Method of separating alkane and alkene fractions

FIELD: chemistry.

SUBSTANCE: invention relates to a method of separating alkane and alkene fractions, possibly containing alkadiene impurities, using extraction rectification in the presence of polar extraction agent(s), wherein the basic amount of alkanes comes out in a distillate stream, and the basic amount of alkenes comes out in a strippant stream distilled from the extraction agent. The method is characterised by that before extraction rectification, the larger part of 1-alkene(s) in the alkane and alkene fractions is isomerised and/or hydroisomerised to 2-alkene(s) at temperature not above 100°C in the presence of heterogeneous catalyst(s) with activity during positional isomerisation of alkene, and possibly a small amount of polar substance which does not deactivate the catalyst(s).

EFFECT: more efficient separation of alkane and alkene mixtures through extraction rectification.

11 cl, 13 ex, 1 dwg

 

The invention relates to the field of separation bizcochada hydrocarbons whose molecules differ by the number of unsaturated bonds. More specifically the invention relates to the field of separation of alkanes and alkenes.

Known [Vbegin. Azeotropic and extractive distillation. L., Chemistry, 1971, s-332] methods of separation bizcochada hydrocarbons, characterized by the number of unsaturated bonds in molecules, in particular the separation of alkanes and alkenes by extractive distillation in the presence of polar extractants with output of more saturated hydrocarbons in the distillate.

In particular butane is separated from the butenes extractive distillation with acetonitrile or acetone. Isopentane (mixed with npentane) is separated from isopentanol extractive distillation with N,N-dimethylformamide or acetonitrile [Pasiecznik, Van, Limpopo. Album technological schemes the main production of the synthetic rubber industry. L., Chemistry, 1986, p.14-17, p.60-61].

The disadvantage of these methods is that in the presence in the reaction mixture alkane(s), with a higher boiling point than some of the alkenes, have to spend inversion and "separation" of their coefficients of relative volatility. This requires more recycled extractant and, consequently, large size is in devices and power consumption. To achieve the required ratios relative volatility when this is possible only when using a small number of the most polar (dimensionwhere µ and ν, respectively, dipolnym moment and molar volume of the molecule) substances generally expensive and often scarce. In Bhutan-butenova mixtures nbutane (intended for selection in the distillate) has a normal boiling temperature (TKip) minus 0.5°C, and 1-butene (intended for selection in desorbed) TKip=minus 6,3°C. the pentane-pentenoic mixtures of n-pentane (intended for selection in the distillate) is TKip=36,1°C, and 2-methyl-1-butene, intended for selection in desorber has TKip=31,2°C.

We found that significantly improve the efficiency of the separation of alkane-alkenovich mixtures by extractive distillation by conversion (isomerization) of 1-alkenes to 2-alkenes having a higher boiling point, for example, 1-butene (TKip=minus 6,3°C) in 2-butenes (TKip=plus of 0.8 and 3.7°C). Chemical equilibrium between 1-alkenes and 2-alkenes strongly shifted towards 2-alkenes at relatively low temperatures, which is quite favorable for isomerization. For carrying out the isomerization should be used catalysts, very active in positional isomerization of hydrocarbons when the temperature is x less than 100°C, preferably 15÷80°C.

We declare the method of separation of alkane-alkenovich fractions, possibly including a mixture of alkadiene(s)using extractive distillation in the presence of polar(s) of the extractant(s)in which the main quantity of alkanes display in the distillate stream, and the main number alkenes output stream decorate, warded off from the extractant, characterized in that prior to extractive distillation in alkane-alkinoos faction conduct the isomerization and/or hydroisomerization mostly contains () to 1-alkene(s) in 2-alkene(s) at a temperature of not more than 100°C in the presence of a heterogeneous(s) of catalyst(s), with(their) activity in the positional isomerization of alkenes, and possibly a small number of not deactivating the catalyst(s) polar substances.

The purpose of the most effective exercise method it is also claimed methods, characterized in that:

- as specified(s) of catalyst(s) used sulfonation(s) and/or catalyst(s)that contain(s) metal(s) from the group comprising Nickel, palladium, platinum, cobalt, and isomerization with catalyst(s)that contain(s) metal(s) from the specified group is preferably carried out in the presence of hydrogen.

to extractive distillation or preceding isomerization in the presence of sulfonate Anita in the presence of alkane-alkinoos fraction alkadiene(s) conducting the hydrogenation specified(s) alkadiene(s), perhaps with the hydroisomerization of 1-alkene(s) in 2-alkenes in the presence of a catalyst containing the metal(s) from the group comprising Nickel, palladium, platinum, cobalt, and alkadiene(s) turn mainly in alkenes and perhaps partly in alkanes.

