Method of separating crude c4-fraction

FIELD: petroleum processing.

SUBSTANCE: separation of crude C4-fraction comprises rectification of C4-fraction containing butanes, butenes, 1,3-butadiene, and small amounts of other hydrocarbons, including C4-acetylenes, 1,2-butadiene, and C5-hydrocarbons, via extractive distillation using selective solvent. Crude C4-fraction is fed to middle part of first extractive distillation column and selective solvent is added to column above crude C4-fraction introduction point. Vaporous side stream containing C4-acetylenes together with 1,3-butadiene1,2-butadiene, C5-hydrocarbons, and selective solvent, wherein concentration of C4-acetylenes is below self-decomposition threshold, is withdrawn from the first distillation column from the point below crude C4-fraction introduction point. Top stream containing crude C4-fraction components, which are less soluble in selective solvent than C4-acetylenes, are withdrawn from upper part of the first extractive distillation column.

EFFECT: optimized order of process operations.

21 cl, 1 dwg

 

The present invention relates to a method of separating crude4-fraction by extractive distillation using a selective solvent.

The term "C4-fraction" refers to mixtures of hydrocarbons having predominantly four carbon atoms in the molecule. With4-faction receive, for example, in the production of ethylene and/or propylene by thermal cracking, usually in a steam cracking installations, in particular installations by cracking naphtha or installations fluid catalytic cracking of petroleum fractions, such as liquefied petroleum gas, gasoline or gas oil. In addition, With4the fraction obtained when the catalytic dehydrogenation of n-butane and/or n-butene. With4-fractions usually contain butane, n-butene, isobutene, 1,3-butadiene and small amounts of other hydrocarbons, including 1,2-butadiene, With5-hydrocarbons and4-acetylene (the butins), in particular 1-Butin (ETHYLACETYLENE) and Butenin (vinylacetylene). The content of 1,3-butadiene in C4the fractions from steam cracking units is usually from 20 to 70 wt.%, in particular from 35 to 65 wt.%, while the content With4-acetylenes (vinylacetylene and ETHYLACETYLENE) usually does not exceed 5 wt.%.

Due to small differences in the relative volatilities of the components separation With4-factions is a complex distillation problem. For this reason, the separation is usually carried out by the so-called extractive distillation, i.e. distillation with the addition of a selective solvent (also referred to as extractant), which has a boiling point higher than the boiling point of the mixture, which must be rectificate, and which increases the difference in relative volatility of the components, which are subjected to the separation.

There are many ways of separation4-fractions by extractive distillation using a selective solvent. Common to all methods is that you want to split With4-fraction in vapor form lead in countercurrent contact with a liquid selective solvent in a suitable thermodynamic conditions, usually at low temperatures, often in the range of 20-80°With, at moderate pressure, often under pressure from atmospheric up to 6 bar, so that the selective solvent load components4-faction to which he has a higher affinity, while the components to which the selective solvent has a lower affinity, remain in the vapor phase and are removed as the top thread. Then from the stream Laden with solvent, there are the components in one or more additional stages in the form of fractions of the selective solvent in suitable thermodyne the economic conditions, i.e. at a temperature that is higher and/or pressure, which is lower than the first stage of the process.

In the methods of thermal separation4fractions C4-acetylene, present, present special problems because they are one of the main causes clogging of the equipment and there is a danger of samorazrusheniya at a wide range of concentrations.

For this reason we have developed methods of separation With4-factions, in which C4-acetylene were subjected to interaction in the first stage of the process by pre-hydrogenation. Preliminary hydrogenation has the additional advantage that in the hydrogenation of C4-acetylenes receive an additional valuable product, namely 1,3-butadiene.

