DE2154288C3 - Process for the separation of hydrocarbons - Google Patents

Description

2. The method according to claim 1, characterized in that the carrier is impregnated. The same is true if the porous indicates that conjugated diene hydrocarbons are softened with a tributylphosphate from mixtures that are saturated or simply made. Polyvinyl chloride is provided that does the role Contain olefinic hydrocarbons, from the solvent takes over. Im polyvinyl chloride be separated. 25 the tributyl phosphate is actually a simple one

'J physical, albeit intimate, mixture with the

i ' macromolecules of the vinyl chloride polymer.

j \ Anyway, the plasticizer isn't chemically attached to the

f macromolecules bound.

"30 In other cases it has been suggested to

»Tion of metal ions not electrically charged

I use membranes. These membranes wear

functional groups according to the nature of the to

The known large-scale process for separating ions. These separation methods are . Separation of hydrocarbons use the 35 in US Patents 34 50 630 and 34 50 631

i liquid / liquid extraction or the extrak- described, which does not, however, refer to the separation

tive distillation. Apply to liquid / liquid hydrocarbon mixtures. ^ Extraction is z. B. Sulfuric acid used to In the following further literature references are treated

} Isobutene from a delt previously freed from butadiene, which relates to the state of the art.

; Extract fraction with ^ hydrocarbons. 40 The US patent 23 88 095 relates to a method

I The sulfuric acid enables a selective solution for refining mineral oils, in particular

I of the isobutene from the mixture of C ₄ -carbons- with respect to the separation of isoolefins from their

I fabrics. The extractive distillation is z. B. the mixtures with normal olefins. The to be treated

I Separation of dienes in C ₄ and C ₅ hydrocarbon gas mixture is in a high pressure chamber

I substances-containing fractions, the butadiene 45 introduced; this is through a membrane that aui

f; from which the fraction containing the hydrocarbons is applied to a perforated metal plate, from

1 tion and the 1,3-pentadiene from the fraction of C ₅ - separated in a low-pressure chamber. On each side

I hydrocarbons is separated. In this case of the membrane, gas fractions are obtained which have mil

f is used as a selective solvent aceto one or the other component of the mixture

I nitrile. The petroleum industry uses N-methyl-50 enriched. The description of the US patent

j 'pyrrolidone as a solvent in the extraction of scripture 23 88 095 mentioned that it was known as

I butadiene and pentadienes. solid solvent rubber membranes for separating

I The disadvantage of this known process for separating gaseous saturated hydrocarbons

; This consists in the fact that their yield will continue to be used with those with gaseous unsaturated substances

progressive extraction or distillation. 55 hydrocarbons are saturated. That in the patent you request, among other things, the use font given comparative example shows that you ,, Complicated devices and important matter separation with such a rubber membranec I, lien, which makes them expensive. Even the sub- is unsatisfactory. The US patent

Maintenance costs of these devices are high. 23 88 095 suggests other types of solid solvents

f Attempts have already been made to identify the various 60 before, in particular membranes, which are produced by polymerisation

Γ To remedy disadvantages by mixing the tion of isobutylene or copolymerizing one

ί to be separated hydrocarbons via porous Trä- isoolefins, such as isobutylene, with a conjugated

^f ger or soils leads that were obtained a selective Extrak diolefin. These membranes act

' _t contain solvent. So z. B. the US as a solid solvent against isoolefins unc

l- Patent 32 44 763 before, isobutene from a fraction 65 are therefore not suitable for the separation of conjugated]

To separate tion with C ₄ hydrocarbons by removing diene hydrocarbons from a containing them

(One can use the hydrocarbon mixture over a po- hydrocarbon mixture. The teaching of this Pa ·

> red carrier impregnated with sulfuric acid conducts. It is therefore tentative that rubber membranes do not

are satisfactory. Furthermore, the process of the membrane is thus heterogeneous in the sense that