- isomerization and/or hydroisomerization is carried out with the formation of dimers and ademero unsaturated hydrocarbons and possible products of interaction of unsaturated hydrocarbons with the specified polar substance in a quantity from 0.2% to 25% of the content of unsaturated hydrocarbons in the original alkane-alkinoos faction, before serving in the area of extractive distillation alkane-alanovoy mixture is separated from the dimers and ademero by evaporation or distillation and preferably serves it in the area of extractive distillation in the form of steam flow.

- in the quality or composition of the polar extractant used the substance(s) from the group comprising acetonitrile, N,N-dimethylformamide, N-organic, methoxypropionitrile, N,N-dimethylacetamide, ketone(s)3-C5the alcohol(s)1-C3.

in the extractive distillation zone below the feed of the extractant support its concentration in the liquid phase, in which the coefficient of relative volatility, which determines the complexity of splitting a pair of components is not less than 1,15, preferably at least 1.25.

- the division is subjected to a butane-butylene fraction, containing up to 10% of isobutene and up to 10% 1,3-butadiene, and when specified(s) isomerization and/or hydroisomerization keep the temperature from 20°C to 90°C.

when the separation by extractive distillation in the composition of decorate deduce the main quantity of 2-butenes, isobutene, 1-butene, and 1,3-butadiene and in the distillate output primarily butane(s) containing not more than 15 wt.%, preferably not more than 1 wt.% of butenes possibly with the admixture is carried out extractant.

when the separation by extractive distillation in the composition of decorate deduce the main quantity of butenes-2 with reduced relative to the original fraction content isobutene, butene-1 and possibly butadiene and distillate output primarily butane(s), at least partially isobutene, butene-1 and possibly butadiene, and possible admixture gone extractant.

separation is subjected to the fraction containing predominantly isopentane and isopentane may npentane, up to 10% of isoprene and up to 5% of piperylene at this isomerization and/or hydroisomerization keep the temperature from 10 to 70°C and extractive distillation in the distillate receive predominantly isopentane, possibly with the admixture npentane, 3-methyl-1-butene, other pentanol and gone extractant, and in decorate are mainly 2-methyl-2-butene.

- in the zone(s) isomerization and/or gidir the tion, and/or hydroisomerization introduce additional amount of alkane(s), possibly in part cleared from the extractant of distillate extractive distillation.

The name "alkane-Allenova fraction" is used based on the primary content in the partial fraction alkane(s) and alkene(s). This does not preclude the content of other components: alkadienes, acetylene hydrocarbons, etc. in quantities significantly smaller than the content of alkanes and alkenes. When dividing fractions containing predominantly isopentane and isopentane not exclude the possibility of content in significantly smaller quantities npentane, npentane and pentadiene.

Isomerization and/or hydroisomerization and/or hydrogenation can be conducted in liquid, gaseous or liquid state hydrocarbons. As the reaction zone (reactor) for carrying out the above isomerization and/or hydroisomerization, and/or hydrogenation can be used in reactors of various types, in particular the flow-through reactors with the movement of the hydrocarbon stream top-down or bottom-up, or reactors with separation and removal taglocity products of the reaction, the reaction-distillation apparatus).

Selfactivity catalysts can be used in various forms, including fine-grained, Faure is consistent, supported on a carrier, in the H+ form, at least partially neutralized form (Na+, etc.)containing typed hydrogenating metals, possibly in a mixture with inert materials, hydrogenating or hydroisomerization catalysts.

Isomerization and/or hydroisomerization can be performed in the presence of small amounts of specifically dosed or made with recycled alkanoyl flow polar substance that does not cause deactivation of the catalyst(s).

In the various processes leading to the alkane-alkenovich fractions, they can go from preceding stages substances are of two types:

1. Substances that can deactivate the catalyst(s) isomerization directly by neutralizing (ammonia, amines, bases, metals, etc. or as a result of their conversion on the catalyst substance capable of such neutralization, for example, acetonitrile in the education of it (and water) ammonia and acetic acid. The presence of such substances is highly undesirable.

