Method of obtaining 2-methyl-2-butene from isopentane and method of obtaining isoprene from isopentane

FIELD: chemistry.

SUBSTANCE: invention pertains to the method of obtaining 2-methyl-2-butene from isopentane, including gas phase dehydrogenation of isopentane in the dehydrogenation zone, extraction of the C5-fraction from contact gas, mainly consisting of isopentane, tert pentanes, isoprene impurities and other hydrocarbons and obtaining a stream from it, mainly consisting of 2-methyl-2-butene, with use of a liquid phase isomerisation catalyst in a C5-fraction 2-methyl-1-butene in 2-methyl-2-butene and distillation. The method is characterised by that, the above mentioned C5-fraction, possibly containing extra piperylene and 2-pentene, directly or after distillation from the larger part of 2-methyl-2-butene, undergoes liquid phase hydroisomerisation in the presence of a solid catalyst, containing group VIII metal(s), capable of simultaneous catalysing hydrogenation of pentadienes, isoprene and possibly, piperylenes, and positional isomerisation of tert pentenes, preferably with subsequent additional isomerisation of 2-methyl-1-butene in 2-methyl-2-butene on a sulfocationite catalyst, and distillation with output of a distillate stream of mainly isopentane, containing not more than 1.0% mass, preferably not more than 0.2% mass of pentadiene(s), which are mainly recirculated in the hydrogenation zone, and output from the lower part of the recirculation stream of mainly 2-methyl-2-butene with impurities of n.pentane and possibly 2-pentenes. The invention also pertains to the method of obtaining isoprene from isopentane, which involves reaction of 2-methyl-2-butene, obtained from gas phase dehydrogenation of isopentane, with hydroperoxide with further conversion of the oxide or products of hydroxylation in isoprene.

EFFECT: obtaining 2-methyl-2-butene and isoprene from isopentane.

13 cl, 8 ex, 2 tbl, 3 dwg

 

The invention relates to the field of obtaining an individual tretinion and production of isoprene (2-methyl-butadiene-1,3). More specifically the invention relates to the field of production of 2-methyl-2-butene and isoprene from isopentane.

The known method [Pasiecznik and other "Album of technological schemes of the main production of the synthetic rubber industry". L., Chemistry, 1986, p.53-70] obtain a mixture mainly trepelkov, including high-temperature gas-phase catalytic dehydrogenation of isopentane, removing gas from the contact dehydrogenation of a mixture of hydrocarbons With5containing predominantly isopentane and isopentane, and subsequent separation of this mixture by extractive distillation in the presence of a polar extractant emitting a stream containing predominantly isopentane and returned to the dehydrogenation, and stream containing primarily a mixture of tretinion (2-methyl-1-butene and 2-methyl-2-butene).

Also known way [Pasiecznik etc. ibid] production of isoprene by high-temperature gas-phase catalytic dehydrogenation mixture tretinion obtained by the above method, in which gas from the contact dehydrogenation extract the mixture of hydrocarbon, C5containing mainly tretinoi, isoprene and piperylene (pentadiene-1,3), from whom its extractive distillation in the presence of a polar agent extract mixture pentadiene and then by distillation separating isoprene from piperylene.

The process of production of isoprene from isopentane, which consistently uses the above methods, usually referred to as the process of two-stage dehydrogenation of isopentane, very complicated and expensive.

The known method [patent Ru - 2102370 from 20.01.1998,] production of isoprene from isopentane, according to which the isopentane is subjected to liquid-phase oxidation mainly in hydropeaking trepania, which epoxidized 2-methyl-2-butene with the formation of oxide 2-methyl-2-butene and tretinoina. Oxide 2-methyl-2-butene and Trepanier separated by distillation and then the oxide 2-methyl-2-butene converted into isoprene. Trepanier is subjected to dehydration to obtain a mixture of 2-methyl-2-butene and 2-methyl-1-butene. From this mixture by distillation give 2-methyl-2-butene, directed by epoxidation, and 2-methyl-1-butene is subjected to isomerization of 2-methyl-2-butene on sulfocationites catalyst in the presence of large quantities of alcohol with subsequent decomposition forms(their)SJ ether(s) and then from the reaction mixture allocate an additional amount of 2-methyl-2-butene.

