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Technics

Successful residential fuel cell program completed
NASA selects Jupiter mission candidate for further study
Improved catalyst screener evaluates emission catalyst formulations
ISO Certification Awarded
Ignition threshold for impact-generated fires

Successful residential fuel cell program completed

SwRI recently completed a year-long residential fuel cell demonstration program conducted at a local military installation.

Funded by the Construction Engineering Research Laboratory (CERL) of the U.S. Army Corps of Engineers, SwRI successfully demonstrated three 5-kW proton exchange membrane (PEM) fuel cells at Brooks City-Base in San Antonio.

The fuel cells, fueled with hydrogen through natural gas reformers, supplemented the power to three individual base housing units at Brooks City-Base. The units were grid-connected, meaning that the electric grid provided additional power to the housing units if the electric load exceeded the capacity of the fuel cell. Fuel cell-generated electricity also flowed into the power grid during times of surplus. The PEM fuel cells, in concert with natural gas reformers, cleanly and silently converted natural gas directly into electricity.

"One of our requirements was that the fuel cells attain 90 percent overall availability for a period of one year," said Alan F. Montemayor, a principal engineer in SwRI's Engine, Emissions and Vehicle Research Division. "We met that requirement on all three fuel cells, with availabilities of 91.6, 93.9 and 96.2 percent.

"The fuel cells were successful in several other areas as well," continued Montemayor. "Program results show that the cells produced more electricity than the residential dwellings used, with the surplus power going into the San Antonio City Public Service (CPS) electrical grid."

The program was carried out by a team from SwRI, CPS and St. Philips College, a local community college. Plug Power Inc. provided the fuel cells under contract. The Institute provided project management and coordination among team members, facilitated training activities, implemented a web-based link to the units, monitored and recorded data on the fuel cells and reported to CERL.

The primary objective of the program was to install, operate, maintain, monitor and report data on the fuel cells to CERL. Secondary objectives included familiarizing Brooks City-Base personnel and San Antonio military installations with fuel cell technology and demonstrating the potential of environmentally friendly electric generation technologies to CPS customers.

Other goals were establishing the basis for a fuel cell education program for St. Philips College, providing feedback to Plug Power for its fuel cells operating in the warm San Antonio climate and demonstrating fuel cell technology to the San Antonio populace through articles, television spots and Internet access.

CERL is one of seven laboratories within the U.S. Army Engineer Research and Development Center. CERL's mission is to increase the U.S. Army's ability to more efficiently design, construct, operate and maintain its installations and to ensure environmental quality and safety at a reduced life-cycle cost.

Fuel cells promise to achieve many of these objectives through their quiet, clean and efficient operation. CERL, beginning in 1993, performed a successful demonstration of 30 phosphoric acid fuel cells powered with natural gas as part of the Department of Defense Fuel Cell Demonstration Program.

The SwRI PEM project was a continuation of these demonstration programs. The main goal of these demonstrations is to gain critical performance data that will be provided to the fuel cell industry, which will push this technology to the commercial market faster.

Contact Montemayor at (210) 522-5720 or alan.montemayor@swri.org, or visit www.swri.org/fuelcell.

NASA selects Jupiter mission candidate for further study

Two science instruments to be developed by SwRI are part of a proposal selected by NASA as a candidate for the next mission in the agency's New Frontiers Program.

The two mission proposals selected by NASA for further study are to orbit Jupiter from pole to pole for the first time to conduct an in-depth study of the giant planet and to drop robotic landers into a crater at the south pole of the Earth's Moon and return samples to Earth.

The SwRI instruments, JADE (Jovian Auroral Distributions Experiment) and Alice, are part of the proposed "Juno" mission to orbit Jupiter.

"The Juno mission will provide the critical information needed to understand how the solar system's largest planet, Jupiter, formed several billion years ago and how it interacts with the solar wind even today," said Dr. David J. McComas, senior executive director of the SwRI Space Science and Engineering Division.

JADE is designed to measure the auroral electron and ion populations along the planet's magnetic field lines and determine what particle populations create the jovian aurora. "The JADE experiment allows us to make the first direct measurements of the particles that create Jupiter's stunning auroral displays," said McComas, who serves as JADE principal investigator and has overall responsibility for the SwRI contribution.

