Natural gas storage methods

Under normal conditions (atmospheric pressure and ambient temperature) NG has an extremely low energy density. Therefore its storage in simple containers is useless. Thus it can either be stored under extremely high pressure and/or at a very low temperature.


Adsorbed Natural Gas (ANG)

Energtek's proprietary Adsorbed Natural Gas (ANG) storage technology has quite a few promising advantages over existing methods. ANG technology allows large amounts of natural gas to be stored at a relatively low pressure, at room temperature. The principles of Natural gas adsorption have been around for decades, however no one had succeeded to develop commercially viable technology until now. 

Compressed Natural Gas (CNG)  

Compressed natural gas is stored at a high pressure, usually 200-250 bars. CNG demands very robust specially-designed cylindrical tanks, which use a lot of space and are heavy. In addition, gas compression requires expensive multi-stage high-pressure compression technology.

Compressed Natural Gas is currently the prevailing technology in the Natural Gas Vehicle industry. A massive implementation of CNG vehicles in most markets is restrained by the need to invest in very expensive refueling infrastructure, and the inconvenience and additional costs of on-board CNG tanks.

Liquefied Natural Gas (LNG)

LNG is another known gas storage method. Natural gas is liquefied under pressure of 10-20 bars at minus 161.5 deg. C. LNG requires the use of complex and expensive liquefaction equipment, thermos-like tanks and significant energy consumption (25-35% of the original energy gas content) for the liquefaction and degasification. LNG storage tanks should have cylindrical or spherical shape. Due to a very distinctive advantage of scale it is applied mainly in the marine transportation of very big quantities of gas.

This technology is not yet mature enough for massive use in vehicles. Several thousands LNG fueled heavy vehicles are operated around the world whereas LNG application for light vehicles is considered to be inefficient. On-board tank for a small vehicle costs almost as much as for a heavy vehicle and has much lower net volumetric storage efficiency. LNG vehicle refueling infrastructure costs even more than CNG.