The specified process is very complicated. One of its main drawbacks is the low conversion (˜7%) of isopentane in hydropeaking trepania. Attempt to increase the conversion rate leads to the formation of large amounts of by-products due to okelani the molecules in isopentane secondary carbon atom, adjacent to the tertiary carbon atom. Proposed EN - 2102370 reception isomerization of 2-methyl-1-butene 2-methyl-2-butene in the presence of alcohol leads to the formation of large amounts of by-products (in particular, esters) and requires further separation of 2-methyl-2-butene from alcohol and by-products.

The known method [patent Ru - 2170225 from 04.08.1998,] joint production of isoprene and monomer with alkenylphenol group (isobutene or alkenylbenzene). When isopentane is subjected to catalytic dehydrogenation, contact gas dehydrogenation extract a mixture of hydrocarbons With5and then from it are 2-methyl-2-butene, using rectification and isomerization of 2-methyl-1-butene 2-methyl-2-butene, and a stream containing predominantly isopentane and partially unsaturated hydrocarbon, C5return to the dehydrogenation zone. Allocated 2-methyl-2-butene then epoxidized alkylhydroperoxide in oxide 2-methyl-2-butene, turn next to isoprene.

Necessary for the epoxidation alkylhydroperoxide obtained by liquid-phase oxidation of the corresponding hydrocarbon (isobutane or alkylbenzene). From alkylhydroperoxide in the process of epoxidation of 2-methyl-2-butene is formed corresponding alcohol, dehydration which the monomer with one alkenylphenol group: isobutene, styrene, α-methylester the L.

A significant drawback of this method is that it is designed for processing With5-faction dehydrogenation, practically does not contain pentadiene (see thread 3 in table 1-3). In fact, such fractions contain 2.5-3% of isoprene and 0.2-0.4% piperylene. When Stripping5-fraction stream containing predominantly isopentane, it also includes up to 4.5% of isoprene, which when recycling the specified stream into the dehydrogenation zone cause coking of the catalyst. Piperylene, especially TRANS, almost inseparable from 2-methyl-2-butene conventional rectification of the nearly tangential esotropia (stream 2-methyl-2-butene its relative volatility with respect to TRANS-piperylene is just 1,07-1,08).

Another drawback of the method according to patent RU 2170225 is that it does not solved the problem of effective output npentane with 2-methyl-2-butene almost tangential esotropia, which leads to excessive accumulation npentane in the system epoxidation or hydroxylation.

The method is limited to use for the epoxidation of 2-methyl-2-butene hydroperoxides of hydrocarbons and does not allow the use of hydrogen peroxide.

We say:

The method of obtaining 2-methyl-2-butene from isopentane, including gas-phase dehydrogenation of isopentane in the dehydrogenation zone, removing the C contact of gas With 5the fractions containing predominantly isopentane, tretinoi, impurities of isoprene and other hydrocarbons, and receiving from it a stream containing predominantly 2-methyl-2-butene, using liquid-phase catalytic isomerization in C5-faction-2-methyl-1-butene 2-methyl-2-butene and rectification, wherein the specified5-faction may additionally contain piperylene and 2-pentene, directly or after distillation from the greater part of 2-methyl-2-butene is subjected to liquid-phase hydroisomerization in the presence of a solid catalyst containing the metal(s) of group VIII of the periodic system of Mendeleev's capable of(e) simultaneously catalyzing the hydrogenation of pentadiene, isoprene and possibly piperylene, and positional isomerization trepelkov, preferably with subsequent isomerization of 2-methyl-1-butene 2-methyl-2-butene on sulfocationites catalyst, and a rectification output as distillate flow predominantly isopentane containing not more than 1.0 wt.%, preferably not more than 0.2 wt.% pentadiene(s), which basically recycle to the dehydrogenation zone, and withdrawal from the bottom of the distillation stream is predominantly 2-methyl-2-butene mixed with npentane and possible 2-pentanol.