The Alice instrument is designed to image ultraviolet emissions from the jovian aurora, which will allow space scientists to relate these auroral observations with JADE observations of the particle populations that create them. "The Alice instrument on Juno will provide Hubble-like images of Jupiter's powerful and dynamic aurora, but from the much better vantage points of directly above the north and south poles," said Dr. G. Randall Gladstone, an Institute scientist at SwRI who serves as Alice principal investigator.

The Alice instrument is similar to instruments of the same name flying on the European Space Agency's Rosetta comet orbiter and scheduled for flight on NASA's New Horizons mission to Pluto.

The Juno team proposes using a highly instrumented spacecraft placed in a polar orbit around Jupiter to investigate the existence of an ice-rock core, determine the global water and ammonia abundances in Jupiter's atmosphere, study convection and deep wind profiles in the atmosphere, investigate the origin of the jovian magnetic field and explore the polar magnetosphere. Dr. Scott Bolton of the Jet Propulsion Laboratory leads the overall investigation.

The other proposal selected by NASA for further study is "Moonrise: Lunar South Pole - Aitken Basin Sample Return Mission," led by Dr. Michael Duke of the Colorado School of Mines. This team proposes to send two identical landers on the surface near the Moon's south pole and return to Earth approximately five pounds of lunar materials from a region of the Moon's surface believed to harbor materials from its mantle.

Each proposal team now receives up to $1.2 million to conduct a seven-month feasibility study focused on cost, management and technical plans. NASA expects to select one of the mission proposals for full development in May 2005 as the second New Frontiers mission, for a June 2009 launch.

The first mission selected by NASA in the New Frontiers Program is New Horizons, which will examine the Pluto-Charon system in 2014 and later target a Kuiper belt object. SwRI manages the New Horizons science investigation for NASA. The spacecraft is currently under construction and is scheduled for a January 2006 launch.

Contact McComas at (210) 522-5983 or david.mccomas@swri.org.

Improved catalyst screener evaluates emission catalyst formulations

SwRI has developed an improved screening tool to evaluate emission catalyst formulations. Designated as the Universal Synthetic Gas Reactor® (USGR®), the second-generation system, for which a patent is pending, can monitor overall catalyst performance in automotive emissions systems under a wide range of operating conditions.

"The Institute has used a synthetic gas reactor for several years to simulate real-world exhaust gas streams, allowing us to evaluate the performance of catalyst core samples rapidly and cost-effectively," said Dr. Gordon Bartley, a senior research scientist in SwRI's Engine, Emissions and Vehicle Research Division. "We recently designed and built the USGR to provide significantly more comprehensive and flexible testing capabilities."

The USGR evaluates the performance of catalyst technologies in a variety of applications, including three-way catalysts, diesel oxidation catalysts, lean oxides of nitrogen (NOx) catalysts/traps and sulfur traps. Additional applications include selective reduction catalysts, reforming catalysts for hydrogen production and other catalytic applications. In addition to testing exhaust gas catalysts, relative durability testing can also be addressed using aged, small-core catalysts.

"Industry has traditionally used engine- and vehicle-based testing to evaluate aftertreatment catalyst candidates. The high cost of these individual test setups, coupled with the long lead time, greatly restricts the ability to evaluate a large matrix of likely catalyst candidates cost-effectively and in a reasonable time frame," explained Bartley.

"Using the USGR, we can blend synthetic gas mixtures, control a wide range of catalyst inlet temperatures and flow rates, and test a variety of catalysts with different operating modes," said Martin Heimrich, manager of SwRI's aftertreatment research and development section. "We can provide our clients with a rapid, cost-effective and flexible service, enabling them to select only the most promising candidates from numerous catalyst formulations to evaluate by engine or vehicle testing."

The Institute-developed, patent-pending device can simulate engine exhaust conditions for nearly all liquid and gaseous fuels including gasoline, diesel, compressed natural gas and liquid petroleum gas. The apparatus can also simulate exhaust emissions from future high-tech vehicle concepts that do not always have hardware available for testing, such as hybrid vehicles, lean-burn engines and homogeneous charge compression ignition engines.

The USGR uses several analyzers to provide real-time, second-by-second data for gas components such as O2, CO, CO2, H2O, total hydrocarbon, selected hydrocarbons, total NOx, NO, NO2, N2O, NH3 and SO2.

Using the USGR and other analytical tests, SwRI provides a comprehensive catalyst screening and testing service for its clients.

Contact Heimrich at (210) 522-3950 or martin.heimrich@swri.org, or visit usgr.swri.org.