This method is described in the publication Proc.-Ethylene Prod. Conf.5 (1996), str-636. In this way, using the so-called KLP catalyst, i.e. a catalyst containing finely dispersed copper particles on the media γ-alumina of high purity, having a specific porous structure is achieved a high degree of conversion vinylacetylene at low losses of butadiene and achieve operational durability of the catalyst. Selective hydrogenation carried out upstream (against the current), makes it possible to simplify twostage the ing extractive distillation of butadiene to one-stage process, and equipment required to complete the distillation carried out downstream, reduced by one separation column. However, the disadvantage of this method is that for the ongoing upstream (downstream) selective hydrogenation of acetylenic impurities requires a separate installation.

In the patent US 4277313 described another method of separation of 1,3-butadiene, offering a first selective hydrogenation, and then extractive distillation of 1,3-butadiene. Selective hydrogenation is carried out in liquid or gas phase, in the presence of catalysts of group VIII of the Periodic system of elements, such as palladium oxide/aluminum. Mentioned extractants are dimethylformamide or diethylformamide, N-organic, furfural and acetonitrile. The method is like the method described above, the disadvantage is manifested in the fact that the selective hydrogenation carried out upstream, requires a separate installation.

Patent US 6040489 describes a method for separating 1,3-butadiene from C4-faction, in which C4-faction hydronaut in the casing and selectively extracted with a solvent stream containing at least butanes and butenes, away from the column as top stream, and the flow of solvent Laden with BUTADIENES, away from the bottom and then share in the column for othank the solvent on the upper thread, containing butadiene, and a bottom stream containing solvent.

Containing butadiene upper stream is separated in a column for distillation of butadiene on the upper stream containing 1,3-butadiene, and the bottom stream containing 1,2-butadiene.

In the method according to the application DE-A 10022465.2 C4-fraction is subjected to extractive distillation and selective hydrogenation over a heterogeneous catalyst in the column with a dividing partition or thermally coupled columns with getting the flow of crude 1,3-butadiene.

Known methods prior removal With4-acetylenes from C4-fractions by selective hydrogenation over heterogeneous catalysts have the disadvantage, which is manifested in the fact that must be expended substantial funds for the purchase of catalysts, and known catalysts often have no operational durability. A particularly critical aspect is that when the catalyst loses its activity, all thermal separation4-faction stops the operation.

Therefore, the object of the invention is to develop a method of pre-remove C4-acetylenes from C4-faction that does not have the aforementioned disadvantages.

This task is achieved by the method of separation of raw From4the fraction containing butanes, butenes, 1,3-butadiene small amounts of other hydrocarbons, including C4-acetylene, 1,2-butadiene and C5-hydrocarbons by extractive distillation using a selective solvent, with raw C4-faction served in the middle zone of the first extractive distillation column, and the selective solvent is fed into the column above where the injected raw C4-faction. Vaporous side stream that contains C4-acetylene together with 1,3-butadiene, 1,2-butadiene, C4-hydrocarbons and the selective solvent and in which the concentration of C4-acetylenes lower limit samorazrusheniya, away from the first extractive distillation column at a location below the inlet wet With4-faction, and the upper stream containing components4-faction, in which the selective solvent is less soluble than4-acetylene, away from the top of the first extractive distillation column.

It was found that the cost is reasonable and possible under the process set such that the operating conditions of the extractive distillation column, in particular in relation to the type of the selective solvent, the amount, temperature, pressure and number of theoretical plates, which provide the ability to selectively separate With4-acetylene, i.e. components4-faction, to the m a selective solvent has the greatest affinity. Such process conditions are unusual for extractive distillation.

Typical raw4-fraction of the installation by cracking naphtha has the following composition in wt.%:

Propane0-0,5
Propene0-0,5
PROPADIENE0-0,5
Propyne0-0,5
n-butane3-10
ISO-butane1-3
1-Butene10-20
ISO-Butene10-30
TRANS-2-Butene2-8
CIS-2-Butene2-6
1,3-Butadiene35-65
1,2-Butadiene0,1-1
ETHYLACETYLENE0.1 to 2
Vinylacetylene0,1-3
With50-0,5

Thus, raw4-faction of the installation by cracking naphtha contain predominantly butanes, butenes and 1,3-butadiene. In addition, there are small amounts of other hydrocarbons. With4-Acetylene often present in an amount up to 5 wt.% or up to 2 wt.%.