As ways of promoting effective to obtain 2-m is Teal-2-butene from isopentane according to claim 1, we also note the ways in which:

- conduct joint hydrogenation of pentadiene and isomerization of 2-methyl-1-butene in the presence of sulfocationites catalyst containing specified(e) metal(s)

in these areas isomerization and/or hydroisomerization introduce additional amount of saturated(s) of hydrocarbon(s)may flow predominantly isopentane in an amount to provide a concentration of alkanes in the mixture of from 50 to 90 wt.%,

- the output produced by distillation stream containing predominantly isopentane, is subjected to rectification in which output a distillate containing primarily 3-methyl-1-butene, and the VAT residue, preferably recycle to the dehydrogenation zone,

is withdrawn from the lower part of the specified rectification flow predominantly 2-methyl-2-butene additionally subjected to distillation from dimers may oligomers and resins.

We claim (regardless of the method according to claim 1):

A method of producing isoprene from isopentane, including gas-phase dehydrogenation of isopentane, removing from contact With gas5the fractions containing predominantly isopentane, tert-pentene, impurities of isoprene and other hydrocarbons, obtaining from it flow predominantly 2-methyl-2-butene using liquid-phase isomerization of 2-methyl-1-butene 2-methyl-2-butene and rectification, kata is iberoame the interaction of 2-methyl-2-butene with hydropredict and subsequent conversion forms(them)by the oxygen-containing(s) connection(s) C 5in isoprene, wherein the specified5-faction may additionally contain piperylene and 2-pentene, directly or after distillation from the greater part of 2-methyl-2-butene is subjected to liquid-phase hydroisomerization in the presence of a solid catalyst containing the metal(s) of group VIII of the periodic system of Mendeleev's capable of(e) simultaneously catalyzing the hydrogenation of pentadiene, isoprene and possibly piperylene, and positional isomerization trepelkov, preferably with subsequent isomerization of 2-methyl-1-butene 2-methyl-2-butene on sulfocationites the catalyst and distillation, distilled stream predominantly isopentane, preferably recycled to the zone dehydrogenation, and is removed from the bottom of the distillation stream is predominantly 2-methyl-2-butene containing not more than 10%, preferably not more than 2%, npentane and possible admixture of 2-pentenol, in the specified thread 2-methyl-2-butene is subjected to interaction with hydropredict hydrocarbon and/or hydropredict hydrogen in the presence of a catalyst containing active at the specified interaction of metal ions of variable valence, IV, V or VI group of the periodic system of Mendeleev, preferably molybdenum, tungsten or titanium, with recirculation stream containing predominantly 2-methyl-2-butene with what Bodom flow with a high content npentane, and the formed oxide 2-methyl-2-butene and/or products of its hydroxylation converted into isoprene removed from the mixture and formed from the gidroperekisi hydrocarbon alcohol may dehydration in the appropriate monomineralic monomer.

As a way conducive to the effective receipt of isoprene from isopentane according to paragraph 8, we also note the ways in which:

thread mainly 2-methyl-2-butene, containing partially npentane are catalyzed interaction with hydropredict at least two zones, one of which supports the molar predominance of 2-methyl-2-butene over hydropredict, and at least part of the unreacted hydrocarbons are served in a reaction zone with molecular prevalence of gidroperekisi over 2-methyl-2-butene, output stream with a high content npentane and output a stream containing Gidropress, food interaction and possibly the catalyst that return in the first of these zones,

- in the first zone of interaction of 2-methyl-2-butene with hydropredict support the molar ratio of the incoming 2-methyl-2-butene and gidroperekisi from 1.4:1 to 10:1, and the second zone is from 0.1:1 to 0.85:1,

- to interact with 2-methyl-2-butene use Gidropress(and), we get(s) the oxidation of hydrocarbon(s) from the group comprising isobutane, ethylbenzene, isoprop benzol, and forming(e)by its interaction with 2-methyl-2-butene alcohol(s) preferably dehydration and receive respectively isobutene, styrene or a-methylsterol or alcohol(s) are recovered from the reaction mixture and used for other purposes,

as specified gidroperekisi hydrocarbon use Gidropress tert-butyl and formed by the interaction of 2-methyl-2-butene tert-butanol receive an additional amount of isoprene by its interaction with formaldehyde and decomposition of the resulting intermediates,

