Technics

Fuel Treatment Unit Saves Tax Dollars and Environment

A mobile fuel filtration/additive demonstration unit (FAU), designed and built by engineers at SwRI, has been delivered to the U.S. Marine Corps Blount Island Command in Jacksonville, Florida, after successfully completing validation testing. The FAU will provide field and maintenance support for Marine Corps vehicles and equipment carried on 13 maritime prepositioned ships.

"This apparatus not only contributes to combat readiness by ensuring fuel quality, but saves the military and the taxpayer money in fuel replacement and disposal costs. It is also environmentally friendly," says SwRI project manager Gary B. Bessee, a research engineer in SwRI's U.S. Army TARDEC Fuels and Lubricants Research Facility. Bessee is shown with FAU instrumentation in the photo above.

"The problems of maintaining fuel quality and of having access to the right fuel in the field were again recognized during Operations Desert Shield and Desert Storm," adds Bessee. "There were instances in that conflict of fuel contaminated by sand, water, and other debris. There were also occasions when the military had no convenient means of converting more widely available commercial Jet-A fuels to the military jet fuel, JP-8, the single fuel on the battlefield."

Historically, fuel filtration problems in military applications have resulted from a range of contaminants that include particles, plastic and rubber components, tarry substances, fuel deterioration by-products, unknown fuel additives, and microbacterial growth.

The FAU solves these problems within a single, compact, transportable apparatus mounted on an 8-by-17-foot M-1073 trailer that incorporates a filtration system, a fuel storage tank, an additive injection system, and a self-contained power source. Within half an hour, the filtration system can filter and treat the front fuel cells of an M1-A1 combat tank.

"Other potential uses for the FAU," says Bessee, "include any place where small quantities of fuel are stored for extended periods of time, making the fuel susceptible to deterioration; locations where waste minimization is critical; or sites where there are severe constraints such as emergency standby power generators."

The FAU is highly flexible and has multiple configurations. The filtration unit is the heart of the system. Hose reels mounted on both sides of the unit are used to pump fuel from one or two vehicles. The fuel is filtered and then returned after the contaminants are removed. The filtration system has three components: the first uses pleated paper filters to remove the larger particles; the second eliminates water; and the third, a polishing filter, is used to remove fine particles.

In a second application of the FAU, up to four additives can be injected into a fuel. These include a corrosion inhibitor, a fuel system icing inhibitor, and an anti-static additive to convert Jet A-1 fuel to JP-8. In another potential application, a biocide can be added to the filtered fuel to discourage microbacterial growth.

The all-electric FAU is powered by an 1,800-rpm generator powered by a 10-kw air-cooled diesel engine.

At Blount Island, the Marine Corps typically completes routine maintenance of an individual ship's load approximately every 45 days. Each ship carries between four to five hundred vehicles and pieces of equipment including combat tanks, construction equipment, personnel carriers, and other inventory that must be available on the battlefield. The Marine Corps estimates that use of the FAU will save between $25,000 and $30,000 per shipload in fuel costs, both from fuel reuse and reduced fuel disposal costs, while providing the added benefit of battle-ready fuel supplies.

Alternative Future for Butane

Engineers in the Institute's Emissions Research Department have completed a project that successfully demonstrates the feasibility of using butane and a variety of butane and propane fuel blends as alternative low emissions automotive fuels. Butane has been an important gasoline blending component for many years, used to upgrade the octane of gasoline and to aid in cold starting during wintry conditions. Reformulated gasoline requirements for lower fuel vapor pressure, however, have resulted in a significant reduction in butane content, thus creating surplus supplies of the potentially useful automotive fuel.

According to SwRI Project Manager and former Senior Research Engineer Matthew Newkirk, the study shows that, for a current technology vehicle converted to operate on liquified petroleum gas (LPG), not only is the use of butane blends feasible, but it results in significantly lower emissions of non-methane organic gases, carbon monoxide, oxides of nitrogen, and substances rated as toxic by the U.S. Environmental Protection Agency, in comparison to operation with conventional gasoline.

