Ship based system for compressed natural gas transport

A system for compressed gas transport comprising:

• a ship;
• a plurality of compressed gas storage cells constructed and arranged to be transported by said ship, each of said compressed gas storage cells including a plurality of interconnected gas cylinders;
• a high pressure manifold, said high pressure manifold including means adapted for connection to a shore terminal;
• a low pressure manifold, said low pressure manifold including means adapted for connection to a shore terminal;
• means for flow connecting each of said compressed gas storage cells to each of said high and low pressure manifolds;
• and
• valve means for selectively controlling the flow of compressed gas between each of said compressed gas storage cells and each of said high and low pressure manifolds,
• whereby each of said compressed gas storage cells selectively may be flow connected to each of said high and low pressure manifolds.

A system for compressed gas transport comprising:

• a ship;
• a plurality of compressed gas storage cells constructed and arranged to be transported by said ship, each of said compressed gas storage cells including a plurality of gas cylinders interconnected by a cell manifold to a single cell control valve;
• a high pressure manifold, said high pressure manifold including means adapted for connection to a shore terminal;
• a low pressure manifold, said low pressure manifold including means adapted for connection to a shore terminal;
• a plurality of submanifolds, each of said submanifolds extending between and connecting said high pressure manifold and said low pressure manifold to a plurality of said single cell control valves;
• and
• means for selectively controlling the flow of compressed gas between each of said submanifolds and each of said high and low pressure manifolds,
• whereby each of said compressed gas storage cells selectively may be flow connected to each of said high and low pressure manifolds.

A ship based system for compressed natural gas transport including a ship having a plurality of gas cylinders, characterized by:

• the plurality of gas cylinders being configured into a plurality of compressed gas storage cells, each compressed gas storage cells consisting of between 3 and 30 gas cylinders connected by a cell manifold to a single control valve, the gas cylinders being vertically oriented within holds of the ship, each hold of the ship being covered with air tight hatch covers thereby enabling each hold of the ship to be flooded with an inert atmosphere at near ambient pressure, each hold and hatch cover being insulated;
• a high pressure manifold including means for connection to shore terminals;
• a low pressure manifold including means for connection to shore terminals;
• a submanifold extending between each control valve to connect each storage cell to both the high pressure manifold and the low pressure manifold;
• valves for controlling the flow of gas through the high pressure manifold and the low pressure manifold;
• each hold having a low pressure manifold to provide initial flood and subsequent maintenance of the inert gas atmosphere;
• and
• each hold being fitted with gas leak detectors so that leaking storage cells can be isolated and vented through the high pressure manifold system to a venting/flare boom.

A system for compressed gas transport, said system comprising:

• a ship having a plurality of cargo holds;
• a plurality of vertically oriented gas cylinders disposed in each of said cargo holds, said plurality of gas cylinders in each of said cargo holds being configured into one or more compressed gas storage cells, each of said compressed gas storage cell including from about 3 to about 30 of said gas cylinders;
• each of said plurality of gas cylinders within each of said compressed gas storage cells being connected by a cell manifold to a single cell control valve;
• each of said cargo holds having at least one substantially airtight hatch cover, whereby each of said cargo holds can be flooded with an inert atmosphere at near ambient pressure;
• each of said cargo holds and said airtight hatch covers being thermally insulated;
• a high pressure manifold, said high pressure manifold including means adapted for connection to a shore based terminal;
• a low pressure manifold, said low pressure manifold including means adapted for connection to a shore based terminal;
• submanifold means for connecting each said single cell control valve to both said high pressure manifold and said low pressure manifold;
• valve means for selectively controlling the flow of compressed gas between said submanifold means and each of said high pressure manifold and said low pressure manifold;
• an inert gas manifold for supplying inert gas to each of said cargo holds for supply and maintenance of said inert atmosphere in each of said cargo holds;
• and
• a gas leak detector in each of said cargo holds, whereby leaking compressed gas storage cells can be detected and vented to a venting/flare boom.

