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Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for the separation and recovery of complexable ligands from a ligand-containing feed stream.

In particular, the present invention may form complexes with such ligands.

An improved method for separating complexable ligands contained in a feed stream by contacting the feed stream with a sorbent cuprous salt dissolved in a complexing solvent. .

In one preferred embodiment, the present invention involves the use of high boiling aromatic hydrocarbon solvents for complexing solutions.

These aromatic hydrocarbon solvents contain high specific gravity polycyclic, high boiling point, low melting point aromatics and mixtures thereof; "high percentage" means about 50 mo1% or more of the total moles of solvent. be.

The complexing solution should further contain low specific gravity, high boiling point, strong complexing, monocyclic aromatics such as alkyl-substituted monobenzenes; "low specific amount" is about 5 moles of total solvent.
This means 0mo1% or less.

No. 3,410,924 discloses contacting complexable ligands with a cuprous halide salt contained in an anhydrous slurry in the presence of a C5 monoolefin sorbent activator to remove them from a feed stream. It describes how to collect it.

Another method described in US Pat. No. 3,218,366 describes the separation of olefins from hydrocarbon mixtures by selective absorption using silver fluoroborate or silver fluorosilicate.

A method for separating non-aromatic unsaturated hydrocarbons from more saturated hydrocarbons by selective complexation using cuprous trifluoroacetate dissolved in a solvent such as propionitrile is described in U.S. Pat. No. 3,401,112. Disclosed in the specification.

Beckman et al. in U.S. Pat. No. 3,517,081 described
Examples teach a method for the separation of unsaturated hydrocarbons from mixtures with saturated hydrocarbons by contact with cuprous fluoroborate or cuprous fluorophosphate dissolved in ethatoluene, ethylbenzene, ethyltoluene, xylenes and tetrahydronaphthalene. are doing.

Finally, U.S. Patent Nos. 3,651,159 and 3,592
No. 865 discloses tetrachloroaluminum acid dissolved in a bimetallic salt, i.e., an aromatic hydrocarbon, i.e., benzene, for the separation and recovery of complexable ligands by a ligand exchange method. Methods for the synthesis and use of cuprous are described.

A disadvantage of the methods described in these referenced documents is that the complexing ligand, e.g. ethylene, causes flash-off of the nibenzene when decomplexed in the decomplexer; this factor relates to the high volatility of the solvent Hensen. necessitating costly extra separation treatment of the benzene vapors.

Therefore, improvements in the operation of conventional techniques are desirable.

According to the invention, the feed stream and the sorbent cuprous salt such as cuprous tetrachloroaluminate (CuAIC14
) provides an improved method for separating complexable ligands from a feed stream.

The improved method incorporates a Daiichi Steel complexing agent into a solvent consisting of a high specific amount of polycyclic, high boiling point, low boiling point aromatics and a low specific amount of strongly complexing, high boiling point, monocyclic aromatics. Find a way to dissolve it.

Separation is accomplished by complexing the sorbent with the ligand, thereby removing the ligand from the feed stream.

Specifically, the present invention describes the use of certain high-boiling aromatic solvent compositions having boiling points of from about 150 to about 450°C, thereby using a complexing agent primary salt such as cuprous tetrachloroaluminate. An improved method for recovering light olefins is obtained in which the light olefins are complexed with a ligand such as ethylene.

From high proportions of polycyclic, high-boiling, low-melting aromatics, such as biphenyl, substituted biphenyls, naphthalenes, and alkyl-substituted mononaphthalenes, and low proportions of strongly complexing, high-boiling, monocyclic aromatics, It has surprisingly been found that when light olefin recovery is carried out in the presence of a complexing solvent, the process provides an effective complexing solution and is economically very attractive.

In accordance with the present invention, it has also been found that the use of the polycyclic, high boiling, low melting aromatics alone as a solvent results in an increase in the overall viscosity of the complexing solution.

This viscosity increase tends to increase process operating parameters and actually reduce the overall efficiency of the process.

Therefore, not only are high amounts of the polycyclic, high-boiling, low-melting aromatics used in the solvent, but also low amounts of the strongly complexing, high-boiling, monocyclic aromatics are used in the complexing solution. Containing it is an essential requirement.

The high viscosity of polycyclic aromatic complexes can be achieved by adding a low specific amount of strong complexing, high boiling point, monocyclic aromatics to prevent chain formation or highly ordered sol that may form in solution. It is thought that this can be effectively reduced.

