Method for processing and transporting compressed natural gas
View Patent ↗A method for processing and transporting compressed natural gas by a floating vessel with a power plant entails obtaining pressurized high-energy content gas, separating the pressurized product stream into saturated gas and liquids, and removing impurities from the saturated gas. Water is removed from the gas forming a dry pressurized gas. The dry pressurized gas is cooled forming a two-phase gas. The gas is loaded into a storage element located on a floating vessel, while the liquids are loaded into the storage element forming a mixture. The floating vessel transports the storage modules and elements to a desired location at a lower cost than comparable submarine pipeline transport costs for distances of less than about 2500 nautical miles while utilizing the vapor phase during transit to power the floating vessel.
1. A method for processing and transporting compressed natural gas by a floating vessel with a power plant, wherein the method comprises the steps:
a. obtaining pressurized high-energy content vapor gas at a first pressure;
b. separating the pressurized high-energy content gas into saturated gas, a natural gas liquid, and a condensate;
c. removing impurities from the saturated gas to create a decontaminated saturated gas;
d. dehydrating the decontaminated saturated gas to remove water forming a dry pressurized gas;
e. cooling the dry pressurized gas forming a two-phase gas comprising a vapor phase and a liquid phase;
f. loading the two-phase gas into a storage element located on a floating vessel, wherein the storage element comprises:
i. a high strength steel alloy inner wall for load bearing purposes forming a cavity;
ii. a stainless steel alloy outer wall for non load bearing purposes; and
iii. an insulation layer of perlite disposed between the inner and outer wall, and wherein the cavity is adapted to hold the vapor phase and the liquid phase;
g. loading the natural gas liquid and the condensate into the storage element forming a mixture;
h. maintaining the mixture at the first pressure ranging from 800 psi to 1200 psi; and
moving the floating vessel to a desired location at a lower cost than comparable submarine pipeline transport costs for distances of less than about 2500 nautical miles while utilizing the vapor phase during transit to power a power plant; and discharging the natural gas at the first pressure.
2. The method of claim 1 , wherein the step of moving the floating vessel comprises a warming the vapor phase during transit forming a high pressure boil-off gas, wherein the high pressure boil-off gas is blended with diesel fuel to power the power plant.
3. The method of claim 1 , wherein the step of removing impurities comprises removing a member of the group consisting of carbon dioxide, mercury, hydrogen sulfide, and combinations thereof.
4. The method of claim 1 , further comprising the step of loading the two-phase gas into the storage element, wherein the storage element is disposed on land and then loaded on the floating vessel.
5. The method of claim 1 , wherein the outer wall is thinner than the inner wall.
6. The method of claim 1 , wherein the inner wall is a high-strength steel alloy or a basalt-based fiber pipe.
7. The method of claim 6 , wherein the high-strength steel alloy is a nickel-steel alloy.
8. The method of claim 1 , wherein the outer wall is steel, stainless steel, an aluminum, a thermoplastic, a fiberglass, or combinations thereof.
9. The method of claim 1 , wherein the storage element is cylindrical.
10. The method of claim 9 , wherein the inner wall comprises a diameter ranging from 8 feet to 15 feet.
11. The method of claim 10 , wherein the inner wall comprises a diameter ranging from 10 feet to 12 feet.
12. The method of claim 9 , wherein the outer wall comprises a diameter that is up to four feet larger in diameter than the inner wall.
13. The method of claim 1 , wherein the storage element is spherical.
14. The method of claim 13 , wherein the inner wall comprises a diameter ranging from 30 feet to 40 feet.
15. The method of claim 14 , wherein the outer wall comprises a diameter that is up to three feet larger in diameter than the inner wall.
16. The method of claim 1 , wherein the insulating layer is a vacuum.
17. The method of claim 1 , wherein the mixture is 90% to 99% liquid phase gas.
18. The method of claim 1 , wherein the two-phase gas is cooled from ambient temperature to a temperature ranging from −80 degrees Fahrenheit to −120 degrees Fahrenheit.