2. Substances which in moderation is practically not inactivate the catalyst(s) isomerization (water, ketones, alcohols, esters and the like), however, contribute to the suppression of undesirable reactions of di - and oligomerization of alkenes. Polar substances are sorbed by the catalyst more strongly than hydrocarbons and in the presence inlarge quantities can reduce the activity of the catalyst. Getting further into the system of extractive distillation (ER), they can accumulate in the extractant and to reduce its selectivity. For example, in the extractant acetonitrile (BP=81,6°C) can accumulate acetone (BP=56,1°C.), methyl ethyl ketone (BP=to 79.6°C.), tert-butanol (BP=82,8°C), ethyl tert-butyl ether (BP=72,8°C), etc.

The main way to prevent a significant accumulation in the extractant / o part of the extractant with them, which leads to loss of the extractant.

Uniquely identify a suitable limit of the presence of such substances is difficult, because the problem lies in the sphere of technical and economic choice, in particular the mapping of the cleanup costs of raw materials from impurities or to prevent the accumulation of these impurities in the extractant.

Preferably, the concentration in the raw material was in the range of 0.2-2.0 wt.%.

The area of extractive distillation (ER) can be performed in a single column or multiple columns connected so that they operate as a single column ER.

The amount of extractant and the point of its supply must provide at least part of the zone air separation in the presence of quantities of extractant which have a significant effect on the relative volatility of the shared components, and results to differ materially from the division of the rivers is eficacia in the absence of a solvent. As a rule, the flow of the extractant is above the point of feed alkane-alkinoos faction close to the top of the column ER, however, technically possible and may be preferred options submission of the extractant at one point with alkane-alkinoos faction or below it (in particular, when the separation of butane-butenova faction you want to get the butenes-2, practically free from butane and other reactive impurities - butene-1, isobutene and butadiene).

Preferably above the point of feed of the extractant is a distillation or absorption zone, in which the separation of the hydrocarbons from the solvent. When the contact of the extractant in the distillate and/or desorbed due to insufficient rectification or education azeotropes may be additional separation of the hydrocarbons from the extractant, for example by water washing. A small portion of the circulating extractant can be cleaned or to ask to remove its impurities with the subsequent return of the pure solvent in the extractive distillation system or its replacement when filing a compensation quantity of fresh extractant.

Illustration of use of the invention shown in the drawing and the examples. Specified on the drawing and the examples do not exclude other technological solutions when is the incorrect signs, specified in claim 1 of the claims.

In particular, in the area of ER can be served two or more alkane-alkenone fraction and one or more extractants. The feed streams in the area ER can be done at one point or several feed points along the column height. In the area of ER can be applied intermediate the refrigerator (capacitors), heaters and boilers (the drawing shows additional boiler for heat recovery of desorbed extractant).

According to the drawing of the liquid alkane-Allenova fraction (AAF) enters the system through line 1 and then it is directed into the zone (node) hydroisomerization (GHIS) on line 2 and/or the isomerization zone (OUT) on line 3. If you use the area of GUISE, on line 4, it serves hydrogen or hydrogen-containing gas mixture. From the zone of GUISE (if used) mix output on lines 5 and later served in the node FROM line 6 and/or in the area of extractive distillation (ER) in line 7 and then line 9 may preliminarily subjecting the distillation (or perispomeni) from taglocity impurities in the zone FROM (the drawing shows the distillation in a distillation column).

From the zone (node), if it is used, output stream in line 8, which is fed into the system ER on line 9 may preliminarily subjecting the distillation from taglocity impurities in the zone FROM.

From the zone FROM (distillation columns is s or evaporator) stream alkane-alkinoos faction on line 10 serves in the area (column) extractive distillation (ER). CBM stream containing mainly dimers and Adimari unsaturated hydrocarbons, is removed through line 11.

In the area of ER on line 12 serves stream of the extractant. From the zone ER output line 13 to the flow of distillate containing predominantly alkane(s)that is fully or partially output line 14. Perhaps part of the distillate zone ER recycle in the area OF and/or GUISE, respectively, on lines 15A and 15B.

Perhaps in the area OF and/or GUISE recycle containing predominantly alkane(s) side selection from the upper part of the column ER (stream 23).

In the lower part of the zone ER if necessary (when using a high-boiling solvent) to lower the temperature, add relatively boiling component (for example, nhacsan by separation of butane-butenova faction) on line 20A.

From the cube (bottom) zone ER output lines 16 a solution of hydrocarbons (mainly alkenes) in the extractant (and possibly added to line 20A boiling component), served in the desorption zone (column) D.