However, I do not intend to be bound by any particular theory.

Not only that, the substitution of the solvent benzene by polycyclic aromatics, such as biphenyl, does not result in any sacrifice in the ability of the complexing solution.

This means that for every two benzene molecules replaced by one biphenyl molecule, the same amount of cuprous (I) salt can be complexed; each ring of the piphenyl compound is
I) This is because it can form a complex with salt ions.

At the same time, the volatility of the complexing solution is significantly reduced, thereby facilitating the recovery of the complexable ligand in the decomplexation step.

The addition of low specific amounts of high-boiling, strong-complexing, monocyclic aromatics to stop the chain and effectively reduce solution viscosity has led to an overall improvement in the process; resulting from the combination of both of the solvent components used in the solvent.

The method uses a variety of complexable ligands such as olefins, acetylenes, aromatics, carbon monoxide, etc.
Suitable for separating.

In particular, unsaturated hydrocarbons include acetylenes, such as C2-C6 acetylenes, preferably C2-C4 acetylenes, such as acetylene, methylacetylene, ethylacetylene, dimethylacetylene, vinylacetylene, etc.; monoolefins, e.g. 02-C20 monoolefins, preferably 02-CIO, more preferably C2
~C5 monoolefins, most particularly ethylene and propylene; conjugated diolefins, such as C4~CI
O preferably C3-C6 conjugated diolefins, such as butadiene, isoprene, etc.; polyolefins, such as C6-C16 preferably C6-C12 polyolefins, such as cyclododecatriene, cyclooctadiene;
Cyclic olefins and alicyclic olefins, such as C
, ~CIO preferably C6-C8 such as cyclopentene, cyclohexene, cyclooctene, etc.; aromatics such as 06-C12 preferably 06-C8 aromatics such as benzenes, xylenes, toluenes;
It may also be diolefins of the diolefin type, such as C3-C6 diolefins of the cumulene type, such as arenes.

It is desirable to apply the method to the separation of complexable ligands such as C2-C4 monoolefins, 02-C4 acetylenes, carbon monoxide and C6-C9 aromatics.

Typically, the complexable ligands separated by the process are contained in the feed stream in admixture with other components which are also preferentially not complexed.

For example, feed streams such as ethane-ethylene or propene-propylene can be processed to concentrate olefins.

Complexing agents or sorbents include cuprous salts of weak basic acids such as tetrachloroaluminate (AICl4-), tetrafluoroborate (BF4-), and trifluoroacetate (CF3CO) and the following compositions: Formula: CuPF6
, CuBCl4, CuAIBr4, CuAIClxBr
y and CuφxAlc1y (where rLx+y=4 and φ is phenyl); the sorbent used is cuprous tetrachloroaluminate (C
uAIC14) is preferable.

As mentioned above, the sorbent solvent contains a high proportion of polycyclic, eg at least bicyclic, high boiling, low melting aromatics.

In the practice of the present invention, the aromatics referred to as being easy to use and having a high boiling point are about 150-450°C, preferably 200-400°C, more preferably about 250-450°C.
It has a boiling point of 300℃.

"Low boiling point" means that the melting point of these aromatics is -
This means that it should be in the range of 100 to 125°C, preferably -50 to +50°C, more preferably -10°C or less to about +40°C.

Examples of polycyclic aromatics useful in the practice of the present invention are biphenyl, substituted biphenyl (by the expression "substituted hiphenyl" is meant biphenyls substituted with groups such as chloro, bromo, alkyl, etc.)
, such as diphenylmethane, 1,1-diphenylethane, 1,2-diphenylethane, 2-methylpiphenyl,
3-methylbiphenyl, 4-methylbiphenyl, 2.2
'-dimethylbiphenyl, 2,3'-dimethylbiphenyl, 3,3'-dimethylbiphenyl, 4,4'-dimethylbiphenyl, 2-isopropylbiphenyl, mixed isofurobilbiphenyl, o- Includes chlorbiphenyl, cumene, etc.

The term "polycyclic aromatics" refers to polyphenylalkanes, substituted polyphenylalkanes, naphthalenes, alkyl-substituted mononaphthalenes such as methylnaphthalene, 1-methyl-9,10-dihydroanthracene, 2-methyl-
It is meant to include polycyclic aromatics such as 9,10-dihydroanthracene and the like.

A mixture of said polycyclic aromatics may form the majority of the sorbent solvent.