Selective solvents suitable for the above extractive distillation, usually are substances or mixtures, which have the b is more high boiling point, than the boiling point of the mixture to be split, and have bòa high affinity to conjugated double bonds and triple relations than simple double bonds and single relations, preferred dipolar, especially preferred dipolar aprotic solvents. From the point of view of the material equipment of the preferred non-corroding cast or slightly corrosive substances.

Examples of selective solvents suitable for the method according to the present invention, are butyrolactone, NITRILES such as acetonitrile, propionitrile, methoxypropionitrile, ketones, such as acetone, furfural, amides, N-alkyl substituted lower aliphatic acids, such as dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, N-formylmorpholine, amides, N-alkyl substituted cyclic acids (lactam), such as N-alkylpyridine, in particular N-organic. In General, use the amides of N-alkyl substituted lower aliphatic acids or amides of N-alkyl substituted cyclic acids. Particularly advantageous selective solvents are dimethylformamide, acetonitrile, furfural, and in particular, N-organic.

However, you can also use mixtures of these solvents with one another, for example N-methylpyrrolidone with acetonitrile, mixtures of these solvents with the cosolvent is, such as water, and/or tert-butyl esters, for example methyl tert-butyl ether, ethyl tert-butyl ether, propyl tert-butyl ether, n - or ISO-butyl tert-butyl ether.

Particularly suitable solvent is N-an organic, preferably in aqueous solution, in particular containing from 8 to 10 wt.% water, particularly preferably 8.3 wt.% water.

In principle there are no restrictions on columns that can be used for extractive distillation.

With4-fraction is fed to the column, in its middle part, and the selective solvent serves above where injected With4-faction.

The column is equipped with internal dividers. They can be of any known type. Preference is given to one or more plates located above the inlet of the selective solvent.

According to the present invention, a side stream containing C4-acetylene together with 1,3-butadiene, 1,2-butadiene, C5-hydrocarbons and the selective solvent is directed to a vapor form of the first column extractive distillation, this column should be operated in such a way that the concentration of C4-acetylenes in the vaporous side stream is lower than the limit of their samorazrusheniya. Usually for this purpose it is enough dilution below 30 mo is.% With 4-acetylenes.

The selective solvent is present in the vaporous side stream in proportions corresponding to thermodynamic equilibrium. Lateral column operates only as a supporting column and is used for the selective recovery of the solvent. It should work in this mode so that at each point of the column was provided with sufficient breeding acetylenes, lower limit their samorazrusheniya.

From the top of the first extractive distillation column assign a top stream containing components4-fractions that are less soluble in the selective solvent than C4-acetylene. This thread is preferably condense in the cooler upper part of the column and part of its return in the form of a return of the product in the column, while the residue is subjected to further processing, preferably in the second extractive distillation column. Partial condensation, in which the condensed part is supplied in the form of a return of the product in the column and the vapor portion is served as raw materials flow into the second extractive distillation column in which carry out the separation in the raffinate 1 and crude 1,3-butadiene is particularly advantageous.

The lower (blue) stream from the first extractive distillation column, of which the first contains predominantly selective solvent, preferably used for heat integration in the first extractive distillation column, condensed and re-fed to the first extractive distillation column.

To achieve the integration of heat can be cooled hot CBM flow from the first extractive distillation column through a raw4-faction. In addition or alternatively, the liquid or part of it could be taken from the first extractive distillation column with a theoretical plate, which is located on one or more theoretical plates below where assign vaporous side stream, the liquid is heated and/or vaporized by indirect heat exchange with kubovy flow from the first extractive distillation column and return to the first extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so that the energy of the first extractive distillation column were minimal.

Here, the term "raffinate 1" is known to the stream containing butane and butenes.