From the zone D as distillate output line 17 stream, containing mainly alkenes (desorbed). From the cube zone D on line 18 output stream of the extractant, which recycle next in line 12 in the area of the ER, possibly pre-exposing the distillation added relatively easily boiling component in the additional decimal is blonay area DD.

When using zone DD on line 20 select the top product, including a relatively boiling component, which is then sent to the area ER (line 20A) and/or zone D (line 20B) to reduce the temperature and/or in the area OF (line 20B), and line 19 as the cubic product selected extractant, which is then recycled to the zone ER on line 12.

If the thread(s) 13 and/or 17 and/or 23 stream contains(at) gone with the extractant, his(their) purified from the extractant (recovery of extractant), for example by water washing and separation of the extractant from the water (not shown). A small portion of the circulating extractant output lines 21 may be subjected to purification from impurities (not shown) and returned to ER on line 22, which serves a complementary output of the extractant from the flow of fresh extractant.

Examples 1 and 11 are given for comparison with the presented invention, and do not contain nodes of isomerization of 1-alkenes.

EXAMPLES

Example 1

The separation is subjected supplied in quantities of 100 kg/h butane-butenova fraction with 60.0% of nbutane, 1.2% isobutane, 1.0% isobutene, 13,0% 1-butene, 23.2% of 2-butenes, 1,6% 1,3-butadiene, also containing 0.1 wt.% water and 0.5 wt.% of acetone.

The division performed in ER+D. the Area of extractive distillation consists of two columns connected so that it is functioning as a single column of AIR, with 60 teoretisk.

In the area of extractive distillation in the middle part on the support plates 70% acetonitrile.

The coefficient of relative volatility hardly separated pair butan-1-butene $ 1.26. Reflux the number in the ER (taking into account sorption extractant) is 4-4,5. The mass ratio of extractant: original mix (S/F) is 7.3.

Get (after water washing) of 62.3 kg/h of distillate containing 96.5% of nbutanol and 3.5% of butenes (0.3% isobutene) and 37.7 kg/h of decorate containing 92.9% of the butenes, 2.9% of n-butane and 4,2% 1,3-butadiene.

Example 2

The separation of the subject From4the fraction having the composition similar to that specified in example 1.

Originally From4-faction is served by line 3 in the isomerization zone (OF), including direct-flow adiabatic reactor sulfonic cation exchanger with a static exchange capacity (SOY) of 4.7 mg·EQ/year Temperature I3-54-58°C.

After the thread 9 is content With4-carbohydrates: 60% n-butane, 1,1% isobutane, 0.5% isobutene, 0.9% of 1-butene, 35.3% of 2-butenes, 1,3% 1,3-butadiene, and a mixture of water and acetone. The Department taglocity remove impurities in the amount of 0.8 kg/h stream 11 containing dimers and Adimari unsaturated hydrocarbons.

The vaporized stream 10 is fed to the zone of the ER with the extractant - acetonitrile with an efficiency of 60 teoretisk.

In the area of ER reflux number is about is 1.65. The ratio of extractant flows: From4-faction (S/F) is 3.2 kg/kg, i.e. at 2.0-2.2 times less than in example 1.

From ER output (hereinafter, after water washing) 61.3 kg/h of distillate containing 98.2% of butane, 1,8% of butenes and 37.9 kg/h of decorate containing 94,0% of butenes, 2.6% of butane and 3,4% 1,3-butadiene.

Example 3

The separation is subjected to 100 kg/h4the fraction having the composition similar to that specified in example 1.

Originally From4-faction serves on line 2 in the area of GUISE, and then out of it in the area OF. Next, after the separation zone FROM taglocity impurities carry out the separation by extractive distillation with acetonitrile. In the area of GHIS use the bubbling reactor type, the catalyst Nickel on kieselguhr, and the temperature of 40°C, in the area OF use once-through adiabatic reactor sulfonic cation exchanger with SOY=3.7 mg·EQ/g, and maintain the temperature 47-50°C. In zone GUISE conversion of 1,3-butadiene in n-butenes is 93%. Isomerization of 1-butene to 2-butenes in the area of GUISE is 37%, in zone I3-55%, a total of 92%. In the area of GHIS 6% n-butenes is transformed into n-butane. After the zone OF the mixture comprises 62,2% n-butane, 1,3% isobutane, 0.5% isobutene, 1.1% of 1-butene, 34,4% 2-butenes, 0,1% 1,3-butadiene and 0.4% of dimers.

When Stripping from taglocity impurities in the area derive FROM 0.4 kg/h flow dimers and ademero.

