LNG Vehicle Fuel Tanks
One of the major barriers to using LNG as an alternative fuel is that very specialized, expensive cryogenic containers are required to store and deliver the fuel to the vehicle engine. Unlike the passive fuels, such as gasoline, diesel, compressed natural gas or propane, LNG is continually changing state as heat enters the liquid fuel through the tank plumbing, suspension system and insulating materials.
Conventional, "industrial gas" type cryogenic containers have been used almost exclusively as vehicle fuel tanks by transit fleets in the U.S. since 1996 as LNG vehicle fuel tanks. Unfortunately, almost all of these projects have been abandoned due to operational problems caused by excessive heat leak that is inherent in these tanks. These problems include weathering of the LNG, variations in tank pressure, fuel density and engine failure.
The LNG vehicular fuel tanks designed and patented by Cryogenic Fuels Inc are engineered and certified specifically for end-use in the transportation fuels market. The tanks are of all stainless steel construction and consist of an inner pressure vessel suspended within an outer tank by means of a non-metallic central support beam.
This rugged beam design is combined with multi-layer insulation and a high order vacuum is provided to reduce the amount of "heat leak" into the cold LNG in the inner tank. The result is a thermal protection system that is, at a minimum, four (4) times more efficient than, conventional cryogenic containers.