- from the reaction mixture is extracted trebujena and get out of it and possibly isobutene additionally isoprene using it(them) interaction with formaldehyde and decomposition intermediates

products hydroxylation of 2-methyl-2-butene is produced by its contact with water and/or alcoholic solution of hydrogen peroxide in the presence of water-soluble and/or solid catalyst containing the metal(s) of the variable valency selected(e) from the group comprising molybdenum, tungsten, titanium,

products hydroxylation and/or dihydroxypropane subjected to catalytic dehydration directly to the receiving water and/or aqueous-alcoholic solution.

The proposed method can be used in different ways (processes) thermal is gidrirovaniya isopentane, in particular, the known processes for the dehydrogenation weighted almograve catalyst, with a stationary layer alimohammadi or platypodinae catalyst and possibly other processes for the dehydrogenation of isopentane, which becomes predominantly isopentane tretinoi.

For the simultaneous hydrogenation of alkadienes in C5-faction dehydrogenation and hydroisomerization 2-methyl-1-butene 2-methyl-2-butene can be used any catalyst suitable for selective hydrogenation of alkadienes without significant hydrogenation tretament.

For the isomerization of 2-methyl-1-butene 2-methyl-2-butene can also be used any catalyst capable of moving the double bond in molecules tretinion without destroying the carbon skeleton, in particular trail (usually selfactivity) catalysts or catalysts containing metals of variable valence, of which the most known and used in industry catalysts containing Nickel, palladium, copper or platinum on a solid medium.

The process of preferential hydrogenation of alkadienes (with concomitant isomerization of 2-methyl-1-butene) can precede the process of isomerization of 2-methyl-1-butene 2-methyl-2-butene on the cation(s) or be carried out after the above isomerization or this is the processes can be combined in a single reaction zone.

As a reactor for isomerization can be used in different devices with a vertical (top-down or bottom-up), horizontal or otherwise of the fluid and its contact with the catalyst. For hydrogenation and hydroisomerization can be used vertical apparatus with bubbling hydrogen-containing stream through the liquid (and catalyst) or the irrigation apparatus of the type system for maintaining a predetermined pressure of hydrogen. One of the distillation zones may precede hydroisomerization and her bottom stream containing predominantly 2-methyl-2-butene.

As catalysts for epoxidation and/or hydroxylation of 2-methyl-2-butene can be used various known catalysts containing molybdenum, tungsten and other metals, effective in these processes.

Obtaining isoprene oxide 2-methyl-2-butene or alcohol(s)receive(s) the hydroxylation and/or dihydroxypropane 2-methyl-2-butene, can be done by decomposition with known selective catalysts, for example, in the presence of borophosphate catalysts or catalysts containing compounds of strontium or other acidic catalysts. It is possible to obtain isoprene from C5-glycols by liquid-phase or vapor-liquid dehydration catalyzed by strong what Isletas (H 2SO4N3PO4and others) or strongly acidic cation exchange resin. Oxide 2-methyl-2-butene to become isoprene may be initially or in the joint process is converted into alcohol(s)5and/or C5unsaturated alcohol with subsequent dehydration.

The use of the proposed methods is illustrated in figures 1 to 3 and examples. These figures and examples do not exhaust all possible options and can be used in other technical solutions provided correspondingly to claim 1 and/or step 8 claims.

The figures used legend: IP - Isopentane, NP - n-pentane, MB - 2-methyl-2-butene, C4- hydrocarbons With4With5- hydrocarbon, C5With6+- hydrocarbons With6and more high-boiling hydrocarbons, KM - compressor, WITH the separator-sump.

According to figure 1, a stream containing predominantly isopentane, served by line 1. The specified stream with recycled thread 15 (thread PIS+) is heated, evaporated and serves on line 2 in the node dehydrogenation (UD). From the UD output gaseous stream 3, which komprimiert in the compressor KM and 4 served in site selection5-mixtures (node UVS). From the UVS output lines 5, 6 and 7 respectively flows abhasa, mainly hydrocarbons With4and hydrocarbons With6+. On line 8 output stream, aderrasi mainly hydrocarbons With 5served directly (line 8A) in the reaction zone R or previously served in the distillation column K-1 (line 8b), which is distilled from the most part contained 2-methyl-2-butene (stream 10), defend from water and line 9 (next 11) serves in the area of R.

