KR101643110B1 - Heavy hydrocarbon removal from a natural gas stream - Google Patents

Abstract

The present invention relates to a process for removing heavy hydrocarbons from a natural gas feed stream comprising the steps of treating a natural gas feed stream to produce a heavier hydrocarbon-lean natural gas stream using the first and second heavy hydrocarbons removal systems Wherein the first and second heavy hydrocarbon removal systems treat the natural gas feed stream so that the first heavy hydrocarbons removal system produces a medium hydrocarbon reduced natural gas stream, Wherein one of the heavy hydrocarbon removal systems is continuously used to treat at least a portion of the heavy hydrocarbon reduced natural gas stream generated from the first heavy hydrocarbon removal system to produce a natural gas stream, And one or more adsorbent beds Adsorption system, and the other of said heavier hydrocarbon removal system is a gas separating a hydrocarbon-rich liquid from the hydrocarbon-containing and hydrocarbon reduced gas of the natural gas the gas-liquid separation system.

Description

HEAVY HYDROCARBON REMOVAL FROM A NATURAL GAS STREAM BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

Cross-reference of related application (s)

This application is herein incorporated by reference in its entirety as if fully set forth herein. U.S. Serial No. 13 / 565,881, U.S. Serial No. 13 / 611,169, filed September 12, 2012, U.S. Application Serial No. 13 / 565,881, filed August 3, 2012, filed August 3, 2012 Gt; PCT / US2012 / 049506 < / RTI >

The present invention relates to a method and apparatus for removing heavy hydrocarbons (i.e., aliphatic and aromatic hydrocarbons having a total of six or more carbon atoms, here referred to as C6 + hydrocarbons and aromatic compounds, respectively) in natural gas streams. In certain preferred embodiments, the present invention relates to a method and apparatus for removing heavy hydrocarbons from a natural gas stream and liquefying the hydrocarbons in the natural gas stream. The natural gas stream is a stream in which aliphatic hydrocarbons having a total of 3-5 carbon atoms (here also referred to as C3-C5 hydrocarbons) are already removed and / or aliphatic hydrocarbons having 2-5 carbon atoms in total -C5 < / RTI > hydrocarbons) may already be removed.

It is important to remove the heavy hydrocarbons before they are liquefied, since otherwise the heavy hydrocarbons can be cooled in the liquefied natural gas (LNG) stream. It is also known that the heavy hydrocarbon components contained in the natural gas feed stream can be removed by using a temperature swing adsorption (TSA) or by using a scrub column.

As is well known in the art, the scrub column is a kind of separator for producing a gas stream from which less volatile components are removed by removing less volatile components from the feed stream. The gaseous streams (as gas streams or two-phase gas-liquid streams) are introduced into the scrub column and come into contact with the reflux stream. The reflux stream is introduced into the column at a position higher than the position at which the feed stream is introduced so that the descending stream of liquid is "scrubbed" by contacting the stream in a direction opposite to the upward flow of the steam originating from the feed stream That is, at least a part of the components with little volatility is removed from the vapor stream). Typically, the scrub column includes one or more separation stages that are lower than the position at which the reflux stream is introduced and higher than the position at which the feed streams are introduced, wherein the separation stage detects the degree of contact between the rising steam and the descending reflux stream and / Or a tray, packing or some other type of insert that serves to increase the time.

When treating a natural gas stream, the scrub column may be effective at removing all of the heavy hydrocarbon components from the natural gas stream, but must be operated at a pressure below the critical pressure of the mixture to achieve gas-liquid phase separation. The operating pressure of the column is lower than the optimum natural gas liquefaction pressure, which lowers the liquefaction process energy efficiency. In addition, a stable operation of the scrub column requires a sufficient liquid (i.e., reflux) retention ratio to avoid dryout of the column. The reflux liquid for the column is typically provided by condensing a portion of the gas stream from the top of the column, and the natural gas feed stream is particularly useful when the content of C3-C5 hydrocarbons and / or C2-C5 hydrocarbons is too low If the concentrations of these components are too low), it is very energy inefficient to maintain the required liquid to bed stay ratio in the column. Therefore, if the natural gas feedstock has a low C3-C5 hydrocarbon and / or C2-C5 hydrocarbon content and a relatively high concentration of heavy hydrocarbons, the technique of conventional scrub columns is energy inefficient.

As is well known in the art, a TSA comprises at least two steps. During the first step (commonly referred to as the "adsorption step"), the gas stream is passed through the at least one adsorbent bed at a first temperature and the adsorbent is selectively passed through a first period of adsorption of one or more components of the feed stream, Thereby providing a gas stream from which the components have been removed. The introduction of the feed stream into the bed is stopped at the end of the adsorption step (when the adsorbent usually reaches saturation). Then, in a subsequent step (commonly referred to as a "desorption step" or "regeneration step"), at a second temperature, which is higher, to allow the bed or beds in question to be used for another adsorption step, The bed is regenerated by desorbing adsorbed components from the bed (s) during a second period of time for desorption. Typically, during the regeneration step, another gas stream (referred to as "regeneration gas") is passed through the bed to assist desorption and removal of the desorbed components. For some TSA processes (also referred to as temperature pressure swing adsorption or TPSA processes), the regeneration step may be performed at pressures less than the pressure during the adsorption step. For most TSA processes, two or more adsorbent beds are used in parallel, and the timing of the adsorption step is staggered between the beds so that at least one bed always experiences the adsorption step, can do. Each adsorbent bed may contain one kind of substance or may contain two or more adsorbent materials, and when two or more beds are present (in particular, when two or more beds are arranged in series), different beds may contain different substances ≪ / RTI > A class of adsorbent materials suitable for selectively adsorbing heavy hydrocarbons is well known.

TSA can be used to effectively remove heavy hydrocarbons from natural gas streams at a pressure optimal for liquefaction of subsequent natural gas streams, thereby enhancing the liquefaction process energy efficiency. However, if the concentration of heavy hydrocarbons is too high, the requirements for TSA vessel size and regeneration gas become economically impractical. Therefore, TSA is effective in removing heavy hydrocarbons in the natural gas liquefaction process only when the concentration of the heavy hydrocarbons is relatively low. In addition, more complex is that the TSA adsorbent bed used to remove hydrocarbons needs to be regenerated at a high temperature (i.e., 450-600 F, 232-315 C). At such high temperatures, the adsorbed heavy hydrocarbons may break and form coke, which disadvantages productivity by disabling adsorbents.

Related arts in this field include WO 2009/074737, WO 2007/018677, US 3,841,058, US 5,586,227 (describing an adsorption process using an adsorption system); US 7,600,395, US 5,325,673, WO 2006/061400, US 2006/0042312, US 2005/0072186 (which describe a process employing a scrub column).

Thus, particularly when the natural gas stream contains a relatively high concentration of heavy hydrocarbons or the precise composition of the natural gas stream is likely to change and / or otherwise unknown, the natural gas stream will sometimes contain a relatively high concentration of heavy hydrocarbons There is a need in the art for improved methods and apparatus for removing heavy hydrocarbons from natural gas streams.

According to a first aspect of the present invention there is provided a process for the removal of heavy hydrocarbons from natural gas streams, the method comprising the steps < RTI ID = 0.0 > Wherein the first and second heavy hydrocarbon removal systems treat the natural gas feed stream to produce a heavy hydrocarbon reduced natural gas stream and the second heavy hydrocarbons removal system processes the natural gas feed stream to produce a heavy hydrocarbon reduced natural gas stream, System is continuously used to treat at least a portion of the heavy hydrocarbon-reduced natural gas stream generated from the first heavy hydrocarbon removal system to produce a heavy hydrocarbon-lean natural gas stream, wherein one of the heavy hydrocarbon removal systems is a heavy hydrocarbons- One or more adsorbent beds for adsorbing and removing heavy hydrocarbons from natural gas And the other of the heavy hydrocarbon removal systems is a gas-liquid separation system for separating heavy hydrocarbon-containing natural gas into a heavy hydrocarbon-reduced natural gas gas and a heavy hydrocarbon rich liquid.

The gas-liquid separation system may be any kind of system suitable for separating a heavy hydrocarbon-containing natural gas (typically partially condensed medium hydrocarbon-containing natural gas) into a medium hydrocarbon reduced natural gas gas and a heavy hydrocarbon rich liquid. For example, the gas-liquid separation system may include a stripping column, a scrub column, or a phase separator. Preferably, however, the gas-liquid separation system comprises a strip calorie or phase separator.

The adsorption system may be any kind of system comprising one or more adsorbent beds suitable for adsorbing and removing heavy hydrocarbons from heavy hydrocarbon-containing natural gas. Preferably, however, the adsorption system comprises a temperature swing adsorption (TSA) system.

The term "portion or portion " used herein and not otherwise indicated in connection with a stream, stream, or stream refers to a portion of a stream that is preferably a divided portion. A portion of the stream is a portion of the stream obtained by separating the stream into two or more portions that maintain the same molecular composition (i.e., contain the same components in the same mole fractions) as the stream that is the object from which the portion is to be separated. Thus, for example, in a first aspect of the present invention, it is preferred that the second heavy hydrocarbon removal system treats the entirety of the heavy hydrocarbon reduced natural gas stream produced from the first heavy hydrocarbon removal system or the second heavy hydrocarbon removal system And a part of the heavy hydrocarbon-reduced natural gas stream generated from the heavy hydrocarbon reduction gas.

