Liquefied Natural Gas for Trucks and Buses

Liquefied natural gas (LNG) is being developed as a heavy vehicle fuel. The reason for developing LNG is to reduce our dependency on imported oil by eliminating technical and costs barriers associated with its usage. The U.S. Department of Energy (DOE) has a program, currently in its third year, to develop and advance cost-effective technologies for operating and refueling natural gas-fueled heavy vehicles (Class 7-8 trucks). The objectives of the DOE Natural Gas Vehicle Systems Program are to achieve market penetration by reducing vehicle conversion and fuel costs, to increase consumer acceptance by improving the reliability and efficiency, and to improve air quality by reducing tailpipe emissions. One way to reduce fuel costs is to develop new supplies of cheap natural gas. Significant progress is being made towards developing more energy-efficient, low-cost, small-scale natural gas liquefiers for exploiting alternative sources of natural gas such as from landfill and remote gas sites. In particular, the DOE program provides funds for research and development in the areas of; natural gas clean up, LNG production, advanced vehicle onboard storage tanks, improved fuel delivery systems and LNG market strategies. In general, the program seeks to integrate the individual components being developed into complete systems, and then demonstrate the technology to establish technical and economic feasibility. The paper also reviews the importance of cryogenics in designing LNG fuel delivery systems