SA97180452B1 - REMOVAL OF AROMATICS AND/OR HEAVIES REMOVAL HYDROCARBONS FROM METHANE BASED FEED BY CONDENSATION AND STRIPPING - Google Patents

Abstract

Abstract: The present invention relates to a method and associated apparatus for extracting benzene, aromatics and/or hydrocarbons components heavier than a methane-based gas stream by a unique condensation and extraction (stripping) process utilizing the light temperature liquefaction of normally gaseous substances for purposes Separation, purification and storage of the components and to transport the aforementioned components in a more economical and suitable formula. Most of the aforementioned liquefaction systems have many common operations regardless of the gases related to that. Therefore, they have many of the same problems and one of the problems that we usually face in liquefaction operations, especially when aromatic compounds are present in the sedimentation or subsequent solidification of these species in the process equipment thereby decreasing efficiency and less dependence on the process Another common problem is the removal of small amounts of chemical species of higher value and higher molecular weight from the gaseous stream immediately prior to the liquefaction of the gas stream into a bulk section and accordingly we shall explain this invention Referring in particular to natural gas treatment but will be applicable to gas treatment in other systems where we encounter similar problems.

Description

Y _ — Aromatics and/or ALES heavies removal of hydrocarbons from a methane-based feed by condensation and stripping Full description BACKGROUND OF THE INVENTION A common procedure in the art of natural gas processing is Exposing the gas to low-temperature treatment to separate hydrocarbons with a molecular weight higher than methane Cot from natural gas lo produces pipeline gas that prevails in methane and the Cot stream is useful for other 0 purposes. Usually, the Cpt stream will be separated into single component streams, for example, Gg and Pa Win. Also, a common procedure is low-temperature treatment of natural gas to liquefy it for locking or storage. The primary reason for natural gas liquefaction is that it results from liquefaction in Reducing the size of about 1/00 to enable the storage and transportation of liquefied gas in containers with a more economical and practical design. For example, when transporting gas by pipeline from a supply source to a remote market, it is desirable to operate the pipeline under a load factor that has already been established. And high. Often the delivery capacity (or efficiency) or capacity of the pipeline will exceed the need while at other times it may exceed the delivery capacity of the pipeline. In order to strip off peaks where the need exceeds the resource, it is desirable to store the excess gas in such a way that it can be delivered when it exceeds 1 The resource is needed to enable future peaks to be met by means of storage. A practical way to do this is to convert the gas into a liquid solution for storage, and then volatilize the liquid as the solution requires. YEAS

Liquefaction and liquefaction of natural gas is of greater importance in enabling Ji gas from supply to market when the source and market are separated by great distances and the pipeline is not available or impractical and this is especially true where it must be completed Transportation by ocean-going tankers and transport by ship in the gaseous state is generally impractical because enormous pressure© is required for a huge specific volume reduction of the gas which in turn requires the use of more expensive storage containers. In order to store and transport natural gas, the liquid state, it is preferable to cool the natural gas to -7540 F to TT, where it has vapor pressure near atmospheric, and there are many systems in the previous art in order to liquefy the natural gas. Or the like, where 0 the gas is liquefied by a successive passage of the gas at high pressure through several cooling stages, where the gas is cooled to higher temperatures in succession until we reach the liquefaction temperature, and cooling is generally achieved by heat exchange with one or More refrigerants such as propane, propylene, ethane, ethylene, methane, or a combination of one or more of them.

B In the art, the refrigerants are arranged in a row in a cascade (sequential) way, and each refrigerant is used in a closed refrigeration cycle, and further cooling of the liquid is possible by expanding (single) natural gas 5L008p_liquefied to atmospheric pressure in one or more stages of expansion and in each stage The liquefied gas is flashed to a lower pressure, Le, which produces a two-phase gas-liquid mixture at a much lower temperature, and the liquid is recovered and may be flashed again.

Tr. In this way, the liquefied gas is cooled to a suitable storage or transportation temperature for storing liquefied gas at near-atmospheric pressure, and in this expansion to near-atmospheric pressure, some additional volumes YEAS

- go from liquefied gas is flashed and the flashed vapors from the expansion relay are generally collected and returned. Recycled for purification or used as fuel gas for power generation is the removal of natural gas and, as mentioned above, an important operational problem in the liquefaction of natural gas and other aromatic compounds from the natural gas stream benzene residual amounts (precipitated) of gasoline 080 8: Immediately before the liquefaction of the largest part of the aforementioned stream and the tendency of these components to precipitate, gas 1, and solidify, causing blockage and severe obliteration of the main pipes and equipment of the process. For example, this blockage can severely reduce the efficiency of heat transfer and out through heat exchangers, especially. Flat wing heat exchangers

Lalo benzene For technical and economic reasons, it is not necessary to remove impurities such as benzene, and in any case it is desirable to reduce its concentration and remove pollutants from natural gas. apart from the fact that the gas must be cooled to a lower temperature for liquefaction vs. separation; The basic refrigeration techniques are the same as those for liquefied benzene with the remaining polluted benzene. It is only necessary to cool the benzene gas and chapter 55 8 so in the field of benzene to a temperature at which part of the feed gas is condensed and may also be achieved. natural gas 10 (6 N gas recovered a le in a low-temperature separation column located at a suitable point in the condensate of the main gas stream, natural liquefied benzene) for the separation of benzene and in the field of operation The effective low-temperature separator column requires the use of low-temperature condensed liquid, which must be withdrawn from the column, for thermal exchange with A warm dry gas stream is supported to a 0 F low temperature separator column

D - In any case, the exchange plan, Jaa, is a problem resulting from the excessive difference in temperature of the two currents that are connected to the heat exchanger, and since the actual difference in temperature may exceed 100 F, the thermal shock to the heat exchanger may damage or shorten the life of use of the device. Heat exchanger designed from traditional materials. o Another consideration associated with efficient operation of a cryogenic separator is the provision of heat exchanger governors that allow automatic starting of the column. Hence, another problem in operating technical gas streams with methane is the lack of a cost-effective means of recovering the higher molecular weight hydrocarbons from the gas stream before liquefying the stream in a large section or returning the remaining stream to a pipeline or processing step. Other hydrocarbons with a weight of 1 up recovered generally have a greater value on a per unit basis than the remaining components in the gas stream. General description of the invention The object of the invention is to remove residual quantities of benzene and other aromatic components from a methane-based gas stream which is to be liquefied in a large portion. Another objective of the invention vo is to remove higher molecular weight hydrocarbons from auld methane gas stream Another objective of the invention is to remove higher molecular weight hydrocarbons from a methane based gas stream which must be liquefied in a section big . Another objective of the invention is to remove benzene and other aromatic components and/or hydrocarbons of higher molecular weight from a gas stream based on methane Y. in an energy efficient manner. YEA

A further object of this invention is a process used to remove benzene and other aromatic components and/or higher molecular weight hydrocarbons that is compatible in integration with technology routinely used in gas plants. Also, an object of this invention is a process and device used to remove benzene and another hydrocarbon component and/or hydrocarbon of 0 molecular weight Sle in a methane-based gas stream that is relatively simple, compact and cost-effective. Also, another object of this invention is the process used to remove benzene and other aromatic constituents (dfs) higher molecular weight hydrocarbons 5 from a methane-based gas stream that is liquefied in large part and that is compatible with and integrated in 0 technical Routinely used in plants that produce liquefied natural gas. Another object of this invention is to provide heat exchange controllers which overcome the aforementioned and other related problems in a low temperature fluid process. Another objective of the invention is to provide an improved control method which reduces primary equipment temperature requirements and heat exchange costs. vo A more specialized goal is to control heat exchange temperatures to allow a warm fluid stream to be cooled against a lower temperature fluid stream without introducing thermal shock to the heat exchange device. Another lian of this invention is to control the heat exchanger to facilitate the automatic start-up of the cryogenic shaft. 1 ¢ A 0

_ No —_— In one of the fields of the invention, benzene and/or other aromatic components are removed from a methane-based gas stream by a process that includes: -1 condensation of a large part of the methane-based gas stream (lie) directly from Before a step where most of the aforementioned gas stream is liquefied, providing a two-phase current.Ye Feeding the aforementioned two-phase stream to the upper section of a stripping column.*- Removing from the upper section of the aforementioned experiment column- Removing an aromatic depleted gas stream. ;- Removing from The lower section of the aforementioned stripping column- removal of a gas stream rich in aromatic component –-o contact by direct heat exchange an aromatic-rich liquid stream with a stripping gas stream rich in methane, resulting in an aromatic-carrying stream Bae and a stream 0 stripping gas, rich in methane, refrigerated. In another field of this invention, the hydrocarbons with the highest molecular weight in a methane-based gas stream are displaced and concentrated by a process that includes: 1- Condensation of a smaller part of the gas stream Which is based on methane to produce a two-phase stream. “- feeding the mentioned two-phase stream into the upper section of the stripping column. YEA

A —_ _ *- removed from the top section of said stripping column - removed the heavier Call Cana gas stream. ;- Removing the upper section of the aforementioned stripping column, removing the stream of liquid rich in heavy components. pad -© by indirect heat exchange: the liquid stream rich in heavy components with the Je oo stream rich in methane, Les methane, produces a stream of lise rich in heavy components, and the stream of stripping gas rich in methane, cooled methane. 1- Feeding the aforementioned methane-rich stripping gas stream to the lower section of the stripping column. In another field of this invention, the invention is a device that includes: la-1-0 where a small part of a methane-based gas stream is condensed to produce a two-phase stream. TY is an abstract column fed into it by a two-phase stream, from which a gas stream and a liquid stream are produced. Jae = F convective contains an indirect heat exchange device that provides indirect heat exchange 1_direct between a gas stream and a liquid stream resulting in a cooled gas stream and a heated liquid stream. ¢—a channel (delivery tube) connected to the upper section of the stripping column to remove the said vapor stream. 5- A delivery channel connected to the upper part of the stripping column to remove the aforementioned vapor stream. 1- A connecting channel between the stripping column and the heat exchanger for the flow of the aforementioned liquid stream. YEAS

“- A connection channel between the said heat exchanger and the said stripping column for the said refrigerant gas stream to flow. In another field of this invention, the foregoing and other objectives and advantages are achieved in controlling the heat exchange treatment of a low-temperature fluid and a warm fluid by providing a sub-channel for the warm fluid, whereby a control valve in the sub-channel is operated in response to the temperature ratio of the heat exchanger fluids 1 According to another area of the invention, automatic starting controllers incorporate a high selector for temporary selection of a temperature for the warm gas flow process that facilitates column start-up innovations and triggers the warm gas flow process in response to a desired temperature. LNG (Liquid Natural Gas) is a low all vo which illustrates the method and apparatus of this invention to remove benzene and other aromatic components and/or hydrocarbon types of high molecular weight from a methane-based gas stream . Figure ?: is an illustrative Amal diagram that shows in greater detail the method and device shown in Figure 1. YEA

11 - FIGURE ©: It is a layout of a hypothermic separating column and the associated adjusting device of this invention in order to maintain the required temperature ratio of the heat exchange fluids. Figure ¢: A schematic showing as in an example for a temporary selection of a temperature that will allow the automatic start-up of a low-temperature separating column. © Detailed Description: While this invention is in preferred fields applicable to: 1- The removal of benzene and/or aromatic components from a benzene-based gas stream, the greater part of which must be condensed. Removing the types of hydrocarbons with the highest molecular weight that are most beneficial from a methane-based gas stream, which must be condensed in the largest part of it. The technology can also be used on the qualitative recovery of these types of methane-based streams. (For example, the removal of natural gas liquids, benzene, and other aromatic components present a unique problem because of their relatively high melting point temperatures. For example, benzene containing 1 carbon atoms has a melting point of \o It has a value of ©, m and a boiling point of 0, h. And hexane - which contains 6 “carbon atoms, has a melting point of -10 m and a boiling point of 59 m. Therefore, when compared with other hydrocarbons, it has a similar molecular weight, benzene benzene and other aromatic compounds present a much greater problem for clogging of process equipment and tubing and aromatic compounds as used herein - are those compounds that have at least one benzene ring and as used herein are hydrocarbon species

11 - - Hydrocarbons with a higher molecular weight are those types of hydrocarbons that have a molecular weight greater than ethane, and this expression will be used here interchangeably with the expression heavy hydrocarbons. For the purposes of simplicity and clarity, the following design will be intended to use the processes of the invention and the associated device in the cryogenic cooling of a natural gas stream to produce liquefied natural gas, and in particular the following description will concentrate the removal of Me benzene and/or other aromatic species and / or higher molecular weight hydrocarbons (heavy hydrocarbons) in a liquefaction scheme where sequential cooling cycles are used. In any case, the usability of the invention processes and associated devices described herein is not limited to 0 AL system used Sequential refrigeration cycles or those having natural gas streams with the exception and associated processes and devices are usable for any refrigeration device where: (a) There are benzene and/or heavier aromatic components in the methane-based gas stream, concentrations that may clog process equipment, especially Heat exchangers used to condense said stream or ve (b) it is desirable for any reason to remove and recover higher molecular weight hydrocarbons from a methane-based gas stream. Natural gas stream liquefaction: low-temperature plants have a variety of forms, and the most efficient and effective of them is the cascade type operation in union with expansion type cooling as well, as LNG production methods include the preference of hydrocarbons with The larger molecular weight of methane, as the first part of it, the description of a low-temperature production plant separates LNG mouth

11- Explain effectively a similar plant for the removal of hydrocarbons (0:0) from the natural gas stream. In the preferred field that uses a cascade (serial) cooling system, the invention relates to the cascade cooling of a natural gas stream at a pressure of LE, for example, about 1.686 © 3, by cascade cooling of the 0 gas stream by passing through several propane cycles Jal all the ethane cycle ethane or ethylene (liu) multiphase and either: (i) a closed membrane cycle followed by a single or multiphase cycle for further cooling and pressure reduction to near atmospheric pressure or (ii) an open-end methane cycle which uses A part of the feed gas as a source of methane in which 0 includes a multi-phase individual (expansion) cycle for further cooling and lowering the pressure to close to atmospheric pressure and in the course of the cooling cycles the refrigerant (refrigerant) that has the highest boiling point is used and finally by a refrigerant for it Lower Boiling Point Pre-treatment steps provide removal of undesirable components such as acid gases mercaptans + mercury and moisture from the natural gas feed stream 0 connected to the operation site The composition of said gas stream may vary greatly and as used Here, a natural gas stream is any stream composed primarily of methane, which is Li in large proportion of a natural gas stream containing, for example, no less than 788 methane by volume, with the remainder being ethane and hydrocarbons. higher, nitrogen, carbon dioxide, and small amounts of other pollutants such as mercury « 0 | Hydrogen sulfide, mercaptans, and treatment steps may be YEA.