The heavy hydrocarbon component to be removed present in the natural gas feed stream comprises aliphatic hydrocarbons having a total of six carbon atoms; Aromatic hydrocarbons, and aromatic hydrocarbons. The heavier hydrocarbon-lean natural gas streams obtained from the second heavy hydrocarbons removal system are significantly reduced in each of the hydrocarbon components than the natural gas feed streams, so that the molar fraction of each of these components in the heavy hydrocarbon-lean natural gas is greater than that of the natural gas feed streams small. The heavy hydrocarbon-reduced natural gas stream obtained from the first heavy hydrocarbon removal system is substantially less than at least a portion of the hydrocarbon components in the natural gas feed stream, so that the total concentration of these components in the heavy hydrocarbon- , The synthetic molar fraction of these components) can of course not be as low as in the mid-hydrocarbon-lean natural gas stream obtained from the second heavy hydrocarbon removal system (through removal of heavy hydrocarbons from the heavy hydrocarbon reduced natural gas stream) It is lower than the concentration in the paddy field. Preferably, the heavy hydrocarbon reduced natural gas stream obtained from the first heavy hydrocarbon removal system is significantly reduced in each of the hydrocarbon components than the natural gas feed stream.

In certain embodiments, the method can be used to remove heavy hydrocarbons from a natural gas feed stream having a composition that makes it difficult to process, using only the TSA system or only scrub columns. For example: natural gas feedstocks can have, for example, a total concentration of any and all of the C3-C5 hydrocarbons in the feed stream (ie, the combined concentration of any and all of the C3-C5 hydrocarbons in the feed stream) Less than 3 mol%, less than 2 mol%, or less than 1 mol% of aliphatic hydrocarbons having a total of 3 to 5 carbon atoms may be lean; And / or the natural gas feedstock may be, for example, the total concentration of any and all of the C2-C5 hydrocarbons in the feed stream (ie, the combined concentration of any and all of the C2-C5 hydrocarbons in the feed stream) , 5 mol% or less, or 4 mol% or less of aliphatic hydrocarbons having a total of 2 to 5 carbon atoms. Similarly, alternatively or additionally, the natural gas feedstock can be a natural gas feedstock, for example, where the natural gas feedstock has a total heavy hydrocarbon concentration of at least 100 ppm or at least 250 ppm (ie, the combined concentration of both aromatic hydrocarbons and C6 + aliphatic hydrocarbons in the feed stream Total of at least 100 ppm, or at least 250 ppm) of heavy hydrocarbons.

In certain preferred embodiments, the method further comprises liquefying at least a portion of the heavy hydrocarbon-lean natural gas stream to produce a liquefied natural gas stream.

In a preferred embodiment, the composition of the heavy hydrocarbon-lean natural gas stream is such that any heavy hydrocarbons and all heavy hydrocarbons still present in the natural gas stream are at a temperature below the respective solubility limit (most preferably, much ) In the gas stream.

In one embodiment, the gas-liquid separation system is the first heavy hydrocarbons removal system, comprising: introducing a natural gas feed stream into the gas-liquid separation system to convert the natural gas feed stream into a heavy hydrocarbons reducing natural gas Separating the gas stream into a liquid stream having a high hydrocarbon content and a medium hydrocarbon content; And passing said at least a portion of said heavy hydrocarbon-reduced natural gas stream so as to adsorb heavy hydrocarbons through at least one bed of said adsorption system to produce said heavy hydrocarbon-lean natural gas stream. The method includes cooling the natural gas feed stream prior to introduction of the natural gas feed stream into the gas-liquid separation system, and passing the heavy hydrocarbon reduced natural gas stream stream or a portion thereof through one or more beds of the adsorption system Further comprising the step of warming said heavy hydrocarbon reduced natural gas stream before said natural gas feed stream and said heavy hydrocarbon reduced natural gas stream are separated from said natural gas feed stream and said heavy hydrocarbon reduced natural gas stream in an economizer heat exchanger, The indirect heat exchange between the gas streams cools the natural gas feed streams and warms up the heavy hydrocarbon reduced natural gas streams. Alternatively, the method may include warming the heavy hydrocarbon reduced natural gas gaseous stream before the heavy hydrocarbon reduced natural gas gaseous stream or portion thereof passes through at least one bed of the adsorption system, Further comprising the step of producing a heavy hydrocarbon lean cooling natural gas stream by cooling at least a portion of the heavy hydrocarbon lean natural gas stream in the economizer heat exchanger, Indirect heating exchange between the medium hydrocarbon reduced natural gas stream and the at least a portion of the heavy hydrocarbon-lean natural gas stream warms the heavy hydrocarbon reduced natural gas stream and the at least a portion of the heavy hydrocarbon-lean natural gas stream is cooled .

In an alternate embodiment, the adsorption system is the first heavy hydrocarbon removal system, the method comprising: passing the natural gas feedstock through one or more beds of the adsorption system to adsorb heavy hydrocarbons, Generating a gas stream; Introducing at least a portion of the heavy hydrocarbon-reduced natural gas stream into the gas-liquid separation system to reduce the gas stream or a portion thereof into a natural gas stream, which provides a heavy hydrocarbon-lean natural gas stream by further reducing heavy hydrocarbons; To a medium hydrocarbon rich liquid stream.

According to a second aspect of the present invention there is provided an apparatus for removing heavy hydrocarbons from a natural gas feed stream comprising a first heavy hydrocarbons removal system for treating the natural gas feed streams to produce a heavy hydrocarbon- And a second heavy hydrocarbon removal system wherein the first heavy hydrocarbon removal system treats the natural gas gasses during use so that the first heavy hydrocarbon removal system produces a heavy hydrocarbon reduced natural gas stream Wherein the second heavy hydrocarbon removal system is adapted to treat at least a portion of the heavy hydrocarbon reduced natural gas stream generated from the first heavy hydrocarbon removal system to produce a heavy hydrocarbon lean natural gas stream, And one of the heavy hydrocarbon removal systems comprises a heavy hydrocarbon-containing natural gas And one or more adsorbent beds for adsorbing and removing hydrocarbons, wherein the other of the heavy hydrocarbon removal systems is a gas-liquid separation system for separating heavy hydrocarbon-containing natural gas into a heavy hydrocarbon reduced natural gas and a heavy hydrocarbon rich liquid System.

An apparatus according to the second aspect of the invention is suitable for carrying out the method according to the first aspect of the invention. Thus, a preferred embodiment of the device according to the second aspect will be clear from the above discussion of the preferred embodiment of the method according to the first aspect.

Especially:

Preferably, the gas-liquid separation system comprises a strip calorie or phase separator.

Preferably, the adsorption system comprises a temperature swing adsorption system.

Preferably, the apparatus further comprises a liquefier fluidly connected to the second heavy hydrocarbon removal system to produce a liquefied natural gas stream by receiving and liquefying at least a portion of the heavy hydrocarbon-lean natural gas stream.

In one embodiment, the gas-liquid separation system is the first heavy hydrocarbon removal system, comprising: a gas containing the natural gas feed stream and separating it into a heavy hydrocarbons reduced natural gas stream and a heavy hydrocarbon rich liquid stream A liquid separation system; An adsorption system in fluid communication with the gas-liquid separation system to receive at least a portion of the heavy hydrocarbon reduced natural gas gaseous stream, the adsorbent system comprising a heavy hydrocarbon And an adsorption system comprising at least one adsorbent bed to produce a lean natural gas stream. The apparatus includes means for cooling the natural gas feed stream prior to introduction of the natural gas feed stream into the gas-liquid separation system through indirect heat exchange between the natural gas feed stream and the heavy hydrocarbon reduced natural gas stream stream, The economizer heat exchanger may further include a hydrocarbon reduced natural gas stream or a portion thereof to warm the heavy hydrocarbon reduced natural gas stream prior to passing through at least one bed of the adsorber system. Alternatively, the apparatus may be configured to indirectly heat-exchange the heavy hydrocarbon reduced natural gas stream with at least a portion of the heavy hydrocarbon-lean natural gas stream to provide the heavy hydrocarbon reduced natural gas stream stream, or a portion thereof, And an economizer heat exchanger to warm the heavy hydrocarbon reduced natural gas stream and cool at least a portion of the heavy hydrocarbon-lean natural gas stream prior to passing the one or more beds.

In an alternative embodiment, the adsorption system is the first heavy hydrocarbons removal system, wherein the apparatus is configured to: receive the natural gas gasses and adsorb heavy hydrocarbons from the natural gas gasses, An adsorption system comprising at least one adsorbent bed to produce a stream; Wherein the at least a portion of the heavy hydrocarbon-reduced natural gas gaseous stream is received and the contained gaseous stream or a portion thereof is separated into a natural gas gaseous stream that further reduces the heavy hydrocarbon-rich liquids and the heavy hydrocarbons to provide a heavy hydrocarbon- And a gas-liquid separation system in fluid communication with the adsorption system.

According to a third aspect of the present invention there is provided a process for removing heavy hydrocarbons from a natural gas stream and liquefying the natural gas stream, the method comprising: contacting the natural gas stream with a corresponding hydrocarbon gas stream to provide a lean hydrocarbon- Passing through an adsorption system comprising at least one adsorbent bed for adsorbing and removing heavy hydrocarbons from a natural gas stream; Liquefying the heavy hydrocarbon-reduced natural gas stream to produce a liquefied natural gas stream; And regenerating one or more beds of the temperature swing adsorption system by passing the flash or evaporation gas obtained from the liquefied natural gas through the one or more beds.

A preferred embodiment of the present invention includes the following aspects of # 1 to # 33:

#One. A method of removing heavy hydrocarbons from a natural gas feed stream comprising treating natural gas feed streams to produce a heavy hydrocarbon-lean natural gas stream using first and second heavy hydrocarbon removal systems, The first and second heavy hydrocarbons removal system may be configured such that the first heavy hydrocarbon removal system processes the natural gas feed stream to produce a medium hydrocarbon reduced natural gas stream and the second heavy hydrocarbons removal system produces a heavy hydrocarbons- Wherein one of the heavy hydrocarbon removal systems is used to adsorb and remove heavy hydrocarbons from the heavy hydrocarbon-containing natural gas, wherein at least one of the heavy hydrocarbon removal natural gas streams is used to treat at least some of the heavy hydrocarbon reduced natural gas streams generated from the first heavy hydrocarbon removal system An adsorption system comprising at least one adsorbent bed, Wherein the other of the heavy hydrocarbon removal systems is a gas-liquid separation system for separating the heavy hydrocarbon-containing natural gas into a heavy hydrocarbon reduced natural gas and a heavy hydrocarbon rich liquid.