The term "crude 1,3-butadiene" refers to a hydrocarbon mixture, in which a valuable product, 1,3-butadiene is present in amount of at least 90 wt.%, predpochtitel is about, at least 95 wt.%, especially preferably at least 98 wt.%, the rest are impurities.

As for the in-situ separation of the elements, all that has been said with respect to the first extractive distillation column, similarly applies to the second extractive distillation column.

From the second extractive distillation column a stream is preferably taken off to the top or near the top of the column, condensed in the condenser and the condensate is partly returned as return product to the second extractive distillation column, and the remainder is to divert as raffinate 1.

From the second extractive distillation column divert the side stream, which preferably by filing a second low side column separating the selective solvent, which again serves the second extractive distillation column, from which the upper thread, which condense in the cooler upper part of the column and partially returned to the column as return of the product, and the remainder is put up in the form of crude 1,3-butadiene.

Integration of heat to the second extractive distillation column is possible in the same manner as in the first extractive distillation column through a drain or part thereof from the second extractive di is tillation column with a theoretical plate, located on one or more theoretical plates below the side of the tailrace, heating and/or evaporation by indirect heat exchange kubovy flow of the second extractive distillation column and returning to the second extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so that the energy consumption for the second extractive distillation column were minimal.

The invention is illustrated below using the drawing and example of its implementation.

The figure schematically shows the installation according to the invention for separation4-fraction by extractive distillation.

Raw4-fraction, stream 1, is served in the middle part of the first extractive distillation column I, and the selective solvent, stream 2, is fed into the column above where the injected raw4-faction. Vaporous stream 3 containing4-acetylene, take away through the side discharge channel below the feed stream 1 and fed to the first side of the column of SK I. In the side column of SK I stream 3 separated by distillation in the upper stream 6 containing acetylene, and CBM stream 7 containing the selective solvent, which is again sent to the first extractive, distillate is nnow column K I.

CBM stream 4 from the first extractive distillation column I, which contains mainly the selective solvent used for the integration of heat with the liquid flow, which divert from the lower zone of the first extractive distillation column I, and for pre-heating raw4-faction, stream 1, condensed and cooled, and returned to the first extractive distillation column To I.

The upper thread 5 from the first extractive distillation column is partially condensed in the cooler upper part of the column, the condensate return in the form of a return of the product in the column and the vapor part divert as stream 8.

In the second extractive distillation column To the second thread 8 lead in countercurrent contact with a selective solvent stream 14, and separated by distillation of the upper thread 9, which condense and part of its return in the form of a return of the product in column II, and the remainder is to divert as raffinate 1, stream 15, and in the side stream 10, which gives a crude 1,3-butadiene after separation of the solvent in the second low-side column of SK II. The second side column of SK II side stream 10 is divided into upper thread 11, which condense in the cooler upper part of the column, and part of its return in the form of a return of the product in the column, and the remainder of the W ill result in the form of crude 1,3-butadiene, thread 16, and the bottom stream 12, which contains predominantly selective solvent, and which again serves the second extractive distillation column II. In the lower part of the second extractive distillation column II To divert the bottom stream 13, is used for heat integration together with the liquid stream from the lower zone of the second extractive distillation column K II, condense and then return in the form of a stream 14 to the second extractive distillation column.

Example

Raw4-the stream position 1 in the drawing containing the following components, present in quantities of more than 0.01 wt.% in each case:

N-butaneof 5.75
ISO-butane2,45
1-butene13,89
ISO-butene25,65
TRANS-2-buteneof 4.44
CIS-2-butene2,96
1,3-butadiene43,84
1,2-butadiene0,14
ETHYLACETYLENE0,13
vinylacetylene0,74

served at a flow rate of 32 t/h in the extractive distillation column I, with 28 of theoretical plates, 15 theoretical plate, counting from the bottom.

The column ex is laterbut at an absolute pressure in the upper part of 4.5 bar, the temperature in the upper part of 58.8°C.

On the top plate of the extractive distillation column K I served 120 t/h extractive solvent N-methylpyrrolidone (NMP)containing 8.3 wt.% water flow 2.

