LNG Storage and Delivery System Analysis

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LNG Storage and Delivery System Analysis--Directed Technologies, Inc., 4001 North Fairfax Drive, Suite 775, Arlington, VA 22203-1614; (703) 243-3383
Mr. Brian D. James, Principal Investigator
Mr. Ira F. Kuhn, Jr., Business Official
DOE Grant No. DE-FG02-97ER82357
Amount: $75,000

To reduce foreign fuel dependence and improve the Nation¿s air quality, new high-efficiency, direct-injection diesel engines running on natural gas are being developed for heavy-duty trucks. The trucking industry¿s preferred method to store natural gas is liquid natural gas; however, the current low (approximately 10¿ pounds per square inch absolute) pressure tank designs are incompatible with the high-pressure requirements (500-3,000 pounds per square inch absolute) to deliver the engine fuel. Thus a need exists to store liquid natural gas onboard so that high-pressure natural gas can be delivered to the new high-efficiency engines. Multiple potential storage and delivery systems could satisfy these requirements. Some combine a high-pressure tank having cryogenic insulation, while others utilize high-pressure fuel injectors or onboard reliquefaction devices. However, the optimal pressures, tank and insulation materials, construction methods, and peripheral system components have not been determined. A systems analysis must carefully balance all competing demands and assess the lowest cost, highest benefit liquid natural gas storage system for integration into the new class of high-efficiency engines.
The Phase I project will examine, design, and evaluate multiple high-pressure cryogenic tanks and innovative fuel delivery systems. For each liquid natural gas system, various metal tank materials, fiber-wrapped pressure vessels, cryogenic insulation, cryo-cooler techniques, conformal tank geometries, and fuel pressurization techniques will be examined. Each system will be evaluated on
the basis of weight, volume, dormancy/boil-off, storage system complexity, energy usage, refueling station impact, storage system cost, safety, and recyclability. Systems promising the highest payoff will be identified, and recommendations for further development will be made. In Phase II, work will be conducted with an industrial partner to fabricate the optimal storage system or critical components identified in Phase I.

Commercial Applications and Other Benefits as described by the awardee: Identification and development of low-cost, liquid natural gas storage and delivery systems having superior performance will grant U.S. companies a strategic advantage in the worldwide race for energy efficient automotive subsystems.