US Pat. No. 2,388,095 does not exclude: a separation the molecules of the component to be separated first

gaseous mixtures applicable. hit the grafted film and then a

British patent 10 69 231 relates to a thick bed of porous inert material through-process for separating liquid or gaseous 5 traversing before they emerge on the other side of the membrane mixtures and in particular an improved advance, possibly in a further direction Implementation of this procedure. The grafted film will have happened when the grafting method makes use of the phenomenon of the throug- hout already described in the literature in fung on both sides of the membrane. This heterogeneity is a hindrance penetration or evaporation (cf. the US io grand for the use of this membrane for patents 25 40 151 and 25 40 152), with separation of certain gaseous or liquid mixtures of one of the components of the mixture to be separated. In certain cases, the constituent that passes through the membrane can dissolve effectively in the film grafted onto a surface under the action of the pressure gradient surface, but then becomes thickened or concentrated. 15 held up by the thick carrier bed, so that the: British patent 10 69 231, for example, sets separation cannot take place. Shows the bed of 'putting such a procedure into practice. Your goal is carrier porosity, then the separation remains inadequate, a device which experiences the use of a large volume, and the overall result of the active membrane surface area per unit volume is small. Lastly, the US Pamperation mentioned; and furthermore, it gives technological parameters 32 25 107 in an imprecise way the application meters (pressure, density and membrane, etc.) which provide the method for separating different best results. These statements relate to hydrocarbon mixtures, but do not disclose the nature of the membranes used or the means for separating conjugated diene hydrocarbons of the separated mixture. Also concern the substances from the mixtures containing them.
Exemplary embodiments of British patent 35 Furthermore, US patents 10 69 231 describe the purification of seawater, of organic 29 53 502 and 29 81680 the general process of niche products or the separation of carbon permeation. The first mentioned patent specification bedioxyd in certain mixtures. The mentioned bri- is limited to the separation of azeotropic mixing tables. Patent specification does not give any suitable means of gen. The second concerns a separation of different separations of hydrocarbons, and it defines 30 mixtures; their aim is a process by destroying the membranes, which for such a purpose turning two different types of membranes, could be suitable. the opposite of certain components of the mixture

The French patent 13 71 343 with their are selective. The device for implementation

Additions 72 416, 72 867 and 72 899 as well as the fran of this procedure are described in detail. The Ver-

French patent specification 15 68 217 relate to driving through 35 is particularly applicable to separation

casual membranes, the active ones, azeotropic mixtures like water and pyridine. the

contain grafted groups. These groups can fractionate hydrocarbon mixtures

be acidic or basic, such as carboxylic acid groups, and mixtures containing conjugated diene hydrocarbons

or of basic monomers of the pyridine type, is in the last two Pa-

or amine. These membranes can not be provided for 40 tentschriften.

Ion exchange in electrodialysis processes or in the case of the present invention is intended to address the disadvantages of

reverse osmosis can be used. Eliminate or reduce unfamiliar processes,

they have a special chemical structure because the method according to the invention for separation

their skeleton is formed by a perhalogenated polyolefin from hydrocarbons, their separation by

forms is. 45 liquid / liquid extraction or extractive

The various mentioned French patent distillation can be carried out by means of permeation

Writings therefore do not describe membranes that evaporate or evaporate through a membrane,

for the separation of hydrocarbon mixtures, one with the selective through the membrane

are reversible. compact hydrocarbon-enriched frac-

The US Patent 32 25 107 relates generally 50 tion and a fraction that predominantly

a process for separating organic compounds into other hydrocarbons in the mixture

Form of a liquid mixture after the permea- another part of the membrane is obtained is

tion process using a polymer now characterized in that the mixture

Membrane, on the surface of which another poly brings into contact with a membrane made of

merisat is grafted on. This grafting can consist of a graft polymer or a copolymer which

one and / or the other membrane surface take place; contains functional groups that have a special affinity

in any case - as the description and the nature of only one component to be separated

fDrawings of US patent specification 32 25 107 show - components of the hydrocarbons to be separated have,

-Is it about membranes from a thick one? The new process is especially for separation

permeable carrier and a very thin, on 60 of conjugated diene hydrocarbons from mi

a surface applied film, which is selective, among other things, saturated or simple

■ Separation guaranteed. Containing ethylenic hydrocarbons, suitable.

~ This surface grafting is done by poly- In particular, it is used to separate butadiene from

merization of an active monomer according to the isobutene from a petroleum fraction with C ₄ hydrocarbons

Iiclien grafting method. Has the existing carrier 65 serstoffen as well as for the separation of isoprene and

■ a thickness of 12.5 to 25 microns, then the pentadiene has suitable. Isobutene can also be used

film grafted onto the surface a thickness of a mixture containing isobutene and butene-1

of 2.5 microns or less. The composition of the be separated.

