On-Board Storage and Home Refueling Options for Natural Gas Vehicles

In this paper options for on-board storage and home refueling of natural gas vehicles are presented and discussed. The on-board natural gas storage options considered are: storage at 2.2 MPa (300 psig) in activated carbon-filled cylinders, and 7.0 MPa (1000 psig) and 16.7 MPa (2400 psig) in hollow cylinders. Information is presented on small home refueling compressors designed to compress the natural gas to the above mentioned storage pressures. Also shown are data on the density and energy density of natural gas at pressures up to 21 MPa (3000 psig), It is found that to achieve a range of 160 km (100 miles), a 12.7 km/L (30 mpg) vehicle requires 232, 170 and 62 liters (8.2, 6.0 and 2.2 ft³), respectively, of natural gas storage volume at the three pressures considered. A preliminary comparison of the three storage options suggests that storage above 7.0 MPa is preferred.