The sorbent solvent has a low specific amount of high boiling point, strongly complexing, monocyclic aromatics, e.g.
It should also contain alkyl-substituted benzenes and heterosubstituted benzenes of from 30 to 30, preferably from 2 to 201, most preferably from 3 to 9.

By "heterosubstituted monobenzenes" is meant a benzene ring having a group such as chloro, bromo attached to the ring or to a carbon of the ring.

Representative examples of useful monocyclic aromatics include triisopropylbenzene, trimethylbenzene, tetramethylbenzene, cumene, tetraethylbenzene, phthylbenzene, cyclohexylbenzene, tetralin, chlorotoluenes, chloroxylenes, and the like.

The capacity of the complexed sorbent is defined as the number of moles of ethylene absorbed per Culmol, and the capacity should be in the range of 0 to about 2, preferably 1.5 to 2, at room temperature and atmospheric pressure.

The sorbent loading capacity into the complexing solvent is O~2 of Cu(I).
It should be 0% by weight, preferably about 10-15% by weight.

The viscosity of the complexing solution is 0.5-12c at 50°C
st, preferably from 3 to 9 cst, more preferably about 5 cst or less at 50°C.

The method can be operated at various temperature and pressure conditions.

In all complexes, the reaction temperature is about 40 to about 149°C.
(-40 to below 300℃), preferably -40 to 93℃ (-
40-2oO), more preferably about 10-66℃ (5
0 to 150'F).

The pressure may vary as well, from about 0.5 to about 100
ATM, preferably 1 to 20 ATM.

Recovery of the desired ligand can be carried out by substitution with other olefins or by decomposition by heating.

In one preferred embodiment of the invention, ethylene and propylene are separately recovered from a feed stream, the feed stream being a stream obtained from the light end section of a conventional steam cracking unit.

Such a feed stream, from which the acetylene and carbon monoxide may first be removed by ammonium acetate cuprous complexation and conventional carbon monoxide absorption methods, contains methane, ethane, etc. in addition to the desired ethylene and propylene ligands. , propane and hydrogen.

These desired ligands can be recovered with a purity of 95% or more, preferably 99% or more, by the method of the present invention.

In standard processes for ethylene recovery from steam cracking or other operations, the feedstock is gaseous C2 or lighter materials.

This stream is produced in a conventional absorbent deethanizer or a low temperature deethanizer.

The 02-1 feedstock typically contains low concentrations of Class 03 to meet specifications of 50 ppm or less for 03+ in the product ethylene.

Sulfur-containing impurities and acid gases are usually removed upstream of the deethanizer.

Although the present invention is illustrated in the following Examples, the present invention is not necessarily limited thereto.

Example 1 CuA at atmospheric pressure using a 100 ml glass reaction equipped with gas inlet and outlet, thermometer and mechanical stirrer
Ethylene complexation and decomplexation were determined using various aromatic complexes of ICl4.

The reactor was immersed in an oil bath which maintained the complex temperature at ±1°C.

Gas intake and delivery during each temperature interval were measured with wet meters in the inlet and outlet tubes.

The gas mixture was examined by gas chromatography.

This device made it possible to measure the complex ethylene loading rate (ethylene mol number/Cumol number) at various temperatures.

All complexes were made as described in US Pat. No. 3,651,159.

Initial tests showed that CuA in three different solvents (benzene, diphenylmethane and cyclohexylbenzene)
The IC14 complex was investigated.

Ethylene loading was determined as described above and bulk viscosity was measured with a calibrated capillary viscometer.

The results obtained are summarized in Table 1.

These data show that solvent volatility is significantly reduced when diphenylmethane is compared to benzene without deleteriously affecting the molecular weight ratio to Cu or other ethylene complexing abilities.

Cyclohexylbenzene (monocyclic high-boiling aromatic)
When compared with benzene, it suffers from a high molecular weight ratio per 1 Cu atom, but the viscosity does not become high.

Example 2 * * The experiment described in Example 1 was repeated using CuAICl, three other aromatic solvents for the complex (methylbiphenyl, triisopropylbenzene and methylbiphenyl triimpropylbenzene mixed solvent).

These results are summarized in Table 2.

These data show that when a small amount of a monocyclic aromatic, such as triisopropylbenzene, is added to a polycyclic aromatic, such as methylbiphenyl, there is a surprisingly large effect on the polycyclic aromatic, such as triisopropylbenzene.