From the system ER+D output of 63.7 kg/h of distillate, with the holding (excluding gone acetonitrile) 98,1% butane and 1.9% of butenes, and 35,9 kg/h of decorate containing (excluding gone acetonitrile) to 2.8% n-butane, 0.9% isobutene, 1.9% of 1-butene, 94,1% 2-butenes and 0,3% 1,3-butadiene.

In column R-55 teoretisk reflux number is 1.6. The ratio of extractant flows: From4-faction is 3.3 kg/kg

Example 4

Unlike example 3, the support of extractive distillation, providing in decorate more concentrated butenes-2 (in particular, with low content of isobutene and 1-butene).

In the column ER reflux number is 4.0. The ratio of extractant flows: From4-faction is 2.3 kg/kg

From the system ER+DR deduce 64,7 kg/h of distillate containing (excluding gone acetonitrile) 97.1% of butane and 2.9% of butenes, as well as to 34.9 kg/h of decorate containing (excluding gone acetonitrile) 2,0% n-butane, 0.03% isobutene, 0,08% 1-butene, which is 97.6% of 2-butenes and 0,29% 1,3-butadiene.

Example 5

In contrast to example 4 in the same column ER use extractant methyl ethyl ketone and support of extractive distillation, providing in decorate concentrated 2-butenes with a low content of isobutene and 1-butene, and butadiene. The extractant is served in the lower part of the zone ER 30 plates below the point of feed With4-faction.

In the column ER reflux number is 5.5. The ratio of flows extrage the t 4the fraction is 0.5 kg/kg

From the system ER+DR deduce 64.4 kg/h of distillate containing 95.85% of butane, 4.0% butenes and 0.15% of butadiene and of 35.2 kg/h of decorate, containing 5.0% n-butane, 0.01% isobutene, 0.05% of 1-butene, 94,94% 2-butenes and 0,002% 1,3-butadiene.

Example 6

Unlike example 3, the area OF no use. In the area of GUISE is achieved by conversion of 1-butene to 2-butenes 90%, the conversion of 1,3-butadiene to butenes 97%, while in butan becomes 10% of butenes.

After the zone OF the mixture comprises (%): 63,6% nbutane, 1.3% of isobutane, 0.6% isobutene, 1,0% 1-butene, 33,15% 2-butenes; 0.05% of 1,3-butadiene and 0.3% of dimers. When Stripping from taglocity impurities in the area derive FROM 0.3 kg/h flow dimers and ademero.

From the system ER+DR deduce 65,0 kg/h of distillate containing (excluding gone acetonitrile) 98,3% butane and 1.7% of butenes, as well as to 34.7 kg/h of decorate containing (excluding gone acetonitrile) to 2.9% n-butane, 1.15% isobutene, and 2.0% 1-butene, 93.8% of 2-butenes and 0.15% 1,3-butadiene.

In the column ER - 60 teoretisk reflux number is 1.8. The ratio of extractant flows: From4-faction is 3.5 kg/kg

Example 7

The separation is subjected supplied in quantities of 100 kg/h butane-butenova fraction containing 21% nbutane, 15% isobutane, 10% isobutane, 21% of 1-butene, 23% of 2-butenes, 9.8 percent 1,3-butadiene and 0.2% vinylacetylene.

In the area of ER use extractant N-organic,to reduce the temperature using n-hexane, warded off additional desorption zone DD and partially circulating in the area OF the number of 45.5 kg/h

Originally From4-faction serves on line 2 in zone GUISE, including 2 consecutive reactor with a catalyst of palladium on a carrier, and then out of it in the area, including 2 consecutive adiabatic reactor type with sulfonic cation exchanger (SOY=5.1 mg·EQ/g). Next, after the separation zone FROM taglocity impurities carry out the separation by extractive distillation. In the area of GUISE temperature 30-40°C, vinylacetylene almost completely hereroense in butadiene and butene, the conversion of 1,3-butadiene in nbutane is 97%, 1-butene to 2-butenes - 5%, is converted into n-butane - 12% n-butenes. In the zone OF the temperature in the first reactor 90-105°C, in the second 40-43°C, the conversion of butenes in the dimers and sumimary of butenes - 24% (from content in the original faction), and the ratio of 1-butene: 2-butenes output is 3.2:96,8.

After the zone OF the mixture comprises 18,1% nbutane, 10.6% of isobutane, 0.6% isobutene, 1,0% 1-butene, 28.4% of 2-butenes; 0.03% of 1,3-butadiene, becomes 9.97% of dimers and 31.3% n-hexane (total content of unsaturated hydrocarbons 40%).