The primer separation steps are located either above the cooling cycles or below one of the pre-cooling stages in the primary cycle. The following is a non-exhaustive list of some of the available means which are immediately available to those skilled in the art and acid gases to a lesser extent the mercaptans are routinely removed by a 0 adsorption process using an ile amine-bearing solution and the said treatment step is generally performed above the cooling stage Used in the primary cycle A large portion of the water is routinely displaced as a liquid by the gas-liquid two-phase separation The following is gas compression and cooling above the primary cooling cycle as well as below the initial cooling stage In the primary cooling cycle Mercury is routinely displaced in liquid form by separating Two-phase gas-liquid by compression 0 Cooling above the initial refrigeration cycle as well as below the initial cooling stage in the primary refrigeration cycle Mercury is routinely removed through mercury-adsorbed bottoms Residual amounts of water and acid gases are removed routinely by using bottoms Appropriately selected adsorbents such as regenerative colloidal sieves and processes that use sorbent bottoms are generally located below the first cooling stage in the primary cooling cycle. vo and the resulting refrigerant stream is generally delivered to the ALY process at lle pressure or compressed to high pressure where the pressure is higher than 015506 3; Preferably around ©0001 to around BCI and better around Jeon 675 1 © 8 and more preferable around Ja Jove 5+0 and better around 801708 . The temperature of the stream is typically near the center to a slightly higher temperature that the representative To temperature range is 60 F to 1101 F . YEA

And 1 - As we noted before, the natural gas stream at this point is cooled in many cycles or steps and multi-stages (such as three) by means of heat exchange other than with many refrigerants, preferably three. The overall cooling efficiency of a cycle improves as the number of stages increases, but this increase in efficiency is accompanied by corresponding increases in capital cost and process complexity. It is preferable to pass the feed gas through an effective number of cooling stages, two, and preferably from Stl to four, and it is better to prefer three stages in the first closest cooling cycle, using a relatively boiling refrigerant Je, and this refrigerant is composed of a larger portion of propane «propylene propylene or mixtures thereof, and the best is propane, and it is preferable that the refrigerant consist of 0 propane mainly, and then the treated feed gas flows through an effective number of stages, two, preferably two to four, and the best is two to three in a close cooling cycle again in heat exchange with a refrigerant having a lower boiling point. And the aforementioned refrigerant is preferred to be in a greater proportion of ethane or mixtures thereof, and the best is ethylene. Separate cooling. In general, the natural gas feed stream will contain these quantities of Cp components, resulting in the formation of a rich liquid, Cot, in one or more stages, and this liquid is removed by the method of separating liquid gases. - Conventional liquids. In general, the successive cooling of natural gas at each stage is controlled to remove as much as possible of 0 cot hydrocarbons and hydrocarbons of small weight.

and 1 - higher than gas to produce a first gas stream that predominates in methane and a liquid stream that contains large amounts of ethane (GY) and fewer components. Say number of gas/liquid separators strategically located below cooling zones in order to remove technical fluid streams with Cpt ° components, exact locations and number of gas/liquid separators will depend on the number of operating variables Jie Cot installation Natural gas feed stream, BTU content required for final product, Cot component value for other uses, and other factors routinely considered by skilled in the art of operating Cpt plants for other uses, and other factors routinely considered By skilled in the art of operating LNG and gas plants.

1 Methane may be removed from the cyt hydrocarbon stream or streams by single stage flashing or fractionation column in the first case the Ses methane rich stream is re-compressed and used or it can be used as a fuel gas in the latter case. The methane-rich stream can be returned directly at compression to the liquefaction process and the Cr+ hydrocarbon stream or streams or the de-methane Cot hydrocarbon stream

methane 10 may be used as a fuel or may be further processed - eg by fractionation in one or more fractionation zones to produce single streams rich in specific chemical constituents eg © Ci (Cas Coy)

In the last stage of the second refrigeration cycle the gas stream is predominantly methane which is conditioned (i.e. liquefied) in large part and preferably entirely and one of the preferred areas to discuss more favorably in a next section is at the process site where the new process and associated equipment can be used from © In order to remove benzene and other aromatic components and/or heavier hydrocarbons. YEA

Z - 1” - The process pressure at this location is slightly lower than the feed gas pressure to the first stage of the first cycle. Then the liquefied natural gas stream is further cooled in a third step or cycle by one or two fields, and in one of the fields the liquefied natural gas stream is further cooled by indirect heat exchange by means of a third closed cooling cycle where the Sub-cooling of the ESA gas stream by passing through an effective number of stages, preferably two to four, and preferably three, where cooling is provided by a third refrigerant that has a lower boiling point than the refrigerant used in the second cycle, and it is preferable that the third refrigerant consist of A larger portion (majority) of methane and the better is methane predominant and in the second and preferred field that 0 uses an open methane refrigeration cycle the liquefied natural gas stream is sub-cooled by contact with the first flash gases in the methane economizer The main way to explain it. In the fourth cycle or step, the liquefied gas is further cooled by an individual and the flash gas is separated from the cooled liquid. In a method we explain, the removal of nitrogen from the system and the condensed product takes place either as part of this step or in a separate next step. That is a major factor that distinguishes the closed cycle from the closed cycle. Open cycle is the initial temperature of the liquefied stream before flashing to the nearest atmospheric pressure and the relevant quantities of flashing vapor at said flashing and flashing vapors are treated Where most of the flashing vapor is reused to methane compressors in an open cycle system, flashing vapor in a closed cycle system is used © Generally as fuel YEA

VS

With an open cycle or methane, and in the fourth cycle or step in any of the closed methane systems, the liquefied product is cooled by one, preferably two to four, and the best is three Joule-Thomson units. Expansions (individual), where each expansion is used, either individual valves followed by individual liquid gas product by means of a separating unit. stream and less vapor production during the flashing step will usually be less cost-effective in view of the increased capital and operating costs associated with a single unit in one of the fields used in the open cycle stream Additional cooling of the high-pressure liquefied product before flashing occurs is made possible hydraulic for the part of this stream by means of one or more hydraulic straighteners Jd flashing 0

Sal, then by means of indirect heat exchange using the aforementioned flash current to cool the high-pressure liquefied before flashing, then the flash is reused by returning to the open site. Methane is suitable based on considerations of temperature and pressure in the methane cycle. And when the liquid product Jalal to the fourth cycle is the joint pressure around 600

VEY 140,71 and the flashing pressures representing the three-stage flashing process are about BCA Ne in oma) (pounds per square inch) and in the open cycle system the flashing evaporation or BCA to explain and the flashing part in the expansion flashing step - is done nitrogen Separation step for nitrogen use as refrigerants in the third step or cycle mentioned above. In closed cycle systems the vapor from the flash phases may also be used as refrigerant Jd ov i.e. recycled or used as fuel and in either Open or closed cycle system YEA

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Yio having a temperature of 6 LN liquefied stream to near atmospheric pressure will produce a product of . +01 to the important nitrogen for the liquefied product there is an acceptable limit at the nitrogen B TU and to maintain the content of the output in the feed stream, the nitrogen 2 must be concentrated and removed at some point in the process and various techniques are available for this purpose at the skilled In the art and below we give examples and when cycle 1 is used in feeding normally lower than open nitrogen and methane concentration by removing a small bypass at the inlet of Loses nitrogen volume 7; Tartrogen removal is achieved by approximately 1. High pressure methane or outlet manhole at methane pressures of up to 1.0 v 7 in nitrogen and for closed cycle at nitrogen concentrations Feed gas and liquefied stream generally flashes from conditions to near atmospheric pressure in a single step 0 nitrogen is thus used usually by flashing barrels and nitrogen-bearing flashing fumes. Generally as fuel gas for gas turbines that direct (drive) compressors (a) that is at atmospheric pressure is directed towards storage when the concentration of NG (product of the cycle padi tg), to about 1 in the inlet feed gas By exposing the liquefied gas stream from an open nitrogen refrigeration cycle the third nitrogen 1 can be removed to a flashover step prior to the fourth refrigeration step. The flashing vapor will contain an acceptable significant concentration of nitrogen 8 and the following may be used as a fuel gas. A typical flashing pressure and when containing 3 086 Ee at such concentrations is at about nitrogen for nitrogen removal greater than about 1.0 A 7 g open cycle nitrogen feed stream is used to obtain a sufficient nitrogen concentration in which case a nitrogen ejection column or a closed flashing step may provide nitrogen removal. © and nitrogen stream producing a nitrogen-rich steam stream dus will be used from nitrogen nitrogen YEA

ya - - liquid and liquid field preferred which uses a nitrogen ejection column Lis nitrogen methane liquefied to high pressure to methane economizer methane is classified into first and second section and first section flashes to about 5060 CA 3 and fed The two-stage mixture as a feed stream to the nitrogen ejection column and the second section of the high-pressure liquefied methane stream is further cooled by flow through a methane economizer explained later as it flashes to CA 5000 and the resulting two-phase mixture or section is fed The liquid has - to the upper part of the column where it acts as reflux (return) currents. The nitrogen-rich steam stream produced from the top of the nitrogen ejection column will generally be used as fuel. The liquid stream produced from the bottom of the column is then fed to the first stage - of methane expansion. Cooling a cooler for natural gas liquefaction: ALY natural gas in a cascade process is to use one or more of Refrigerants, by transferring the heat energy from the natural gas stream to the refrigerant, and finally transferring the aforementioned heat energy to the medium. The stream is sequentially cooled to lower and lower temperatures. The liquefaction process uses various modes of cooling that include, but are not limited to (i) indirect heat exchange, (ii) evaporation, and (iii) reduction of expansion or pressure. and cools the material without actual physical contact between the cooling agent and the material to be cooled. To be cooled is a fin Adie » aluminum plate. It can be varied based on system needs and the type of heat exchanger chosen - hence - in the process of the invention a shell and tube heat exchanger will typically be used where the cooling work is in the case of Liquid and the material to be cooled is in a liquid state or where the coolant is in a gaseous fin state, where it will typically use a gas plate-fin 0 heat exchanger and the material to be cooled is in a liquid state and finally the boiler core heat exchanger will It is typically used where the substance to be cooled is liquid or gas and the coolant undergoes a change in . The phase from the liquid state to the gaseous state during substitution, and evaporative cooling refers to the cooling of the material by sublimation or evaporation of a part of the material while the system remains at constant pressure, and then during evaporation, part of the material evaporates, absorbing heat from -0 The part of the substance that remains in a liquid state and cools the liquid part. Finally, cooling by expansion or by decompression refers as an expression to the cooling that occurs when the pressure of a gas, liquid, or biphasic system is reduced by passing through a Joule-Thomson pressure reducing device. In one field, the individual means is an expansion valve, or gaseous, and now hydraulic, and in one of the fields, the individual means is a hydraulic expander yo the expanders recover the work energy from the expansion process, so lower temperatures for the process are possible. When expanding (individual) and in the discussion and figures that follow it, the discussions or figures may explain the expansion of the coolant by flow through a throttle valve followed by a subsequent separation of the gas and liquid sections in coolers or condensers - indirect cooling and while this arrangement is heat exchange Whatever the case - where the heat exchange takes place » Simplified is feasible and sometimes referred to because of cost and simplicity, it may be more effective

