3366 results about "Liquefied natural gas" patented technology

A method and apparatus for increasing the efficiency of a combined cycle generation plant by assisting the vaporization of cold liquid including liquefied natural gas ("LNG") or liquefied petroleum gas (LPG) in a combined cycle power plant. Cold liquid vaporization is assisted by circulating a warm heat transfer fluid to transfer heat to a LNG/LPG vaporizer. The heat transfer fluid is chilled by LNG/LPG cold liquid vaporization and warmed by heat from a gas turbine. The heat transfer fluid absorbs heat from the air intake of a gas turbine and from a secondary heat transfer fluid circulating in a combined cycle power plant. Chilling the gas turbine air intake densifies the air and increases the gas turbine output. Chilling the steam condenser cooling water increases steam turbine output. The effects of chill recovery is higher output and better efficiency of the combined cycle plant.

Liquefied natural gas is used as a fracturing fluid to stimulate production of hydrocarbons from and/or injectability of fluids into subterranean formations. Proppants may be blended with the LNG prior to pumping the liquefied natural gas into the well. Optionally, the liquefied natural gas is heated after it is pumped and before it is introduced into the subterranean formation.

A power plant including an air separation unit (ASU) arranged to separate nitrogen, oxygen, carbon dioxide and argon from air and produce a stream of substantially pure liquid oxygen, nitrogen, carbon dioxide and argon; a steam generator, fired or unfired, arranged to combust a fuel, e.g., natural gas, liquefied natural gas, synthesis gas, coal, petroleum coke, biomass, municipal solid waste or any other gaseous, liquid or solid fuel in the presence of air and a quantity of substantially pure oxygen gas to produce an exhaust gas comprising water, carbon dioxide, carbon monoxide, nitrogen oxides, nitrogen, sulfur oxides and other trace gases, and a steam-turbine-generator to produce electricity, a primary gas heat exchanger unit for particulate/acid gas/moisture removal and a secondary heat exchanger arranged to cool the remainder of the exhaust gases from the steam generator. Exhaust gases are liquefied in the ASU thereby recovering carbon dioxide, nitrogen oxides, nitrogen, sulfur oxides, oxygen, and all other trace gases from the steam generator exhaust gas stream. The cooled gases are liquefied in the ASU and separated for sale or re-use in the power plant. Carbon dioxide liquid is transported from the plant for use in enhanced oil recovery or for other commercial use. Carbon dioxide removal is accomplished in the ASU by cryogenic separation of the gases, after directing the stream of liquid nitrogen from the air separation unit to the exhaust gas heat exchanger units to cool all of the exhaust gases including carbon dioxide, carbon monoxide, nitrogen oxides, nitrogen, oxygen, sulfur oxides, and other trace gases.

A process for liquefying natural gas in conjunction with processing natural gas to recover natural gas liquids (NGL) is disclosed. In the process, the natural gas stream to be liquefied is taken from one of the streams in the NGL recovery plant and cooled under pressure to condense it. A distillation stream is withdrawn from the NGL recovery plant to provide some of the cooling required to condense the natural gas stream. The condensed natural gas stream is expanded to an intermediate pressure and supplied to a mid-column feed point on a distillation column. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas, and is routed to the NGL recovery plant so that these heavier hydrocarbons can be recovered in the NGL product. The overhead vapor from the distillation column is cooled and condensed, and a portion of the condensed stream is supplied to a top feed point on the distillation column to serve as reflux. A second portion of the condensed stream is expanded to low pressure to form the liquefied natural gas stream.

A method for the production of liquefied natural gas (“LNG”) and nitrogen is provided. The method may include the steps of: a) providing a nitrogen production facility, wherein nitrogen production facility comprises: a main heat exchanger, an air separation unit, a nitrogen recycle compressor, a first nitrogen refrigeration supply configured to provide refrigeration to the main heat exchanger for cooling a main air feed, b) providing a secondary refrigeration supply; c) liquefying a natural gas stream using refrigeration from the secondary refrigeration supply to form an LNG product stream; wherein the secondary refrigeration supply is configured to compress and expand a refrigerant to produce refrigeration, wherein the refrigerant of the secondary refrigeration supply is shared with refrigerant of the first nitrogen refrigeration supply

Methods for loading a compressed fluid, such as natural gas, into and discharging the compressed fluid out of containment are provided. The compressed fluid is injected into a bottom portion of a container system for storage and/or transport until a target pressure is reached after which gas is withdrawn from an upper portion of the container system at a rate to maintain the target pressure while the compressed fluid is injected in the bottom portion. The compressed fluid is cooled through an expansion valve and by refrigerated chillers or by injecting a cold liquid of the same chemical composition as the compressed fluid, such as liquid natural gas, into the compressed fluid prior to injection into the container system. Withdrawal or discharge from the container system to a receiving facility begins with blow down from the bottom portion of the container system without a displacement fluid and continues until pressure falls below an acceptable differential pressure. The discharge stream is passed through a separator and a light gas from the separator is pressurized and injected into an upper portion of the container system to drive the compressed fluid out the bottom. The light gas is pressurized using either a compressor or a heated tank system, where two vessels operate in parallel, trapping and heating the light gas and then discharging to the container system from one while filling the other and alternating the operation between the two.

A process for liquefying natural gas in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane is disclosed. In the process, the natural gas stream to be liquefied is partially cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it, expanded to an intermediate pressure, and then supplied to a distillation column at a first mid-column feed position. The second stream is also expanded to intermediate pressure and is then supplied to the column at a second lower mid-column feed position. A distillation stream is withdrawn from the column below the feed point of the second stream and is cooled to condense at least a part of it, forming a reflux stream. At least a portion of the reflux stream is directed to the distillation column as its top feed. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas. The residual gas stream from the distillation column is compressed to a higher intermediate pressure, cooled under pressure to condense it, and then expanded to low pressure to form the liquefied natural gas stream.