"In addition," says Newkirk, "the specific reactivity, or ozone-forming potential, of exhaust emissions for the butane/propane blends was lower than for conventional gasoline. As a consequence, the converted vehicle was able to easily meet California's Ultra Low Emissions Vehicle standards.

"Because the engine conversion system was configured for LPG, which by definition has no evaporative emissions, the vehicle can also be classified as an Inherently Low Emission Vehicle, or ILEV," notes Newkirk. "And because butane/propane blends have a fuel economy approximately 80 percent that of gasoline, they provide significant onboard energy storage advantages in comparison to other types of alternative fuels."

In response to requests from industry and government, Institute engineers are continuing to work on butane/propane fuel blends through a proposed multi-client cooperative research program. The program is open to industry for participation.

Cheruvu named Fellow of ASM International

Dr. N. Sastry Cheruvu, a staff engineer in the Power Generation Materials Department of the Materials and Structures Division, has been elected a Fellow of ASM International.

Cheruvu was recognized for his contributions to the field of applied physical metallurgy research as related to power plant materials and the reliability of steam and gas turbines for the generation of electricity.

Before joining the Institute earlier this year, he was employed at Westinghouse Electric Corporation in Orlando, Florida, where he was engaged in applied materials research on both steam and gas turbine components. His previous work includes programs concerned with the development of gas turbine coatings and alloys, stress corrosion cracking of nuclear and fossil turbine discs, corrosion of steam turbine blades, and in-service degradation and remaining life assessment of steam turbine rotors.

The author of more than 30 technical papers, Cheruvu holds a bachelor's degree in metallurgy from the Indian Institute of Metals, Calcutta, India; a master's degree in physical metallurgy from the University of Roorkee, Roorkee, India; and a doctorate in materials science from the Oregon Graduate Center. He is a member of ASM International, the American Society for Testing and Materials, The Metallurgical Society, and the American Institute of Mining, Metallurgical, and Petroleum Engineers.

Cheruvu will be formally recognized as an ASM Fellow at an awards dinner to be held October 8, 1996, in Cincinnati, Ohio.

70-Year-Old Fuel Comes Clean

Preliminary evaluations of diesel fuels produced from natural gas and coal using advanced Fischer-Tropsch (F-T) processing technology show promising emissions results, with the potential to qualify as commercially viable, "clean" diesel fuels.

Test fuels provided by three major industrial participants and produced using different raw materials and processes yielded similar results in a modern, heavy-duty diesel engine; these included a 20 percent reduction in hydrocarbons, a 36 percent reduction in carbon monoxide, a 4 percent drop in nitrogen oxides, and a 26 percent reduction in particulate emissions when compared to a 10 percent aromatic, 50 cetane number reformulated diesel fuel.

The benefits were even more pronounced when compared to a current national average diesel fuel. In this case, the F-T fuels produced a 38 percent reduction in hydrocarbons, a 46 percent reduction in carbon monoxide, an 8 percent drop in nitrogen oxides, and a 30 percent reduction in particulates.

Because they contain no sulfur or aromatic compounds, F-T diesel fuels can provide these significant emissions reductions. Emissions levels are further reduced by the fuels' high cetane ratings.

The tests are being conducted at SwRI under a contract from the Bechtel Corporation, in cooperation with the U.S. Department of Energy and the three industrial participants.

The technology was developed in the early 1920s by two German scientists, Franz Fischer and Hans Tropsch, who succeeded in converting coal to synthetic liquid fuels. The process was further improved in Germany during World War II. Most recently, research by the industrial participants in the areas of syngas production, catalysis, and reactor design has greatly improved the quality of F-T fuels.

"We have just begun to explore the possibilities of F-T technology," notes Dr. Thomas Ryan III, project manager in the SwRI Engine Research Department. "The emissions results are very promising. In the next two phases of this project we hope to achieve even more significant reductions through a number of design modifications to heavy-duty diesel engine systems that will take full advantage of the useful characteristics of these fuels. F-T technology provides the promise of producing clean liquid fuels from coal or natural gas."

GasRail USA Enters Second Phase

Southwest Research Institute engineers recently reported to members of the GasRail USA consortium that they have made significant technical breakthroughs in natural gas locomotive engine design.