#2. The method of aspect of # 1, wherein the gas-liquid separation system comprises a strip calorie or phase separator.

# 3. The method of aspect 1 or 2 further comprises the step of producing a liquefied natural gas stream and liquefying at least a portion of the hydrocarbon-lean natural gas stream to produce a liquefied natural gas stream How to.

#4. The method of any one of aspects # 1 to # 3, wherein the gas-liquid separation system is the first heavy hydrocarbon removal system, the method comprising: introducing a natural gas feed stream into the gas- Separating the feedstock into a heavy hydrocarbons reducing natural gas stream and a heavy hydrocarbons rich liquid stream; Reducing at least a portion of said heavy hydrocarbon reduced natural gas stream so as to adsorb heavy hydrocarbons through said at least one bed of said adsorption system to produce said heavy hydrocarbon-lean natural gas stream.

# 5. The method comprising cooling the natural gas feed stream prior to introduction of the natural gas feed stream into the gas-liquid separation system, and recovering the heavy hydrocarbons reduced natural gas stream, or a portion thereof, Further comprising warming the heavy hydrocarbon reduced natural gas gaseous stream prior to passing through at least one bed of the adsorption system.

# 6. The method of aspect 5, wherein the natural gas feed streams and the heavy hydrocarbon reduced natural gas stream stays in the economizer heat exchanger through indirect heat exchange between the natural gas feed streams and the heavy hydrocarbon reduced natural gas stream stalls, Wherein the gas feed stream is cooled and the heavy hydrocarbons reduced natural gas stream is warmed.

# 7. The method of aspect of claim 6, wherein the natural gas feed stream is further cooled by direct or indirect heat exchange with the expansion of the natural gas feed stream and / or one or more other streams prior to introduction into the gas- .

#8. 7. A method as claimed in claim 6 or claim 7, wherein the method further comprises liquefying at least a portion of the heavy hydrocarbon-lean natural gas stream.

# 9. The method of aspect < RTI ID = 0.0 ># 5 < / RTI > further comprising cooling at least a portion of the heavy hydrocarbon-lean natural gas stream to produce a heavy hydrocarbon lean cooling natural gas stream, At least a portion of the hydrocarbon-lean natural gas stream is indirectly heat-exchanged between the heavy hydrocarbon reduced natural gas stream stream and the at least a portion of the heavy hydrocarbon-lean natural gas stream in the economizer heat exchanger, And at least a portion of said heavy hydrocarbon-lean natural gas stream is cooled.

# 10. As a method of aspect of # 9, the method further comprises liquefying the heavy hydrocarbon lean cooling natural gas stream.

# 11. Wherein the natural gas feed stream is cooled and the heavy hydrocarbon lean cooled natural gas stream is liquefied in a liquefier, the natural gas feed stream is introduced into a hot end of the liquefier and the liquefied Wherein the heavy hydrocarbon lean cooling natural gas stream is introduced into the intermediate position of the liquefier and recovered from the low temperature end of the liquefier.

# 12. A method as claimed in any one of claims 4 to 11, wherein the gas-liquid separation system is a strip calisthe, said method comprising introducing strip gas into said strip cal after said natural gas stream is introduced into said strip cal Said method further comprising the steps of:

# 13. A method as claimed in any one of claims 6 to 8, wherein the gas-liquid separation system is a strip calorie, the method further comprising: introducing the strip gas into a strip cal- < Said strip gas comprising: natural gas taken from natural gas feed streams before being cooled and introduced into said strip calves; A portion of the hydrocarbon-reduced natural gas stream warmed in the economizer heat exchanger; A portion of a hydrocarbon-lean natural gas stream; A gas obtained from re-burning all or part of the medium hydrocarbon rich liquid stream; And a flash or evaporation gas obtained from the liquefied gas.

# 14. A method as claimed in any one of claims 9 to 11, wherein the gas-liquid separation system is a strip calorie, the method further comprising: introducing the strip gas into a strip cal- < Said strip gas comprising: natural gas taken from natural gas feed streams before being cooled and introduced into said strip calves; A portion of said heavy hydrocarbon-lean natural gas stream not cooled in the economizer heat exchanger; A portion of the heavy hydrocarbon-reduced natural gas stream warmed in the inocomerizer heat exchanger; A gas obtained from re-burning all or part of the medium hydrocarbon rich liquid stream; And a flash or evaporation gas obtained from the liquefied gas.

# 15. A method as claimed in any one of claims 4 to 14 wherein the adsorption system is a temperature swing adsorption system and wherein the method comprises contacting a gas selected from a flash or evaporation gas obtained from the liquefied natural gas or a portion of the heavy hydrocarbon- Further comprising regenerating the one or more beds of the temperature swing adsorption system by passing the one or more beds, wherein the temperature of the one or more bed being regenerated is from the heavy hydrocarbon abatement natural gas stream or a portion thereof The temperature of the at least one bed being adsorbed by the hydrocarbon.

# 16. 15. A method as claimed in claim 15, wherein the method comprises cooling the gas obtained from the at least one bed of the temperature swing adsorption system during the regeneration of the at least one bed and separating the gas phase into a liquid phase and a gas phase, Recycle to the natural gas feed prior to introduction into the liquid separation system.

# 17. The method of aspect of < RTI ID = 0.0 ># 15, < / RTI > wherein the gas liquid separation system is a strip calorie and the method comprises cooling the gas obtained from the one or more beds of the temperature swing adsorption system during regeneration of the one or more beds, And introducing said gaseous phase as stripping gas into said strip calves to a position below said position where said natural gas gasses are introduced into said strip calves.

# 18. The method of any one of claims 1 to 3, wherein the adsorption system is the first heavy hydrocarbon removal system, the method comprising: passing the natural gas feed stream through one or more beds of the adsorption system to adsorb heavy hydrocarbons Thereby producing a heavy hydrocarbon-reduced natural gas stream; Introducing at least a portion of the heavy hydrocarbon-reduced natural gas stream into the gas-liquid separation system to reduce the gas stream or a portion thereof into a natural gas stream, which provides a heavy hydrocarbon-lean natural gas stream by further reducing heavy hydrocarbons; Lt; RTI ID = 0.0 > heavier < / RTI > hydrocarbon-rich liquid stream.

# 19. 18. The method of aspect 18, wherein the method further comprises cooling the heavy hydrocarbon reduced natural gas stream or portion before being introduced into the gas-liquid separation system.

# 20. The method of aspect 19, wherein the method further comprises liquefying the heavy hydrocarbons lean natural gas stream.

# 21. As a method of aspect 20, in the liquefier, the heavy hydrocarbon reduced natural gas stream or a part thereof is cooled and the heavy hydrocarbon diluted natural gas stream is liquefied, and the heavy hydrocarbon reduced natural gas stream, or a part thereof, Wherein the heavy hydrocarbon-lean natural gas stream is introduced to an intermediate position of the liquefier and recovered from the low-temperature end of the liquefier.

# 22. Wherein the gas-liquid separation system is a strip calyc, and wherein the method further comprises the step of introducing the heavy hydrocarbon reduced natural gas stream or a portion thereof into the strip calv from a position where it is introduced into the strip cal- < Further comprising the step of introducing a stripping gas into the lower position.

# 23. 22. The method of aspect 22 wherein said strip gas comprises: natural gas taken from said natural gas feed stream prior to passing through at least one bed of said adsorption system; A portion of the heavy hydrocarbon-reduced natural gas stream; A gas obtained from re-burning all or a portion of said heavy hydrocarbon rich liquid stream; A flash or a vapor obtained from liquefied natural gas; and a gas comprising at least one gas selected from the group consisting of:

# 24. A method as claimed in any one of claims 18 to 23, wherein the adsorption system is a temperature swing adsorption system, the method comprising the step of passing a gas selected from flash or evaporation gas obtained from a portion of the heavy hydrocarbon- Further comprising regenerating the one or more beds of the temperature swing adsorption system by passing the one or more beds, wherein the temperature of the at least one bed being regenerated is greater than the temperature of the at least one bed during the adsorption of heavy hydrocarbons Higher than the temperature of the at least one bed.

# 25. The method of aspect 24, comprising: cooling the gas obtained from the at least one bed of the temperature swing adsorption system during the regeneration of the one or more beds and separating the gas phase into a liquid phase and a gaseous phase; Recycle to said natural gas feed stream prior to passing through said one or more beds of a swing adsorption system.

# 26. The method of aspect 24, wherein the gas liquid separation system is a strip calorie, the method further comprising: introducing the strip gas into the strip cal after a portion of the strip- Wherein the strip gas comprises: a gas obtained from the at least one bed of the temperature swing adsorption system during the regeneration of the at least one bed; Or the gas phase obtained from cooling the gas obtained from the at least one bed of the temperature swing adsorption system during the regeneration of the one or more beds and separating into a liquid phase and a gaseous phase.

# 27. The method of any one of claims 1 to 26, wherein the natural gas feedstock is a mixture of lean aliphatic hydrocarbons having 3-5 carbon atoms in total and / or lean hydrocarbons having 2-5 carbon atoms in total / RTI >

# 28. An apparatus for removing heavy hydrocarbons from a natural gas feed stream comprising a first heavy hydrocarbons removal system and a second heavy hydrocarbons removal system for treating the natural gas feed streams to produce a heavy hydrocarbon lean natural gas stream, Wherein the first and second heavy hydrocarbon removal systems treat the natural gas feed stream so that during use the first heavy hydrocarbon removal system produces a heavy hydrocarbon reduced natural gas stream and the second heavy hydrocarbons removal system is operated to remove heavy hydrocarbons Wherein one of the heavy hydrocarbons removal systems is connected and continuously arranged in fluid communication with one another to treat at least a portion of the heavy hydrocarbon reduced natural gas stream generated from the first heavy hydrocarbon removal system to produce a natural gas stream, One that adsorbs and removes heavy hydrocarbons from hydrocarbon-containing natural gas Wherein the other of the heavy hydrocarbon removal systems is a gas-liquid separation system that separates the heavy hydrocarbon-containing natural gas into a medium hydrocarbon reduced natural gas gas and a heavy hydrocarbon rich liquid.

