Natural gas is only combustible at a concentration of 5 to 15 percent when mixed with air. And, its flame speed is very slow. These facts may best be experienced by a simple demonstration often done at LNG fire schools. A large pit, i.e., 20' x 20', is filled with LNG, allowing the vapor cloud to drift with the wind. The cloud is ignited with a torch from a downwind side.
Ignition typically occurs near the visible fringes of the cloud.
The resulting flame front moves back toward the pit at a speed only slightly faster than a walk. Currently, there are 39 satellite and 55 liquefaction facilities in the United States. In other countries, there are 81 satellite and 14 liquefaction facilities. Since deregulation of the natural gas industry, the construction of LNG facilities in the United States has increased. The role of LNG facilities is changing from peak shaving natural gas demand to base loading or supplying of natural gas year round.