EV

Expanding, separating, and then partially evaporating as separate steps, for example, combining throttling valves and barrels in coolers or condensers, and in another field subject to heat exchange. Flashing before the heat exchange of the procedure, the throttling or expanding valve may not be a separate part, but an integral part of it. The refrigerant or the condenser (i.e. the flash is present when the liquid refrigerant enters the refrigeration unit. In a similar way, the cooling of various streams for a specific refrigeration stage may occur within a single vessel (i.e. a refrigeration unit) or 0 within multiple refrigeration vessels. For equipment In the Jd cycle, the first is generally preferred from the point of view of the head costs of cooling the first. Cooling is provided by compression of a gaseous refrigerant with a higher boiling point, preferably to pressure, as it can be liquefied by indirect thermal conversion by propane. A heat-reducing medium that is ultimately used as a heat sink and the heat sink is 0 condensed from one or more of the individual cooling steps by means of an appropriate expansion method, resulting in two-phase mixtures with very lower temperatures, and in one of the fields the main stream is characterized Preferably two to four streams and preferably three streams where BY is made into two separate streams on single each stream separately to a specified pressure and each stream then provides evaporative cooling by indirect heat transfer with one or more of the selected streams and one or more of the stream is a natural Ne gas to be liquefied and the number of separate refrigerant streams will correspond to the number of refrigerant compressor fields and the evaporated refrigerant from each of the dependent streams is then returned to the appropriate stage at the refrigerated compressor (eg two separate streams will meet a refrigerated compressor Dual (stages) and in a better field to provide tue, all the liquefied refrigerant is unrolled to a predetermined pressure and this stream is used _ evaporative cooling by means of indirect thermal transformation one or more of the selected streams and is 0 to be liquefied. natural gas One of the streams is the natural gas stream

YEA

- - A part of the liquid refrigerant is then displaced from the indirect heat transfer method and expansion cooling by individual to a lower pressure and correspondingly lower temperature whereby evaporative cooling is provided by an indirect heat transfer method with one or more of the designed means and one of the streams is a stream The natural gas required to be liquefied, especially since this field will use two steps of evaporative cooling / evaporation by expansion, preferably from two to four, and the best is triple Jay. In the preferred cascade field, most of the cooling from liquefaction of refrigerants with a lower boiling point (i.e. the refrigerants used in the second and third cycles) is done by cooling these streams by means of indirect heat exchange with refrigerant streams with a lower boiling point Olle top selected and this method of cooling is referred to as "cascade cooling" procedurally was the refrigerants with higher boiling act as heat sinks for the refrigerants with lower boiling or in a different way energy is pumped thermally from the natural gas stream to flow for a period lower-boiling refrigerant then pumped (i.e. diverted) to one or more higher-boiling refrigerants for conversion to ddl 1 by means of an environmental heat sink (eg sweet water) ele salty; surrounding atmosphere. As in the first cycle, the refrigerant used in the first and second cycles is compressed by means of multi-stage compressors i.e. pre-selected compression and when economically feasible the vapor of the compressed refrigerant is first cooled by indirect heat exchange by one or more refrigerants ( eg air) salt water; Direct conjugated sweet water © environmental heat sinks Cooling may be by interstage cooling between fs compression stages Cooling of the compressed product The compressed stream is further cooled by indirect heat exchange with one or more of the previously discussed cooling stages for point refrigerants highest boil. YEA

Secret - and the refrigerant of the second cycle, preferably ethylene, it is preferred to be cooled first by indirect heat exchange with one or more refrigeration agents accompanied directly by an inter-stage heat sink (i.e. inter-stage and/or subsequent refrigeration after compression). Cascade contact route with 1st and 2nd refrigerant stages or 1st 2nd and 3rd for higher boiling point 0 refrigerant used in the first cycle and the preferred second and first cycle refrigerants are ethylene (plod) and propane respectively. When using a triple-cooled closed-cycle cascade system, the refrigerant in the third cycle is compressed in a staggered manner preferably through optional cooling via indirect heat transfer to an interstitial heat sink (i.e. interstage and/or post-compression) and then exchange cooling 0 Thermal heat exchange by any or all of the cooling stages selected in the first and second cooling cycles, which is preferable to use ethylene propane (lids propane) as a successive refrigerant, and it is preferable to contact this stream in a sequential manner with each successive colder stage of cooling in the cooling cycles In a cascade refrigeration system with an open loop as shown in Figure (1), the first cycles 1 and the second are operated in a manner that tends to be mentioned in relation to closed, and in any case the open methane cycle system is immediately distinguished from the cycles The traditional closed cooling.As we noticed, Ys, in the occasion of the fourth cycle or step, an important part of the liquefied natural gas stream present Sd at high pressure is cooled to about GY by cooling by expansion in a gradual manner to a pressure near Atmospheric at each step produces large quantities ge 0 steam rich in methane ie methane a certain pressure and it is preferable that each steam stream passes a significant heat transfer in the methane economizers methane and it is preferable to return it to the nozzle entering the compressor phase at YEA degree

? - A heat approaching a middle temperature and in the path of flow through methane economizers, the fumigating vapors are in contact with warmer currents in an opposite direction and in succession to increase cooling of the warmer currents and the pressure chosen for each stage of expansion cooling is for each case so that it results in The volume of gas generated plus the compressed volume of vapor from the adjacent lower stage© is an efficient overall process from a multi-stage compressor. Inter-stage cooling and final compressed gas cooling is preferred. The procedure is preferred by indirect heat exchange with one or more associated cooling agents directly to an environmental thermal sink. The compressed methane-rich stream is further cooled by indirect heat exchange by means of a refrigerant in the cycles. The first and second stages are preferred, all stages 0 associated with the refrigerant used in the first cycle, and the best are the first two stages, and the best is the first stage only. The natural gas feed stream at a location in the liquidation process where the natural gas feed stream and the cooled methane-rich stream are under similar conditions of temperature 1 and pressure, preferably by entering one of the ethylene cooling stages And the best is right before the cooling phase of ethylene, where methane is liquefied in a larger section (i.e. Ca Ca ethylene). Optimization by interphase heat transfer between cycles: In preferred areas, steps are taken to further improve process efficiency by returning the refrigerant gas streams to the inlet nozzle of the following compressors at a temperature close to the medium temperature. This step not only improves efficiencies. comprehensive, but by reducing a

-Dr? Difficulties associated with exposure of compressor components to hypothermic conditions. This is achieved by the use of economizers in which the streams present in the bulk of the liquid and before flashing are first cooled by indirect heat exchange with one or more steam streams generated in a downward expansion step (ie stage) or steps in the same cycle or down cycle and in a suspended system it is preferable to use economizers to obtain additional cooling from the flashing vapors in the second and third cycles. When using an open methane cycle system, the flashing vapors from the fourth stage are preferably returned to one or more of the economizers, where (1) these vapors are cooled by indirect heat exchange in the liquefied product streams before each pressure reduction stage and (? 0 ) These vapors are cooled by indirect heat exchange of compressed vapors from the open methane cycle prior to union of this stream or streams with the natural gas feed stream and with the natural main. These cooling steps include the previously described third stage From refrigeration and we will explain it with greater preference in discussing Figure (1) in one of the fields Cus ethylene 0 and methane are used in the second and third cycles, the contact can be made through a series of ethylene and methane economizers methane, and in the preferred field shown in Figure (1), which will be explained preferably later, the process uses a main ethylene economizer, a main methane economizer, and one or more additional methane economizers, and these additional economizers are referred to here as the methane economizer the second and the third methane economizer and so on and each additional methane economizer 0 thereof corresponds to a separate bottom flash step. Remove benzene 56 and another fragrance component fs heavier hydrocarbon: YEA

- The process of the invention to remove benzene and other aromatic components and/or higher molecular weight id hydrocarbons from the Sind methane liquefied gas stream is a very energy efficient process and is simple procedurally and because of the method of operation the aforementioned column Here it is an abstraction column that achieves SIS abstraction and segmentation functions.

The process includes cooling the methane-based gas stream so that 1.1 to 7 mol Yo is preferably condensed from 0 to about 01 mole grams, and preferably about 1.78 to 7 mole grams 7 of the total gas stream, including It is a two-phase stream and the optimal molar percentage will depend on the composition of the gas undergoing liquefaction and other relevant process variables known to Tam Fanfan.

1 In one field, the required two-phase stream is produced by cooling the total feed stream to an extent that produces the required percentage of liquids. In the preferred field, the gas stream is first cooled to near the liquefaction temperature, then divided into a first stream and a second stream, and the first stream undergoes additional cooling and condensation. Mole and then combined with the second stream, which produces a second-stage stream that contains the required ratio of fluids, and the last field is preferable because of the ease of operation and the extent of control over

The accompanying process.

Then the two-phase stream is fed to the upper part of the column, where the current touches the steam stream rising from the lower section of the column, which results in a liquid stream rich in heavy components, which acts as a return stream, and a depleted steam stream - ALE components, which resulted from Column As used herein, the expression “ALD parts” will refer to any dominant organic compound having a molecular weight of greater than ethane. Reboiler to generate steam. YEA

The - and as LS before, the stream of stripping gas rich in methane is fed to the column. It is preferable to lay this column from an upper location where the gas stream, which is based on methane, undergoes cooling, including some degree of cooling and removal of liquids, before Entering the base of the column, the male gas stream is cooled by indirect contact, preferably in a countercurrent manner, with the liquid product 0 produced from the bottom of the column, resulting in a stream rich in heavy components and warm, and a stream of stripping gas rich in methane and coolant. The methane-rich strip gas may suffer partial condensation upon cooling and the methane-rich strip gas 8 and the resulting refrigerant containing two stages may be gassed; Directly to column 0 and the use of cold stripping gas containing small amounts of Cat components by itself lad 0 generated from a reboiler that contains substantial amounts of Cy components This use greatly reduces the problems associated with fluids in the column facilitating It reduces free conditions when it results in a weak separation of the components, and this factor becomes especially important when operating in the best pressure range, with a capacity of about 880 to 676 tons. The critical temperature and pressure for methane is 117.4 F, 177.7 Paisa, the critical temperature and pressure for propane are 11" and .5/11 Paisa, and the critical temperature and pressure for normal butane is 0.7 »?P5 501,78.z and the presence of significant amounts of +0 components will (1) lower the critical pressure by approximately the preferred operating pressures of the process and (?) raise the critical pressure temperature. The resulting effect is to make the components separate by Vapor/liquid contact is more difficult, Ys. A second factor that distinguishes the uses of stripping gas rich in methane and cooled from steam from a reboiler is the temperature difference between these successive streams and the liquid emission from phase P.

L - the latter, but because the methane-rich stripping gas is preferred and the coolant is more las than the sloping vapor from the reboiler, this preferred stream has a greater ability to strip the liquid length of the lighter components and the temperature difference between the liquid emitted from the column And the stripping gas exported to the column is at best Ye F to 100 F, the best is more 66 C to 0" 0, and the best is about 60 F to about 00 F. The theoretical pall number will depend on the composition, temperature, and flow rate of the vapor stream entering the column and the composition, temperature, flow rate, and liquid-to-vapor ratio of the two-phase stream fed to the top of the column. This determination is really within the capabilities of those of ordinary skill in the art, and the theoretical number 0 may be provided by various types of column packing (bolt diaphragm rings ... etc.) or different contact stages (eg trays) located in the column or union thereof and in general two to fifteen theoretical stages are required, the best three to ten, the best four to eight, and the best more than about five theoretical stages, and trays are generally preferred when the shaft diameter is greater than about six feet. 0 Preferred domain of “- open cycle liquefaction process: The overall layout and apparatus shown in Figures 1 and ? is a preferred domain of the open cycle liquefaction process mentioned for illustrative purposes and is omitted for the purpose of the preferred domain OY nitrogen removal system This system is dependent on the lad nitrogen content of the feed, however as we have noted in the preceding discussion of nitrogen removal techniques 00 procedure methods applicable to this preferred field are readily available to those skilled in the art. M

and - and be represented by the figures “and ; in greater preference for purposes of illustration the hypothermic column of the invention and in particular the method for cooling and adjusting the temperature of the stripping gas fed to the cryogenic column and those skilled in the art will know that Figures 1-4 are schematic only and that many of the equipment which may be required in a laboratory COMMERCIAL FOR SUCCESSFUL OPERATION © omitted for clarity. This procedure may include, for example, compressor controls, flow and level gauges, and corresponding governors. Additional temperature and pressure controls ¢ pumps; engines; filters; additional heat exchangers; Valves...etc. These parts may be provided as per parts engineering standard. and to make it easier to understand the figures oY 1 » ; The items with numbers 1 to 94 generally correspond to ied 0 practical and equipment directly related to the liquefaction process, and items with numbers 001 to 14 correspond to flow lines or delivery channels that contain a large percentage of methane. Sections with thicknesses 0 through YA correspond to flow lines or delivery channels containing refrigerant ethylene or optionally ethane and parts with numbers 3036© through TAA correspond to flow lines or delivery channels containing All propane 3 To the extent possible, the numbering system used in Figure 1 has been used in Figures (FY 4). Also, the following numbering system has been added for additional elements not shown in Figure 1 and items with Numbers 400 to £49 correspond to additional flowlines or additional channels Part numbers 5056 to 094 correspond to additional process equipment such as column vessels, heat exchanger and process control valves Items numbers 20 to 759 generally relate to the process control system except for 0 control valves and include In particular, sensors, governors, and fixed-point inputs. YEA