# 29. 28. The apparatus of claim 28, wherein the gas-liquid separation system comprises a strip calorie or phase separator.

# 30. Wherein the apparatus further generates a liquefied natural gas stream and the apparatus is adapted to receive and liquefy at least a portion of the heavy hydrocarbon-lean natural gas stream to produce a liquefied natural gas stream Further comprising a liquefier fluidly connected to the second heavy hydrocarbon removal system.

# 31. Wherein the gas-liquid separation system is the first heavy hydrocarbons removal system, the apparatus comprising: means for receiving the natural gas feed stream to produce a heavy hydrocarbons reduced natural gas stream, A gas-liquid separation system for separating the hydrocarbon-rich liquids into hydrocarbon-rich liquids; An adsorption system in fluid communication with the gas-liquid separation system to receive at least a portion of the heavy hydrocarbon reduced natural gas gaseous stream, the adsorbent system comprising a heavy hydrocarbon An adsorption system comprising at least one adsorbent bed to produce a lean natural gas stream; Cooling the natural gas feed stream prior to introducing the natural gas feed stream into the gas-liquid separation system through indirect heat exchange between the natural gas feed stream and the heavy hydrocarbon reduced natural gas stream stream, And an economizer heat exchanger to warm the heavy hydrocarbon reduced natural gas stream prior to passing the gas stream or portion thereof through at least one bed of the adsorber system.

# 32. Wherein the gas-liquid separation system is the first heavy hydrocarbons removal system, the apparatus comprising: means for receiving the natural gas feed stream to produce a heavy hydrocarbons reduced natural gas stream, A gas-liquid separation system for separating the hydrocarbon-rich liquids into hydrocarbon-rich liquids; An adsorption system in fluid communication with the gas-liquid separation system to receive at least a portion of the heavy hydrocarbon reduced natural gas gaseous stream, the adsorbent system comprising a heavy hydrocarbon An adsorption system comprising at least one adsorbent bed to produce a lean natural gas stream; Through indirect heat exchange between the heavy hydrocarbon reduced natural gas stream and the at least a portion of the heavy hydrocarbon-lean natural gas stream, passing the heavy hydrocarbon reduced natural gas stream or a portion thereof through the one or more beds of the adsorber system An economizer heat exchanger for warming said heavy hydrocarbon reduced natural gas gaseous stream and cooling at least a portion of said heavy hydrocarbon-lean natural gas stream.

# 33. The apparatus of any one of claims 28 to 30 wherein the adsorption system is the first heavy hydrocarbons removal system, the apparatus comprising: means for receiving the natural gas feed stream and for adsorbing heavy hydrocarbons from the natural gas feed stream An adsorption system comprising at least one adsorbent bed to produce a heavy hydrocarbon-reduced natural gas stream; Wherein the at least a portion of the heavy hydrocarbon-reduced natural gas gaseous stream is received and the contained gaseous stream or a portion thereof is separated into a natural gas gaseous stream that further reduces the heavy hydrocarbon-rich liquids and the heavy hydrocarbons to provide a heavy hydrocarbon- And a gas-liquid separation system in fluid communication with the adsorption system.

Figures 1A-1F illustrate an embodiment of a first set of the present invention in which a gas-liquid separation system is continuously arranged upstream of an adsorption system to remove heavy hydrocarbons from natural gas feed streams;
Figures 2a-2d illustrate a second set of embodiments of the present invention in which a gas-liquid separation system is continuously arranged upstream of an adsorption system to remove heavy hydrocarbons from natural gas feed streams;
Figures 3a-3d show an embodiment of the third set of the invention in which the adsorption system is continuously arranged upstream of the gas-liquid separation system to remove the heavy hydrocarbons from the natural gas feed streams;
4 is a graph showing the results of successive use of an adsorption system and a gas-liquid separation system to remove heavy hydrocarbons from natural gas feed streams, compared to using only scrub columns to remove heavy hydrocarbons from natural gas feed streams .

In certain aspects, the present invention is directed to a method and apparatus for using an adsorption system with a gas-liquid separation system to effectively remove heavy hydrocarbons (i.e., one or more C6 + hydrocarbons and / or aromatics) from a natural gas stream.

If the natural gas stream contains a relatively low level of heavy hydrocarbons with a low content of C3-C5 and / or C2-C5 components, then some of the hydrocarbon removal schemes employing only the TSA system or scrub column are inefficient or energy-inefficient . The inventors have found that this problem can be solved by using an adsorption system (preferably a TSA system) with a gas-liquid separation system (preferably including a phase separator or a strip calil).

Specifically, the method and apparatus of the present invention can improve the energy efficiency of the liquefaction process by allowing the phase separator or strip calorie (or other gas-liquid separation system) to operate at higher pressures than conventional scrub columns.

In addition, LNG plants face the challenge of uncertain hydrocarbon content when LNG plants receive natural gas feedstock from natural gas feedstocks or natural gas feedstocks contaminated with heavy hydrocarbons. The method and apparatus according to the present invention can prevent the LNG plant from having a problem of freezing within a wide range of heavy hydrocarbon concentrations, thus providing operational flexibility for the plant in handling uncertain gas composition or changes in gas composition .

Also, in the method and apparatus of the present invention, the load on the adsorbent bed of the TSA (or other adsorption) system is reduced due to the fact that some of the heavier hydrocarbons are removed in the gas-liquid separation system, 600 < 0 > F, 232-315 < 0 > C) during the regeneration of the TSA system, the breakage can otherwise disarm the bed.

In the method and apparatus of the present invention, the adsorption system and the gas-liquid separation system are continuously used to remove heavy hydrocarbons from the natural gas stream by treating the natural gas stream.

The adsorption system may be located downstream of the gas-liquid separation system so that the gas-liquid separation system removes most of the heavy hydrocarbons and controls the amount of heavy hydrocarbons at the inlet of the adsorption system, The remaining hydrocarbons are removed to the extent necessary or acceptable to prevent subsequent freezing.

Alternatively, the adsorption system can be operated to remove the majority of the heavy hydrocarbons from the adsorption system, and the gas-liquid separation system can remove the gas-liquid May be disposed upstream of the separation system. The composition of the natural gas stream for the gas-liquid separation system is controlled by the adsorption system design and capacity in this case.

The adsorption system and the gas-liquid separation system may be installed as a front-end hydrocarbon removal unit that processes the natural gas stream before the natural gas stream enters the individual liquefaction unit. Alternatively, the adsorption system and the gas-liquid separation system can be integrated into the liquefaction unit.

Typically (and in part depending on various factors such as the starting temperature of the natural gas stream and whether the gas-liquid separation system is upstream or downstream of the adsorption system), the gas-liquid separation system is fed into the gas- Lt; RTI ID = 0.0 > partially < / RTI > As will be discussed in further detail below, this cooling may be accomplished by any suitable means, including but not limited to: cooling provided through the Joule-Thomson effect (i.e., through constant enthalpy expansion of the gas stream or mainly constant enthalpy expansion); Cooling of the gas stream through indirect heat exchange within the portion of the natural gas liquefier; Indirect heat exchange in other heat exchangers (cooling of gas streams through different process gases and / or for individual coolants such as mixed coolant); Or addition of LNG for cooling through direct heat exchange to the gas stream.

By way of example only, various preferred embodiments of the present invention will be described with reference to the accompanying drawings. The first group is represented in FIGS. 1A-1F, the second group is represented in FIGS. 2A-2D, and the third group is represented in FIGS. 3A-3D. In the drawings, if a given feature is common to two or more views, the feature is designated with the same reference numeral in each figure for clarity and brevity.

≪ RTI ID = 0.0 &

In the first group of embodiments shown in Figures la-1f, the gas-liquid separation system processes a natural gas feed stream (the subject of heavy hydrocarbon removal) so that the gas-liquid separation system produces a medium hydrocarbon reduced natural gas stream The adsorption system is located upstream of the adsorption system to process at least a portion of the mid-hydrocarbon reduced natural gas stream produced from the gas-liquid separation system to produce the desired natural gas stream where the heavy hydrocarbons are lean.

More specifically, in the first group of embodiments, the natural gas stream is cooled in an economizer heat exchanger and then introduced into a gas-liquid separation system, separated into a heavy hydrocarbons reducing natural gas stream and a heavy hydrocarbon rich liquid stream do. Heavy hydrocarbons abatement natural gas stays are then heated in the economizer heat exchanger through indirect heat exchange with natural gas feed streams. Subsequently, the thus obtained warmed hydrocarbon-reduced natural gas gaseous stream or a portion thereof is passed through at least one bed of the adsorption system to adsorb the medium hydrocarbons and thereby further reduce the concentration of heavy hydrocarbons in the gaseous stream or a portion thereof To obtain the desired natural gas stream in which the heavier hydrocarbons are lean).

Referring now to FIG. 1A, there is illustrated a specific embodiment in which a stripping column and a temperature swing adsorption system are continuously used to remove heavy hydrocarbons from natural gas feed streams. The natural gas feed stream 100 having a high methane content is passed through the economizer heat exchanger 10 where the natural gas feed stream is passed indirectly to the heavy hydrocarbon reduced natural gas stream 104, Cooled through heat exchange. Thereafter, the cooled natural gas feed stream 101 is further cooled through pressure reduction through the Jou-Thomson (J-T) valve 20. The partially condensed natural gas feed stream 102, which has been further cooled, is then introduced into the strip calf 30.

