Patent ID: 6652243
Filing Date: 2003-11-25
Classification: F04F,F17C

Abstract:
A method for filling a storage vessel with compressed natural gas, comprising:(a) substantially filling a first tank assembly with compressed natural gas from a gas source to a pressure greater than atmospheric; then (b) drawing hydraulic oil from a reservoir and pumping the hydraulic oil into the first tank assembly into direct contact with the gas contained therein, causing the gas in the first tank assembly to flow into a storage vessel as the first tank assembly fills with hydraulic oil; (c) while step (b) is occurring, supplying compressed natural gas from the gas source to the second tank assembly to a pressure greater than atmospheric, the pressure of the gas in the second tank assembly causing any hydraulic oil in the second tank assembly to flow into the reservoir; then (d) when the first tank assembly is substantially filled with hydraulic oil and the second tank assembly substantially filled with gas and emptied of any hydraulic oil, performing step (b) for the second tank assembly and step (c) for the first tank assembly; and (e) repeating step (d) until the storage vessel is filled with gas to a selected pressure.