In combination:

• a. an on-shore compressor station;
• and
• b. a ship based system for compressed natural gas transport including a ship having a plurality of gas cylinders, characterized by:
• the plurality of gas cylinders being configured into a plurality of compressed gas storage cells, each compressed gas storage cells consisting of between 3 and 30 gas cylinders connected by a cell manifold to a single control valve;
• a high pressure manifold including means for connection to said on-shore compressor station;
• a low pressure manifold including means for connection to said on-shore compressor station;
• and
• a submanifold extending between each control valve to connect each storage cell to both the high pressure manifold and the low pressure manifold;
• and
• valves for controlling the flow of gas through the high pressure manifold and the low pressure manifold.

In combination:

• (a) a shore based facility including compressor means;
• and
• (b) a ship based system for compressed gas transport, said ship based system including:
• a plurality of ship transportable compressed gas storage cells, each of said compressed gas storage cells including a plurality of gas cylinders connected by a cell manifold to a cell control valve;
• a high pressure manifold including means adapted for connection to said shore based facility;
• a low pressure manifold including means adapted for connection to said shore based facility;
• a submanifold extending between and connecting a plurality of said cell control valves to both said high pressure and said low pressure manifolds, to thereby connect a plurality of said compressed gas storage cells to both said high pressure manifold and said low pressure manifold;
• valve means for controlling the flow of compressed gas between said submanifold and each of said high pressure manifold and said low pressure manifold.

A method for filling a ship-borne storage system with compressed gas from a shore facility adapted to supply compressed gas from a supply pipeline to said ship at a first pressure corresponding substantially to supply pipeline pressure and at a second pressure which is greater than supply pipeline pressure, said ship-borne storage system including a low pressure manifold adapted to receive gas at said first pressure from said shore based facility, a high pressure manifold adapted to receive gas at said second pressure from said shore based facility and a plurality of gas storage cells each of said gas storage cells including a plurality of interconnected gas cylinders, said method comprising the steps of:

• (a) connecting a first gas storage cell to said low pressure manifold;
• (b) conducting a portion of said compressed gas at said first pressure through said low pressure manifold to partially fill said first gas storage cell to substantially said first pressure;
• (c) isolating said first gas storage cell from said low pressure manifold;
• (d) connecting said first gas storage cell to said high pressure manifold;
• (e) conducting a portion of said compressed gas at said second pressure through said high pressure manifold to said first gas storage cell to fill said first gas storage cell to substantially said second pressure;
• (f) connecting a second gas storage cell to said low pressure manifold;
• and
• (g) continuing said steps until substantially all of said gas storage cells are filled with compressed gas at substantially said second pressure.

A method for discharging compressed gas from a ship-borne storage system to a shore facility adapted to supply such gas at pipeline pressure to a gas pipeline, said shore facility including decompression means for decompressing gas received from said ship prior to supplying the same to said pipeline and compressor means for compressing gas received from said ship prior to supplying same to said pipeline, said ship-borne storage system including a high pressure manifold adapted to discharge gas to said decompression means and a low pressure manifold adapted to discharge gas to said compressor means and a plurality of gas storage cells each of said gas storage cell including a plurality of interconnected gas cylinders containing compressed gas at a ship borne pressure which is substantially greater than said pipeline pressure, said method comprising the steps of:

• (a) connecting a first gas storage cell to said high pressure manifold;
• (b) discharging a portion of said compressed gas from said first gas storage cell through said high pressure manifold to said decompression means;
• (c) isolating said first gas storage cell from said high pressure manifold;
• (d) connecting said first gas storage cell to said low pressure manifold;
• (e) conducting a portion of said compressed gas from said first gas storage cell through said low pressure manifold to said compressor means;
• (f) connecting a second gas storage cell to said high pressure manifold;
• and
• (g) continuing said steps until substantially all of said gas storage cells have discharged a portion of their compressed gas through each of said high pressure and low pressure manifolds.