The strip calf 30 may have any suitable design. As is well known in the art, condensed or partially condensed gasses (in this case partially condensed natural gas gasses) are introduced into the strip calves within the strip calves and contacted with the strip gases in the columns. The stream is introduced at a position higher than the position where the strip gas is introduced into the strip callee so that the descending flow of the liquid falling from the feed stream comes into contact with the strip gas of the rising stream in the opposite echo, Strip ". Typically, the strip calves are positioned between the position at which the feed stream is introduced and the position at which the strip gas is introduced and at the same time act to increase the degree and / or time of contact between the feed liquid and the strip gas stream, Or some other type of insert. ≪ RTI ID = 0.0 > [0002] < / RTI > Typically, there is no separation stage higher than the position at which the troughs are introduced into the strip collar.

In the embodiment shown in Figure 1A, a further cooled and partially condensed natural gas feed stream 102 is introduced into the top of the strip calf 30, the strip gas 109 is introduced into the bottom of the strip calf, Includes at least one separation stage located between the feed position of the stripping gas and the natural gas feed stream. The strip gas used in the strip calorie may be provided from any of a variety of different sources described in more detail with reference to Figure 1C, but in the particular embodiment shown in Figure < RTI ID = 0.0 & And natural gas stream 109 taken from natural gas feed stream 100 of natural gas.

The strip calob 30 separates the partially condensed natural gas stream 102 into a medium hydrocarbon reduced natural gas stream 104 recovered from the top of the strip calf and a middle hydrocarbon rich liquid 103 ). Alternatively, if it is desired to raise the temperature of the medium-rich hydrocarbon-rich liquid stream 103 or to reduce the methane content in the liquid stream, the temperature of the strip gas 109 entering the strip calor 30 may be increased by a heater (not shown) . ≪ / RTI >

The medium hydrocarbon reduced gas natural gas stream 104 recovered from the top of the strip calf 30 is then passed through the economizer heat exchanger 10 to recover the cooled state and cool the natural gas feed stream 100 . Thereafter, the warmed hydrocarbon-reduced natural gas stream 105 warmed from the economizer heat exchanger 10 is passed through one or more adsorbent (s) that is selective (i.e., preferentially adsorbs the heavy hydrocarbon component of the gas stream) to the heavy hydrocarbon component of the natural gas stream Bed to a temperature swing adsorption system 40 that includes a bed. If multiple beds are present, these beds may be arranged in parallel and / or in series. Heavy hydrocarbon-depleted natural gas stream 105 passes through at least one of the beds to lower the concentration of heavy hydrocarbons in the gas stream (to an acceptable level) and provides the desired medium hydrocarbon-lean natural gas stream 107 do.

Thereafter, the heavier hydrocarbon-lean natural gas stream 107 is fed to the natural gas liquefaction system 90 as a natural gas feed 107 and liquefied to provide the LNG gas stream 110. The heavy hydrocarbons adsorbed by the adsorbent (s) can subsequently be removed at the adsorbent regeneration stage (not shown in FIG. 1A).

Referring now to FIG. 1B, as an alternative embodiment, a partially condensed natural gas feed stream 102 (instead of the strip calves used in the embodiment shown in FIG. 1A) Hydrocarbon-reduced natural gas 104 recovered from the top of the vessel and the medium-rich hydrocarbon liquid 103 recovered from the bottom of the vessel.

As is known in the art, the phase separator may be separated (e.g., via gravity) from the liquid phase to a substantial portion of the gaseous phase without contacting the partially condensed feed stream with any additional strip gas or countercurrent stream, It differs from the strip calf in that it is acceptable. Thus, in comparison with the strip calf 30 of FIG. 1A, the phase separator 31 of FIG. 1B is created without separation stages (i.e., trays or packings to improve mass transfer between streams that are in opposite directions) No strip gas is supplied. Compared with the embodiment shown in FIG. 1A, the embodiment of FIG. 1B has the advantage of lower capital cost, but has the disadvantage that more methane is lost in the heavy hydrocarbon rich liquid stream 103.

As described above, the embodiment shown in FIG. 1A (and FIG. 1B) provides additional cooling to partially condense natural gas feed stream 102 to strip calf 30 (or phase separator 31) The cooling added to that provided by the economizer heat exchanger 10). However, other options are additionally or alternatively available. As also noted above and as noted above, this case may be used as a strip gas for the strip calorie 30 instead of or in addition to using the natural gas 109 taken from the natural gas feed stream 100 upstream of the economizer heat exchanger 10, In addition to use, other sources of strip gas may be used. These modifications are further illustrated in Fig. 1C.

1C, additional cooling for partial condensation of the natural gas feed stream 102 relative to the strip calf 30 may be accomplished by cooling the natural gas stream exiting the economizer heat exchanger 10, May be provided by another strip that is cooler than torrents 101. For example, natural gas streams can be cooled by indirect heat exchange with coolant streams 130, 131, such as mixed refrigerant streams in heat exchanger 21. This heat exchanger may be arranged as a unit separate from the economizer heat exchanger 10 unit and the natural gas liquefier 90 unit as shown in Fig. 1C, or may be arranged as a single unit between the economizer heat exchanger 10 and the natural gas liquefier (90), or both. Alternatively or additionally, the natural gas stream can be cooled by direct heat exchange, for example by direct injection of the cold stream into the natural gas stream 101, 102. In the case of direct injection, the cold stream 133 is itself obtainable from the stream 132 which is further cooled through the pressure drop through the J-T valve 82. A suitable source of the cooling streams 132, 133 for direct injection into the natural gas feed stream may be a portion of the LNG obtained from the liquefier 90, for example, in a liquid pump (not shown).

1C, in another embodiment, the strip gas 129 supplied to the strip calorif 30 may include: natural gas upstream of the economizer heat exchanger 10 (already described in connection with FIG. 1A) A natural gas stream 109 taken from the feed stream 100; A portion 119 of the hydrocarbon-reduced natural gas stream warmed from the inocomether heat exchanger 10; Or a portion 108 of a mid-hydrocarbon-lean natural gas stream 106 generated from the temperature swing adsorption system 40 (in this case, only a portion 107 of the hydrocarbon-lean natural gas stream is liquefied for liquefaction, (Which may be referred to as " a "). When a portion of the heavy hydrocarbon reduced natural gas stream 119 and / or a portion 108 of the heavier hydrocarbon diluted natural gas stream 106 is used as the strip gas 129, they are first used as the strip gas 129 It may be necessary to be compressed in the compressor 75 beforehand. Preferably, the stripping gas (or at least a portion of the stripping gas) is natural gas 109 taken from the flue gas stream 100 because the natural gas feed stream is typically at a pressure higher than the pressure at the bottom of the strip cake So that the natural gas taken from the feed stream will typically not require any compression to be used as the strip gas.

1D and 1E, it is also possible to recover some of the gas produced during the regeneration of the bed or beds of the adsorption system 10 via the strip caloric, in the embodiment in which the strip calorif 30 is used. As illustrated in Figures 1d and 1e, the adsorption system may comprise, for example, two or more side by side beds 40A, 40B, one of the beds 40A undergoing an adsorption step, While other hydrocarbons are adsorbed from the gas stream 105, the other hydrocarbons are regenerated and the regeneration gas passes through the bed during the regeneration step to assist desorption and removal of the adsorbed medium hydrocarbon from the adsorption step (The temperature of the bed during the regeneration step is higher than the temperature of the bed during the adsorption step).

The regeneration gas passing through the bed 40B undergoing the regeneration step may comprise a portion 120 of the medium hydrocarbon lean natural gas 106 obtained, for example, from the outlet of the bed 10A undergoing the adsorption step. Alternatively or additionally, the regeneration gas can be obtained, for example, from the treatment or storage of the LNG gas stream 110 in the LNG storage facility 91, and is primarily compressed within the compressor 92, -off) gas stream < RTI ID = 0.0 > 111. < / RTI > As illustrated in FIG. 1D, the compressed flash or vapor gas may additionally or alternatively be used as all or part of the strip gas 112 used in the strip calorie 30, It should be understood that it can be used as an alternative to any and all of the sources of the strip gas, additionally or in combination, as described above.

The gas stream of the desorbed gas 121 exiting the bed 40B or beds of the adsorption system during regeneration, which typically has a pressure lower than the pressure of the natural gas feed stream 102 fed to the strip calorie 30, Can be partially condensed after being cooled in cooler 60 and phase separated into liquid condensate 124 and natural gas vapor stream 125 containing most of the heavy hydrocarbons in phase separator 70.

1D, the recovered natural gas gaseous stream 125 is recompressed in the compressor 50 and cooled in the additional cooler 80 and then fed into the strip calorie 30 as a natural gas feed stream 102) to provide another additional or alternative source of stripping gas. The cooler 80 following the compressor 50 is optional and can be used to control the temperature of the recovered natural gas stream 125 entering the strip calorie. Alternatively, as shown in FIG. 1E, the recovered natural gas gas stream 125 can be recovered, for example, by recirculation to the natural gas feed stream 100 upstream of the feed gas boost compressor 51. Between the feed gas boost compressor 51 and the economizer heat exchanger 10 there may be various equipment (designated as unit 55 as a whole) such as a dryer, a cooler, and the like.

Although Figures 1d and 1e represent only two parallel adsorbent beds 40A and 40B, this is only for brevity and in practice the methods shown in these figures are performed using a single or multiple adsorbent beds in parallel or successive .

The above-described methods and apparatus in which the bed (s) of the TSA system are regenerated using a flash gas obtained from an LNG gas stream or a gas comprising an evaporation gas are likewise different from regenerative adsorption systems (e.g., PSA systems) It should also be noted that the present invention can be applied to a method and apparatus for removing heavy hydrocarbons from a natural gas feed stream using the adsorption system alone (i.e., without combining with a gas-liquid separation system) or with any other system.

