A process of liquefying a natural gas stream in a liquefied natural gas facility is provided. The process includes cooling the natural gas stream in a first refrigeration cycle to produce a cooled natural gas stream. The process also includes cooling the cooled natural gas stream in a first chiller of a second refrigeration cycle, the cooled natural gas stream exiting the first chiller at a first pressure. The process further includes cooling the cooled natural gas stream in a first core of a second chiller of the second refrigeration cycle. The process yet further includes cooling a refrigerant of a refrigerant recycle stream separate from the cooled natural gas stream in a second core of the second chiller of the second refrigeration cycle, wherein the refrigerant recycle stream enters the second chiller at a second pressure that is lower than the first pressure of the cooled natural gas stream.

A system for liquefying production gas from a gas source containing a fluid having C1-C12 entrained gases includes a first phase separator for separating the C1-C12 gases from the fluid from the gas source. The first phase separator has an inlet in fluid communication with the gas source, a gas outlet and at least one alternative outlet. A first cryogenic liquefaction vessel has an inlet and an outlet. The inlet is in fluid communication with the gas outlet of the first phase separator. The first cryogenic liquefaction vessel cools the C1-C12 gases to liquefy the C3-C12 petroleum gases. A second phase separator is provided for separating the C3-C12 liquefied gases from the C1-C2 gases. The second phase separator has an inlet, a liquid outlet and a gas outlet. The inlet is in fluid communication with the outlet of the first cryogenic liquefaction vessel. At least one storage vessel is provided in fluid communication with the liquid outlet of the second phase separator for collection of the liquefied C3-C12 petroleum gases.

A system and method for treating associated gas in which a stream of raw gas is passed through safety valving, an inlet pressure control mechanism, and an inlet scrubber. Pressure/temperature data is transmitted to a control system via pressure and temperature transducers. The raw gas is sent to a gas compressor to generate pressurized gas, which is sent to an aerial cooler and a chiller heat exchanger, in which a chilling media contacts the pressurized gas. The chilled pressurized gas is sent to a vapor liquid separator to generate processed gas, which is routed through either a system backpressure valve or a pressure reducing recycle valve that directs the processed gas to the inlet scrubber. The processed gas that has passed through the system backpressure valve is delivered as fuel or routed through a backpressure regulating recycle valve that directs the processed gas to a system inlet pressure reducing valve.

A method is described for removing carbon dioxide during Liquid Natural Gas production from natural gas at gas pressure letdown stations. The above method removes carbon dioxide from a Liquid Natural Gas production stream by using hydrocarbon fractions taken from a gas for consumption stream as a carbon dioxide stripping adsorption agent for a stripping column used to remove carbon dioxide.

An apparatus for using nitrogen within a closed loop cryogenic system is described. A cryochamber is provided that has a first nitrogen flow line with an inlet for connection to a nitrogen source and an outlet. At least one cryogenic cooling loop is provided that has a nitrogen inlet and a nitrogen outlet. The nitrogen inlet and outlet are in fluid communication with the first nitrogen flow line. The nitrogen inlet is positioned upstream of the nitrogen outlet. A heat exchanger is provided on the at least one cryogenic cooling loops through which the nitrogen passes. The heat exchanger has a fluid inlet and a fluid outlet. A turbo expander is in fluid communication with the outlet of the first nitrogen flow line and the nitrogen source. The turbo expander re-cools the nitrogen that passes through the first flow line and the at least one cryogenic cooling loop.

A process for producing liquefied natural gas, in which natural gas feed having methane and higher hydrocarbons including benzene is cooled down to a first temperature level in a first cooling step using a first mixed coolant and then subjected to a countercurrent absorption using an absorption liquid to form a methane-enriched and benzene-depleted gas fraction, wherein a portion of the gas fraction is cooled down to a second temperature level in a second cooling step using a second mixed coolant and liquefied to give the liquefied natural gas. In the plant proposed, the first and second mixed coolants are low in propane or free of propane, and the absorption liquid is formed from a further portion of the gas fraction which is condensed above the countercurrent absorption and returned to the countercurrent absorption without pumping. The present invention likewise provides a corresponding plant.

Provided are mixed refrigerant systems and methods and, more particularly, to a mixed refrigerant system and methods that provides greater efficiency and reduced power consumption via control of a liquid level in a cold vapor separator device.

A liquefaction system that is configured to use a single methane expander to provide primary refrigeration duty. The liquefaction system can include a first or main heat exchanger and a fluid circuit coupled with the heat exchanger, the fluid circuit configured to circulate a process stream derived from an incoming feedstock of natural gas. The fluid circuit can comprise a compression circuit, methane expander coupled with the compression circuit and the main heat exchanger, a sub-cooling unit coupled with the methane expander, the sub-cooling unit configured to form a liquid natural gas (LNG) product from the process stream, and a first throttling device interposed between the main heat exchanger and the sub-cooling unit. The first throttling device can be configured to expand the process stream to a process pressure that corresponds with the suction pressure internal to the compression circuit.

Systems and methods for improving the efficiency of open-cycle cascade-based liquified natural gas systems by utilizing one or more ejectors to reduce and/or eliminate compression stages. The systems and methods may thus, be used to improve the efficiency of new and preexisting open-cycle cascade-based liquified natural gas systems to reduce in the flow rate through each compressor, which reduces the energy consumption of the overall process.

A main heat exchanger receives and partially condenses an effluent fluid stream so that a mixed phase effluent stream is formed. A primary separation device receives and separates the mixed phase effluent stream into a primary vapor stream including hydrogen and a primary liquid stream including an olefinic hydrocarbon. The main heat exchanger receives and warms at least a portion of the primary vapor stream to provide refrigeration for partially condensing the effluent fluid stream. The main heat exchanger also receives, warms and partially vaporizes the primary liquid stream. A mixed refrigerant compression system also provides refrigeration in the main heat exchanger.