A stream with a flow rate of 224 kg/h, POS. 3 of the drawing and containing the following components, present in quantities of more than 0.01 wt.% in each case:

1,3-butadiene2,45
1,2-butadiene1,21
ETHYLACETYLENE1,67
vinylacetylenethe 10.40
water70,10
NMP14,08

away from the third theoretical plates.

The solvent is removed from this thread in the side column of SK I, which functions only as a supporting column, with the return of the product. The result is an upper stream position 6 in the drawing containing the following components, present in quantities of more than 0.01 wt.% in each case:

1,3-butadiene3,24
1,2-butadiene1,60
ETHYLACETYLENE2,20
vinylacetylene13.56MHz
With5-hydrocarbons0,16
water79,24

Extractive solvent N-organic, which was acquired considerable cost, completely separate, except for 1 mln, in the upper stream side of the column, and return to the first extractive distillation column To I.

In this way the process can be removed acetylene (ETHYLACETYLENE, vinylacetylene) essentially lossless expensive component N-methylpyrrolidone in the upper stream side of the column SK I.

1. Method for distillation of crude4the fraction containing butanes, butenes, 1,3-butadiene and small amounts of other hydrocarbons, including4-acetylene, 1,2-butadiene and C5-hydrocarbons by extractive distillation using a selective solvent, while wet With4-faction served in the middle part of the first extractive distillation column, and the selective solvent is fed into the column above the point of entry of raw4-faction, and vaporous side stream that contains4-acetylene together with 1,3-butadiene, 1,2-butadiene, With5-hydrocarbons and the selective solvent and in which the concentration of C4-acetylenes lower limit samorazrusheniya, away from the first extractive distillation column at a point below the point of feed raw With4-faction, and the top of the second stream, containing raw components4-faction, in which the selective solvent is less soluble than4-acetylene, away from the top of the first extractive distillation column.

2. The method according to claim 1, characterized in that the vaporous side stream is fed to the first side of the column where it is separated into a top stream containing4-acetylene, which condense in the cooler upper part of the first side of the column and part of its return in the form of a return of the product in the first side of the column, and the residue assign and CBM stream containing the selective solvent, which is returned to the first extractive distillation column.

3. The method according to claim 1 or 2, characterized in that from the first extractive distillation column assign a bottom stream and is cooled by indirect heat exchange With raw4-faction, condense in the condenser and returns in the form of a stream of selective solvent in the first extractive distillation column.

4. The method according to claim 1 or 2, characterized in that from the first extractive distillation column with a theoretical plate located on one or more theoretical plates below the point of diversion vaporous side stream that drains the liquid or part thereof, which is heated and/or evaporated by indirect t is loobman kubovy flow from the first extractive distillation column and return to the first extractive distillation column at the same theoretical plate or above it, this theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption of the first extractive distillation column.

5. The method according to claim 3, characterized in that from the first extractive distillation column with a theoretical plate located on one or more theoretical plates below the point of diversion vaporous side stream that drains the liquid or part thereof, which is heated and/or vaporized by indirect heat exchange kubovy flow from the first extractive distillation column and return to the first extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption of the first extractive distillation column.

6. The method according to claim 1 or 2, characterized in that the top stream from the first extractive distillation column condense in the refrigerator the top of the first extractive distillation column and part of its return in the form of a return of the product, and the remainder is condensed upper thread serves the second extractive distillation column where it is separated into a stream containing butanes and butenes, and a crude 1,3-butadiene.

7. The method according to the .3, wherein the top stream from the first extractive distillation column condense in the refrigerator the top of the first extractive distillation column and part of its return in the form of a return of the product, and the remainder is condensed upper thread serves the second extractive distillation column where it is separated into a stream containing butanes and butenes, and a crude 1,3-butadiene.