(a) In most control systems some combination of electrical, pneumatic or hydraulic signals is used, however the use of any other type of signal transmission compatible with the process and equipment used is within the scope of the invention. Considering the invention illustrated in figures 1 up to; The lines passing through it are lines of 0 signal, which are indicated by dashed lines in the figures, and it is preferable that these lines be electric or pneumatic. The spectrum of this signal is not always indicated for the sake of simplicity because it is well known in the art that if flow is measured in gaseous form the energy must be converted into electrical form if it is to be converted into electrical form by means of a flow transducer. Referring to Figure 1, gaseous propane is compressed in a multi-stage compressor YA that works by a gas turbine directive (engine), which is not shown, and the AE stages of compression are preferred to be present in one unit, although each stage of compression may be A separate unit and the units must be mechanically elevated by means of a signaling router. When compressed, the compressed propane ve passes through the delivery channel 06 to the refrigerant 01, where it liquefies and the pressure and temperature representing the period of cooling the liquid propane before flashing is about 001 F and about 6 8 098 © 3 Although it is not shown in Figure 1, there may be a container to separate the bottom of the Yo-cooler and the top of the pressure reducing device, showing that the VY individual is designed to remove the remaining light components of liquefied propane, which may form These vessels are of a single-phase gas-liquid separator or may be more complex and consist of an accumulator section, a condenser section, and a gas section. The last two may operate continuously or periodically in contact to remove residual light components of propane (YEA).

S and the current from this receptacle or the current from the radiator 0? Whatever the case it is passed through the connection channel 17 to a pressure reducing device shown as a single valve 11 where the propane pressure Jed propane is reduced by vaporizing or flashing part of it then the resulting two-phase product flows through the connection channel 04 to a propane refrigeration unit High-phase propane, where the methane refrigerant 0 gaseous entered through the delivery channel 0" and fed the natural gas entering through the channel 001 ethylene 6 refrigerant gas entering through the sll 01 is then cooled by means of channels, Cv-T Voi, and the gas is fed into a channel to deliver 154 to a main methane economizer, VE, which we will explain in detail in a next section, where the stream is cooled by means of an indirect heat exchange AA and the compressed refrigerated methane recycle stream 0 produced via the VOA conduit are then combined with the steam stream drained from the heavy components in the conduit 0 from the desoldering column and fed from the methane retainer 6 . The propane gas 6 in the refrigeration unit is returned to the compressor VA through the delivery channel VO and this gas is fed to the inlet phase ad of the compressor VA and the remaining propane Jal propane 0 is passed through the delivery channel YA and the pressure is reduced Further by command via a pressure reducing device shown as a single valve Cua VE an additional portion of liquefied propane is flashed. Then the resulting two-phase stream is fed to the refrigeration unit, YY, through a connecting channel, le 01. It provides refrigerant to the refrigeration unit, YY, and the feed gas stream flows to a refrigerant from the refrigeration unit? Through the delivery channel 0 011 to an isolation vessel 01 where the gas and liquid phases are separated and the liquid phase that is rich in Cot components is displaced through the delivery channel .017 and the gaseous phase is displaced through 48 connections ; 0 and then bisects into two separate streams which are connected via channels Vo YEA

The - and 8110 and the stream is fed into the sual 01 to a propane refrigeration unit (YY propane) and the stream in the delivery channel becomes 018 feed to the heat exchanger TY and is finally a stripping gas to the component removal column (Adi) 70 and a duration Ethylene cooling from the refrigeration unit? Introduced to the refrigeration unit YY via the duct in the refrigeration unit YY the feed gas stream is also referred to herein as methane-enriched and refrigerant streams | Ethylene is subsequently cooled by means of an indirect heat transfer YE and 7, which produces streams of ethylene refrigerant, rich in methane, through the delivery channels 011 and 7016, and the evaporated part is separated from the propane refrigerant. propane and passes through channel 11? to an intermediate phase inlet VA and liquid propane refrigerant is removed from the refrigeration unit YY through channel (1m0) and flashes through the pressure reducing device indicated by the individual valve 16 Then it is fed to a third-stage cooling unit YA through channel 1m. As shown in Figure 1, the methane-rich stream flows from the intermediate stage propane refrigeration unit YY to the low stage propane condenser/cooler YA through the connection channel 0 In the aforementioned refrigeration unit, the stream is cooled by means of an indirect heat exchange method, To. In a similar way, the ethylene refrigerant stream flows from the intermediate stage propane refrigeration unit 77 to the propane condenser/cooler. Low stage TA through channel 70 and at the last in the period of cooling ethylene 06 is condensed or almost completely condensed by means of indirect heat exchange TY and the evaporated propane 6 is removed from the propane condenser/cooler mist “propane” stage 0 #78 and returned to the low stage inlet at the VA compressor via channel YY although Figure 1 shows the cooling of the streams provided by channels 011 and 00 to be carried out in separate process receptacles (Sti) a separate refrigeration unit or separate condenser in series) and in a similar way the cooling steps of YEA

For the previous one, where the cooling of the multiple streams may increase in a common vessel (for example, a cooling unit), which may also take place in separate vessels, and the first arrangement is due to the cost of the many vessels, as well as the less space required for the laboratory. As shown in Figure 1, the methane-rich stream leaving the low-stage propane refrigeration unit is fed into the high-stage ethylene refrigeration unit 7; Through the channel 1 VY and the ethylene refrigerant exits from the low-stage propane refrigeration unit YA through the channel YO A and it is preferable to be fed into a separation vessel YY where the light components are removed through the channel 8+ and the condensed ethylene is displaced through channel 701 and the separation vessel is similar to the previously described vessel to remove the -0 components of the liquefied propane refrigerant and it may be a single-stage gas-liquid separator or it may be a multi-stage process Which provides greater selection in removing light components from the device. Ethylene refrigerant from this site in the process is generally at a temperature of about Yim F and a pressure of about 788 Basia. The ethylene refrigerant then flows through channel 701 to polyethylene, Ye thylene 0, where it is cooled by an indirect heat exchange method, YA, removed through channel 711, and passed to a pressure reducing medium shown as an expansion valve. 5+0 where the refrigerant is flashed to a pre-selected temperature and pressure and fed into a stage 7 thylene Ae refrigeration unit; via delivery channel 7117. The steam from the aforementioned refrigeration unit is moved through the delivery channel 114 and directed to the 0 ethylene economizer TE ethylene, where the steam acts as a refrigerant by means of an indirect heat exchange 87, and the ethylene vapor is removed from the ethylene economizer through the channel 19? YEA

Hess and fed to the high stage inlet on a 4 ethylene compressor; And the ethylene refrigerant that did not evaporate in the dle ethylene refrigeration unit stages 47 is removed through channel 8? It is returned to the YE ethylene economizer for further cooling via an indirect heat exchange method 0 and is displaced from the ethylene economizer via the channel YY oo and flashes in a pressure reducer indicated as an expansion valve oF when inserted The two-phase product produced into one AU ethylene cooling phase through channel 777. displacement from the high-phase Aiglin refrigeration unit 16 7; Via channel 11” there is a film rich stream and this stream is then condensed by cooling supported by an indirect heat exchange method 7© in a 0f low stage ld ethylene refrigeration unit providing 0 two-phase current Which runs through a delivery channel 118 to a column for removing benzene / aromatic components / heavy components 60 . The liquid containing a high concentration of benzene and other aromatic substances and/or heavier hydrocarbon components is removed from the benzene/heavy components Z 01 removal column via channel VV preferably by flashing by means of Flow control ve that can act as a pressure reducing device AY Preferably a guage valve to a heat exchanger TY by means of a connecting conduit 1117 Preferably flash current is flashed by means of a flow adjusting device 57 to a pressure of approximately or is greater than the pressure from the high-phase inlet orifice to the methane compressor also flashing achieves greater cooling efficiency of said stream and in the heat exchanger 17 the stream connected by channel 11 provides cooling efficiencies (capacities) by means of indirect heat exchange © TE and exits from the aforementioned heat exchanger through channel 1115 and in the column for removing benzene / aromatic components / heavy components Te, the phased stream entering through channel 1118 is in contact with the stream of stripping gas rich in methane methane YEA

Dom - and the inlet refrigerant via channel 01 in an opposite direction Ley produces a methane rich vapor stream drained of heavy parts / benzene through channel Slog 11 liquid rich in benzene / heavy components Through channel 1117. The stream in channel 119 is rich in benzene and other aromatic components and/or 0 other JF hydrocarbons and this stream is thus separated into liquid and vapor sections or at best flashing or fractionating in vessel 7+. In all Als a liquid stream rich in benzene and other aromatic and/or heavier hydrocarbon components is produced via channel 177 and a second vapor stream rich in methane Ja is produced via channel 171 And in the preferred domain positioned in the form 0? Therefore, the current in channel 171 is combined with a second stream supplied via channel VTA, and the collected current is fed through channel 50 to a high-pressure inlet above the Had.AY methane compressor. LS, previously mentioned gas in channel 108 is fed to a prime methane economizer VE where the stream is cooled by an unsuitable heat exchange method AA and the compressed methane recycle stream 1 _ the resulting cold or coolant stream in the channel 158 is collected in the preferred field by steam stream depleted with heavy parts from the heavy components displacement column 01 delivered to the channel 171 and fed to the low-stage ethylene condenser TA and in the low-stage ethylene condenser cooled This current and its condensation through an indirect heat exchange method, Vo, by means of the liquid emitted from the low-phase ethylene refrigeration unit, ot, which is directed to the low-phase ethylene condenser 0, through channel 777 and product The methane-rich condensate from the low-phase condenser is produced by channel 177 . YEA

The steam is collected from the low-phase ethylene refrigeration unit, 0 * 4, drawn through channel 4? ¥ and a low-phase ethylene condenser (TA) drawn through the channel (YYA) through the channel 710 to the ethylene economizer (YE ethylene), where the vapors act as a cooling agent through an indirect heat exchange method (OA), then the current flows through Channel path YY © ethylene economizer 4 © to the low-phase side of the ethylene (pi!) compressor. As we have noticed in Figure 1, the compressor emission from the steam entering through the low-phase side is displaced by The channel YE is cooled by a phase intercooler VY and the compressor is returned EA via channel 137 for injection with the high phase current in channel 777. Mechanically levered with a common guide (common guide) and the ethylene product, compressed from the compressor, goes to a cooler below VY through channel 001, and the cooled product flows through channel 7 and enters - as previously explained - to a high-phase propane refrigeration unit. The liquefied stream in channel 17 is generally at a temperature of about GV Yom and 0 storage is about Psia 0 and this stream passes through the VYY channel through the main methane economizer VE where the cooling of the stream is increased by An indirect heat exchange means VY as we explained before and from the main methane economizer VE the path gas passes through the channel YYE and its pressure is reduced by a pressure reducing means shown as an expansion valve VA which of course evaporates or flows part of the gas stream - The flash current is then passed to a high-phase methane flash barrel (Ae©) where it is separated into an expelled gas phase through channel 177 and a liquid phase discharged through channel 171 and then the gas phase is transferred to the methane economizer (ud) methane through the channel 173 Where YEA Steam Works

7S - As a refrigerant by means of an indirect heat transfer (AY), the vapor exits from the main methane economizer via channel 074, where it is combined with the gas stream delivered by channel 11, and these streams are then fed to the high-pressure entry port compressor AY and the liquid phase in channel 32 .1 passes through a second methane economizer AY where the liquid is further cooled 0 by bottom flash vapors by means of an indirect heat exchange method 88 and the cooled liquid exits the methane economizer AY The second AY via channel VY and expands or flashes through a pressure reducing device indicated by an expansion valve 91 to further reduce the pressure and at the same time vaporize the second part of it and then passes the said flash stream to a methane flash barrel intermediate stages AT Where the stream is separated into a gas phase passing through the channel 117 and a liquid phase passing through the channel IVE yo and the gas phase flowing through the channel 17 to the second methane economizer AV where the liquid vapor entering the AY is cooled by Tube method 0 by means of an indirect heat exchange method 84 and channel 1 vA serves as a flow connecting channel between the indirect heat exchange method 4 4 in the second methane economizer AY and the heat transfer medium other than 1 Direct 8 in the main methane economizer &\ This vapor leaves the main methane VE through the VE channel that is connected to the intermediate phase inlet on the AY methane compressor. The liquid coming out of the intermediate stage flashing barrel 97 through channel 2178 developed a further reduction in pressure by passing through a pressure reducing device shown as a single valve AY YT and again a third part of the liquefied gas is vaporized or flashed. YEAS

R -

And the fluids pass from the individual valve AY to the final flashing barrel or the low phase 14 and in the flashing barrel 14 the vapor phase is separated and passed through the channel VEE to the Cua AY methane steam works as a cooling medium by means of an indirect heat exchange A and exits from the second methane economizer through channel 147 which is linked to the first methane 0 destination VE where the steam acts as a cooling medium via an indirect heat exchange method AT and is left at the end The first methane economizer by means of the VEA channel which

It is connected to the low pressure orifice above the compressor AY and the liquefied natural gas product is passed from the flashing barrel 94 which is at

Atmospheric pressure approximately through the VEY channel to the volume .