ISO Certification Awarded

The SwRI Mechanical Sciences Section has earned ISO 9001:2000 certification. ISO 9001:2000 is a set of international standards used to provide guidance in the development and implementation of an effective quality management system for the development of products.

The section, part of SwRI's Mechanical and Materials Engineering Division, is certified as a "provider of independent mechanical systems and component design, analysis and environmental testing services for industry and government."

The Mechanical Sciences Section provides services in mechanical design and analysis, structural dynamics and acoustics research and development, environmental testing, including seismic, vibration, salt/fog and humidity testing, and electromagnetic compatibility (EMC) testing for a wide range of industries as well as government and military clients. The section also leads SwRI's NEBS (Network Equipment-Building Systems) program for the telecommunications industry.

"We now have in place a quality management system for all aspects of our business including design, analysis, testing and documentation," said Section Manager Timothy A. Fey. "Formal quality programs are now required by most industries and government agencies, and our client base directed us toward ISO 9001:2000 certification. While the process to achieve ISO certification was quite involved, it also gave us the opportunity to address client satisfaction and standardize certain aspects of our business. We can now offer our clients a more efficient, more consistent and more successful program."

Perry Johnson Registrars Inc., Southfield, Mich., audited the section on March 30, 2004, and issued the certification on June 9, 2004.

Contact Fey at (210) 522-3253 or tim.fey@swri.org.

Ignition threshold for impact-generated fires

Scientists conclude that 65 million years ago a 10-kilometer-wide asteroid or comet slammed into what is now the Yucatán peninsula, excavating the Chicxulub impact crater and setting into motion a chain of catastrophic events thought to precipitate the extinction of the dinosaurs and 75 percent of animal and plant life that existed in the late Cretaceous period.

"The impact of an asteroid or comet several kilometers across heaps environmental insult after insult on the world," said Dr. Daniel Durda, a senior research scientist at SwRI. "One aspect of the devastation wrought by large impacts is the potential for global wildfires ignited by material ejected from the crater reentering the atmosphere in the hours after the impact."

Large impacts can blast thousands of cubic kilometers of vaporized impactor and target sediments into the atmosphere and above, expanding into space and enveloping the entire planet. These high-energy, vapor-rich materials reenter the atmosphere and heat up air temperatures to the point that vegetation on the ground below can spontaneously burst into flame.

"In 2002, we investigated the Chicxulub impact event to examine the extent and distribution of fires it caused," said Durda. This cosmic collision carved out a crater some 40 kilometers (25 miles) deep and 180 kilometers (112 miles) across at the boundary between two geologic periods, the Cretaceous, when the dinosaurs ruled the planet, and the Tertiary, when mammals took supremacy.

"We noted that fires appeared to be global, covering multiple continents, but did not cover the entire Earth," Durda continued. "That suggested to us that the Chicxulub impact was probably near the threshold size event necessary for igniting global fires, and prompted us to ask 'What scale of impact is necessary for igniting widespread fires?'"

In a new study, Durda and Dr. David Kring, an associate professor at the University of Arizona Lunar and Planetary Laboratory, published a theory for the ignition threshold for impact-generated fires in the August 20, 2004, issue of the Journal of Geophysical Research. Their research indicates that impacts resulting in craters at least 85 kilometers wide can produce continental-scale fires, while impact craters more than 135 kilometers wide are needed to cause global-scale fires.

To calculate the threshold size impact required for global ignition of various types of vegetation, Durda and Kring used two separate, but linked, numerical codes to calculate the global distribution of debris reentering the atmosphere and the kinetic energy deposited in the atmosphere by the material. The distribution of fires depends on projectile trajectories, the position of the impact relative to the geographic distribution of forested continents and the mass of crater and projectile debris ejected into the atmosphere.

They also examined the threshold temperatures and durations required to spontaneously ignite green wood, to ignite wood in the presence of an ignition source (such as lightning, which would be prevalent in the dust-laden energetic skies following an impact event) and to ignite rotting wood, leaves and other common forest litter.

"The Chicxulub impact event may have been the only known impact event to have caused wildfires around the globe," Kring noted. "The Manicouagan (Canada) and Popigai (Russia) impact events, however, may have caused continental-scale fires. The Manicouagan impact occurred in the late Triassic, and the Popigai impact event occurred in the late Eocene, but neither has been firmly linked yet to the mass extinction events that occurred at those times."

Contact Durda at (303) 541-9084 or daniel.durda@swri.org.

Published in the Winter 2004 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.

Winter 2004 Technology Today
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