8. The method according to claim 4, characterized in that the top stream from the first extractive distillation column condense in the refrigerator the top of the first extractive distillation column and part of its return in the form of a return of the product, and the remainder is condensed upper thread serves the second extractive distillation column where it is separated into a stream containing butanes and butenes, and a crude 1,3-butadiene.

9. The method according to claim 5, wherein the top stream from the first extractive distillation column condense in the refrigerator the top of the first extractive distillation column and part of its return in the form of a return of the product, and the remainder is condensed upper thread serves the second extractive distillation column where it is separated into a stream containing butanes and butenes, and a crude 1,3-butadiene.

10. The method according to claim 1 or 2, otlichalis the same time, in the refrigerator the top of the first extractive distillation columns hold the partial condensation and the condensed part of the top stream from the first extractive distillation column is used as return the product and its vaporous part serves the second extractive distillation column.

11. The method according to claim 3, characterized in that the refrigerator in the top of the first extractive distillation columns hold the partial condensation and the condensed part of the top stream from the first extractive distillation column is used as return the product and its vaporous part serves the second extractive distillation column.

12. The method according to claim 4, characterized in that the refrigerator in the top of the first extractive distillation columns hold the partial condensation and the condensed part of the top stream from the first extractive distillation column is used as return the product and its vaporous part serves the second extractive distillation column.

13. The method according to claim 5, characterized in that the refrigerator in the top of the first extractive distillation columns hold the partial condensation and the condensed part of the top stream from the first extractive distillation column is used as the return is atny product, and its vaporous part serves the second extractive distillation column.

14. The method according to claim 6, characterized in that the upper flow away from the second extractive distillation column, condensed in the condenser and part of his return as return the product to the second extractive distillation column, and the residue away as a stream containing butane and butenes, the lateral flow away from the second extractive distillation column below the point of feed flow and preferably serves it in the second side of the column where it is separated into the upper stream, which condense and part of his return as return the product to the second side of the column and the remainder is put up in the form of a stream of crude 1,3-butadiene, and CBM the stream containing the selective solvent, which returns to the second extractive distillation column.

15. The method according to one of claims 7 to 9, characterized in that the upper flow away from the second extractive distillation column, condensed in the condenser and part of his return as return the product to the second extractive distillation column, and the remainder is to divert as a stream containing butane and butenes, the lateral flow away from the second extractive distillation column below the point of feed flow and preferably serves it in the second side of the column where it is separated into the upper stream, which condense and part of his return as return the product to the second side of the column and the remainder is put up in the form of a stream of crude 1,3-butadiene, as well as the VAT stream containing the selective solvent, which returns to the second extractive distillation column.

16. The method according to claim 10, characterized in that the upper flow away from the second extractive distillation column, condensed in the condenser and part of his return as return the product to the second extractive distillation column, and the remainder is to divert as a stream containing butane and butenes, the lateral flow away from the second extractive distillation column below the point of feed flow and preferably serves it in the second side of the column where it is separated into the upper stream, which condense and part of his return as return the product to the second side of the column and the remainder is put up in the form of a stream of crude 1,3-butadiene, and CBM stream containing the selective solvent, which returns to the second extractive distillation column.

17. The method according to claim 11, characterized in that the upper flow away from the second extractive distillation column, condensed in the condenser and part of his return as return the product to the second extractive distillation column, and the remainder is to divert as on the OK containing butanes and butenes, the lateral flow away from the second extractive distillation column below the point of feed flow and preferably serves it in the second side of the column where it is separated into the upper stream, which condense and part of his return as return the product to the second side of the column and the remainder is put up in the form of a stream of crude 1,3-butadiene, as well as the VAT stream containing the selective solvent, which returns to the second extractive distillation column.

18. The method according to claim 6, characterized in that from the second extractive distillation column with a theoretical plate located on one or more theoretical plates below the lateral diversion, divert fluid or a part that is heated and/or vaporized by indirect heat exchange kubovy flow from the second extractive distillation column and return to the second extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption for the second extractive distillation column.