The polymers mentioned used in the process according to the invention are known per se. .Man Membrane consists of a high polymer that can be mixed with vulcanizing agents on the basis of Plastic or elastomeric material is. As synthetic sulfur or with peroxides: or, with irradiation Fabric material can e.g. work polystyrene, polyethylene, poly.

vinyl chloride or polytetrafluoroethylene used 5 The above considerations relate to the type of use. According to the invention, elastomeric membranes are usually preferred to be used in the membrane, since the macromolecular chains are mobile high polymers and the practical ones are more practical and thus a higher diffusion process. It is about relative condition coefficients. The basic materials for these conditions with regard to the substrate of the membrane, where elastomers are the natural and synthetic io when it is assumed that the latter in particular rubbers, such as ethylene-propylene mixed polymer, is represented by other characteristics,
sate, butyl rubber, polyisoprenes, polybutadienes, in the general definition given above

Polyoxypropylene, butadiene-acrylonitrile rubbers have been noticed that the macromolecules of the poly, etc. merisates chemically combined in a homogeneous manner

The polymers mentioned are in the form of 15 functional groups in the interior of the polymer a membrane, d. H. of a thin membrane, which is opposite to one of the components of the helix. In practice, membrane thicknesses of V1000 are the mixture to be separated, especially one of the suitable up to 0.5 mm. In theory, hydrocarbons are even stronger, having a physicochemical affinity Thickers can be used, but they lead to lower possessions.

Separation yields. To achieve the best results, the term "chemically in result one uses the functional groups combined with the mechanical homogeneous way inside the polymer and the durability of the membrane" means that the tolerable minimum thickness. The functional groups are usually applied in a regular manner in the membrane to a porous support, which is distributed over the polymer mass, in contrast to contributing to the mechanical strength of the structure. So 25 membranes, which consist of a skeleton support and one, the membrane itself does not need a mechanical active film on a surface. To be exposed to stresses, and their thickness in other words, this means that if one is used it can be very small, for example 1 micron. Membrane according to the invention, the molecules of the classic processes for the production of hydrocarbons which have been selectively separated through the membrane, which is more of a membrane made of polymeric starting materials, are known and in the total thickness of the membrane. The first method consists in grinding the membrane, always having the same composition of the Mades polymeric material under pressure. With it, terials can come into play, whereby the distribution of the functional ^{groups in the mass over the membrane thickness does not achieve any membrane thicknesses below about 1} mm, but the crosslinking or vulcanization can be uniform.

be carried out in the press at the same time. The functional groups can thus be fixed chemically in a second preferred according to the invention by grafting onto the macromolecules of the prior process, a solution of the polymer in existing high polymers; or they can be a solvent such as an aromatic carbon in the course of the polymerization directly with a hydrogen, z. B. benzene, chlorinated solvents with other monomers can be integrated into the skeleton of the macromolecules, such as chloroform, aromatic chlorinated hydrocarbons, as is the case with mixed hydrogen, etc. Usually depolymerization is the case, where one of the monomers holds the solution also still vulcanization constituent - provides an active functional group,
share. One of the membranes to be produced is dipped in the following examples illustrate the phy-

corresponding form in the polymer solution, its sicochemical affinity. When separating the die concentration, the thickness of the final membrane, such as butadiene and pentadiene, can be varied. Then the form will be provided, due to the extractive distillation, for evaporation of the solvent in the case of room functional groups in the solution temperature used and then under nitrogen or a medium to be present for a selective extraction of other inert gas in an oven at 40 ° C to enable. Thus, pyrrolidone alone does not allow drying to avoid oxidation; 50 closing the extraction of dienes of C ₄ - and C ₅ -Kohlenlich is at temperatures around 140 to 160 ⁰ C overall hydrocarbon fractions, while N-methylpyrrolidone dried. It is essential to evaporate all of the solvent- a selective extraction of butadiene and pentatel and avoid bubbles in order to produce a serve. Thus, the presence of the very thin and continuous membrane seems to preserve the N-substituted group with the ability to select. According to this known method, it is easy to be associated with the solvent,
possible to make elastomeric diaphragms of V100 mm. Similarly, the decisive role

aim. the nitrile groups found when looking at acetonitrile

In practice and in the case of the extraction _{solvent of dienes from C 4} - and an elastomeric membrane, it is usually ^ -hydrocarbon mixtures used. It is advisable to use a vulcanized membrane. Acetonitrile works by increasing the boiling point. An essential condition is these connections.