Area R contains the catalyst(s), with(e) activity in the hydrogenation reactions of alkadienes and hydroisomerization alkenes with changing the position of the double bond. Hydrocarbons, C5in the area of the P support is preferably in a liquid state. The bottom of the zone R via the distribution device along the line 12 serves hydrogen or hydrogen-containing gas mixture. From zone R top output line 13 of the gas stream comprising unreacted hydrogen. Part of the flow 13 can be recycled at the entrance to the area P on line 13B.

From the upper part of zone P deduce hydrocarbon stream 14, which is served in a distillation zone To a-2. As the distillate from the zone K-2 output stream 15 containing predominantly isopentane, which recycle line 15 to the node U.

Bottom area K-2 on line 16 output stream containing predominantly 2-methyl-2-butene, which is then output on line 16 or line 16B served in the apparatus And, where distilled from dimers and other heavy impurities (line 18) and remove line 17 (the line 10A), possibly connecting with the flow 10.

<> According to figure 2 the dehydrogenation of isopentane in the node UD and selection With5-a mixture of hydrocarbons in the node UVS performed similarly shown in figure 1.

In contrast to figure 1 the hydroisomerization 2-methyl-1-butene and hydrogenation of pentadiene carried out in the reactor R-1 irrigation type containing the catalyst metal(s)active(s) for these reactions.

Liquid hydrocarbon mixture (pot and possibly path) served in the R-1 through top switchgear. Hydrogen is served in a small amount on line 9 (hereinafter 9a, 9b), regulate the pressure in the R-1.

From R-1 from the bottom on the line 10 the reaction mixture is poured from above into the reactor R-2 (possible stream 20B) via the distribution device. R-1 contains selfactivity catalyst. Below R-2 output liquid stream 11, which is served in a distillation column K-1.

From K-1 from the bottom to the output stream 12 containing mainly 2-methyl-2-butene. His next output line 12A or line 12B served in the apparatus for distillation of heavy impurities. These admixtures output line 15 and distilled stream containing predominantly 2-methyl-2-butene, output line 16. Perhaps the threads 12A and 16 are combined and output line 17.

Top K-1 the gas stream condenses and rasclaat in the separator-sump WITH. Bottom remove the water layer. Hydrocarbon stream 14 basically recycle in the D on line 14a (hereinafter, 20, 20A, 20B) and/or line 14b serves in column K-2, from which the top on line 18 deduce distillate containing primarily 3-methyl-1-butene, and the bottom line 19 output stream containing predominantly isopentane, which recycle mainly in UD (lines 20, 20A, 20B).

According to figure 3 the processing is carried out by dehydrogenation of isopentane (IP) node UD, followed by separation With5-a mixture of gas contact dehydrogenation node UVS. Then5the mixture is processed in the site hydroisomerization (and possibly additional isomerization) and rectification (node PIR) as shown in figure 1 or figure 2.

Allocate stream 10 containing mainly 2-methyl-2-butene (MB), which is directed to the interaction with hydropredict, and stream 9 containing predominantly isopentane, which recycle to the node U.

Thread 10 figure 3 corresponds to the thread 10A in figure 1 or stream 17 in figure 2, the flow 9 figure 3 corresponds to a flow of 15 to 1 or stream 20 in figure 2.

Stream 10 is sent to the node processing hydropredict (UCP). Possible pre-flux 10 is mixed with the flow of gidroperekisi (stream 11), the mixture is fed to the column and line 12 is distilled off light hydrocarbons (e.g., isobutene when using gidroperekisi trebuie). On line 13 cast from light impurities, the mixture is fed to the UCP.

In UCP recircu irout streams of unreacted 2-methyl-2-butene 14a and 18 and the flow 17 of the node DOGP (if used).

From the UCP node output stream of unreacted MB on line 14 and the stream 15 containing predominantly the products formed by the interaction MB with hydropredict. Stream 14 is partially (mostly mostly return in the UCP on line 14a, and partially served in a host of additional processing hydropredict on line 14b).