19. The method according to one of claims 7-10, 14, 16, or 17, characterized in that from the second extractive distillation column with a theoretical plate, located nodo or more theoretical plates below the side outlet, divert the liquid or part thereof, which is heated and/or vaporized by indirect heat exchange kubovy flow from the second extractive distillation column and return to the second extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption for the second extractive distillation column.

20. The method according to one of 11 to 13, characterized in that from the second extractive distillation column with a theoretical plate located on one or more theoretical plates below the lateral diversion, divert fluid or a part that is heated and/or vaporized by indirect heat exchange kubovy flow from the second extractive distillation column and return to the second extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption for the second extractive distillation column.

21. The method according to item 15, wherein the second extractive distillation column with a theoretical plate located on one or more theoretical plates below the entrance is on a bend divert the liquid or part thereof, which is heated and/or vaporized by indirect heat exchange kubovy flow from the second extractive distillation column and return to the second extractive distillation column at the same theoretical plate or above it, in this case theoretical plate from which divert the liquid or part thereof, is chosen so as to minimize the energy consumption for the second extractive distillation column.



 

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16 cl, 3 dwg

FIELD: petrochemical processes.

SUBSTANCE: C4-hydrocarbon fractions obtained by cracking and/or pyrolysis of hydrocarbon feedstock in presence of amine-type extractant are subjected to rectification additionally involving butylene-isobutylene fraction resulting from butylene-to-isobutylene isomerization and containing 30-70% butylenes, 25-65% isobutylene, and 3-8% butanes. Weight ratio of C4-hydrocarbon fractions to added butylene-isobutylene fraction is 1:(3-7).

EFFECT: increased separation efficiency.

3 ex

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: C5-hydrocarbons with different degrees of saturation are separated by extractive rectification in extractive rectification column using dimethylformamide as extractant followed by desorption of pentenes or pentadienes therefrom and passing desorbed extractant to extractive rectification column. Part of hot desorbed extractant is subjected to liquid-phase mixing with starting hydrocarbons at vigorous stirring, after which resulting mixture is introduced into column in liquid form.

EFFECT: reduced power consumption.

2 dwg, 1 tbl, 5 ex

The invention relates to a method of separating a mixture WITH4hydrocarbons by extractive distillation in the presence of the extractant on the basis of acetonitrile and can be used in the synthetic rubber industry, in particular the separation of the cracking butane-butylene fraction (BBF)

The invention relates to a method of purification of benzene from coke production and benzene obtained from fractions of pyrolysis oil from impurities saturated and unsaturated hydrocarbons, thiophene and carbon disulfide

FIELD: industrial organic synthesis.

SUBSTANCE: crude 1,3-butadiene is recovered from C4-fraction by extractive distillation using selective solvent on column separated by a partition installed along longitudinal direction of the column to form first and second subzones and underlying common column zone. The column is connected to preswitched flush column. Distillation column operation is controlled by energy supply with the aid of lower evaporator and distribution of a series of theoretical plates within underlying common zone to create bottom stream therefrom consisting of purified solvent.

EFFECT: simplified process technology.

23 cl

FIELD: petrochemical processes.

SUBSTANCE: invention provides a process flow rate comprising at least (i) zone of extractive rectification in presence of polar extractant to produce distillate mainly containing butanes and butane(s); (ii) desorption zone wherein desorption of extractant gives stream containing mainly 1,3-butadiene and. as impurities, at least 2-butene(s) and acetylene hydrocarbons; and (iii) optionally rectification zone for mainly 1,3-butadiene-containing stream. In the latter, α-acetylene hydrocarbons are subjected to liquid-phase selective hydrogenation with hydrogen or hydrogen-containing mixture in presence of solid catalyst containing metal(s) exhibiting high activity in hydrogenation process, preferably non-precious metal(s) on solid support. Temperature is maintained within a range 5 to 75°C at contact time ensuring hydrogenation of no more then 6%, preferably no more than 2% of butadiene present. After hydrogenation, 1,3-butadiene is optionally additionally separated from impurities via rectification.