1 and the steam stream coming out of boiling 6 27 1. of low pressure and low temperature from the storage unit and optionally the return steam from cooling the reduction or stop lines associated with the filling device 6 17 1. It is preferable to recover it by combining this stream or streams with flashing vapors of The low pressure in any of the channels is 1548 VET OV EE, and the chosen channel is based on the request to match the steam stream temperatures as closely as possible.

AY the high, intermediate and low stages of the compressor 1 shown in Fig. LS yo preferably united as a single unit however each stage may exist as a separate unit where the units are mechanically coupled together to be directed by a single wave and the gas passes Compressed from section 060 and combined with the intermediate pressure gas in the low phase channel AS through an internal phase cooler through the AY before the second stage of compression and the compressed gas of the intermediate phase is passed from the compressor

0 internal phase refrigerant 4 and it is combined with the high pressure gas in the channel 040 before the AAD stage of compression and the gas is discharged from the high-phase methane compressor through the channel vou YEA.

M - It is cooled in the AT cooler and flows to Baa by cooling the high-pressure propane through the YoY channel as we explained before. Figure 1: Explains the expansion of the liquefied phase using individual valves with the following separation of the gas and liquid sections of the refrigeration unit or condenser. While this simplified arrangement is practical and used in some cases 0, it is often more effective and efficient to perform the evaporation and partial separation steps in separate equipment. pL A single valve and separate flashing barrel may be used before any separated vapor or liquid flows into a propane refrigeration unit. In a similar way, certain process streams undergoing expansion are optimal outputs for the use of a single hydraulic hydraulic unit as part of the pressure reduction device, which enables the recovery of operating energy 0 as well as the reduction of the two-phase minimum temperatures. As for the router/compressor units used in this process, Figure 1 shows the router units: single compressor (i.e. single compression locomotive) for the open cycle methane, ethylene and propane compression stages, however in a preferred field for any cascading operation, the reliability of the process can be greatly improved by using a compressor drive 1 multiple incorporating two or more drive unions: a compressor in parallel with the single drive/compressor units shown and if the compressor drive unit is not available the operation can be performed Also less efficient. The preferred area for an innovative removal process and device: Represented in the form of ? There is a preferred area of the process of removing benzene / other aromatic components and / or To _heavier hydrocarbon components and an associated device. YEA

Q4 Via channel VIA produced from cooling and partial condensation of the current in channel 117 by means of cooling: provided by means of heat exchange 07 in a refrigeration unit and partial condensation of the current in channel VV by means of cooling provided by means of exchange The heat exchange © in the ot ethylene cooling unit and in one of the fields the total current in the channel 111 © is cooled and in a preferred field shown in the figure? The two-phase stream is produced by partial cooling and condensation of a part of the current in channel 111, and this part is then combined with the remaining part of the current generated through channel 117. With reference to form? The current delivered via channel 111 is divided into a first current flowing in channel 0; a second current flowing in channel EO and current flowing in channel 7.5© via an optional OTY valve 0 preferably a manually controlled valve. - to the channel; 0, which connects the first stream to the OF ethylene refrigeration unit, where the streams suffer at least partial condensation through an indirect heat exchange method 01 and exit from the aforementioned method through the channel oA lal, the second in the channel gov runs through valve OFF and preferably a regulating valve in the delivery channel All £07 then collects with the first current connected from the channel £0A and the currents collected now SE ve two-phase stream is connected to the column 720 through the channel 118 From a practical plastic perspective, the length of the channel 118 must be sufficient to ensure an appropriate mixing of the two streams so that the approach conditions are met. The amount of fluid in the two-phase stream in conduit 118 is preferably controlled by maintaining the currents at a required temperature. located in channel 118 provides the TAT input signal to the TAY temperature governor and is also connected to the YEA

41 - - The governor by the operator or the computer logarithm is a constant point temperature signal 4 and the governor TAY responds to the differences in the two inputs and transmits the signal 186 to the flow control valve 0 which is located in a channel where the part of the current delivered through the channel flows Which does not suffer from cooling through the heat exchange method 01 heat exchange in the refrigeration unit 08 and the signal 0 transmitted 1860 is shown graphically to be representative of the position of the control valve + oF required to maintain the flow rate necessary to obtain the required temperature in the channel 118. The aforementioned feed streams to the gravity of the process where benzene and other aromatic components and/or heavy hydrocarbons components are removed are the two-stage process stream from the ethylene refrigeration unit © 4 delivered via channel 118 to the upper section 0 From the column Te at the methane-rich stripping gas delivered via channel 04 although it is shown in Figure 1 as Li from the feed gas stream from the first stage of this propane 8 cooling The stream can lay from any location within the process, or it may be outside the methane-rich stream, as shown in the figure? At least ie fraction of the methane-rich stripping gas 6 undergoes cooling in the heat exchanger VY by means of an indirect heat exchange device 1 TY before entering the column base 630 . And the streams emanating from the gravity of the mentioned process are a gas stream drained from the heavy components from column 0 resulting through channel 11, and the heated stream rich in heavy components produced through channel 04, as shown in the figure? The current, La with the heavy component, is produced from column 01 and passes heating in the heat exchanger 7+ by means of an indirect heat exchange method 6" Yo. In this way, the column emission generated through channel 116 cools the feed stripping gas to Column on the channel road 0018. YEA

- 7 = The number of theoretical phases in the Te column will be dependent on the composition of the feeding currents of the column. Generally, it will be required from two to fifteen theoretical phases, and the preferred number of phases is from three to ten, and the best is four to eight. From a procedural and cost perspective, the best number be about five. 0 Theoretical phases may consist and become available by packing and plates/trays or a combination of them. Generally, packing is preferred in columns less than about six feet in diameter and plates/trays on columns larger than about six feet in diameter. As shown in the form? The upper section of the column where the two-phase stream in channel 118 is fed is preferably designed to facilitate gas/liquid separation. This device is located between the entry point of VIA channel and the exit point of channel 071. As shown in the figure, the liquid stream rich in heavy components produced by 116 sll flows through the control valve AY and channel 111 to the heat exchanger 67, where the said stream provides cooling by means of an unsuitable heat exchange method VE and is produced from Heat exchanger TY Ne through channel 119 as a heated stream rich in heavy components and based on the lower process operating pressure the cooling efficiency of this stream can be improved by flashing to a lower pressure when flowing through the regulating valve 997 . The said process stream via channel 111 may be used directly or undergo post-treatment to remove lighter components and in the preferred range shown in Fig. ? The current is fed to 0 de-methane, 17 methane. YEA

DC - The rate of flow of the heavy-component liquor from column 00 may be controlled by various treatment methods immediately available to one skilled in the art. The control device shown in Figure 1 is a preferred device and is composed of a leveling device 0, a sensor and a signal transducer associated with said leveling device operationally located in 0 section below column 01 and governor 0000 is the output signal 017 which Either sets the flow rate in the delivery channel 14 required to maintain a required rate in column 10 or indicates that the actual level may exceed a predetermined rate that the flow meter and transducer 104 are operational in the delivery channel 116 be output signal 606 constitutes the flow rate The actual flow of the fluid in the VV E delivery channel and the means of measuring the rate are located procedurally above the adjusting valve in order to avoid 0 sense of the two-phase current. respectively in the flow governor 104 and the governor 1068 is an output signal 114 in response to the difference between the signals 107 and 06 and the TYE signal is provided to the adjusting valve AY and the valve 97 is processed in response to the signal 16+ that the computer control point signal by setting logarithm and based on Operating conditions the work or computer automatic logic is used to determine whether 1 if the control is fluid level based or flow rate based and in response to the variable flow rate input of the signal and the fixed point signal selected the provision 6008 provides an output signal 1754 which is responsive to the difference between the dependent input and the fixed point signal . This signal is graded graphically in order to be responsive, Uf, if the case is to set the adjustment valve AY required to maintain a flow rate of the fluid basically equal to the required flow rate or that 0 the liquid level is basically equal to the required fluid rate (level) whatever the case. YEA

- os

In the heat exchanger TY the heavy-component-rich stream that cools the methane-rich refrigerant stream is forced into the heat exchanger via the conduction channel 1117 and the heavy-component stream flows by an indirect heat exchange method 176 and is produced from the heat exchanger via The channel and degree to which the methane-rich strip gas 0 is carried by the stream carrying the heavy fractions before entering the column may be controlled by various methods readily available to those skilled in the art and in one field the methane-rich strip gas stream The aggregate is fed to the heat exchanger and the degree of cooling is governed by these variables as the amount of liquid stream rich in heavy fractions is made available for heat transfer the heat transfer surface areas available for heat transfer and/or settling times for methane fluids and in favor of the methane-rich gas stream dad suffers heating or cooling whatever 0 where the fee is to the channel 0 flows through the control valve 08 connected through the channel and 0 and the current flowing through the channel £07 flows in YY characterizing the current and its transmission by pipes

The end through the indirect heat exchange means ;0 in the CTY heat exchanger

A means of factoring the relative flow rates of a fluid in channels ET EY is provided in

ve Which of the two channels, Sear Jey, and the method shown in Fig. ? They are simple manual control valves denoted by the numbers 5607 ort which are connected on Jal to channels 4064

In any case, a control valve is treated to be positioned by a ruler whose input is the ruler

From a point of stability of a signal representative of the flow in the channel as we explained (SUE) for the current carrying heavy components;

may be replaced by one or more manual set-off valves and in any event the valves are actuated so that the temperature difference of the streams in the channels Ee 117 to Jae thermal VOY exceeds 50 F when the heat exchanger spill may result and the fluid leaves Radiator means heat exchanger

4 through conduit 406 and collected at a connection point by means of a stripping gas rich in mechanization

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And - methane and non-cooled delivered via channel 407 Le The stream of cooled refrigerant gas rich in methane is methane, which is delivered to the column via channel 008.

and is operationally located in channel 01 flow diverter 117 which is in combination with a flow sensing device such as a slotted plate (not shown) the TVA output signal constitutes rate 0 _ the actual flow of fluid in the channel and the signal TVA is provided As a variable input of the process to a flow governor 0 and it is also available either manually or via a computer output The value of the stability point of the flow rate is represented by signal 177 Then the flow rule provides an output signal 174 that is responsive to the difference between the dependent input and the stability point signals that are graphically integrated to be Representative of a deaf situation

The setting required to maintain the required flow rate in the delivery channel 018.