that the membrane is not in the liquid phase during liquid / liquid extraction

one or the other component of the isobutene to be separated is expediently capable of dissolving the mixture. In addition, the inability of sulfuric acid to selectively loosen vulcanized elastomeric membranes is sensitive. 65 Isobutene from a butadiene-freed C ₄ -CoIi-In all cases where one of the constituents is liquid, a hydrogen fraction is used. A vulcanized membrane can therefore be used on it. pointed out the active role of sulfuric acid. The cross-linking and vulcanization processes of the past are the phenomena that occur in these selective

7 8

■ tive. Extraction reactions by solvents play a special role due to their usability on a • role, not yet known exactly. To set temperature substantially above its ^l Giä'süBeYgarjgsivcrschiedenc physical and chemical forces is be- temperature. In addition, it is noted that they see the solvent and the constituent of the active, grafted or part of the 'poly mixture on' which the solvent exerts its selec- torisate macromolecule-forming groups after the dive. customary vulcanization treatment not modified

It is therefore important that the membranes are per se.

or, on the basis of their active groups, the extra- To increase the yield during the separation

solves this component. In any case, this shows it to be beneficial to mix the ingredients in

the occurrence of a solvation energy between the io liquid state in contact. In rivers

active groups, which are chemically linked to the Memsiger phase, the polymer membrane is subject to a

brane yellowing polymer are combined, or stronger swelling, and the yield of separated

with the chemical functions of the polymer tem component increases. Due to the above in

itself. The nature of this action is not decisive with regard to the polymer substrate.

dend as long as the solvation energy is high enough. The polymer skeleton resists the conditions

This energy can electrostatically or quantitatively migrate the molecules of the material to be separated

impossible to add further sub-components. It is noted that in the course

be supportive effects. the passage of a component through the mem-

There is a practical criterion that two parameters have an influence on the brane, namely-

A person skilled in the art enables the physicochemical affini- ao borrowed the solubility of the constituent in the mem-

ity of a membrane according to the invention to be determined. brane and the value of the diffusion coefficient through

This criterion is that - if the poly- the membrane.

mere membrane under the influence of one component Of course, the overall effect of the

the mixture to be separated a noticeable open membrane on the component to be separated

The swell is subject to the effect of the active, chemical with the, due to the cross-linking

can be limited - one is certain that the meme polymer combined groups and those

There is a pumping effect on this constituent of the polymer itself. Therefore, the correct effect must

to trcnnei.den mixture through the membrane limp on "the substrate polymer be so that it

by exercising. Effect of the active groups favors.

Available are polymers in which the active 30 For the separation of dienes from which they contain-

ven groups by conventional methods, such as grafting the hydrocarbon mixtures, can be one

or mixed polymerization, with the macromolecules membranes with nitrile groups and in particular one

combined and chemically bound. The membrane is based on a copolymer

Grafting that use in the bulk of the starting polymer from butadiene and acrylonitrile. The acrylic

sates can take place, one brings the polymer and 35 nitrile content of the copolymer can be about 5 to

at least one connection with active groups with 60%. It is expediently 20 to 30%.

Catalysts based on peroxide or one of such copolymers are known as "Buna N"

Diazoverbindyng in touch. A familiarity is often enough. Others are from Sociote Piastimer

fold heating to achieve the grafting. Im known as "Butadryl" in stores. A membrane on the

preferred case of using elastomeric Mem- 40 based on butadiene-acrylonitrile copolymers

The membrane expediently preserves the membrane after it has the property of conjugated dienes

followed by grafting their elastomeric properties. The physicochemical affinity between the nitrile

the interpolymerization groups and the dienes to soak up according to the usual methods,

if radical or ionic catalysts are used Other active groups for the separation of conju-

or a simple warming. Examples of these 45 gated dienes are N-substituted or pyrrolidone