7 shows a much greater reduction in viscosity than that achieved by the corresponding dilution with the 7-tic component.

Example 3 Biphenyl of CuAIC14 and.

The experiment described in Example 1 was repeated using the -chlorbiphenyl complex with the results shown in Table 3.

These data demonstrate that monocyclic aromatic components (0-chlorobiphenyl has only one complexable aromatic ring) can be used alone to form non-liquid complexes even with the addition of relatively small amounts of major components such as biphenyl. This shows that even when the

In other embodiments, the invention provides a method for contacting a feed stream containing a complexable ligand with a complexing solution, then stripping impurities from the solution, decomplexing by high pressure or multi-stage flashing, and removing the solvent. An improved method for separating the ligands by recycling them into a complexer followed by recovery of a high purity light olefin product.

The improvements achieved are the overall economic benefits realized as a result of lower equipment costs, lower solution inventory requirements, and shorter processing times at elevated temperatures that minimize solution decomposition.

Figure 2 shows the constant loading rate of olefin [(mol number of olefin/Cu
2 mol) x 100%].

The olefin separation cycle is shown by going counterclockwise around ABCDE in the diagram, with point A representing standard conditions at the top of the anchorage, where the poor complex (typically C
2 - loading factor is 10%) is recycled to the complexer.

Temperatures on the order of 50° C. can be maintained by the cooling p-water and the heat exchanger temperature gradient.

The olefin pressure is determined by the desired olefin recovery rate from the feed gas.

To the vertical line A-)H? The 85 motion represents the passage of the complexing solution flowing down the complexer: the temperature remains constant as the heat of complexation is recovered.

At point B, which represents the situation at the feed point of the olefin-gas mixture in the leadizer, the complexing solution is approximately 90% loaded with olefin.

The next step in the cycle is the olefin constant load line (BC).
is expressed by

In C, the complex is pumped to the desired olefin product pressure, which is typically between 15 and 25
It is ATM.

segment} (CDE) is approximately 14
This is done by heating to 0°C, the exact temperature being limited by the stability of the complex.

In the first stage, the olefin product is removed while heating to about 140<0>C, typically at a pressure of 15-25 atm.

the first increment of product at a higher pressure,
It should be understood that this can be removed if this proves desirable.

The next decomposition step, represented by points a and b on the constant temperature line (DE), serves to liberate the olefin at intermediate pressures while maintaining the complexing solution at about 140°C.

By E, which represents the end of the third stage, the olefin in the complexing solution has been reduced to about 10%.

The complex is then recycled to the complexer while cooling (line (EA)) and the cycle is repeated.

In the cycles described in this section, the product olefin gas from the second and subsequent stages should normally be compressed to the desired product pressure.

Furthermore, it has been found that product gas recovery at low pressures can be avoided by utilizing the embodiments described below.

In this embodiment, at low pressure, e.g. 3 atm, the gas is reabsorbed by a fraction of the olefin-poor complex at a low complexation temperature of 49-93C (below 120-200C).

The resaturated complex is sent to a first decomplexation stage where the olefins are liberated by flashing at the desired high product pressure.

The ratio of poor complex flow rate to the reabsorber: poor complex flow rate to the complexer is on the order of about 0.45.

In one embodiment, the present invention provides very high purity, such as that required in chemical operations such as polyethylene production, such as 99.9 mo1%. related to the recovery of olefin.

For other purposes, such as for fuel processes such as alkylation of C4 hydrocarbons using ethylene and propylene, the desired purity of the product olefin is 95 to 9
This will be eased somewhat to around 8%.

The process may be operated to complex a majority of the feed stream olefins, ie, >50%.

Furthermore, it is desirable to omit or reduce the impurity treatment section at the bottom of the complexer.

It is also desirable to combine the preferred decomposition methods, namely flashing by heating and stripping using a stripping gas such as C4 hydrocarbons.

This is a particularly advantageous method in which the recovered olefins and C4 hydrocarbons are then accompanied, for example, to an alkylation reactor.

After complexing the light olefins contained in the feed stream, impurities are driven out of the solution.

This step of the process can be carried out by recycling some of the light olefins recovered downstream to the complexer to drive impurities, such as ethane, out of solution; ligand purity is critical. If not, the impurity stripping device can be omitted or reduced.