1F, the strip calf 30 is divided into two parts, i.e., a separation stage (both of which are natural gas tanks 101 ) Is present, as shown in Figure < RTI ID = 0.0 > 1, < / RTI >

It is also possible to use a reboiler 90 at the bottom of the column to reboil a portion of the heavy hydrocarbon rich liquid stream 103 obtained from the bottom of the strip calf, Another additional source of strip gas may be provided, which is then reintroduced to the bottom as strip gas. The heat source for reheating may be steam, hot oil, power, or any stream that is hotter than the desired gas temperature returning to the column. Such use of this reheater can equally be applied to any of the preceding embodiments in which strip calves are used.

2a-2d

In the second group of embodiments shown in Figures 2a-2d, the gas-liquid separation system processes a natural gas feed stream (the subject of heavy hydrocarbon removal) so that the gas-liquid separation system produces a medium hydrocarbon reduced natural gas stream The adsorption system is likewise located upstream of the adsorption system so as to treat at least a portion of the medium hydrocarbon-reduced natural gas stream produced from the gas-liquid separation system to produce the desired medium hydrocarbon-lean natural gas stream. However, in comparison with the first group of embodiments (shown in Figures la-1f), the second group of embodiments (as shown in Figures 2a-2d) are used to cool the natural gas feed stream supplied to the gas- The way in which the mid-hydrocarbon reduced natural gas stream from the gas-liquid separation system is warmed up is different.

More specifically, in the second group of examples, the natural gas feed streams are again introduced into the gas-liquid separation system and separated into a medium hydrocarbon reduced natural gas vapor stream and a heavy hydrocarbon rich liquid stream, and a heavy hydrocarbon reduced natural gas vapor stream Or a portion thereof, passes through at least one bed of the adsorption system from which the heavy hydrocarbons are adsorbed to further reduce the concentration of heavy hydrocarbons in the gas stream (thus obtaining the desired natural gas stream in which the heavier hydrocarbons are lean). However, in the second group of examples, the heavy hydrocarbon-reduced natural gas gaseous stream may be separated from at least a portion of the medium hydrocarbon-lean natural gas obtained from the adsorption system prior to passing the gas stream or a portion thereof through at least one bed of the adsorber system (And thus at least a portion of the heavy hydrocarbon-lean natural gas stream is also cooled in the economizer heat exchanger to provide a medium hydrocarbon-lean cooled natural gas stream).

In the second group of examples, the recovered cooling from the medium hydrocarbon reduced natural gas stream is transferred to at least a portion of the heavy hydrocarbon-lean natural gas stream in the economizer heat exchanger (as in the first group of embodiments) Due to the fact, in the second group of embodiments, a natural gas stream with a lower hydrocarbon concentration and a lower temperature (compared to the heavy hydrocarbon lean natural gas stream obtained in the first group of embodiments) is obtained, In order to "replace" the cooling that was being supplied to the natural gas stream by the economizer heat exchanger in the example, it is necessary to cool the other source for the natural gas stream.

Thus, compared to the first group of embodiments (in which the heavy-hydrocarbon-lean natural gas stream is introduced into the hot end of the natural gas liquefier and recovered from the cold end of the liquefier as the preferred case), the second group of embodiments Is cooled by being introduced into the hot end of the natural gas liquefier and recovered from the intermediate position of the liquefier before the natural gas feed stream is introduced into the gas-liquid separation system, and the heavy hydrocarbon lean cooling from the economizer heat exchanger The natural gas stream is introduced into the middle position of the liquefier and is recovered from the cold end of the liquefier.

Referring now to FIG. 2A, a methane-rich natural gas feed stream 100, 201 is introduced into the hot end of the natural gas liquefier 90 and cooled in a warm stage of the liquefier, ) Is recovered from the intermediate position (i.e., the position between the two cooling stages of the liquefier, that is, neither the high temperature end of the liquefier nor the low temperature end). This cooled natural gas stream 202 exiting the middle position of the liquefier 90 may be a partially condensed stream (i.e., it may be partially condensed after being cooled in the warm stage of the liquefier). Alternatively, the natural gas stream 202 exiting the middle position of the liquefier 90 may be pressurized (e.g., using a JT valve, not shown) to further cool and partially condense the natural gas stream 202 Lt; / RTI >

In Figures 2a-2d, the liquefier is represented as a single unit with two cooling stages. For example, if the liquefier is a coil-wound heat exchanger, the liquefier may include two bundles each representing a cooling stage. However, in an equivalent case, the liquefier may include more cooling stages, and instead of all of the stages being contained within a single unit, the liquefier may comprise two or more units arranged in series and a cooling stage distributed between the units have.

The cooled and partially condensed natural gas stream 202 is then introduced into the upper portion of the strip calf 30 where it is recovered from the top of the strip calf as in the embodiment described above with respect to Figure 1a, (204) and a medium hydrocarbon rich liquid (203) that is removed from the bottom of the strip calybdenum. The strip gas 209 is likewise introduced into the strip calf at its bottom, and the strip calf may likewise include at least one separating stage for separating the feed position of the strip gas and the natural gas feed.

The medium hydrocarbon reduced natural gas stream 204 recovered from the top of the strip calf 30 is then passed through the economizer heat exchanger 10 to recover cooling therefrom. Typically, the economizer heat exchanger 10 warms the heavy hydrocarbon reduced natural gas stream 204 to a temperature of (0-40 < 0 > C).

Thereafter, the warmed hydrocarbon-depleted natural gas stream 205 from the economizer heat exchanger 10 is sent to a temperature swing adsorption system 40, which is also a selective one for the heavy hydrocarbon components of the natural gas stream Of the adsorbent bed and the heavy hydrocarbon reduced natural gas stream 205 passes through at least one bed of the bed so that the concentration of heavy hydrocarbons in the gas stream is further reduced to an acceptable level If the adsorption system 40 comprises a plurality of beds, these beds may be arranged in series and / or side by side, and the adsorbent (s) The adsorbed heavy hydrocarbons can then be removed at the adsorbent regeneration step (not shown in the figure).

The heavier hydrocarbon-lean natural gas stream 206 obtained from the outlet of the adsorption system 40 is then passed into the economizer heat exchanger 10 where it is cooled through indirect heat exchange with the heavy hydrocarbon reduced natural gas stream 204, The cooling is recovered as described above. Thereafter, the mid-hydrocarbon lean cooling natural gas stream 208 from the economizer heat exchanger 10 is introduced into the neutral position of the natural gas liquefier 90 to provide the LNG gas stream 110 recovered from the cold end of the liquefier, The cooled and partially condensed natural gas stream 202 is returned to an intermediate position that is the same as the intermediate position where it is recovered, cooled and liquefied in the cooling stage (or the lower temperature stage) of the liquefier.

Referring now to FIG. 2B, as an alternative embodiment, a partially condensed natural gas feed stream 202 may be separated from the phase separation vessel 31 using phase separator 31 (instead of the strip calorie used in the embodiment shown in FIG. 2A) Hydrocarbon-reduced natural gas 204 recovered from the top of the phase separation vessel and a medium-rich hydrocarbon-rich liquid 203 recovered from the bottom of the phase separation vessel. As described above with respect to the operation of the phase separator shown in FIG. 1B, the strip gas is not produced or used in this embodiment because the phase separator 31 does not include any separation stages or uses strip gas. Compared with the embodiment shown in FIG. 2A, the embodiment of FIG. 2B has the advantage of lower capital cost, but also has the disadvantage that more methane is lost in the heavy hydrocarbon rich liquid stream 203.

Similar to the various embodiments of the first group of embodiments shown in FIGS. ≪ RTI ID = 0.0 > 1A-1F, < / RTI > for the second group of embodiments in which the strip calorif 30 is used, It is also possible to recover some of the gas produced during the regeneration of the beds or beds of the adsorption system 40 through the strip calves. These modifications are further illustrated in Figures 2C and 2D.

2C, the strip gas (or at least a portion thereof) supplied to the strip calorie 30 is supplied to the natural gas stream 209 taken from the natural gas feed stream upstream of the liquefier 90 ), But various additional and / or alternative sources are possible. For example, the strip gas may additionally or alternatively include: a portion 209 of a heavy hydrocarbon reduced warmed natural gas stream obtained from the economizer heat exchanger 10; A portion 208 of the mid-hydrocarbon-lean natural gas stream 206 obtained from the temperature swing adsorption system 40 (only a portion 107 of the hydrocarbon-lean natural gas stream 106 in this case is subsequently introduced into the economizer heat exchanger 10) Cooled and sent to liquefier 90 for liquefaction); Or flash or evaporative gases 111, 112 obtained, for example, from the treatment or storage of LNG gas streams 110 in the LNG storage facility 91; ≪ / RTI > A further / alternative source of such a strip gas will typically require compression (e.g., at compressor 75 or 92 as shown in Figure 2C) before it is used as stripping gas.

Referring to Figures 2c and 2d, the adsorption system comprises one, two or more beds 40A, 40B arranged and operated in any of the manners, for example, as described above with reference to Figures la-1f , The regeneration gas is passed through the bed during the regeneration of the bed and some of the gas produced during regeneration of the bed or beds is recovered through the strip calyc. Specifically, the regeneration gas may include a portion 120 of the medium-lean lean natural gas stream 106 or a stream of flash gas or vapor stream 111 obtained from the outlet of the bed 40A undergoing the adsorption step. The desorbed gas stream 121 exiting the regenerating beds or beds may then be cooled in the cooler 60 to be partially condensed and the liquid condensate 124 (FIG. 1) containing most of the heavy hydrocarbons in the phase separator 70 ) And the natural gas stream 125.