We will drive in the following with the special groups. N-alkyl groups can be named,

application of the method according to the invention as the N-methyl group. Also connections mi

give. Pyrrolidone groups are useful, e.g. B. N-methyl

It is emphasized that the selectively from the mixture pyrrolidone, N-vinylpyrrolidone and N-methylmalein

separated constituent diffuse imid through the membrane. If these groups by grafting on expeditious

dated; However, this remains fixed after the elastomer has passed through, then the meme obtained has

Component chemically unchanged. It is believed that the brane has the ability to selectively produce butadiene and pentadiene

to extract gaseous or liquid molecules from the treated hydrocarbons selectively

separate hydrocarbons pass through the macrorenes. The polymers that form the N-substituted graft

Molecules of the membrane in a dissolved state, if 55 groups, such as N-methyl groups, are circulated

they are brought into contact with the membrane. the usual procedures mentioned above are obtained. S <

After separation, the membrane is without z. B. modified with N-methylpyrrolidone »

further treatment ready for reuse. Rubbers in Bull. Soc. Chim. (1961), p. 1433, be

A fundamental difference seems to be described here. These modified rubbers carry eim

agreed methods of exchanger or other 60 variable number of groups fixed on the molecule

Resins, in which a regeneration area in particular between 10 and 30 per weight

action is necessary to selectively apply this center, based on the original polymer, bc

Eliminate resin type fixed component. It is able to carry. The rubbers obtained will be

it can be seen that the process according to the invention according to the solvents described above

Due to this property, it converts into a membrane particularly well for the steaming process

suitable for continuous work. Suitable solvents are aromatic chlorinated

The elastomeric membranes allow the Er- solvents and heavy ketones,

aimuns of an increased ductility coefficient, ins- The N-substituted groups, such as. B. N-alkyl

ίο

. Or pyrrolidone groups, can also be grafted onto various plastic materials, such as polyacrylonitrile (cf. "Graft Polymers", p. 78, from "Battaerd and Tregear, Series Polymer Review, | ir. 16, Interscience Publ. [1967]).
] '~ A third category of membrane that is suitable for separating isobutene is made from polymers that carry combined or grafted strong acid groups. Such polymers are z. B. described in French patent specification 69 41 159, which relates to a "process for the preparation of sulfonated polymers and products obtained therefrom". The substrate elastomers suitable for producing these sulfonated polymers are rubbers made from polybutadiene, polyisoprene and ethylene-propylene copolymers. Such sulfonic groups can also be fixed on plastic materials such as polystyrene, polyethylene and polytetrafluoroethylene (Teflon). The fixation on polystyrene is z. B. in "Chemical Reaction of Polymers", pp. 280 to 283, by HMFettes, High Polymers Series, Volume XIX, Interscience Publ. (1964), described. All such membranes enable dip separation of isobutene from a mixture containing isobutene and 1-butene.

According to the invention, a pressure gradient or chemical potential gradient can be applied to the membrane apply in such a way that the migration of the selectively separated component through this membrane becomes possible.

In particular, this chemical potential gradient can be obtained by looking at differences in the Partial pressure of the component to be separated on one side of the membrane, a difference in concentration of the component or provides a temperature difference.

It is expedient to apply pressure to the membrane surface which is brought into contact with the mixture off, with one on the other membrane surface, d. H. the one on which you can see the detached component collects, applies a vacuum; or you can apply both measures separately. Furthermore, it can be useful to create a temperature gradient between the two through the membrane use separate media. The examples given below show in particular that lowering the temperature means achieving an increased yield of the separated gaseous constituents enables.

A device according to the invention essentially consists of a device separated by a membrane Reactor with at least two chambers, the membrane being made of a porous flat or cylindrical There is a carrier, means for introducing the mixture to be separated into one of the chambers and means for evacuating the separated components into the second chamber and means for Applying a pressure gradient to one and the other part of the membrane.

The mixture to be separated is left in gaseous form or liquid state at atmospheric or superatmospheric pressure in the first (upstream) chamber dwell or circulate.

In the second, following (downstream) chamber, the separated product or Permeate evacuated by a carrier gas or liquid or extracted under vacuum The present The invention is illustrated in various embodiments with reference to the drawings.

F i g. 1 is a schematic cross section of an embodiment of the method according to the invention with a membrane applied to a porous support;

F i g. Figure 2 is another embodiment having one made up of a porous tubular support

ίο membrane;

F i g. 3 is a modification of the embodiment of FIG. 2;

F i g. Fig. 4 is a graph showing the influence of temperature on the separation yield.