It is preferable to carry out the dissolution process of the method by one of the following methods; one method is by flushing, that is, by heating at high pressure [1 to 40 at.
m. Desirably 20 to 40 atm. More preferably 25
〜35atm, heating is 10〜260℃
(lower than 50-260°C), preferably 93-204°C (2
00-400℃), more preferably 93-149℃ (2
00-300'F), e.g. 107-138°C (225
~280'F)].

Another preferred method of decontamination is by multistage flushing.

Multistage flushing is described as flushing off by heating in multiple stages where the pressure decreases from one flash column to the next downstream flash column.

The first flush may be at a pressure equal to or greater than the product ethylene line pressure.

Subsequent flash steps may be at or above the pressure of the impurity stripping section of the complexer, and the final flash is at a reasonably low pressure, e.g. 1-5 atm., to obtain good ethylene recovery in the complexer. It will be held in

Solvent recovery as a step in the method includes recycling the complexing solution to the complexing vessel.

This is the slip stream of the complex.
(ream) treatments may be further included to maintain low levels of species that may catalyze chemical reactions or promote corrosion.

This slipstream treatment may include stripping, settling and contacting with solid cuprous chloride to remove free AIC13, etc.

Finally, the high purity light olefin product, such as ethylene, is recovered and the final purification process includes removal of trace solvents and light reaction by-products.

As shown in FIG. 1, the apparatus includes a deethanization zone 10 followed by a complexing-decomplexing zone.

The purpose of the deethanizer is to prepare a C2 feed stream that is sent to the complexer.

Ethylene is selectively removed from the 02-gas in the complexer 16 and then recovered in high purity from the complexer.

Deethanization operations remove C3 and heavier materials from C5-cuts from steam cracking or other operations.
Typically 16-66°C (60-150”F) and a gauge pressure of 10.5-17.5 kg/d (150-150”F)
250 psig).

Alternatively, a low temperature distillation method may be used. The feed to the deethanizer is scrubbed with caustic or amine in a caustic scrubber overhead 12 to remove acid gas impurities such as carbon dioxide and sulfur compounds.

Typically, the deethanizer removes 50 ppm of C3+ in the ethylene product.
C2 and C3 sufficiently complete to meet the following standards:
Achieve separation of components.

In an absorption deethanizer, the absorbing solution may be a C5-06 oil cut consisting primarily of allo-dimatics and diolefins.

Following the deethanizer is a heavy sponge oil scrubber 14 which removes the C.I.O. oils carried away into the C.sub.2 sm.

C2- from the top of the sponge column passes through an acetylene converter and a dryer at a temperature of 10-66°C (below 50-150°C) and a gauge pressure of 7.0-17. 5 kg/crA (100~
250 psig) into the ethylene complexer 16.

The ethylene complexer may be a conventional plate column in which the column is poor in ethylene (typically about 0.1 per Culmo).
~0.5 mol of ethylene), a complex consisting of an aromatic solution of a sorbent cuprous salt is fed to the top tray and flows countercurrently to the feed gas stream fed at the bottom of the column. do.

Ethylene is complexed into the liquid phase, while other gases go to the top.

An intercooler is installed along the column to remove the heat of ethylene complexation from the complexing solution.

Typically, up to three gold draw-off pumparounds are used for heat removal.

The temperature profile in the complexer is about 49°C (120'F) at the top of the column. 49-66 at feed plate
°C (120-150'F'), with a maximum intermediate temperature of 7
The temperature is 7-88°C (170-190T).

The total pressure in the complexer is typically 5-20 atm.

Uncomplexed gases such as hydrogen, methane, ethane are directed to the top of the column and normally pass into the fuel system.

A section of the column below the feed plate is provided to drive off dissolved saturated hydrocarbons, such as ethane, and undesirable complexing species, such as carbon monoxide and acetylenes.

The stripping gas used in this section is a complexing gas of high purity olefin gas from the intermediate decomposition flash.
It is fed by recirculation to the bottom of the Zuping column.

The temperature in the stripping area is 49-71℃ (120-1
60 and below).

highly ethylene loaded (typically Culmo1
1.5 to 1.9 mol of ethylene), the bottom oil from the complexing-stripping column is pumped by pump 18 to 15 to 4 mol of ethylene.
．． Oatm is pressurized and sent through a heat exchanger into the first flash of a series of decomposition flashes.

Standard temperature is 121-149℃ (250-300℃) and gauge pressure 17.5-24.5 k9/crA (2
In the first flash 20, which is between 50 psig and 350 psig, most of the ethylene is flashed off into the product tube.