The original thread containing Gidropress, enters the process through line 11. Part of his line 11b served in the node DOGP.

From DOGP on line 16 output stream containing npentane (NP) and possibly light components, such as isobutene (IB). On line 17 output stream containing predominantly hydropeaking and products of its interaction with MB served in the UCP node.

In the streams fed to the UCP, the total molar support the predominance MB over hydropredict. The streams that fed into DOGP, total molar support the predominance of gidroperekisi over MB.

Thread 15 of the UCP is fed to the separation zone ROHP.

From AGP output line oxide 19 MB and possibly trebujena, or on line 20 deduce oxide MB and/or alcohols With5. On line 21 (hereinafter 21A) output stream containing alcohol formed from the gidroperekisi hydrocarbon (for example, methylphenylcarbinol, dimethylphenylcarbinol or tert-butanol), or water, then the output on line 21B.

Stream 19 is served at the site thermostaticallycontrolled and separation (DDR), where deduce at least the flux of isoprene, Ypres (line 23), water flow (stream 24), by-products (total flow of 25) and you can stream isobutene (stream 26).

Thread 20 serves in site preparation, liquid-phase dehydration and separation (node GDR), which derive at least the flux of isoprene (stream 27), water flow (stream 28) and by-products (total flow 29).

Thread 21A containing alcohol formed from the gidroperekisi hydrocarbon may submit to the site alcohol dehydration and separation (JEM), from which derive at least monoolefinic hydrocarbon (monomer) MOM on the line 30, the water line 31 and a total of (conditionally) by-products on line 32.

If the stream 21A contains tert-butanol, it is available on line 21B to receive additional quantities of isoprene by reacting with formaldehyde and subsequent decomposition of the intermediates in the isoprene.

EXAMPLES

Example 1

Obtaining 2-methyl-2-butene from isopentane carried out according to figure 1

Dehydrogenation of isopentane in UD spend on a system with a fluidized bed alimohammadi catalyst at 530-540°C. Serve 1100 kg fresh isopentane (<0.5 percent) npentane and recycle stream. Selection With5-a mixture of gas contact (UVS) is carried out by absorption of hydrocarbons of high boiling hydrocarbon solvent, followed by distillation for the thanki thread containing mainly hydrocarbons With4and then With distilled5the mixture of6and more high-boiling hydrocarbons.

With5a mixture of (pot) is subjected to rectification in the column K-1 from 2-methyl-2-butene (mixture npentane and possible 2-pentanol), which output line 10. The distillate (pot) after sedimentation of the water fed into the reactor hydroisomerization P containing catalyst Ni on kieselguhr" (˜30% by weight of Ni). The bottom of the "P" via a distribution device serves stream containing hydrogen, part of which is after the release of "P" recycle on the entrance.

Hydroisomerized of "P" on line 14 serves in a distillation column 2. As distillate output stream 15 containing predominantly isopentane, which recycle in UD. Bottom output stream 16 containing mainly 2-methyl-2-butene, which is combined with stream 10 and the output line 10A. In the reactor R maintain the temperature of 25°With a load of 1.1 kg liquid/kg of catalyst per hour. The overall conversion of 2-methyl-1-butene 2-methyl-2-butene is to 89.5%. The main hydrocarbon streams are given in table 1.

The result 839 kg/h flow (10A), containing mainly 2-methyl-2-butene (97,3%) mixed with npentane (1,7%), 2-pentanol (0,6%), 2-methyl-1-butene (<0.1%) and piperylene (0,3%). On the dehydrogenation return 2145 kg/h of a stream containing predominantly from the pentane (95,6%) with a mixture of 0.3% npentane and 4% of pentanol, less than 0.1% of isoprene.

In column K-1 75 theory. plates, reflux 5, in column K-2 70 theory. plates, reflux number 4,5.