When the distillation taglocity impurities in the zone FROM the output of 15.2 kg/h flow dimers and ademero. From the system ER+DR derive a 41.3 kg/h of distillate containing 99.0% butane and 1.0% of butenes, as well as 44,5 kg/h of decorate containing a 2.0% n-butane,1,8% of isobutene, 2.7% of 1-butene, 92.9% of 2-butenes, 0,1% 1,3-butadiene and 0.5% impurities of n-hexane.

In column R - 55 teoretisk reflux number is 2.0. The ratio of extractant flows: From4-fraction is 2.5 kg/kg

Example 8

The separation is subjected supplied in quantities of 100 kg/h butane-butenova fraction containing 9% n-butane, 15% isobutane, 10% isobutane, 25.9% of 1-butene, 40% 2-butenes, 0,1% 1,3-butadiene.

In the area of ER use extractant methoxypropionitrile in a mixture with methanol. In the area OF the recycle portion of the distillate ER in the number of 52.6 kg/hour, providing concentration of alkanes on the sign-in area OF 50%.

With4-faction is served by line 3 in the area OF including sequentially cooled shell-and-tube reactor (loaded cation exchange resin with SOY=3.1 mg·EQ/g, the temperature of 55-70°C) and the adiabatic reactor (sulfonic cation exchanger loaded with SOY=5.2 mg·EQ/g, the temperature of 30-35°C). In the area OF education of butenes over taglocity products due to the dimerization and interaction with methanol - 25% of the content in the original faction), the ratio of 1-butene: 2-butenes output is 3.5:96,5. In the area OF the injected quantity of methanol 3.1 kg/hour, required to compensate for its losses in the area of extractive distillation.

After the zone OF the mixture comprises 17.7% of nbutane, 29.6 per cent of isobutane, 0.65% of isobutene, 1,35% 1-butene, 37,33% 2-butenes; 0,02% 1,3-butadiene, 12,25% of the products is imerissia alkenes and their interaction with methanol (methyl-alilovic esters) and 1.1% methanol.

When the distillation zone FROM the output of 19.5 kg/h flow taglocity products.

In the system of ER+DR get 78,1 kg/h of distillate containing 93,5% butane, 3.5% of butenes and 3.0% of methanol, of which 25.7 kg/h output (after washing from methanol), and the remaining amount returned to recycling in the area, and also deduce (after washing from methanol) to 59.4 kg/h of decorate containing a 2.0% n-butane, 0,35% isobutene, 1.1% of 1-butene, 96.5% of 2-butenes and 0.05% 1,3-butadiene.

In column R - 65 teoretisk, reflux number of 3.8. The ratio of extractant flows: From4-fraction is 2.5 kg/kg

Example 9

The separation of the subject From4-faction in the amount of 100 kg/h, similar to the one mentioned in example 8. As extractant used formylmorpholine.

Use straight-through reaction zone GUISE with catalyst CNG (containing palladium on the carrier). In the area of GUISE temperature 30-35°C, the conversion of 1,3-butadiene in nbutane is 92%, the ratio of 1-butene: 2-butenes output 3,2:96,8, n-butane hereroense - 1.5% of n-butenes.

After the zone GUISE mixture comprising 9.9% of nbutane, 15.1% of isobutane, 9.9% isobutene, and 2.0% 1-butene, 63,0% 2-butenes, 0,02% 1,3-butadiene, served in an area of AYR.

In the system of ER+DR get 36,0 kg/h of distillate containing predominantly butane (67,3%)contained in the feeding of 1-butene and isobutene (31,8%) and 0.9% 2-butenes, and infer as decorate 64,0 kg/h of koncentrira is the R 2-butenes (98,0%), containing as impurities 12% n-butane, 0,64% isobutene, 0.15% of 1-butene and 0.01% 1,3-butadiene.

In the column ER - 70 teoretisk reflux number ~of 4.0. The ratio of extractant flows: From4-faction is 2.8 kg/kg

Example 10

The separation is subjected to Bhutan-butenova faction in the amount of 100 kg/h, terzidou 62% n-butane, 1% isobutane, 0.9% isobutene, 14% of 1-butene, 22% of 2-butenes, 0,1% 1,3-butadiene. In the area of ER use methyl ethyl ketone extractant.