0 In another respect, the relative flow rate of the fluid through channels SEY 4072 can be controlled by placing a temperature sensing device and a thermal transducer associated with the said device - if required in channel 01 and using the resulting output and set point temperature as the input of the flow governor, which An output signal may be generated in response to the difference in the two signals and represented graphically to be in response to setting a control valve required to maintain the required flow rate in conduit 018 and the control valves

. The mentioned 504 may be replaced by manual valves 907 and/or 1

And in another area shown in the form of? The stripping gas temperature of the 60 column is controlled

It is in the following way: The temperature transducer 04 in combination with a dual Jie measuring device

Thermal located procedurally in channel 1 117 provides the VA output signal that is representative of temperature

Actual fluid flow in channel 111 and reference 7065 is provided as the first input to the ratio calculator

15 no and ratio calculator 7001 is also supported by a second temperature signal 706 muzzle

For the temperature of the fluid flowing into the conduit 015 and the signal 705 formed in the temperature transducer A

1 whose output signal is 006 responding to a sensor element as a dls thermocouple practically in the channel 01 in response to 718 Ve signals, the ratio calculator 0 provides an output signal of 10 L, which is representative of the signal ratio 07 to 7068 and the signal is provided 01 as input to the YOY ratio governor and the ratio governor 07 is further augmented by the stability point signal 06 which is 0 representative of the required temperature ratio of the fluids operating in channels 014 and 11 . In response to the signals VE 01 the ratio governor VY provides a VAT output signal which is in response to the difference between signals 701 and 4 VY and the graphs of signal 716 are scaled to be representative of the position of the OTE valve which is operationally located in Subchannel 7068 required to maintain the required ratio represented by anchor point signal 704 and the control valve OE is set in response 0 A to signal 06 . And according to the preferred control method shown in Fig. ; Where the reference numbers are used for the element represented in the previous figures, the automatic start of the Te column is performed by a selector on VYA and it is noted that the stability point VIE of the temperature governor is 777, a required degree stabilization at a temperature compatible with the liquid in column 60 and when starting Operating - however - the temperature in channel 01 ae will be at or close to the medium temperature and accordingly the binding signal VY directly to treat valve 7 may close the valve OT to close or not allow the flow of gas warm dry to hypothermic separation column 01 during start-up and the problem is overcome by a temporary selection of the VEY signal to treat valve 5776 as described below. In response to signals and 74 the VYY temperature governor provides a VY output signal in response to the difference between signals 705 and 75 and the signal gradient 777 graphically responds to a deaf position 2 which is located procedurally in channel 0118 required to maintain the actual fluid temperature in YEA

Channel 005 is essentially equal to the required temperature represented by signal 1765. As mentioned earlier, the required value of the fixed point signal VY E will not allow the column to start and the VY signal is supported accordingly with the VIA signal selector and the signal selector 774 is further augmented by a set VEY signal which is responsive to the difference between the YT and +74 signals and graphically represented to be responsive to the set valve position 7 required to maintain the fluid temperature in channel 19 essentially equal to the required temperature represented by Reference 7506 and when the column is started, the actual temperature of the fluid in channel 49 will be JH from the required temperature represented by reference 7408 and according to that the signals linking VEY to valve 0 may open valve 7 to lower the temperature represented By signal 1 the high selector VIA decides which of 0 signals 777 and 47 will treat the OFT valve and start-up proceeds therewith as the feed gas is introduced into the top of the cut-off column 01 in the upper section and when 0°C cooled Heat the feed gas to a condensing temperature to remove impurities, the liquid begins to form a level in the column 0 and the rate governor 2600 senses the level and opens its output the valve AY in response to the signal 616 then passes the low temperature liquid to the heat exchanger 37 and exchanges the heat 1 by Warm dry gas stream through channel 0118, valve OFF and valve OT opened initially by signal 17 at settling point temperature . After the start of the dry gas flow, the thermal solution 107 senses a sharply colder temperature, Lay, which results in the signal 777, which is selected by the high selector VY A. The warm liquid stream 0 rich in heavy components is fed from the heat exchanger TY via channel 108 to the demethane column VY methane which contains both straightening and stripping sections The straightening and stripping sections may contain different phases (eg sonic slabs) or may provide continuous mass transfer by packing YEA.

- column ip (eg saddles; twisted wire notched rings) or a combination of the above Generally packing is preferred for poles having a diameter less than about 7 ft Distinctive stages are preferred for poles having a diameter greater than about ft The theoretical number of stages in each section The rectification and stripping are dependent on the composition 1 required for the final products and the composition of the feed stream. It is preferable that the lowest section or stripping of the stages contains 01 typical stages, and the best is about 11 theoretical stages, and the best + to Yo Ee

Yo The top or calendar section of a column should preferably contain ; To (ff) theoretical and in a similar way. Theoretical stages 01 typical stage and the best is about 11 typical stages and the best to at the bottom to provide stripping steam and in the preferred field OYE and a conventional reboiler is provided to be provided to methane shown in Fig. ?, a liquid from the lower stage in the methane, where the aforementioned fluid is heated by means of heat exchange EVA reboiler through the channel . 0 7 indirect 4 5 ?© with a heating medium that delivers The channel route is £80 and is returned through the channel ;;; and sll Ung ye, which in turn is OY, which is connected to the flow rate valve, is returned through the channel 4758 and the fluids methane steam from the reboiler are returned to the demethane column from the reboiler via channel 97 and said stream in channel 177 may optionally be combined via an optional methane channel in channel 477 with a second fluid stream originating from the bottom of demethaner 1 1 via channel 771 and/or methane The total liquids produced from the Lins EVE methane extractor mean that the EFA is produced through the OF + channel, meaning that the case may optionally apply through the cooler from the previous channels and in one of the areas SIS to control the flow of the liquid Inserted into one or the SEY as shown in Figure ¥, the flow control device is composed of a control valve controlled by an OTF governor and an adjustment valve position NYT SETA inserted between the channels ve The flow 177 which is responsive to the differences between the input signal of the fixed point 174 of the control device

CTY represented by the signal EVA level 1776 and the actual flow rate of the fluid in the channel F

and 4 - the stability point flow rate 190 of the rate governor 77+ may be provided by factor A input to the computer logarithm and the output from the governor TTY is the signal TYE which is graphically inserted to be representative of the YY adjustment valve position required to maintain the required flow rate in the YA channel to maintain the desired rate at 67 .

° Although techniques for adjusting Ac sth are immediately available to regulate the flow rate of the stripping steam to the column TY via channel 470, it is a preferred technique to be based on the reflux steam temperature and the temperature transfer device 177 in combination with the sensing device such as a double thermocouple located in channel 50 provides input signal 14 to EY temperature governor also available to governor by operator or computer algorithm is fixed point temperature signal 1560 and governor 747 responds

0 to the differences in the two inlets and transmits the VEE signal to the flow control valve OY which is Lad in a channel containing the heating medium preferably channels £80 or £68 and the best channel is £66 as shown. The transmitted signal £68 is graphically inscribed to represent the position of the control valve 577 required to maintain the flow rate required to obtain the required temperature in conduit 446. vo A new aspect of the methane removal column is the way in which reflux fluids are generated, and as shown in Figure 1, the upper product exits the methane removal column TY through channel 10, where At least part of said stream is partially condensed when flowing through the unsuitable heat exchange method 501 in heat exchanger TY which is cooled by the heavy-component liquid product from the heavy-duty removal column 0-01 and in In a preferred field, the liquid product rich in heavy fractions is first used to cool at least part of the upper vapor stream and then used to cool the methane-rich stripping gas stream.

Coen and the condensed liquids resulting from cooling through the rich liquid stream heavy components become heat exchange Jalal preferably 117 methane The return source of the methane column between the two aforementioned streams is done in an opposite way and in one area the complete system It may apply to the heat exchanger 77 in the way we explained previously to cool the methane-rich stripping gas and the condensate liquids resulting from the cooling by means of the liquid stream rich in heavy components methane © heat. Between the two aforementioned currents, it takes place in an opposite way, and in one of the fields, the complete exchange system may flow to the heat exchanger 17 in the way we explained before to cool the total methane abstraction gas, and in a preferred field, which is shown in the form of ? The upper product of Bukhari is methane

Sl is subdivided into currents flowing through channels 70; And 40, the current in 401 in the channel 0 heat is cooled by the flow of the aforementioned current through the heat exchange medium VY in the heat exchanger 4 and the resulting cold current is produced through the VY channel in the indirect heat exchanger 0 exchange and 18; EVE 497 m?; And the relative flow rates and the relative flow rates of the steam streams are controlled by the means of controlling the flow, and it is preferable to control the flow of a cross valve. 007 in force in channel 7 in force is a means of adjusting the flow then resulting in a two-phase current collector refrigerant VAS 7 channel 417 channels connected. 4700 which runs through the conduit there is a temperature sensing device preferably a thermocouple that provides a signal 0 and in conduit 57 ' to a temperature governor EY representing the actual temperature of the fluid flowing in the conduit 158 YT. To the ruler 667, either manually or via Tor, that the required temperature is logarithm in the computer, and based on the comparison of the input by means of the transfer 647, the stability point

DH - 0 and the governor NOY provides an input signal 154 to valve 507 which graphs to treat valve 0 appropriately as the set point temperature is approached or maintained and the resulting two-phase fluid in channel 470 is then fed to the separator € 01 from where a vapor stream rich in methane is produced through the channel YY and a liquid stream returns through the channel 474 and in Jae 0 preferred AT the mentioned treatment method is used, but first it is done using the stream rich in heavy components 111" In order to cool the stream delivered via channel 8 6) before cooling the stream delivered via channel 414 and as shown in Figure 1, the methane-rich steam stream in channel 171 can be returned to the open methane cycle from The order of subsequent fluidization and the pressure of the methane and associated equipment is controlled by a manually operated control valve 11#0 in response to a pressure diverter 10 instrumentally located in conduit 77; the control valve is engaged above the inlet side of conduit 577 and over the outlet side of conduit 111 which is preferably Ua ye directly or indirectly to allow pressure inlet port on methane control and pressure transfer device 701 in combination with a sense device providing an eA signal to a pressure governor 160 which is an example of the actual pressure in Channel EY The TTY se point pressure signal is also provided as input to the pressure governor 3760 at which point the governor generates a response signal 1764 representing the difference between the pressure sensor signal 658 and the set point signal 67 . The VE signal is inserted graphically in such a way as to activate (actuate) valve A (©) in order to approach and maintain the set point pressure in one of the spheres, the governor, the check valve, and optionally the pressure-sensing transducer 107 being internal to a signaling device commonly called a return pressure regulator. , and the reflux from the separator at the end applies to methane remover, and in the preferred field shown in Figure Y, the reflux leaves separator 514 via channel 76; It flows through pump 007 and then flows through channel £Y0, check valve 79 and channel 4775 where current is introduced to the section

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- 0 is the highest of the methane removal column, and in this field, the reflux flow rate is controlled by input from the rate control means 157, which is responsive to a sensor in the lower section of the separator ove and ruler 7 generates NIA BLY representing the rate Flow in channel 473 required to maintain the required rate in separator 006 Signal 1748 is provided as a 0-point input to the flow governor TY which is further fed into signal 371 which constitutes the actual flow rate in channel 8? . Then the governor +70 generates the signal 7974 of the adjusting valve ©05 which is representative of the difference in the signals and graphically of an appropriate fluid rate via the rate adjusting valve 014 so that the fluid rate is controlled in the separator 814 . The previously described governors may use the various known systems of control such as relative 0 (proportional) integral-relative or derivative-integral-relative (PD). A digital computer having return equipment is preferred in the preferred domain shown in Fig. ; To calculate the required setting signals based on the measured process variables as well as the stability points available to the computer and any digital computer programs that allow to run an effective time medium to read external variable values and conversion signals to external means that is appropriate to use and 0 BA rulers shown in figures POY Ne And the?; They can use various systems of control such as the proportional integral or the derivative of the proportional integral. In the preferred field, a relatively integrated system is used. In any case, any ruler that has the ability to accept two or more input signals and produce a representative graphic input signal to compare two input signals is within the scope of the invention. And the indication of the output signal by means of a ruler that is known in the art of control systems, and basically, the output of the ruler can be standardized to represent any required factor or variable.

Cero is necessary to make the required and actual temperatures a representative of the gas flow rate 5 equal. On the other hand, the same output signal may be graphically graduated to represent the pressure required to make the required and actual temperature equal. On the other hand, the same signal The required and actual dead temperature output may be graphically graded to represent the required pressure. equal 0

Lily units, the output signal of the ruler may represent Vom, and if the ruler output can be scaled from zero, a specific flow rate, or a special temperature, 790 has a rate of © units corresponding to boa, so that the means of transmission used measure the variables Which distinguishes a process in various signals It may play a variety of shapes or patterns, for example, the controls for this system may be generated by Lay J, equipped using electrical, electronic, digital analog types; pneumatic hydraulic; Mechanical 0 The control lugs selected in 0 other similar types or combinations of these types of equipment are used Variety of process condition to select appropriate adjusting effect Typically a normal control signal is provided by a secondary adjusting signal which has higher precedence in case Special process eg comprehensive conditions or required characteristics may be avoided as the automatic start can be equipped by . Temporary selection of a secondary tuning signal eo The specific hardware and/or software used in said feedback control systems 6 are known in the field of process lab tuning See eg chemical engineering reference; Nature. 17-77 to 1-7 McGrohill p. While low specific temperature methods, materials, parts of equipment, and control equipment are referred to herein, it should be understood that these formal statements are not intended as a limitation of scope but are for better illustration. method according to the invention