As can be seen from Fig. 1, this embodiment comprises one through a porous support 4, which can be flat, convex or concave, into an upper one (first) chamber 2 and a second chamber 3 separate reactor 1. The chambers 2 and 3 delimiting Parts of the reactor 1 are held by the flanges 5 and 6. A membrane 7 is on the porous Carrier 4 applied. A tube 8 extends into the first chamber 2 to contain the mixture to be separated to introduce under pressure. Another pipe 9 is used to evacuate excess mixture the first chamber 2. In chamber 3, a tube 10 is provided for extracting the permeate.

In the apparatus of Fig. 2, the reactor 11 has a cylindrical shape. He is through a porous tubular Carrier 14, which carries a membrane 17 over its entire circumference, in its first (outer) Chamber 12 and a second (inner) chamber 13 are separated. As in Fig. 1, the tube 18 is used for introduction the mixture to be separated and the pipe 19 for evacuating excess mixture Chamber 12. The tube 20 is used to evacuate the permeate from chamber 13.

FIG. 3 is an embodiment analogous to FIG. 2. The chamber 21 is also cylindrical and also the porous support 24 is tubular. The inner surface of the tube 24 is connected to the membrane 27 Mistake. The first chamber 22 is in this case inside the tube, and the second Chamber 23 is provided outside. The pipe 28 is used to introduce the mixture to be separated and Tube 29 of evacuation of the excess mixture. Pipe 30 is used to obtain permeate.

The inventive method is expedient at medium temperature or a temperature below Room temperature, in particular between about 0 to 40 ° C carried out. The hydrocarbon mixture is used in gaseous or liquid form, and the hydrocarbons are also separated off in gaseous or liquid phase.

example 1

A hydrocarbon mixture consisting essentially of butadiene and isobutene was treated.

The membranes used were rubbers made from butadiene-acrylonitrile copolymers used by Societe Piastimer (France) under the Names »Butacryk are in trade. The product »BT 205« is a copolymer with 20% acrylonitrile, while the product »BT 305« contains 30% acrylonitrile. Own in the vulcanized state these products have the following densities: BT 205

11 12

= 0.98; BT 305 = 0.99. Example 2 were in the raw state Mooney Viscosities; BT 205 = 45 to 55; BT 305

= 50 to 55. Example 1 was treated by treating a mixture

The following formulation was used for the Vulka- of 75 percent by volume butadiene and 25 percent by volume

used: 5 cents isobutene on a membrane made from a buta

diene-acrylonitrile copolymer of the type »But-

Repeated parts by weight of acrylic BT 205 with a thickness of 150 microns.

Rubber 100 ^{The fol} g ^{s <len} pressure conditions was the overall

measured separation coefficient between 2.5 and 3:

Zinc oxide 5 ₁₀

Stearic acid 2 outlet pressure of the permeate 1 bar

Sulfur 1.5 pressure difference between the

',, "Inherited and second chamber

Accelerator (cyclohexylbenzo- (pressure gradient) 0.8 bar

thiazylsulfenamide) 1.5 15

The usable membrane surface was

After vulcanization for 20 minutes at 153 ° C, 38 cm ² ; it was the execution shown in Fig. 1

the products had the following properties:

Under these conditions at a temperature of

BT 305 ^ao 17 ° C after the introduction of a gaseous _, j, 1. · Ληη, τ, ·> ice mixture and purging of the second chamber with expansion module at 300 Vo, kg / cm * 15.5 nitrogen to remove the permeate Tear strength, kg / cm ² 25 measured on separated butadiene, the 2.11

Elongation at break, · /. 670 ₃₅ P ^r ° J ^aI \ ^r and per m ² membrane.

^{6 s} was worked at 10 ° C and ems liquid to volume expansion in toluene (treatment mixture used, the measurement was at room temperature), the amount of separated butadiene after purging (swelling) 160 of the second chamber with nitrogen 6 s, 3 t per year and

per m ² membrane.

30 *

The vulcanized product BT 205 had analogs

Properties, but the volume expansion r> · _; 1 ■,

in toluene was 192%. ^P.