Originally From4-faction in the amount of 100 kg/h is served by line 3 in the area OF incorporating uniflow adiabatic reactor sulfonic cation exchanger (SOY=4,7 mg·EQ/g). The temperature in the I3 - 40-45°C, the ratio of 1-butene: 2-butenes after is 3.3:96,7. After the stream 9 contains 61% n-butane, 1.0% isobutane, 0.6% isobutene, 1.2% of 1-butene, 35.8% of 2-butenes, 0,1% 1,3-butadiene and 0.3% of dimers and of ademero of butenes.

When perispomeni from taglocity impurities in the zone FROM the mixture taken to 0.6 kg/h of stream 11 containing dimers and Adimari unsaturated hydrocarbons.

The vaporized stream 10 is fed to the zone AIR, with 80 teoretisk. From ER deduce 62,0 kg/h of distillate containing 99% butane and 1% of butenes and 39.4 kg/h of decorate containing 97,2% of butenes, 1.5% butane and 0,3% 1,3-butadiene.

In the area of ER reflux number is 1.65, the ratio of the extractant flows: From4-faction costs 3.2 kg/kg, respectively, 2.7 and 2.1 times is anise, than to achieve the same quality division ER no prior isomerization of 1-butene.

Example 11

The separation is subjected to the isopentane-isopentenyl mixture (100 kg/h), containing a 60.2% isopentane, 1.3% of n-pentane, 1,4% 3-methyl-1-butene (MB), a 3.2% n-pentanol, 11.5% of 2-methyl-1-butene (MB), 20,3% 2-methyl-2-butene (MB), 1.4% of isoprene and 0.7% of piperylene.

The division performed in ER+D. In the area of extractive distillation in the middle part on the support plates 75% N,N-dimethylformamide (DMF). Used columns ER efficiency 55 teoretisk, reflux number is 3.5 to 4.0.

The coefficient of relative volatility hardly separated pair npentane-MB is 1.36. The ratio of extractant flows:From5-fraction equal to 6.0 kg/kg

Get to 63.8 kg/h of distillate containing 94,8% of pentane and 5.2% of pentanol and 36.2 kg/h of decorate containing 2.8% of pentane (0.8% of isopentane and 2.0% n-pentane), with 91.4% of pentanol (29,0% 2-methyl-1-butene, 55.8% of 2-methyl-2-butene and 6.6% n-pentanol), 3.9% of isoprene and 1.9% of piperylene.

Example 12

The separation is subjected to the isopentane-isopentenyl mixture similar to the one mentioned in example 9, with the same extractant and efficiency columns ER.

Source4-faction serves on line 2 in zone GUISE, including the reactor irrigation type with a catalyst of palladium on the carrier, and later in the area, including adiabati the mini-reactor sulfonic cation exchanger (SOY=5.1 mg·EQ/g). Next, after the separation zone FROM taglocity impurities carry out the separation by extractive distillation. In the area of GUISE temperature 10-20°C, the conversion of diene hydrocarbons alkenes is 95%, 2-methyl-1-butene 2-methyl-2-butene - 15%. In the area OF temperature 40-45°C, the conversion of pentanol in dimers and Adimari - 0.5%, and the ratio of 2-methyl-1-butene: 2-methyl-2-butene output is 9.2:90,8. In the area of GHIS 8% pentenol turns into pentane.

The coefficient of relative volatility hardly separated pairs of n-pentane-MB 1.70. In the area of the air flow ratio extractant:5the fraction is equal to 4.5 kg/kg, reflux number of 2.8.

When the separation in the system ER+DR get 66,6 kg/h of distillate containing 96,0% of pentane and 4.0% of pentanol, and 33.1 kg/h of decorate, containing 1.2% of pentane (0.6% of isopentane and 0.6% n-pentane), with 91.4% of pentanol (7.6% of 2-methyl-1-butene, 82.7% of 2-methyl-2-butene and 8.2% n-pentanol), 0.2% isoprene and 0.1% piperylene.

Example 13

Unlike example 10 support extractive distillation, providing in decorate more concentrated 2-methyl-2-butene (in particular, with low content MB).

The coefficient of relative volatility hardly separated pair npentane-MB is 1,77. The ratio of extractant flows: From5-fraction equal to 2.5 kg/kg, and reflux the number of 4.0.

Get to 69.7 kg/h of distillate containing 92.1 per cent p is tanov and 7.9% of pentanol, and 30.0 kg/h of decorate containing 0.4% npentane, with 91.4% of pentanol (0.3% of 2-methyl-1-butene, 91.3% of 2-methyl-2-butene and 7.7% n-pentanol), 0.2% isoprene and 0.1% piperylene.