The described invention relates to processes and systems for treating a gas stream, particularly one rich in methane for forming liquefied natural gas (LNG), said process including: (a) providing a gas stream; (b) providing a refrigerant; (c) compressing said refrigerant to provide a compressed refrigerant; (d) cooling said compressed refrigerant by indirect heat exchange with a cooling fluid; (e) expanding the refrigerant of (d) to cool said refrigerant, thereby producing an expanded, cooled refrigerant; (f) passing said expanded, cooled refrigerant to a first heat exchange area; (g) compressing the gas stream of (a) to a pressure of from greater than or equal to 1,000 psia to less than or equal to 4,500 psia; (h) cooling said compressed gas stream by indirect heat exchange with an external cooling fluid; and heat exchanging the compressed gas stream with the expanded, cooled refrigerant stream.

A process and apparatus for the recovery of ethane, ethylene, propane, propylene, and heavier hydrocarbons from a liquefied natural gas (LNG) stream is disclosed. The LNG feed stream is divided into two portions. The first portion is supplied to a fractionation column at an upper mid-column feed point. The second portion is directed in heat exchange relation with a warmer distillation stream rising from the fractionation stages of the column, whereby this portion of the LNG feed stream is partially vaporized and the distillation stream is totally condensed. The condensed distillation stream is divided into a “lean” LNG product stream and a reflux stream, whereupon the reflux stream is supplied to the column at a top column feed position. The partially vaporized portion of the LNG feed stream is separated into vapor and liquid streams which are thereafter supplied to the column at lower mid-column feed positions. The quantities and temperatures of the feeds to the column are effective to maintain the column overhead temperature at a temperature whereby the major portion of the desired components is recovered in the bottom liquid product from the column.

An approach is provided for vaporizing liquefied natural gas (LNG). A system utilizing closed circulation of a heat transfer medium heated by ambient air and waste heat from a waste heat source vaporizes the LNG.

Disclosed is a method which uses coke-oven gas as the raw material to produce liquefied natural gas; the method includes that the coke-oven gas is pretreated firstly to enable the tar, naphthalene and benzene impurities contained in the coke-oven gas to be purified deeply; and the purified coke-oven gas is processed with methanation reaction after compression and desulfurization; the liquefied natural gas product which contains CH4 with the content of more than 85% through the cryogenic separation process; the residual non-condensable gas is prepared to obtain the hydrogen with the purity of 99% through the PSA separation technique; the residual desorbed gas can be used as manufactured gas. The method which uses the coke-oven gas as the raw material to produce liquefied natural gas has the advantages of making full use of the compositions, saving energy, water and the investment, simple process and realizing the trinity coordinated development of economy, environment and energy sources.

Process for the liquefaction of natural gas and the recovery of components heavier than methane wherein natural gas is cooled and separated in a first distillation column into an overhead vapor enriched in methane and a bottoms stream enriched in components heavier than methane, wherein the first distillation column utilizes a liquefied methane-containing reflux stream. This reflux stream may be provided by a condensed portion of the overhead vapor or a portion of totally condensed overhead vapor that is subsequently warmed. The bottoms stream may be separated in one or more additional distillation columns to provide one or more product streams, any of which are partially or totally withdrawn as recovered hydrocarbons. A stream of unrecovered liquid hydrocarbons may be combined with either the condensed portion of the overhead vapor or a portion of totally condensed overhead vapor that is subsequently warmed.

The separation of methane from an admixture (110) with ethane and higher hydrocarbons, especially natural gas, using a scrub column (114), in which the admixture is separated into a methane-rich overhead (116) that is partially condensed (122) to provide reflux to the column (114) and liquid methane-depleted bottoms liquid (126), is improved by providing additional reflux (136) derived from an ethane enriched stream (130) from fractionation (128) of the bottoms liquid. Preferably, absorber liquid (140) from the fractionation (128) also is introduced into the scrub column. The vapor fraction (120) remaining after partial condensation can be liquefied (122) to provide LNG product (124).

A process for liquefying natural gas in conjunction with processing natural gas to recover natural gas liquids (NGL) is disclosed. In the process, the natural gas stream to be liquefied is taken from one of the streams in the NGL recovery plant and cooled under pressure to condense it. A distillation stream is withdrawn from the NGL recovery plant to provide some of the cooling required to condense the natural gas stream. A portion of the condensed stream is expanded to an intermediate pressure and then used to provide some of the cooling required to condense the natural gas stream, and thereafter routed to the NGL recovery plant so that any heavier hydrocarbons it contains can be recovered in the NGL product. The remaining portion of the condensed stream is expanded to low pressure to form the liquefied natural gas stream.

A compact and modular cryogenic method and apparatus for liquefying natural gas. The liquefaction process is highly efficient and requires no external refrigeration system, and the apparatus is small enough to be transportable from one remote site to another. A compressed natural gas feed stream is cooled and then expanded to form a bi-phase stream comprising a first refrigerated vapor component and a first liquid component. The first liquid component is then separated from the bi-phase stream and expanded to form a second bi-phase stream comprising a second refrigerated vapor component and a second liquid component. The second liquid component is then introduced into a means configured for storage and transport. The remaining feed stream can then be recycled, and at least a substantial portion of the original feed stream can be processed into liquefied natural gas (LNG). The first and second vapor components are recycled through the system and comprise at least a portion of the feed stream in the repeated steps.