Table 1

for example 1
HydrocarbonsT bales, °Flows, % wt
Pot 1Pot 8Pot 9=11Sweat 10Pot 14Sweat 15Pot 16Sweat 10A
Isopentane27,899,567,081,3-of 83.495,6--
Npentane36,10,50,80,61,50,60,32,01,7
3-M-1-butene20,11,41,7-1,71,9--
1-penten30,00,30,4-0,30,4--
2-pentene36,3 and 36.90,40,40,550,4 0,30,60,6
2-M-1-butene31,29,4the 11.6-1,21,10,1≤0,04
2-M-2-butene38,618,31,297,412,40,397,397,32
Isoprene34,12,32,80,05≤0,1≤0,1-≤0,04
Piperylene42.0 and a 44.20,1-0,5---0,3
The dimers>100-------
Weight, kg/h11002984245652824562145311839

Example 2

Obtaining 2-methyl-2-butene perform like specified in example 1. Unlike example 1 as catalyst hydroisomerization use selfactivity catalyst containing the th of 0.7 wt.% palladium. In the reactor, maintain the temperature of 30°C, the load on the catalyst 0.7 kg liquid/kg of catalyst per hour. In contrast to example 1 the growth of isopentane in 2 times above, but the formation of dimers With10in the amount of 0.2% of the total amount of liquid. From them the product parisparamus apparatus "And".

The result 862 kg/h of a stream containing predominantly 2-methyl-2-butene (97,1%) mixed with npentane (2,1%), 2-pentanol (0,5%), 2-methyl-1-butene (0.1%) and piperylene (0,3%).

On the dehydrogenation return 2121 kg/h of a stream containing predominantly isopentane (95,3%) mixed with npentane (0,35%), pentanol (4,3%), less than 0.05% of isoprene.

Example 3

Obtaining 2-methyl-2-butene from 1100 kg/h isopentane (0.5% npentane) carried out according to figure 2. Dehydrogenation of isopentane and selection With5-mixtures of conduct similar to that specified in example 1. As a catalyst hydroisomerization in the reactor R-1 use palladium (1.2 wt.%) on the aluminum oxide in the reactor R-2 (isomerization) - fine-grained sulfonation Amberlyst-35. In R-1 temperature 35-40°C, a hydrogen pressure of 3.5 to 4.0 ATA, P-2 -25°C. Loading on the catalyst in the R-1 - 2.0 kg/kg catches, R-2 - 6.5 kg/kg catches.

In column K-1 80 theory. plates, reflux 5. Characteristics of the main hydrocarbon streams is given in table 2

The result 793 kg/h flow (pot)containing 8.2% of 2-methyl-2-butene, 1,3% npentane, 0,5% npentane, ≤0.05% piperylene (isoprene missing) and receive the stream for recycle to the dehydrogenation (pot)containing 94.1% of isopentane, 0.7% of npentane, 1.9% of 3-methyl-1-butene, 0,8% npentane, 2.6% of trepelkov, ≤0.1% isoprene.

Example 4

Obtaining 2-methyl-2-butene from 1100 kg/h isopentane (0.5% npentane) carried out similar to example 3. In contrast to example 3 in the R-1 reactor using the catalyst Nickel on kieselguhr" (30% Nickel), in the reactor R-2 is molded in the form of rings (diameter 3-5 mm, length 4-6 mm) catalyst type'KEEFE. In R-1 temperature 20-25°C, a hydrogen pressure of 3.3 to 3.5 ATA, P-2, the temperature of 35-40°C. Loading on the catalyst in the region of 1 to 1.5 kg liquid/kg of catalyst, P-2 - 2 kg liquid/kg of catalyst.

The compositions of the streams close to the specified in table 2.

Example 5

Obtaining 2-methyl-2-butene from 1100 kg/h isopentane (0.5% npentane) have similarly indicated in example 3 (figure 2). Unlike example 3, warded off the thread 14 and recirculated to the dehydration is subjected to rectification in the column K-2, with efficiency of 80 theory. plates with specific reflux (reflux ratio of flow to the stream power) of 3.9.

As distillate from K-2 output ˜42 kg/h stream containing 98% 3-methyl-1-butene and ˜2% isopentane (other pentanol less than 0.03%). From the cube display and recycle to the dehydrogenation 2146 kg/the thread containing 95,8% isopentane, 0.7% of npentane, ˜3.4% of pentanol and ≤0.1% isoprene (see table 2).