As illustrated in Figure 2C, the recovered natural gas gaseous stream 125 is then recompressed in the compressor 50 and cooled in the additional cooler 80 before being introduced into the strip calorie 30, ) To provide another additional or alternative source of stripping gas. The cooler following the compressor 50 is optional and can be used to control the temperature of the recovered natural gas stream 125 entering the strip calipers. Alternatively, as shown in FIG. 2 (d), the recovered natural gas gas stream 125 can be recovered, for example, by recirculation to the natural gas feed stream 100 upstream of the feed gas boost compressor 51. Between the feed gas boost compressor 51 and the economizer heat exchanger 10 there may be various equipment (designated as unit 55 as a whole) such as a dryer, a cooler, and the like.

Figures 3a-3d

In the third group of examples shown in Figures 3a-3d, the adsorption system treats the natural gas feed stream (which is the target of heavy hydrocarbon removal) so that the adsorption system produces a heavy hydrocarbon reduced natural gas stream and the gas- Is disposed upstream of the gas-liquid separation system to process at least a portion of the medium hydrocarbon-reduced natural gas stream generated from the adsorption system to produce the desired natural gas stream with the hydrocarbon lean.

More specifically, in a third group of embodiments, the natural gas feed stream passes through one or more beds of the adsorption system, from which the heavy hydrocarbons are adsorbed, resulting in a medium hydrocarbon reduced natural gas stream. The heavy hydrocarbon reduced natural gas stream is introduced into the gas-liquid separation system after at least a portion of the cooling has been completed to provide a natural gas stream with a reduced hydrocarbons (thereby providing a desired natural gas stream with a low content of medium carbon monoxide) Rich hydrocarbons. Preferably, in the natural gas liquefier, the heavy hydrocarbon reduced natural gas stream or a portion thereof is cooled, the heavy hydrocarbon diluted natural gas stream is liquefied, and the heavy hydrocarbon reduced natural gas stream or a portion thereof is introduced into the hot end of the liquefier Recovered from the intermediate position of the liquefier, and the heavy hydrocarbon-lean natural gas stream is introduced into the middle position of the liquefier and recovered from the low-temperature end of the liquefier.

In the third group of embodiments, the beds of the adsorption system should be larger than the beds of the adsorption systems of the first and second group of embodiments (shown in Figs. 1a-1f and 2a-2d) In the case of the embodiment, the gas-liquid separation system removes most of the heavy hydrocarbons in the natural gas feed stream. In other words, for the same size adsorbent beds, the method and apparatus according to the first and second group of embodiments (shown in Figs. 1a-1f and 2a-2d) can provide a higher concentration of heavy hydrocarbons To provide better operational flexibility if the natural gas source changes or the concentration of heavy hydrocarbons fluctuates widely. The smaller adsorption beds used in the first and second group of embodiments means that these embodiments have low requirements for the use of the regeneration gas and low power costs associated with the feed gas compression. However, the third group of embodiments (as shown in Figs. 3a-3d) do not require an economizer heat exchanger for recovery of the cooling from the gaseous stream obtained from the gas-liquid separation column, thus providing savings in terms of capital cost .

Referring to FIG. 3A, in one embodiment, a high methane feed stream 100 is introduced into an adsorption system 40 that includes one or more beds of adsorbent selective for heavy hydrocarbon components of a natural gas stream, , And the natural gas feed stream (100) passes through at least one of the beds to adsorb heavy hydrocarbons thereby producing a heavy hydrocarbon reduced natural gas stream (301). 1 and 2, if the adsorption system 40 comprises a plurality of beds, these beds may be arranged in series and / or side by side and likewise adsorbed by the adsorbent (s) Heavy hydrocarbons can subsequently be removed at the adsorbent regeneration stage (not shown in Figure 3A).

Thereafter, at least a portion of the heavy hydrocarbon-reduced natural gas stream 301 is introduced into the hot end of the natural gas liquefier 90 and cooled in the warm stage of the liquefier, cooled from the intermediate position of the liquefier, (303). This cooled gas stream 303 from the intermediate position of the liquefier 90 can be a partially condensed stream (i.e., cooled and partially condensed in the warm stage of the liquefier). Alternatively, the cooled stream 303 exiting the middle position of the liquefier 90 may be reduced in pressure to further cool and partially condense the stream (e.g., using a unshown J-T valve). Similarly, although the liquefier is represented as a single unit with two cooling stages in Figs. 3a-3d, in an equivalent case the liquefier may include more cooling stages, the liquefier may be arranged continuously and the cooling stages may be distributed ≪ / RTI >

The cooled and partially condensed medium hydrocarbon reduced natural gas stream 303 is introduced into the upper portion of the strip calorie 30 where it is recovered from the top of the strip calorie and the natural hydrocarbon gas stream 305 The gas stream is the desired natural gas stream with a medium carbon hydrogen sparse) and a medium hydrocarbon rich liquid 304 that is removed from the bottom of the strip calybdenum. The strip gas 209 is likewise introduced into the strip collar at its bottom, and the strip collar includes at least one separator stage for separating the feeding position of the strip gas and the natural gas feed stream. The strip gas can come from a variety of different sources, but in the embodiment shown in FIG. 3A: the remainder 302 is cooled in the natural gas liquefier 90 and taken from the medium hydrocarbon reduced natural gas stream 301 prior to partial condensation A portion (306) of heavier hydrocarbons reducing natural gas; And / or a natural gas stream 307 taken from the natural gas feed stream 100 prior to treatment in the adsorption system 40.

Thereafter, the heavier hydrocarbon-lean natural gas stream 305 obtained from the upper portion of the strip calorie 30 is fed to the intermediate position of the natural gas liquefier 90 (preferably the middle position of the natural gas liquefier 90) to provide the LNG gas stream 110 recovered from the low- To an intermediate position where the partially condensed medium-hydrogen-reduced natural gas stream 303 is recovered, which is cooled and liquefied in the cooling stage (or the lower temperature stage) of the liquefier.

In a third group of embodiments with the first and second group of embodiments, phase separators may be used instead of strip calories, which would reduce capital cost but increase the loss of methane in the medium hydrocarbon rich liquid stream 304 .

Thus, referring now to FIG. 3B, as an alternative embodiment, a partially condensed hydrocarbon-reduced natural gas stream 303, using phase separator 31 (instead of the strip calorie used in the embodiment shown in FIG. 3A) Separated from the upper portion of the phase separation vessel and separated into the natural gas stream 305 (the desired medium-lean hydrocarbon-lean natural gas stream) in which the heavy hydrocarbons are further reduced and the heavy hydrocarbon rich liquid 304 recovered from the bottom of the phase separation vessel do. As described above with respect to the operation of the phase separator shown in FIG. 1B, the strip gas is not produced or used in this embodiment because the phase separator 31 does not include any separation stages or uses strip gas.

Similar to the various embodiments of the first group shown in Figures 1d-1f, a third group of embodiments using the strip calorie 30 may be used to remove the gas (s) produced during regeneration of the beds or beds of the adsorption system 40 through the strip calorie It is also possible to recover a part of the image.

The desorbed gas stream 121 exiting the bed 40B or beds to be regenerated is then cooled in the cooler 60 and partially condensed to form a liquid condensate stream 124 containing a plurality of heavy hydrocarbons in the phase separator 70, And the natural gas stream 125.

3C and 3D, the adsorption system may comprise one, two or more beds 40A, 40B arranged and operated in any of the manners described above with reference to Figs. 1A-1F, Wherein regeneration gas is passed through the bed during regeneration of the bed and a portion of the gas produced during regeneration of the bed or beds is recovered through the strip calyc. Specifically, the regeneration gas may include a portion 320 of the medium hydrocarbon reduced natural gas stream 301, or a stream 111 of flash gas or vapor, obtained from the outlet of the bed 40A undergoing the adsorption step. The desorbed gas stream 321 exiting the bed 40B or beds to be regenerated can then be cooled and partially condensed in the cooler 60 and the liquid condensate containing most of the heavy hydrocarbons in the phase separator 70 (323) and the natural gas stream (324).

As illustrated in FIG. 3C, the recovered natural gas vapor stream 324 is then recompressed in the compressor 50 and cooled in the additional cooler 80 and then introduced into the strip calf 30, Can be reused by being reintroduced at a location below the substrate 303 to provide another additional or alternative source of strip gas 326. [ The cooler following compressor 50 is optional and can be used to control the temperature of the recovered natural gas stream 324 entering the strip calipers. The compressor 50 is also optional and may not be necessary if the adsorption system is regenerated at a pressure higher than the pressure at the bottom of the column. In a further variation, the phase separator 70 may be omitted so that the entire cooled desulfurized gas stream 321 exiting the cooler 60 is directed to the strip calyc. 3C, the strip calf 30 may include at least two separation stages such that there is a separation stage above and below the point where the recovered natural gas stream 324 enters the strip collar, Provision of strip gas to the strip calf 30 may be provided by using a reheater 95 at the bottom of the column to reheat a portion of the medium hydrocarbon rich liquid stream 304 obtained from the bottom of the strip calf.

Alternatively, as shown in FIG. 3D, the recovered natural gas gas stream 324 may be recycled to the natural gas feed stream 100 upstream of the feed gas boost compressor 51, for example. Between the feed gas boost compressor 51 and the economizer heat exchanger 10 there may be various equipment (designated as unit 55 as a whole) such as a dryer, a cooler, and the like. As also illustrated in FIG. 3D, flash gas or vapor may again or alternatively be used as the strip gas 112 for strip calorie 30. FIG.

