HIGH-ENERGY DENSITY STORAGE OF NATURAL-GAS IN LIGHT-HYDROCARBON SOLUTIONS

The storage of natural gas in other light hydrocarbons is one procedur e for automotive natural gas usage that reduces the requirement of hig h-pressure or cryogenic storage. Model solutions of methane in n-butan e, propane, and a liquefied-bottled-gas mixture were simulated using t he Benedict-Webb-Rubin-Starling equation of stare to determine the pre ssures necessary to maintain a liquid phase with perturbations in both temperature (- 1 degrees C to 38 degrees C) and mole fraction (50 to 80 mol% methane). Methane storage in these liquid solutions is between 45 and 93% of an equal ''tank''volume of compressed natural gas (CNG) at 21 MPa and 15 degrees C. The simulation results indicate that solu tions of this type contain 40 to 67% of the energy of gasoline at pres sures that range from 60 to 40% that of CNG at 21 MPa and 15 degrees C .