The used membranes had a density of _{this BuspM zei t the influence of the} Temperate 150 μ for the hergestell- with the rubber BT 205 35 _{to yield} separated gaseous Pray _m rows and 300 μ in the rubber-st-n ^ il &&

^BT u ° L ^here ! ^{Set Zdlen} - ^Ver Sl ^ei fhs ^white j? «" « ^{Y n} " Example 2 was divided with identical conditions

Also membranes of pure polybutadiene without _Abän alteration of temperature repeated, you

Acrylonitrile produced in a thickness of 300 μ. According _{to the results shown} in Table j: the vulcanization of the membranes became the 40
wetting calculated as about 3.4%.

The device from FIG. 1 was used. 1 with table 1

a porous plane support 4, which is a used

|. surface of the membrane 7 of 38 cm * ent- Temperature yield (g / h)

ί spoke. The pressure in the first chamber 2 was 45 surface = 38 cm *

|, 2 bar, while the pressure in the second chamber 3 (o q

0.1 bar abs., D. H. 7.6 cm Hg.

^r The gaseous mixture 5 introduced into the pipe 8

Contained 36 percent by volume butadiene and 64 percent by volume ^ q

percent isobutene. 50 _1f) "'

With a 300-ji. Membrane made of vulcanized '

BT 305 had a diffusion rate of H 2.40 at 20 ° C

speed of butadiene of 0.4 g / h through the mem- 12 2.16

brane 7 with a separation coefficient of 15 j 40

2.85 measured. 55 ₂ 0 0 * 72

With a membrane without nitrile groups, the '

Diffusion rate measured at 20 ° C ^{0> 4 o}

5 g / h; the separation coefficient was 0.26 for two un-30

dependent measurements, however, 1.02 and 1.01, which is 35 0.20

shows that, taking measurement errors into account, 60 49 rj, 16

The effective separation of the butadiene takes place ^ q * a

was. , '

This example shows the decisive influence ^{u> iJ} the presence of functional acrylonitrile groups in

the polymer membrane. These groups confer 65 F i g. 4 is a graph showing where

a physicochemical affinity for the butan on the abscissa the temperature in ° C was recorded

] serve and enable the separation of butadiene genes; the ordinate shows the bulge

Isobutene mixtures. of separated butadiene, expressed in t per yes]

Isobutane 0.6 0.7 0.2 η-butane 3.7 3.9 1.8 i-butene 12.6 14.1 10.0 ' Isobutene 33.8 35.6 21.4 trans-2-butene 6.3 6.4 5.8 cis-2-butene 6.1 6.0 6.1 Butadiene 38.8 33.4 54.6

and per m ^{2 of} membrane according to the mixture and permeate given in table 1 are shown in table 2 results. given:
As can be seen, the yield increases with low- ", ...

lower temperature, which is why working at Tem- l aDelle 2

Temperatures of about 5 to 20 ° C from special 5 ^ -charge ("/") Remaining permeate

Interest is. . mixture

(Vo) C / o)

. Example 4

IO

To obtain butadiene of high purity, a mixture of 75 percent by volume butadiene was used and 25 percent by volume isobutene treated according to the invention in four successive separation stages. Each step was of the form shown in FIG. 15 The properties and treatment conditions were same as in example 2.

Received at the exit of the fourth separation stage

a butadiene with less than 1 ^fl / o impurities - Under these conditions, the separation was

worked. ao coefficient of butadiene, based on isobutene,

Equivalent results were achieved by using 2.6 and the permeate yield 26.8 g / h, which corresponds to an Ausdie mixture to be separated in a series of preliminary prey of 52 'per year per m ^{2 of} membrane, directions with tubular membranes on one The present invention is not limited to the above

porous support as in FIG. 2 and 3 dealt with. Embodiments limited. It is applicable

as on very different separations and in general

. . my shape on all hydrocarbon mixtures,

Example 5 <previous separation by liquid / liquid

extraction or extractive distillation through

In this example a mixture of was feasible.

