|
|
|
How Natural Gas Is Stored
Natural gas in its original naturally occurring gaseous form is transported via pipelines. When the gas is concentrated into a liquid then a much greater amount of energy can be concentrated into a smaller space. Because the liquified form of natural gas is only 1/614th the volume of natural gas, it is commercially and economically feasible to transport by ship or store in large quantities. Before commercial shipping of liquified natural gas began in the 1960's, only countries and regions with pipeline access to the gas could utilize the resource.
Liquified gas is often stored in below-ground storage facilities using depleted reservoirs, aquifers and salt caverns which is done under high pressure. Florida's geology isn't suited to in-ground storage since there are not any of these suitable structures. Gas in specialized above-ground insulated tanks can be stored at normal atmospheric pressure making it a much safer facility. Utilizing above-ground storage tanks allows projects to be constructed where they are needed and have the most benefit so the stored gas supply will be near where the customers are located, a great benefit in case of potential supply curtailment such as hurricanes. This also allows added gas supply to be delivered into the pipeline system close to consumers on peak days when the demand for gas is at its highest for power generation.
Gas will be delivered to the Floridian Natural Gas Storage facility via the two existing pipelines that bring gas to Florida from the Gulf Coast. Then, to change natural gas into a liquid for storage, the gas will be refrigerated to a temperature of minus 260 degrees Fahrenheit, the point at which gas turns into liquid. As a liquid, natural gas is clear and about half as dense as water.
The liquid is pumped into a specialized insulated storage tank where it is stored at atmospheric pressure. The tank acts like a large Thermos bottle, keeping the gas cold enough to remain in the liquid form. Any gas that warms above the -260 degrees is automatically re-refrigerated by the plant and returned to a liquid state in the tank.
The storage tank is designed with an inner tank of Nickel-Steel, a layer of insulation, another steel tank which is surrounded by a concrete shell. The design makes the tank very, very difficult to breach. Should a breach somehow occur, a dike surrounding the tank will contain any liquid natural gas releases. And, since methane is lighter than air, any spill would evaporate, rise and dissipate leaving nothing remaining in or on the ground.
When the gas is ready to be returned to the pipeline, it is warmed by the temperature of the outdoor air in a regas unit until it returns to its original gaseous state and is then sent back through the existing pipeline grid to consumers.
|
| Home | Top | Contact Us |
| © 2008 Floridian Natural Gas Storage, LLC. All rights reserved. |
|
