Exxonmobil Upstream Research Company

Exxonmobil Technology and Engineering Company

Fritz Pierre, Jr

Yijun Liu

Richard Alan Huntington

Parag A Gupte

Robert D Kaminsky

Robert D Denton

Ananda K Nagavarapu

Donald J Victory

Xiaoli Y Wright

A method for liquefying a feed gas stream. A refrigerant stream is cooled and expanded to produce an expanded, cooled refrigerant stream. Part or all of the expanded, cooled refrigerant stream is mixed with a make-up refrigerant stream in a separator, thereby condensing heavy hydrocarbon components from the make-up refrigerant stream and forming a gaseous expanded, cooled refrigerant stream. The gaseous expanded, cooled refrigerant stream passes through a heat exchanger zone to form a warm refrigerant stream. The feed gas stream is passed through the heat exchanger zone to cool at least part of the feed gas stream by indirect heat exchange with the expanded, cooled refrigerant stream, thereby forming a liquefied gas stream. The warm refrigerant stream is compressed to produce the compressed refrigerant stream.

Managing make-up gas composition variation for a high pressure expander process

A method and system for liquefying a methane-rich high-pressure feed gas stream using a first heat exchanger zone and a second heat exchanger zone. The feed gas stream is mixed with a refrigerant stream to form a second gas stream, which is compressed, cooled, and directed to a second heat exchanger zone to be additionally cooled below ambient temperature. It is then expanded to a pressure less than 2,000 psia and no greater than the pressure to which the second gas stream was compressed, and then separated into a first expanded refrigerant stream and a chilled gas stream. The first expanded refrigerant stream is expanded and then passed through the first heat exchanger zone such that it has a temperature that is cooler, by at least 5° F., than the highest fluid temperature within the first heat exchanger zone.

Natural gas liquefaction by a high pressure expansion process

A method and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a first heat exchanger and re-combined with the natural gas stream, and heavy hydrocarbons are removed therefrom to generate a separated natural gas stream and a separator bottom stream. Liquids are separated from the separator bottom stream to form an overhead stream, which is cooled and separated to form a recycle gas stream. The recycle gas stream is compressed. A first portion of the compressed recycle gas stream is directed through the first heat exchanger and directed to the separator as a column reflux stream. The separated to natural gas stream is used as a coolant in the first heat exchanger to thereby generate a pretreated natural gas stream, which is compressed and liquefied.

Pretreatment and pre-cooling of natural gas by high pressure compression and expansion

A method and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a heat exchanger and combined with the natural gas stream. Heavy hydrocarbons are removed from the combined natural gas stream, and the resulting separated natural gas stream is partially condensed in the first heat exchanger, with a liquid stream separated therefrom. The natural gas stream is warmed in the first heat exchanger and then is compressed and cooled. The resultant cooled compressed natural gas stream is expanded, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream recycled to the heat exchanger to be warmed through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are liquefied.

A method is disclosed for start-up of a system for liquefying a feed gas stream comprising natural gas. The system has a feed gas compression and expansion loop, and a refrigerant system comprising a primary cooling loop and a sub-cooling loop. The feed gas compression and expansion loop is started up. The refrigerant system is pressurized. Circulation in the primary cooling loop is started and established. Circulation in the sub-cooling loop is started and established. A flow rate of the feed gas stream and circulation rates of the primary cooling loop and the sub-cooling loop are ramped up.

Primary loop start-up method for a high pressure expander process

A method and apparatus for producing liquefied natural gas. A pretreated natural gas stream is compressed in at least two serially arranged compressors to a pressure of at least 1,500 psia and cooled. The resultant cooled compressed natural gas stream is expanded in at least one work producing natural gas expander to a pressure less than 2,000 psia and no greater than the pressure to which natural gas stream has been compressed, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream is warmed in a heat exchanger through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are then liquefied.

A method for liquefying a feed gas stream. A compressed first refrigerant stream is cooled and expanded to produce an expanded first refrigerant stream. The feed gas stream is cooled to within a first temperature range by exchanging heat only with the expanded first refrigerant stream to form a liquefied feed gas stream and a warmed first refrigerant stream. A compressed second refrigerant stream is provided is cooled to produce a cooled second refrigerant stream. At least a portion of the cooled second refrigerant stream is further cooled by exchanging heat with the expanded first refrigerant stream, and then is expanded to form an expanded second refrigerant stream. The liquefied feed gas stream is cooled to within a second temperature range by exchanging heat with the expanded second refrigerant stream to form a sub-cooled LNG stream and a first warmed, second refrigerant stream.

Heat exchanger configuration for a high pressure expander process and a method of natural gas liquefaction using the same

A method for producing liquefied natural gas (LNG) from a natural gas stream having a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received at an LNG liquefaction facility. The LIN streams may be produced at a different geographic location from the LNG liquefaction facility. A natural gas stream is liquefied by indirect heat exchange with a nitrogen vent stream to form a pressurized LNG stream. The pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. The pressurized LNG stream is directed to one or more stages of a column to produce an LNG stream and the nitrogen vent stream. The column has upper stages and lower stages. The LIN streams are directed to one or more upper stages of the column.

Method and system for liquefaction of natural gas using liquid nitrogen

Described herein are systems and processes to produce liquefied natural gas (LNG) using liquefied nitrogen (LIN) as the refrigerant. Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.

Increasing efficiency in an LNG production system by pre-cooling a natural gas feed stream

A method for loading liquefied nitrogen (LIN) into a cryogenic storage tank initially containing liquid natural gas (LNG) and a vapor space above the LNG. First and second nitrogen gas streams are provided. The first nitrogen stream has a lower temperature than the second nitrogen gas stream. While the LNG is offloaded from the storage tank, the first nitrogen gas stream is injected into the vapor space. The storage tank is then purged by injecting the second nitrogen gas stream into the storage tank to thereby reduce a natural gas content of the vapor space to less than 5 mol %. After purging the storage tank, the storage tank is loaded with LIN.

Method of purging a dual purpose LNG/LIN storage tank

Described herein are systems and processes to produce liquefied nitrogen (LIN) using liquefied natural gas (LNG) as the refrigerant. The LIN may be produced by indirect heat exchange of at least one nitrogen gas stream with at least two LNG streams within at least one heat exchanger where the LNG streams are at different pressures.

Systems and methods for the production of liquefied nitrogen using liquefied natural gas

A method for producing liquefied natural gas (LNG). A natural gas stream is transported to a liquefaction vessel. The natural gas stream is liquefied on the liquefaction vessel using at least one heat exchanger that exchanges heat between the natural gas stream and a liquid nitrogen stream to at least partially vaporize the liquefied nitrogen stream, thereby forming a warmed nitrogen gas stream and an at least partially condensed natural gas stream comprising LNG. The liquefaction vessel includes at least one tank that only stores liquid nitrogen and at least one tank that only stores LNG.

Method of natural gas liquefaction on LNG carriers storing liquid nitrogen

A method for separating nitrogen from an LNG stream with a nitrogen concentration of greater than 1 mol %. A pressurized LNG stream is produced at a liquefaction facility by liquefying natural gas, where the pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received from storage tanks, the at least one LIN stream being produced at a different geographic location from the LNG facility. The pressurized LNG stream is separated in a separation vessel into a vapor stream and a liquid stream. The vapor stream has a nitrogen concentration greater than the nitrogen concentration of the pressurized LNG stream. The liquid stream has a nitrogen concentration less than the nitrogen concentration of the pressurized LNG stream. At least one of the one or more LIN streams is directed to the separation vessel.

Growing community of inventors

Humble, TX, United States of America

Fritz Pierre, Jr