The complex then enters a second flash which is at the same temperature as the first flash and at a lower but higher pressure than the complex-stripping column to remove the product and some of the complex-stripping column for recycle. Produces stripping gas.

Finally, the low pressure flashes 2, 4 liberate further ethylene which must be compressed to product pressure.

The standard pressure sequence for dissolution flashes is: 1st flash
Gauge pressure 1 7.5 ~ 2 4.5 kg/crA (2
50~350 psig); 2nd flash
Gauge pressure7. 0 to 1 4. 0 kg/crA (
100 ~ 200 psig) ; 3rd flash gauge pressure 0 ~ 3.5 kg/c4 (0 ~ 50
psig); fourth atmospheric pressure flush (
(not shown) may also be present.

The poor complex from the final flash is recycled to the complexing column overhead after being cooled by heat exchange with the ethylene-rich complex.

A complex processor for removing undesirable side reaction products or impurities may be included in the slipstream complex processor 26 to treat 1-10% of the complex stream.

A stage compressor 28 is provided for ethylene from the intermediate and low pressure decomposition flash.

A small amount of aromatic solvent carried away from the decomposition flash is transferred to a compressor knockout drum.
um) and any remaining traces are removed from the product stream by adsorber 30 or by final rectification.

A portion of the product may be liquefied by mild freezing for storage.

The invention is further illustrated by the following examples.

EXAMPLE 4 In this example, C2 and lighter products from a steam cracking furnace containing mainly hydrogen, methane, ethane and ethylene but also traces of carbon monoxide, propane, propylene, methylacetylene and propadiene are used. Ethylene from fraction to gauge pressure 1 8.
It was recovered with a purity of 99.9 mo1% at 9 kg/cA (270 psig).

The aromatic complex solution contains 0.9 mol of i-propyl biphenyl per 1 Culmol and 0.7 mol per 1 mol of Cu.
The sorbent cuprous salt CuAIC14 was dissolved in a low solubility solvent mixed with triisopropylbenzene.

This was prepared by mixing a mixed solvent with CuC1 and AIC13.

Complexation was carried out using a 12-tier perforated tray (perf
The complex solution was brought into contact with the ethylene-containing feed gas in a water-cooled complexation tower with an orated tray.

The temperature was 54-66°C (130-150'F) and the total pressure was 10 atm.

The raw material gas contained 40 mo1% ethylene.

99.5% of the ethylene was recovered from the feed gas as determined by gas chromatography analysis.

1. The ethylene-loaded complex containing 75 mol% C2-/Cu 1mol was then sent to an impurity stripper, a perforated plate column with 24 trays.

The ethylene stripping gas flow rate is 0.0000000000000000 1 mol; temperature is 54-71°C (13
pressure was 10 atm.

High purity ethylene was fed as stripping gas to the stripper bottom.

Non-ethylene components include recovered ethylene with <10 ppm carbon monoxide, <700 ppm methane and ethane, <
It was expelled from the solution to a purity containing 50 ppm of 03 min.

For decoupling, the ethylene-loaded chain solution is brought to a pressure of 20. 5 8 kg/crA (2 9 4
psig) and heated to 138°C (280″F) in heat exchanger tubes with heat provided by insulating hot oil.

The ethylene flashed off under these conditions was 13
Separated from the complex solution in a flash drum of Qcc volume.

The complex from the first flash containing 1.15 mol of ethylene per Culmo was brought to a pressure of 9. 8 ky
/cwt (140 psig) to a second flash, which increases the ethylene loading rate to Culmo
0 per 1. The amount was reduced to 85 mol.

Gauge pressure 2. 73 kg/crA (39ps
In the third flash in ig), the ethylene is Culm
The amount of ethylene was reduced to 0.5 mol per o.

Impurities in the recovered ethylene were analyzed using gas chromatography.

Example 5 In this example, a catalytic cracker off-site containing C3 and lighter materials such as propane, propylene, methane, ethylene, ethane, hydrogen, carbon dioxide and nitrogen is used.
Mixed ethylene-propylene from gas stream at 1 gauge pressure 8. 9 kg/crA (270psi
g) and an olefin purity of 98.5 mo1%.

The cuprous solution was CuAiCl4 dissolved in a mixed, low volatility, aromatic solvent consisting of 1.1 mol of diphenylmethane per mol of Cu; complex preparation and equipment used were as described in Example 4.