1. The method of separation of alkane-alkenovich fractions, possibly including a mixture of alkadiene(s)using extractive distillation in the presence of polar(s) of the extractant(s)in which the main quantity of alkanes display in the distillate stream, and the main number alkenes output stream decorate, warded off from the extractant, characterized in that prior to extractive distillation in alkane-alkinoos faction conduct the isomerization and/or hydroisomerization mostly contains () to 1-alkene(s) in 2-alkene(s) at a temperature of not more than 100°C. in the presence of a heterogeneous(s) of catalyst(s), with(their) activity in the positional isomerization of alkenes, and possibly a small number of not deactivating the catalyst(s) polar substances.

2. The method according to claim 1, characterized in that, as specified(s) of catalyst(s) used sulfonation(s) and/or catalyst(s)that contain(s) metal(s) from the group comprising Nickel, palladium, platinum, cobalt, and isomerization with catalyst(s)that contain(s) metal(s) from the specified group is preferably carried out in the presence of hydrogen.

3. The method according to claim 1, characterized in that prior to extractive re is the certification or previous isomerization in the presence of sulfonic cation exchanger in the presence of alkane-alkinoos fraction alkadiene(s) conducting the hydrogenation specified(s) alkadiene(s), perhaps with the hydroisomerization of 1-alkene(s) in 2-alkenes in the presence of a catalyst containing the metal(s) from the group comprising Nickel, palladium, platinum, cobalt, and alkadiene(s) turn mainly in alkenes and perhaps partly in alkanes.

4. The method according to claim 1, characterized in that the isomerization and/or hydroisomerization is carried out with the formation of dimers and ademero unsaturated hydrocarbons and possible products of interaction of unsaturated hydrocarbons with the specified polar substance in a quantity from 0.2% to 25% of the content of unsaturated hydrocarbons in the original alkane-alkinoos faction, before serving in the area of extractive distillation alkane-alanovoy mixture is separated from the dimers and ademero by evaporation or distillation and preferably serves it in the area of extractive distillation in the form of steam flow.

5. The method according to claim 1, characterized in that the quality or composition of the polar extractant used the substance(s) from the group comprising acetonitrile, N,N-dimethylformamide, N-organic, methoxypropionitrile, N,N-dimethylacetamide, formylmorpholine, ketone(s)3-C5the alcohol(s)1-C3.

6. The method according to claim 1, characterized in that in the area of extractive distillation following the filing of the extractant support its concentration in the liquid phase, in which the coefficient of relative lettuces and determining the complexity of splitting a pair of components is not less than 1,15, preferably at least 1.25.

7. The method according to claim 1, characterized in that the separation is subjected to a butane-butylene fraction, containing up to 10% of isobutene and up to 10% 1,3-butadiene, and when specified(s) isomerization and/or hydroisomerization keep the temperature from 20°C to 90°C.

8. The method according to claim 7, characterized in that the separation by extractive distillation in the composition of decorate deduce the main quantity of 2-butenes, isobutene, 1-butene, and 1,3-butadiene, and distillate derive primarily butane(s) containing not more than 15 wt.%, preferably not more than 1 wt.%, of butenes possibly with the admixture is carried out extractant.

9. The method according to claim 7, characterized in that the separation by extractive distillation in the composition of decorate deduce the main quantity of butenes-2 with reduced relative to the original fraction content isobutene, butene-1 and possibly butadiene, and distillate derive primarily butane(s), at least partially isobutene, butene-1 and possibly butadiene, and possible admixture gone extractant.

10. The method according to claim 1, characterized in that the separation is subjected to the fraction containing predominantly isopentane and isopentane may npentane, up to 10% of isoprene and up to 5% of piperylene at this isomerization and/or hydroisomerization keep the temperature from 10 to 70°C and extractive distillation in dis is illite receive predominantly isopentane, possibly mixed with npentane, 3-methyl-1-butene, other pentanol and gone extractant, and in decorate are mainly 2-methyl-2-butene.

11. The method according to claim 1, characterized in that the zone(s) isomerization and/or hydrogenation and/or hydroisomerization introduce additional amount of alkane(s), possibly in part cleared from the extractant of distillate extractive distillation.



 

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6 cl, 3 dwg, 6 tbl, 6 ex

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23 cl

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21 cl, 1 dwg

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3 cl, 1 dwg, 1 tbl, 3 ex

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EFFECT: simplified process and reduced power consumption.

4 cl

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