GasRail USA is a multiyear, cooperative industry research project initiated by SwRI in 1993 to develop natural gas engine technology for U.S. freight and passenger locomotives to demonstrate that the use of liquified natural gas (LNG) fuel contributes to lower emissions.

"The specific goals of the project are to significantly reduce nitrogen oxide (NOx) emissions, without increasing other emissions or reducing fuel economy and power output," says Project Manager David P. Meyers, a senior research engineer in SwRI's Engine and Vehicle Research Division.

"The program is part of a broad national effort by railway and energy companies to reduce locomotive exhaust emissions. In addition, fuel costs have always played a major role in railroad economics, and LNG shows promise as a fuel with lower costs and more stable prices than diesel fuels," he adds.

After evaluating a number of potential combustion systems appropriate for LNG applications, engineers selected a late-cycle high-injection pressure combustion system, termed LaCHIP, to test and develop during the second phase of the program. The LaCHIP combustion system supplies a unique gas-diesel hybrid technology and meets program goals in terms of emissions, efficiency, and operational considerations. The second phase will include installation and demonstration of an engine in a commuter locomotive.

"A major problem that needed to be resolved in this program was the search for an acceptable gas injector," explains Meyers. In the past, diesel-engine conversions using direct injection of natural gas have been plagued by injector performance and durability problems. To overcome these difficulties, SwRI engineers worked with Moog Controls, a leader in electrohydraulic control systems in Buffalo, New York, to custom-manufacture a direct-injection gas injector that provides superior performance and flexibility.

"By varying the injector tip parameters to provide greater penetration and better air utilization within the cylinder, we were able to achieve lower NOx emissions without sacrificing power or engine efficiency," notes Meyers.

According to SwRI Senior Research Engineer John Kubesh, the use of computational fluid dynamics (CFD) modeling was an important contribution to the new tip design. CFD modeling allows rapid evaluation of different injector tip designs and configurations. A conventional design evaluation process would have required time-consuming experimental efforts.

GasRail USA grew out of the Institute's extensive experience in developing heavy-duty engines that operate on natural gas and other alternative fuels. The research and development phases of the project include both single and multicylinder engine development, as well as the integration of an LNG-fueled engine and its associated fuel storage and handling systems into a passenger train locomotive. Following integration, practical on-track demonstrations of the locomotive will be conducted by the Southern California Regional Rail Authority.

Program participants represent a wide range of organizations: the federal government, state agencies, freight and passenger railroads, original equipment manufacturers, and the natural gas industry. Members have included the Department of Energy, the South Coast Air Quality Management District, the Southern California Regional Rail Authority, the California Air Resources Board, the Union Pacific Railroad, the Electromotive Division of General Motors, the Southern California Gas Company, and the Gas Research Institute.

SwRI Awarded Fifth Design Engineering Program

Southwest Research Institute has been selected as one of four contractors by the Ogden Air Logistics Center (ALC) at Hill AFB, Utah, to improve the reliability and maintainability of existing Department of Defense systems, equipment, and software. The total value of the five-year Design Engineering Program (DEP) is $240 million.

In the past nine years, SwRI has won three similar DEP awards from the Sacramento ALC and one from the San Antonio ALC.

"The $240 million amount of this program is a ceiling figure," notes SwRI Training Systems and Simulators Department Director and Ogden ALC DEP Program Manager Curtis Heinen. "Individual task orders may add up to several million dollars each.

"Most of the task orders we receive will be for work on ammunition and explosives, strategic missile systems, aircraft structural components, training devices, and cameras and other photographic equipment," Heinen adds. "We will perform studies and analyses of existing systems and components, design hardware and software, build prototypes, and conduct a variety of engineering tasks necessary to improve reliability and maintainability."

Though awarded by a particular ALC, the contract calls for the Institute and the other contractors -- Battelle-Memorial Institute, Science Applications International Corporation, and BDM International, Inc. -- to provide engineering services fulfilling the terms of the contract for any of the ALCs in the U.S. The centers are located at Kelly, McClellan, Hill, Tinker, and Robins Air Force Bases. TRW and MTL are subcontractors on the SwRI project team.

Published in the Summer 1996 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.

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