Example

In order to illustrate the effect of using a TSA system and a gas-liquid separation system in combination to remove heavy hydrocarbons from a natural gas stream, in removing heavy hydrocarbons from a natural gas stream, FIGS. 1A, 1E, , The performance of the embodiment shown in Figures 2b, 2c, 3a, 3b, 3c and the performance of prior art processes (not according to the invention) using only scrub columns to remove heavy hydrocarbons from natural gas streams Respectively. The operating conditions used in the scrub column in the first run using the conventional (scrub column only) process can result in a risk of dry-out of the scrub column (and failure of the heavy hydrocarbons removal process). Therefore, a second run using a conventional (scrub column only) process was performed using different operating conditions (i.e., lower column temperature) to prevent any risk of dry-out of the column. Data for all runs, ie, data for both employing the embodiments of the present invention described above and employing the prior art process (using scrub column only), are provided by ASPEN ™ Plus software (© Aspen Technology, Inc.) The SIMPAC (internal adsorption smoothing tool SIMPAC) is a three-dimensional adsorption process simulator that takes into account multi-component adsorption isotherms, various mass transfer modes, multiple adsorbent beds, and general process drawings - more detail in Chemical Engineering Science Volume 49, Quot; Kumar et al., Pages 3115-3125).

The starting composition of the natural gas feedstocks used (in all cases the same) is given in Table 1 below, and each embodiment (i.e., Figures 1a, 1e, 2a, 2b, 2c, 3a, (From each of the examples shown in FIG. 3C) and a conventional stream obtained from a conventional (scrub column only) process (quantum run) (i.e., a natural gas stream that requires medium- Are given in Table 2 below. In Table 2, the first execution employing the prior art (scrub column only) process with the risk of dry-out of the scrub column is indicated by the "tray can be dry out" Scrub column only), the second execution employing the process is indicated as "no tray dry-out ".

Table 2 shows: the gas-liquid separation system operating conditions (i.e., the scrub column / strip calorie / temperature and pressure of the phase separator vessel); The flow rate of the natural gas stream fed into the gas-liquid separation system as the ratio of the flow rate of the heavy hydrocarbon-rich liquid obtained from the gas-liquid separation system (designated as LPG as% of Feed); Represents the total LNG flow rate (indicated in the table as "Relative LPG Production") generated by each run expressed as a percentage of the total LNG generation flow obtained in the first run using the prior art process. Referring to the data provided in Table 2, for example, 9.9E-01 in Table 2 refers to 9.9 ^{x 10 &lt}; 0 > ^_1 , or 0.99 since the alphabet E represents an exponent when used as part of a number, as is well known in the art.

As can be seen from the data in Table 2, embodiments in accordance with the present invention allow the gas-liquid separation system to operate at higher pressures and temperatures than the temperature and pressure of the scrub column in prior art processes Effective removal of heavy hydrocarbons from the NG gas stream and removal of excess LNG from the prior art (using the scrub column only) process, even under the prior art process conditions where the scrub column operates at a temperature that would cause dry out Lt; / RTI >

These results indicate that the relative LNG productivity (i.e., the total LNG flow produced by each run expressed as a percentage of the optimal total LNG generation flow obtained using prior art processes) is less than the LPG flow - the flow rate of the heavy hydrocarbon-rich liquid obtained from the gas-liquid separation system as a percentage of the flow rate of the natural gas stream fed to the liquid separation system). As also exemplified, embodiments according to the present invention provide improved LNG generation rates compared to prior art processes when performed under conditions that pose a risk of dry-out of the column, (I. E., High enough to be provided by operating the scrub column at a low temperature to increase the production of heavy hydrocarbon rich liquids < RTI ID = 0.0 > %).

Song River composition ingredient mol% nitrogen 7.0E-01 methane 9.6E + 01 ethane 2.8E + 00 Propane 4.8E-01 i-butane 5.0E-02 n-butane 8.5E-02 i-pentane 2.0E-02 n-pentane 2.2E-02 Cyclo-pentane 3.0E-05 n-hexane 3.2E-02 Cyclo-hexane 5.0E-05 Methyl-cyclohexane 4.0E-05 Heptane 2.9E-02 octane 3.3E-03 Nonan 1.1E-03 benzene 1.9E-03 toluene 3.4E-03

It is to be understood that the invention is not limited to the details of construction described above with reference to the preferred embodiments, but that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as defined in the following claims.

Claims (33)

A method for removing heavy hydrocarbons from a natural gas feed stream comprising:
Cooling the natural gas feed stream;
Introducing the cooled natural gas feed stream into a gas-liquid separation system, separating the cooled natural gas feed stream into a heavy hydrocarbons reducing natural gas gas stream and a heavy hydrocarbon rich liquid stream;
Heating the heavy hydrocarbon reduced natural gas stream;
Passing at least a portion of the warmed hydrocarbon-depleted natural gas stream over the at least one adsorbent bed of the adsorption system to adsorb heavy hydrocarbons from the heated hydrocarbon-depleted natural gas stream so as to produce a heavy hydrocarbon-lean natural gas stream ; And
Cooling at least a portion of the heavy hydrocarbon-lean natural gas stream to produce a cooled medium-lean lean natural gas stream
Wherein in the economizer heat exchanger, the heavy hydrocarbon reduced natural gas gaseous stream is warmed up through intermittent heat exchange between the heavy hydrocarbon reduced natural gas gaseous stream and at least a portion of the heavy hydrocarbon-lean natural gas stream And at least a portion of said heavy hydrocarbon-lean natural gas stream is cooled. The method of claim 1, wherein the gas-liquid separation system comprises a strip column or phase separator. The method of claim 1 or 2, further comprising the step of liquefying at least a portion of the cooled medium-lean hydrocarbon-lean natural gas stream to produce a liquefied natural gas stream, Lt; RTI ID = 0.0 > natural gas feed stream. ≪ / RTI > 4. The method of claim 3, wherein the natural gas feed stream is cooled and at least a portion of the cooled medium hydrocarbon-lean natural gas stream is liquefied in a liquefier, the natural gas feed stream is introduced into a hot end of the liquefier Wherein at least a portion of the cooled medium-lean lean natural gas stream is withdrawn from an intermediate position of the liquefier and is withdrawn from the cold end of the liquefier and introduced into an intermediate position of the liquefier, Removal method. 3. The method of claim 1 or 2, wherein the gas-liquid separation system is a strip column, the method comprising introducing strip gas into the strip column at a location below the location where the cooled natural gas feed stream is introduced into the strip column Further comprising the step of removing the heavy hydrocarbons from the natural gas feed stream. 6. The method of claim 5, wherein the strip gas comprises: natural gas taken from a natural gas feed stream prior to being cooled and introduced into the strip column; A portion of said heavy hydrocarbon-lean natural gas stream not cooled in said economizer heat exchanger; A portion of said heavy hydrocarbon reduced natural gas stream warmed in said economizer heat exchanger; A gas obtained from re-burning all or part of the medium hydrocarbon rich liquid stream; And a flash or evaporation gas obtained from the liquefied gas. ≪ Desc / Clms Page number 20 > 3. The method of claim 1 or 2, wherein the adsorption system is a temperature swing adsorption system, wherein the method comprises passing a gas selected from flash or vaporized gas obtained from the partially hydrocarbons lean natural gas stream or liquefied natural gas, Further comprising regenerating the one or more beds of the temperature swing adsorption system by passing the bed through the bed, wherein the temperature of the one or more bed being regenerated comprises adsorbing heavy hydrocarbons from the heavy hydrocarbon abatement natural gas stream or a portion thereof Wherein the temperature of the at least one bed is greater than the temperature of the at least one bed. 8. The method of claim 7 wherein the method further comprises cooling the gas obtained from the at least one bed of the temperature swing adsorption system during the regeneration of the one or more beds and separating the gas phase into a liquid phase and a gas phase, And recycling the natural gas feed stream prior to introduction into the system. ≪ RTI ID = 0.0 > 18. < / RTI > 8. The method of claim 7 wherein the gas liquid separation system is a strip column and the method comprises cooling the gas obtained from the one or more beds of the temperature swing adsorption system during regeneration of the one or more beds and separating them into a liquid phase and a gas phase And introducing the gaseous phase as stripping gas into the strip column at a location below the location where the cooled natural gas feed stream is introduced into the strip column. ≪ RTI ID = 0.0 > Way. The natural gas feed stream according to claim 1 or 2, wherein the natural gas feed stream is lean aliphatic hydrocarbons having 3-5 carbon atoms in total or lean hydrocarbon aliphatic hydrocarbons having 2-5 carbon atoms in total, A method for removing heavy hydrocarbons from a feed stream. An apparatus for removing heavy hydrocarbons from natural gas feed streams and producing liquefied natural gas streams comprising:
A gas-liquid separation system for receiving the natural gas feed stream and separating the natural gas feed stream into a heavy hydrocarbons-reduced natural gas stream and a heavy hydrocarbon rich liquid stream;
An adsorption system in fluid communication with the gas-liquid separation system to receive at least a portion of the heavy hydrocarbon reduced natural gas gaseous stream, the adsorbent system comprising a heavy hydrocarbon An adsorption system comprising at least one adsorbent bed to produce a lean natural gas stream;
Through indirect heat exchange between the heavy hydrocarbon reduced natural gas stream and the at least a portion of the heavy hydrocarbon-lean natural gas stream, passing the heavy hydrocarbon reduced natural gas stream or a portion thereof through the one or more beds of the adsorber system An economizer heat exchanger for warming said heavy hydrocarbon reduced natural gas stream and cooling at least a portion of said heavy hydrocarbon-lean natural gas stream; And
At least a portion of the heavy hydrocarbon-lean natural gas stream is received to cool the natural gas feed stream prior to introduction of the natural gas feed stream into the gas-liquid separation system and to produce the liquefied natural gas stream Liquid separating system and a liquefier fluidly connected to the adsorption system, wherein the natural gas feed stream is introduced into the hot end of the liquefier and recovered from an intermediate position of the liquefier, the heavy hydrocarbons Wherein at least a portion of the lean natural gas stream is introduced into the intermediate position of the liquefier and is recovered from the cold end of the liquefier,
And removing the heavy hydrocarbons from the natural gas feed stream to produce a liquefied natural gas stream. 12. The apparatus of claim 11, wherein the gas-liquid separation system comprises a strip calorifier or phase separator. 12. The apparatus of claim 11, wherein the gas-liquid separation system comprises a strip calorifier or phase separator. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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