50 percent by volume isoprene and 50 percent by volume 30 According to the invention, tranc-l, 3-pentadiene can be used for all types of separation treated. sized membranes made of a high polymer with active

The advance shown in FIG. 1 was used, groups chemically bound to the macromolecular chain direction with a usable membrane surface are used. This meme of 38 cm ² . The outlet pressure of the permeate ^ carried branches have the property that the extraction 0.1 bar and the pressure difference between 1 of the 35 medium in liquid / liquid extractions or upper and lower chamber (pressure gradient) 1 bar extractive distillery

A membrane was used from an elation to increase or decrease the boiling point of the butadiene-acrylonitrile mixed polymer to be extracted, the organic phase type “Butacryl BT 305” with 30% acrylonitrile to replace one.
Thickness of 150 microns. 40 The present invention is also applicable to

Under these conditions there was a case in which the polymer itself had this property of an insulation coefficient of 2.5 and one at 17 ° C., or in the case where the polymer had a separated yield of 1,3-pentadiene of 1 t per year in a manner analogous to corresponding liquid solutions and per m ^{2 of} membrane, whereby a liquid mixture has the role of a solvent for a part of the membrane and is part of it,
the separated pentadiene was gaseous. _R · -17

With a membrane made of »BT305« from 300Mi- Example /

cron was obtained after treatment of the mixture. The device of FIG. 1 was awarded a po-

under a pressure of 1.4 bar in the first chamber, a surface of 10 cm ^{2 is} used, corresponding to a membrane useful surface and in the second chamber of 0.1 bar,
separation coefficients of 2 ± 0.5 and a penta treatment was mainly benzene and

diene yield of 1.2 g / h at 36 ° C. Hydrocarbon mixture containing heptane (Ge

contains 20 to 88% benzene). BT-305 membranes with a thickness of 150 μ were used, with

Example 6 55 1% dicumol peroxide 10 minutes at 165 ° C vulka

had been nized. The following table gives

In this example, a C ₄ industrial factory was treated with separation coefficient values and yields by evaporation. The used at 30 ° C for the specified benzene ratios in the device corresponded to FIG. 1 with a beneficial binary mixture:
membrane surface area of 44 cm ² . The exit 60
pressure of the permeate was 1.0 bar and the pressure difference between the first and second chamber (pressure gradient) 0.9 bar. Was used
a membrane made of an elastomeric butadiene-acrylonitrile copolymer of the type "B 308" with 65 20
30% acrylonitrile that vulcanizes with dicumyl peroxide
was; the membrane thickness was 16 microns.

The compositions of charge, remaining

benzene K yield C / o) (t / year / m ¹ ) 20th 9.5 0.28 50 5.2 0.76 88 2.1 5.8

Example 8

16

5 benzene

Example 7 was repeated for the treatment of benzene-heptane mixtures with 0 to 20% benzene. The membranes used were butadiene-styrene copolymers with 53.5% styrene with a thickness of 200 μ, a usable surface of 10 cm ² , which had been vulcanized for 10 minutes at 165 ° C. with 1.3% dicumene peroxide.

The following table gives the values of the separation

Calculation coefficients and yields at 30 ° C for the given benzene ratios in binary Mixture.

Yield (t / year / m =)

1 2.6 1.5 9 2.45 3 0 2.25 4.9

For this purpose 2 sheets of drawings

Claims (1)

% 1/2 #% ■ _____ The isobutene is based on the effect of the grand there S / "· Patent claims: located, immobile sulfuric acid through the gf carrier pumped. It can be so on the other hand 9 * 1. Method of separating hydrocarbons from the porous support by a solvent such as ψ substances, the separation of which is extracted by liquid / liquid 5 hexane. Liquid extraction or extractive distillation Similarly, the British patent ^Λ · it is possible to carry out a separation treatment by means of permeation or note 10 90 096, ρ evaporate through a membrane, whereby instead of using hydrocarbons - / one with the hydrometallurgical preparations selectively hydrogenated by the membrane. ί: penetrated hydrocarbon-enriched fraction. This particularly concerns the separation , ι tion as well as a fraction that predominantly consists of uranyl nitrate from solutions, among other things , * 'contains other hydrocarbons in the mixture, contain iron nitrate and aluminum nitrate. To the [\ At another point of the membrane separation can obtain the solutions through a porous ü. is, characterized in that run carriers on which a bed of tributyl s ¹ ν the mixture is softened with a membrane in 15 phosphate or another phosphoric ester. ['V "" brings about stirring, which is deposited from a graft or mixed polyvinyl chloride. {> -, ' polymer, the functional groups in the embodiments of the above K , which has a particular affinity for literature references, is the selective solvent only _.;. only one component to be separated which is physically united with the porous carrier. It & \ possess separating hydrocarbons. ao is actually one with sulfuric acid