ISSN: 1073-5623)
10.
Garberoglio, G., et al., “Adsorption
of Gases in Metal Organic Materials: Comparisons
of Simulations and Experiments,” Journal of Physical Chemistry B, 109(27):
13094-13103, 2005. (ISSN: 1089-5647)
Return to the Complete List of Topics
| Program Information, Instructions and Requirements | Technical Topic Descriptions | Download Program Information | Download Technical Topics |