Low-Pressure Storage of Methane on High-Surface-Area Carbon for Natural Gas Vehicles: Record Performance in the Lab and on a 40-Liter Prototype Tank

Under contract #500-08-022 from the California Energy Commission (2011-14), the University of Missouri has developed monolithic nanoporous carbon with a storage capacity of 0.13 kg methane/liter carbon and 0.26 kg methane/kg carbon at 35 bar and 25 ºC [1, 2]. This is 4.5 times what a tank without carbon without carbon would hold at 35 bar and is world record volumetric storage capacity for adsorbed natural gas (ANG). The technology, showcased on a 40-liter conformable ANG tank, offers (i) reduced fueling costs because of low pressure (7 times lower than CNG, 250 bar); (ii) a tank that weighs 50% less than a CNG tank and has a 20% lower total volume; (iii) a rectangular tank geometry that can be integrated into the chassis of a vehicle, making NG vehicles an attractive alternative to gasoline and diesel vehicles. Data to be presented ranges from density of adsorbed methane films, 0.39-0.41 g/ml, comparable to the density of liquid methane at –161 ºC, to flow rates and pressure/temperature profiles for fast/slow fill and various discharge modes.