EFFECT: simplified process.

13 cl, 3 dwg, 2 tbl, 10 ex

FIELD: petroleum industry.

SUBSTANCE: process in carried out in column having divider arranging in longitudinal direction to form the first section, the second one and the third bottom joint section, wherein extractive scrubber is includes before divider.

EFFECT: simplified technology.

16 cl, 3 dwg

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for isolation and purification of butadiene prepared by thermal cracking of hydrocarbons followed by removing heavy by-side products from crude butadiene flow after the selective hydrogenation of undesirable impurities. The flow outgoing from the reaction zone of the selective hydrogenation is fed into evaporator with fraction zone for extraction of butadiene wherein this zone is sprayed with the raffinate flow from the zone of butadiene extraction. From the evaporator the vapor phase containing butadiene with reduced concentration of by-side products is removed and fed to the stage for isolating the concentrated liquid phase comprising heavy by-side products of the reaction. Butadiene-containing vapor phase is recovered to the zone for extraction of butadiene. The fraction zone comprises from 3 to 7 theoretical plates. The temperature in evaporator is maintained in the range from 27°C to 93°C under the pressure value from 375 to 790 kPa. Invention provides the improved technology in preparing the purified butadiene.

EFFECT: improved method for treatment.

5 cl

FIELD: petrochemical processes.

SUBSTANCE: 1,3-butadiene is obtained via catalytic dehydrogenation of n-butylenes at 580-640°C and essentially atmospheric pressure while diluting butylenes with water steam at molar ratio 1:(10-12) and supplying butylenes at space velocity 500-750 h-1. Catalyst is composed of, wt %: K2O 10-20, rare-earth elements (on conversion to CeO2) 2-6, CaO and/or MgO 5-10. MoO3 0.5-5, Co2O3 0.01-0.1, V2O5 0.01-0.1, and F2O3 the balance. Once steady condition is attained, dehydrogenation is carried out continuously during all service period of catalyst.

EFFECT: increased yield of 1,3-butadiene and process efficiency.

2 ex

FIELD: catalysts of selective hydrogenation of alkynes of C4 fractions.

SUBSTANCE: proposed catalyst contains 1-30 mass-% of copper used as first active component, 0.001-5 mass-% of palladium used as second active component, at least 0.001-6 mass-% of one metal selected from Al, Pt, Pb, Mn, Co, Ni, Cr, Bi, Zr and Mo as co-catalyst; the remainder being one carrier selected from aluminum oxide, silicon dioxide and titanium oxide. Method of production of catalyst includes impregnation of carrier calcined preliminarily with solutions of active components depending on their content in catalyst. Alkynes are removed from C4 fractions enriched with alkynes by means of selective hydrogenation with the use of said catalyst.

EFFECT: enhanced selectivity and stability of catalyst.

31 cl, 2 tbl, 13 ex

The invention relates to methods for production of 1-butanol (options), 1,3-butadiene and high-octane fuel from ethanol

The invention relates to the field of polymers butadienestyrene

The invention relates to the field of production of 1,3-butadiene and high-octane products

The invention relates to the production of butadiene-1,3 single-stage vacuum dehydrogenation of n-butane

FIELD: catalysts of selective hydrogenation of alkynes of C4 fractions.

SUBSTANCE: proposed catalyst contains 1-30 mass-% of copper used as first active component, 0.001-5 mass-% of palladium used as second active component, at least 0.001-6 mass-% of one metal selected from Al, Pt, Pb, Mn, Co, Ni, Cr, Bi, Zr and Mo as co-catalyst; the remainder being one carrier selected from aluminum oxide, silicon dioxide and titanium oxide. Method of production of catalyst includes impregnation of carrier calcined preliminarily with solutions of active components depending on their content in catalyst. Alkynes are removed from C4 fractions enriched with alkynes by means of selective hydrogenation with the use of said catalyst.

EFFECT: enhanced selectivity and stability of catalyst.

31 cl, 2 tbl, 13 ex

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