YEA

Example (1) This example shows a computer simulation of the efficiency of the process described in the full description of the displacement of benzene and heavier components from the methane-based stream immediately prior to the liquefaction of the methane-based stream in a large proportion and the flow rates are represented by Those in M6 plant 7.9 million tons m/year using the ALY technique) shown in Figures 1 and ? The benzene concentrations in the methane-based gas streams used in this example are similar to those found by any natural gas streams shown at this point in the process. In any case, the methane-based gas streams pass with a relative tendency in the heavier hydrocarbon components. (i.e. Cot) Simulated results were produced using: Hyprotech's Process Simulation HYSIM, version 386/C2.10, Prop.Pkg PR/LK. To column A the heavier components and the simulation is based on the column containing its theoretical phases and the partially condensed current - also referred to as two-phase current - which will suffer from the last liquefaction in a large proportion is fed first to the highest stage in the column (phase 1) 0 The temperature of this stream is 117.5 F, and the pressure is 887 6 m © 8. As we mentioned before, this stream suffered from partial condensation, as it is steam 98.74 mol Q7, the stripping gas rich in methane 6, and the refrigerant fed to The lower stage is taken from the higher location shown in Figure 1, and this stream is cooled from about? 0 What is shown in the figure?; This stream is heated from about YA= to about dF, and this stream may be used to cool the upper vapors from the methane removal column. YEA

represented in the table? There are simulated temperatures and pressures and relative flow rates for each phase on the basis of the phase within the column and represented in Table © for each phase there are representative liquid compositions and vapor equilibrium. The heated fraction-rich stream AE is then fed to a de-methane column 0 which contains straightening and stripping segments from which the ethane-rich stream [methane-methane preferred by sale] is produced and used as a feed to an orifice Entering the gaseous phase above the methane compressor and a stream rich in natural gas liquids. The efficiency of the process for removing heavy parts / aromatic components is demonstrated by comparing combined nitrogen, methane, and the percentage percentage in moles of ethane 0 in the feed streams to stages 1 and # and the product from stage 1. These percentages for each stream are respectively, s Ad « 1 414 AA 4 and 4.8 mol per cent, and then the process produces a product stream that is richer in these light components than any of the two gaseous feed streams. The removal and process efficiency of benzene and JN aromatics is demonstrated by comparing the enrichment ratios which are determined as the percentage in moles of said component in 1_liquid product from phase © divided by the percentage in moles of said component in vapor product from phase A Using benzene as an example, the molar parts represented are 2,116 -8; 0, YOY and this results in an enrichment ratio of about YY. An additional basis for demonstrating the efficiency of the process are the enrichment ratios of the Crt components in the feed© streams to stages 5,1 and the resulting liquid product stream from stage 1 and vary This percentage of approx

1e - ©; to 000008 propane to about 100 octane usual. The dependent ratios between the product streams vary from about 00 for propane to about 00508 for p-octane. Example () This example, like the previous one, through a computer simulation of the effectiveness of the process described in oo, shows the full description of the displacement of benzene and components of JE from a methane-based gas stream directly before the stream is liquefied with a large proportion, and the flow rates are represented to those from the LN ©, ?mt/yr plant using the liquefaction technique shown in Figures 1 and ?. The benzene concentrations in the methane 6 feed used in this example 868 are representative of the concentrations present for several gas streams The yield at this site of the process is 0. However, the concentrations of ethane and heavier constituents in the gas stream were greatly increased, representing a richer gas stream and a greater load was placed on the process to remove both components and benzene. This example illustrates in detail The process’s ability to simultaneously remove benzene is greater and the components of Ne hydrocarbon are less. This example also shows the ability of the benzene displacement process to withstand major problems in the process in the form of large increases in ethane and hydrocarbon concentrations that are heavier without Strongly affecting the efficiency and operating efficiency of the benzene removal process. Also, this example demonstrates the ability of the process to recover heavier hydrocarbons as a separate liquefied stream. It has horsepower on the representation results using Hyprotech's Process Simulation HYSIM, version 386/C2.10, prop.

Pkg PR/ZLK TY: . The table shows; Compositions, temperatures, pressures, and phase states of the upstream currents to the heavy component displacement column, and the simulation is based on the YEA column.

Cay - which contains theoretical phases. The partially condensed current is also referred to as the two-phase current, which suffers from a large proportion of liquefaction that is fed to the higher stage in the column (phase 1). The temperature of this current is -90.7 V and the pressure 047 Zoom. As we have noted in the full description, this stream has suffered partial condensation so that 0 vapor stream is 45.04 mol # and the stream for rich stripping Meshan 06 fed to the lower stage (Stage 0) is taken from the higher location shown in Figure 1 This Sal is cooled from about 10 F by heat exchange in opposite direction with the liquid product stream produced from the © phase, and as we have noticed from the table, this stream has suffered partial condensation in the cooling path, Ve, and is represented in the table. © Simulated temperatures, pressures, and relative flow rates for each phase on a phased basis within the column, represented in the column JOT, a phase where the liquid compositions and sequential vapor equilibrium are found. In the feed stream on ve respectively to stages 1 and #4 and the product stage of phase 1 these percentages respectively VT AVA are 88,715 mol per cent and the process produces a product stream that is much richer in these components than either of the two feed streams The efficiency of the process to remove the aromatic components (JEN) is demonstrated by comparing the enrichment rates that are specific to benzene, as shown in Example 1, and the mole fractions (ADE) are 1 Array WH, which results in an enrichment rate of about CT An additional basis for demonstrating the efficiency of the process is the grouting ratios of the Cat components in the feed streams to stages 1 and 0 and the resulting liquid product streams from stages 1, and this ratio varies from about 0 for propane to about 0 for the usual octane 0-0068 and the dependent ratios between streams YEA

— Meh for octane - the usual 119000 for propane to about TY the product varies from about . n-octane 1 Table Hossam | sdsm mm [rem | es [ea| A, eed va YANA een VY ey Nitrogen

Vou a YVR Qul Yay t= E+ ANN ; =F + , VoAY CO.sub.2

TIER Akhtafa CANA Cav Methane

LL FOVY ER Carty ce Yan Cae Ethane zero zero zero zero Ethylene

Le YRAsY 0

ETAL! EL vee eed n-Butane solves for SNR -; 1 +, 8,7) ¢E Petey i-Pentane

Ceara o— KE, ANY t— FE, 7) ¢E «YY. n-Pentane A ¢— 16 GE. FT| 3 tab n-Hexane

SX e—F vo | t — FE rake t= F YY. n-Heptane Eden 1 1 vect ¢—F M (FAM n-Octane carnivorous veh ¢ —F "," ¥:\0 ¢- FE khkh Benzene ia zero zero zero n-Nonane

GVA - | Qa 1197 - Gye =| Temperature 411 m s psia 4 psia eAY psia 1 + psia Pressure Dlakh [7 steam nm m zero ak 7 7 F 1b mole/hr Flow rate Comparisons are made on the basis of mole fraction

YEA

Eh - table? Simulation results of flow and fluid properties in column M || wo Phase temperature Psia Liquid Steam Nutrition Tharat oAY All May 1115 OAY,0 Squirt 9/8 3 His 01 Acla YAAY,E q.,A OAA,© 9 thousand 5 m VAN m 11 mrb 1 - feeding to stage 1 is 4 moles mol vapor "- product displaced from stage 1001 mol 7001 bar" - feeding to stage 001 co mol mol 7 vapor - displaced product of © phase ; zero mol 7 vapor q

- 1. Table ¥ b m [IX] 4 - 0. Simulated liquid vapor stream structures leaving each phase of view Mole Fraction ‎n-Butane i-Butane | Propane Ethane Methane Nitrogen IR Vapor Gee Tie Lalabelin Laklak | Lean Fai RY liquid for eee eee to remember 0 a Va behind the vapor matt to 0 lat | TO PAL LAQEE OD 0 LIQUID GAYYVAL eae vox eee YAY VT TYLA oro VYAA AEE to 18 Vapor SY Maccabee V to AEE liquid Gea TAY NER ERLL kalka trap oc YAY Landry 7 Steam is nicknamed Al-Fahh Essence CoA Con AY eee The liquid is converted into 5 to the suffocation of the Al in the PYM LATTE The title of the steam LER ARE vee 4 NEN AA Lakh Kalkh rea Vat ae Ne tA Takhkh to the liquid Lee YVA Gee dey Ah in Avai under LAY YAN AC Follow schedule? [pee | 0 m mah a peer oe steam 1i- EAM NENA either TY 6 -E tah | Transfer liquid hip IL to Cored Co AVA with vapor EF A,0t¢ eee -? 74 1-1 7 2 -+ 1-5 v-E v8 The liquid was added to B Gee NET "compound for ARE for vapor TE TY VE VA VE, V A-E 0 A AE eae Nd liquid aa YER Lan AVY BERL RN en YASE RL Vapor EVA evan year id - 1,1 1-20 Liquid in 45 LE AV - dla yal e Vapor YH yeaa YY Tv Y,oV 1 6- Hose FE with FE ¢,AY liquid Yn Ceara teflon 1 0 YEA

—_ “1 — Table; Feed Current and Simulation Product Current > Composition and Properties (Mole Part J) AAA | arousal | Dsj ras a a hara what m

Nitrogen eet Gea Yr Gat Geat tt

EI Cava VY - E Amal t-F “Labla CO,

CF ETAAS Anh e0 LAr GLAEVA Methane

EFT IAY! A M Kfk Fthane Safar Safar Safar So Ethylene

LYTVeaA A Bin YVY ERY CNY Propane

Lave eee EY eat etd i-Butane A Ce TA n-Butane i-Pentane

CA TEYAY Coen tt coed Gene A n-Pentane 0 ahY CoA Cay n-Hexane

La TETVY o— FE 0 eed vee n-Heptane cated 1 eed vee n-Octane

NEAL H-E YAY Geant AE Ae o—E “AVE o-E +, tA0Y n-Nonane Fa Ahlyf AAAS Give - Gay - Temperature psia xh psia 241 psia 01- psia Pressure scan / zero JARRE 7 Vapor volume 1 Perspiration 1 4 77 A 1b mole/hr Flow rate Formation of compositions on the basis of mole fraction

YEAS

vy - - Table No. (5) Simulation results of the properties of a fluid flow within the column No. Pressure, degree of liquid, vapor, supply, product streams, stage 8, heat, 8 Z, for God, liquefied, poison, for a decisive cause, a, no »© Al-Aan Sass, er Miss a me | en Le SAS-1 feeding in stage 1 is 54.04 mol 7 vapor. - Displaced product from stage 10,001 mol # vapor. ?- Feed to stage 8 54 mol # vapor. ;- Displaced product from stage 0; zero mol # vapor. YEA

Table (6) Composition of a simulated liquid vapor stream, leaving each phase of view (Ksr Hziger M) n-Butane i-Butane Propane Ethane Methane Nitrogen HE Vapor Gee YT Mechanism 01471 etc. in Gees TY ere EY liquid ALA Takahtah protects medal yi ban 1/1 ad mkhi l mlkali qalak yin AAA to eee (liquid in to decipher GAT Aare. Branches of the steam the in LAY EV 117 Twisted to 8 liquid ye to smoke This is in the oven #4 of the flavors 0 The vapor is empty of the LEAVY, so the masses of the liquid are 80 vay a0. Gees. Pentane i-Pentane IE Vapor 4N LTM VY Gere 7-2 Pentane Collector Fum Liquid Halam V4 YY144 + Mtkhi T-Cac Tenl Vapor RNS Tel Hebi 1,11 EY, vA + 0 v-E Y,YY¥ 1-E Liquid Ged gay Vr YAYAA Pal Be 7 Mf FINE} Veeco Lees Steam TH Veet CeeeN YR Ra 6 v=E Y,AY 2-6 7i Liquid A Stay in Cay ov CAA oa TARY LeNevve Le TAENE Vapor E £.AY ATA v=-E av “-E v,Y\ eve EY a eee IVY Liquid 0 Ca YYYOV ALAL TAYE EM Makhni All vapor YVY bin een AY vee VA NTS for eee VY v-E liquid volume to each rubbing Geena Lavra vet Cede YEA

Claims (1)