The feed gas contained 8 mo1% ethylene and 30 mo1% propylene.

Complexation takes place at 52-66°C (125-150°C) and impurity stripping takes place at 60-7PC (140-16°C).
It was carried out at 0〒).

9 of mixed olefins fluffed by adjusting the amount of highly striated (ethylene + propylene) stripping gas.
An olefin purity of 8 mo1% was achieved.

The amount of stripping gas required is 0.000 stripping gas per Culmo.
It was 0.75 mol of (ethylene+propylene).

127°G (below 260) and gauge pressure 1 8.4 4 kg
/C4 (292 psig). 1 0. 5k9
/Ct(150psig), 2.45
k9/ca (35 psig). The olefin loading rate in the complex is 1.0% per mol of Cu by stepwise flash dissolution in . 8 5 mol to 0.
It exited the low pressure flash stage reduced to 6 mol.

20 by gas chromatographic analysis of the product gas.
．． 6 mo1% ethylene and 7 7. 4 mo1%
of propylene was found to be present.

The embodiments of the present invention are as follows.

(1) The high-boiling, low-melting, polycyclic aromatics are selected from the group consisting of biphenyl, alkyl-substituted biphenyl, polyphenylalkanes, substituted polyphenylalkanes, naphthalene, and alkyl-substituted mononaphthalene. The claimed method.

(2) The method according to claim 1 or claim 1, wherein the sorbent is cuprous tetrachloroaluminate.

(3) The method according to claim 1 or 2, wherein the monocyclic aromatic is alkyl-substituted benzene, and the alkyl substituent thereof has 2 to 30 carbon atoms.

(4) The complexable ligand is a C2-C6 acetylene, 0
4. A method according to claim 1 or claim 3, characterized in that it is selected from the group consisting of 2-C20 monoolefins, C4-C1o conjugated diolefins, C6-C9 aromatics and carbon monoxide.

(5) The method according to item 4, wherein the desired complexable ligand to be separated is ethylene or propylene.

(6) Complexing solvent is 0.5 to 1 2 c at 50°C
6. The method according to claim 1 or the method according to claim 1, wherein the method has a viscosity of st.

(7) The method according to claims 1 to 6, characterized in that the complexing solvent consists of a high proportion of methylbiphenyl or imbrobilbiphenyl and a low proportion of triisoprobylbenzene. .

(8Xa) Contacting the raw material stream with a complexing solution in a complexing vessel to complex the dog portion of the ligand contained in the raw material stream; (b) 1 ~40atm pressure and 93~204℃ (2
Flushing ( f
lashing); or ←→ a multi-stage flash-off in which the pressure is reduced in each successive step; (-) recovery of the ligand as a product of desired purity; or the first claim characterized in that
~The method described in item 7.

(9) The pressure used in the above procedure ←→ is the gauge pressure of the first flush of approximately 17.5 to 24.5 kg/c
n7L (250 to 350 psig) to final flush gauge pressure 0-3.5 kg/crA (0
9. The method of claim 8, wherein the temperature is within the range of 50 psig).

(lO) The method according to items 8 and 9 above, wherein the ligand is a C2-C4 monoolefin.

Impurity stripping treatment from αυ complexing solutions. 8th to 1st, characterized in that this precedes the dissolution treatment
The method described in item 0.

(12) The method according to item 1o above, characterized in that a portion of the recovered C2-C4 monoolefins is recycled to a complexing vessel to strip impurities from the complexing solution.

(13) The method according to items 8 to 12 above, characterized in that the decomplexing solution is recycled to the complexing vessel.

[Brief explanation of the drawing]

FIG. 1 is a process flow sheet. FIG. 2 is a pressure-temperature diagram of the decomposition caused by simple heating of olefin under vapor pressure.

Claims (1)

[Claims] 1 feedstock stream to CuAIC14 and CuAI
contact with a sorbent consisting of a cuprous salt selected from Br4, the sorbent being a high boiling point, low melting point, polycyclic compound of 50 mol% or more selected from biphenyl, alkyl-substituted biphenyl and polyphenylalkane; aromatics and a low specific amount of complexing, high-boiling, monocyclic aromatics dissolved in a complexing solvent, the contact of which forms a complex between the ligand and the sorbent, thereby a ligand-containing raw material stream, characterized in that the reaction is carried out under reaction conditions that remove the ligand from the raw material stream, and the complexable ligand is a lower olefin. Method for separating complexing ligands.