Fact: While this statement may be true for CNG tractors, LNG tractors actually fuel at a comparable rate to diesel tractors at a rate of 12 or more DGEs per minute. LNG refueling requires the use of gloves and protective eyewear to protect drivers from exposure to unintentional release of cryogenic LNG. In addition, drivers must use air hoses at the LNG fueling island to blow debris from the LNG fuel nozzle and tank receptacle to prevent contaminants from entering the LNG fuel tank.
CNG, on the other hand, has two fueling options: “fast fill” and “time fill”. The latter is used most commonly in return-to-base operations where trucks can be parked overnight and refueled over the course of several hours depending on the size and number of CNG fuel tanks onboard the truck. This method is commonly used in refuse, transit bus and pickup and delivery applications.
CNG fast fill uses compressors to quickly fill tanks for over-the-road and port drayage applications. However, the compressors and electrical systems add significant cost to the station buildout, and most fueling islands share a compressor. As a result, if two CNG trucks are refueling simultaneously on two islands powered by a single compressor, the truck with the most pressure in its tank(s) will not receive any CNG until the pressure in the tank(s) of the second truck is equalized.