Claims of Claims 1 1 - Process 85 to remove and concentrate hydrocarbon species of higher molecular weight from a methane-based gas stream. The steps include: (i) Condensing a large part of the methane-based stream to produce a three-phase stream two-phase stream i ° B feeding the two-phase stream SL mentioned in the upper section of 1 column No c) Remove the drain gas stream - from the heavier fractions hydrocarbons + 0 the upper part of the said column. 4 2) Remove the liquid stream rich in ALED particles from the lowest part of the mentioned column. j) Contact (through indirect heat exchange) the liquid stream 1 rich in heavy fractions with a stream of stripping gas rich in methane, Le methane, producing a stream rich in heavy fractions as a heater and a stream of stripping gas rich in methane radiator. (0” ws” feed the said cooled methane stripping gas stream to the lower section ¢/ of the column and Ve s) the JB stream touches the phases and a gas stream in the cooled methane VT stripped gas at The aforementioned column is what produces the stream of gas depleted from the heavier fractions and the stream of YY gas rich in the heavier fractions. 1 ¥ - the process according to item 1; Where step A includes dividing the gas stream, which is “- methane based, into a first stream and a second stream, and cooling the aforementioned first stream, which results in many condensed first streams, and the union of the aforementioned partially condensed first stream with the second stream, which produces Mala no - - ¢ the mentioned two-phase stream. 1 = process according to item 7; Where the amount of liquids in the two-phase stream 1 | is controlled by determining the methane-based gas stream Y and the temperature of the two-phase stream corresponding to the required liquid content at ; Balance conditions, measuring the temperature of the two-phase stream, maintaining a fixed flow rate for the first stream, the amount of cooling achieved for the said stream, and adjusting the flow rate of 1 for the said second stream in response to the temperature of the two-phase stream so that the temperature of the two-phase stream The two-phase stream is close to the degree A temperature of the calculated two-phase stream. 1 £ - the process according to item 1 and includes additionally the step: e - sequential cooling of the methane-based gas stream before step (a) by means of the flow of - the said stream through at least one indirect heat exchange method in contact ae 2 The first refrigerant stream, Le, produces a methane-based refrigerant gas stream, and the refrigerated methane-based gas flow through at least one indirect thermal refrigeration method, 1 in contact with a second refrigerant stream, where the boiling point of the second refrigerant stream be "below the boiling point of the first refrigerant stream 'Le' produces a feed stream to step (a). And the stream of the second refrigerant mentioned is present within, Y, a large part of ethane, ethylene, or a mixture thereof. 11 - the process according to the element; It includes: YEA 1 ¥ - Withdrawing a side stream from the methane-based gas stream at the lowest location of the indirect heat exchange method 1 and using the mentioned side stream as a stripping gas ¢ rich in methane in step (j). 1 no = process according to element; ; Where is the aforementioned cooling by means of exchange? - At least one indirect heat in contact with a first refrigerant stream to be included? che said gas stream to be cooled through ethane or more dE indirect heat exchange media in a sequential manner and where the first coolant of each indirect heat exchange © method has been flashed to a steadily lower temperature and pressure 1 - In a manner composed in a sequence and where the aforementioned cooling is by means of at least one indirect heat exchange method in contact with a second refrigerant stream that is composed of a gas stream A cooled through two or more indirect heat exchange means in a successive manner 1 and where the refrigerant The second for each indirect heat exchange medium has been flashed to a steadily lower temperature and pressure, Ve, in a sequential formation method. A) = process according to item 7; Where the three indirect heat exchangers X are used for cooling by the first refrigerant stream and two or three indirect heat exchange means 7 are used for cooling by the second refrigerant stream. 1 1 - the process according to item 1; Where the pressure of the feed gas, which is based on methane, methane X, is from 800 to 008 and the type. VEAS 1 01 = process according to item 7; where the pressure of the feed gas which is based on the XY membrane is about eyo to about 10 Psia . 11 1 - the process according to item 01; It also includes: indirect heat exchange and the use of the aforementioned side stream as gas 3 stripping rich in methane 6 in step (V). VY 1 = the process according to item 1 and additionally includes: e - Feeding a stream rich in heavy hydrocarbons heated from step 7 (j) to a demethane consisting of a fractionator, a reboiler and a detector by Produces a liquid stream rich in ALE fractions and a vapor stream rich in methane 1 1 - process according to element VY where a large portion of the work performed 0 (yield) for cooling of the condenser is provided by the fraction rich liquid stream Heavy “all Y” of a product by | step 5 (2) or (J). Indirect thermal contact with "L" the caliber of the liquid rich in heavy particles from step (d) and the liquid stream rich in heavy particles becomes (AL) 3 and the resulting processor + is the feeding stream carrying the ALE particles to step (j). a + - 101 operation 05 according to item 17; Where the cooling yield is provided by 1 splitting the upper gas stream into a first steam stream and a second steam stream and partial cooling and condensation X of the aforementioned first stream through indirect heat exchange by means of the liquid stream rich in heavy parts from step (d), which results in a first stream Partially cooled condenser and the union of the aforementioned first ¢ stream and the aforementioned second stream and feed the aforementioned combined stream to a liquid © gas separator from where it produces a return stream to the fractionation column and a vapor stream rich in methane 1. for 1 - the process according to item 5; Wherein, the flow rate of the return stream is controlled 1 by calculating the upper steam stream temperature of the phased stream corresponding to the liquids required Y at equilibrium conditions and measuring the temperature of the two-phase stream 1 and maintaining a constant flow rate The first stream and the amount of cooling achieved ¢ to the aforementioned current and adjusting the flow rate of the mentioned second stream in response to the degree of the Ase two-phase stream so that the temperature of the two-phase stream is approached. VV 1 - the process according to the VY element; It includes additionally between steps (3) and (3) Y the following additional step: 1 1 — flashing the liquid stream rich in ALED particles to a lower pressure, which further reduces the temperature of the said stream. And - VA 1 - the a process of the element VY, which also includes the step "0 g) condensation of the drained gas stream from the heavy parts to produce a natural gas stream Jae ¥ 111 - the process according to the element 0, where the aforementioned condensation is composed of Ge gas stream drained from the parts ALE via a non-¥ direct heat exchange medium cooled by the aforementioned second refrigeration stream 0 1 - the a process of element 15 where pressure The methane-based gas stream x is 800 to 68 YY) = the process according to item 010 and further consists of steps: x k - flashing in one or more steps of the liquefied product From step (x) to “- atmospheric pressure approximately to produce an ING (LNG) product stream and one or more ¢ methane vapor streams. 9 L - Compressing the bulk of the vapor streams from step (k) to a pressure of 500 to BCAG 0. M > Cooling of the said compressed vapor stream from step (L). Its basis is methane feeder q to step (a) or the product produced from one heat exchange fluid exchange 1.621 other than 0 - directly from step (a). - and YY 1 - the process according to item 1 where the methane technical steam stream, methane Y from step (e) is combined with one of the steam streams from step (k) before step (J) Y 1 9?- the process according to item 71; Where the pressure of the methane-based feed gas X gas stream from step (1) is about 8 to about 1586 Psia. 1; - the process according to item 1; Where the column V0 Ul provides a theoretical phase of gas-liquid contact. YO 1 - process according to item 1; Where the column provides? To 01 theoretical stages of "gas-liquid contact. YY) = process according to element YY where the column provides * to 10 theoretical phases of gas-liquid contact. YA 1 - Operation 5 to remove benzene and other aromatic components from a stream of methane-rich gas 68 The steps include: “0) condensation of a large portion of the methane-rich gas stream, resulting in a 3-phase, two-phase stream stream. YEAS 1 - 8 b) feeding the two-phase stream to the upper part of the column. (z 1) Removal of an aromatic depleted gas stream / benzene from the upper part of the said column. Contact by indirect heat exchange - of an aromatic liquid stream / 11 benzene with a stripping gas stream rich in methane, resulting in a heated stream of aromatic VY benzene and a cooler stream of stripping gas rich in methane. 0" f) feed the methane-rich strip gas stream uel methane 2 to the lower section of the 1014 column. The stream of depleted aromatic gas / gasoline (VY) and the stream of aromatic-rich liquid / benzene are excreted Its basis is methane 068 in a first stream and a second stream, and the aforementioned “first stream” is cooled, resulting in a partially condensed first stream and the union of the first stream (casa) in part; - The aforementioned with the second current to produce the aforementioned two-phase stream. 0 \ - the process according to the element; Where the amount of fluids in the mentioned (Sh al two-phase stream) is controlled by determining the methane-based gas stream by the degree of a two-phase stream JE two-phase stream The fluid content ¢ required under equilibrium conditions and measuring the temperature of the two-phase stream two-phase YEA For - stream 5 and maintaining the stability of the flow rate of the first stream and the amount of cooling achieved to a the said stream and adjusting the flow rate of the mentioned second stream in response to the temperature of the two-phase stream so that the temperature of the two-phase stream two-phase stream A approaches the temperature of said two-phase stream. 1 1 ¥ = the process according to the element YA and includes additional steps: 1 e) sequential cooling of the methane-based gas stream before step (a) by means of the said ult flow through a one-on-one indirect heat exchange method The lowest is in contact with the first refrigerant flow, resulting in a refrigerated methane-based gas stream and the flow of gas stream 4, which is methane-based; The refrigerant through at least one indirect heat exchange method is in contact with a second refrigerant stream where Ada the boiling point of the second refrigerant stream is * less than the boiling point of the first refrigerant stream resulting in the feed stream to step (a). YY) = process according to item 71 ; Where the first refrigerant stream is composed of ead larger than it from ss propane, the mentioned second refrigeration is composed in the greater part of it from 1 ethane or ethylene or a mixture thereof. 1?? = process according to item 31 ¢ and also includes: “p - withdrawal of a bypass stream from the methane-based gas stream at a location below one of the TF indirect heat exchange means and the use of the bypass stream; - mentioned as a stripping gas Rich in methane in step J. YEA IV; where said cooling by exchange 1 according to process element ;? - At least one indirect thermal process in contact with a first coolant stream that is made up of Y or more heat exchange means Ee the flow of said gas stream to be cooled Y indirectly in a sequential manner and where the first coolant to Each of these indirect heat exchangers ¢ has been flashed to a lower temperature by age and pressure in a consistent manner © in succession and where said cooling by one indirect heat exchange device on 7 contact with a second cooling stream is made up of a single stream of heat The aforementioned gas ERY (from indirect heat exchange means with a sequential method (SS) is cooled through two or + and where the second refrigerant to each indirect heat exchange method has been joined to 4 . steadily lower temperature in a steadily constant way 0 where three methods of TE exchange according to the element (process - Yo) indirect heat are used to cool the first coolant stream and two or three means of Y. Indirect heat is used for cooling by the second cooling stream, JET - where the pressure of the feed gas is based on. YE According to the element process - 1 1 . Methane is 800 to 00 oz, where the pressure of the methane-based feed gas is the process TE according to the element - YY). Hawal 596 and Nom Jove about Y: also includes TY according to the element process process = TA 1 g - withdrawal of a side stream from the methane-based gas stream at a location below Uhud 1 And for - ¥ the unsuitable heat exchange means and the use of the mentioned side stream ¢ as a stripping gas rich in methane in step (j). 001 ¥4 = process according to element YA and includes additionally: Y e feeding the heated stream rich in aromatic / benzene from step (j) v to a demethane of a fractionating column, a reboiler and a condenser including It produces a liquid stream ¢ rich in aromatic benzene and a vapor stream rich in methane. 0 1 - process according to item 79; Where a large part of the cooling yield Hall X is provided by the available aromatic / benzene-rich stream - by step (d) or (j). 1 1; - the process according to item 79; where the bulk of the cooling yield Y of the condenser is provided by flow through an indirect contact heat exchange method With the stream of aromatic / benzene rich liquid from step (d) and the stream of aromatic / benzene rich liquid 5602686 becomes the feed stream carrying aromatic / °J benzene from step (j). £Y 1 - process Process According to element 0; Cua the cooling yield is provided by Y classifying the upper vapor stream into a first vapor stream and a second vapor stream and partial cooling and condensation 1 of said first stream by indirect heat exchange with the liquid stream 1 rich in aromatic / benzene 6 of Step (d) By what results in a partially cooled first airflow ° and the union of the mentioned first stream and the mentioned second stream and feeding the said combined stream 1 any liquid-gas separator from where the return stream to the fractionation column and the YEA stream are produced yo - - VY methane-rich steam. 1 "; -_process according to item 8X wherein the return stream flow rate ¥ is controlled by calculating the upper steam stream for the temperature of the two-phase stream 3 against the required fluid content in cases of equilibrium and temperature measurement ¢ The temperature of the two-phase stream, maintaining the stability of the first alo flow rate and the low amount of cooling to the said stream, adjusting the mentioned second stream flow rate, and adjusting the said second stream flow rate in response to the temperature of the two-phase stream so that the temperature of the stream JE Calculated phases are + approached. \£1 - process according to element 500 and incrementally between steps (d) and (j) an additional shall Y of: 1 g - flashing of the aromatic-rich liquid stream/gasoline benzene to a lower pressure, which reduces the temperature of the aforementioned stream more. 3 liquefied natural gas stream 1 7 - process according to element £0, where the aforementioned condensation is composed of Y flow of aromatic depleted gas stream / benzene through an indirect heat exchange method ¥ and cooling by the second cooling stream mentioned. YEA EV \ — the process according to item 46 where the pressure of the methane-based gas stream Y is 800 to 08 and a note . £A 1 = the process according to the element £Y and additionally includes the steps: p - flashing in one or more steps of the liquefied product from step (x) to 1 atmospheric pressure approximately, resulting in a product stream (ING) natural gas liquefied (and one or more ¢ methane vapor streams. ° l - pressure of most of the steam streams from step (k) i.e. pressure 00 to 008 m - cooling of the said compressed steam stream from step (\ ). ln - collection The resulting refrigerant with the methane-based gas stream fed to step (a) or A the product produced by one of the indirect heat exchange means from step q (e). According to element uc EA the methane-rich Jad stream from step (e) is combined with one or more steam streams from step Y from step (k) before step (f). 0 1 — The la process of element 48, where the pressure of the Y-based feed gas is methane and the gas stream from step (a) Jove Js is about 186 Psia. 1 1 © — the laa process of element Yo Where the column from ? to Yo provides a theoretical phase of gas-liquid contact 1 © — the process according to the YA element where the column provides ? To 10 theoretical stages of gas-liquid contact. OF 1 - process according to element 0; Where provides the column? To 15 theoretical Y stages of gas/liquid contact. ot 1 - the process according to item 6 where column 7 to Jal se Ve Y provides a theory of gas-liquid contact. YEA