Table 2

examples 3-5
HydrocarbonsFlows, % by weight (examples 3-4)Flows, % by weight, for example 5
Pot 1Pot 2Pot 8Sweat 10Pot 11Pot 12Pot 14Sweat 17Pot 18Sweat 19
Isopentane99,595,9567,068,568,5-94,1-2,095,75
Npentane0,50,60,70,80,81,30,71,3-0,7
3-M-1-butene1,31,41,41,4-1,9-97,98≤0,05
1-penten0,20,30,30,3-0,3--0,3
2-pentene 0,20,40,40,40,50,30,5-0,5
2-M-1-butene1,49,46,92,0-2,2-≤0,022,2
2-M-2-butene0,318,221,626,497,750,498,15-0,4
Isoprene0,052,3≤0,1≤0,08-≤0,1--≤0,1
Piperylene-0,3≤0,01≤0,01≤0,05-≤0,05--
The dimers---0,10,4----
Weight, kg/h110032882984298429847962188793˜4 2146

Example 6

Obtaining isoprene from isopentane and at the same time isobutene of isobutane is carried out according to figure 3. This dehydrogenation of isopentane and receiving With5-mixtures of conduct similar to that specified in example 1, and obtaining 2-methyl-2-butene from C5-mixture - similar to that specified in example 3.

796 kg/h stream containing 98.2% of 2-methyl-2-butene, 1,3% npentane, 0,5% other pentanol (mainly npentane), ≤0.05% piperylene, served on interaction with hydropredict trebuie.

The flow of gidroperekisi trebuil, state, containing 70% of the state (1001,6 kg/h), 10% trebuetsya (143,1 kg/h) and 20% isobutane, available on line 11. A large part of it (line 11a) connected to the flow MB (line 10)is distilled off from the stream in the column To the isobutane and VAT residue (pot) served in the node of the UCP. In the UCP serves the thread 18 (MB) from a node separation AGP and stream 17 from node DOGP. In total, served in the UCP flows support the molar ratio MB and state=2,5:1 and a temperature of 90-110°C. In the UCP is almost complete conversion of the state.

Unreacted MB evaporated and partially recycle the UCP on line 14a, partially sent to the node DOGP on line 14b. In DOGP on line 11b serves part of the thread 11. In DOGP support the molar ratio MB:state=0,4:1 and the temperature of 85-100°C.

As a catalyst in the UCP and DOGP IP is result the molybdenum naphthenate at a concentration of 0.05%.

From DOGP distilled stream 16 containing npentane and isobutane, and output a stream 17 is supplied to the UCP.

From the UCP output stream 15 containing predominantly oxide MB and trebujena served in the node separation ROHP. From AGP mixture of oxide MB and trebuetsya served at the site of thermal dehydration and separation DDR containing catalyst dehydration.

From DDR output 658 kg/HR of isoprene (stream 22) and 730 kg/h of isobutene (stream 21), water (stream 22) and by-products (conventionally stream 23), including 70 kg/h of methylisobutylketone.

Example 7

Obtaining isoprene from isopentane and simultaneously styrene from ethylbenzene carried out according to figure 3. Dehydrogenation of isopentane and receiving With5-mixtures of conduct similar to that specified in example 1, and obtaining 2-methyl-2-butene (MB) from C5-mixture - similar to that specified in example 3. 796 kg/h stream containing 98.2% of 2-methyl-2-butene, 4,3% npentane, 0,5% other pentanol, ≤0.05% piperylene, served on interaction with hydropredict ethylbenzene (GPEB).

A stream containing 35% GPAB (1525 kg/h), 60-63% ethylbenzene (EB) and 2-5% of methylphenylcarbinol (with a mixture of acetophenone) served by the line 11. Part of the flow (˜50-60%) on lines 11a served at the site of the UCP, and the other part along the line 11b served in the node DOGP.

From the UCP part of the unreacted MB with impurities is distilled off through line 14. A large part of the thread 14 on the line who 14a recycle at the site of the UCP, and a smaller part with content ˜25 kg/h npentane serves on line 14b in the node DOGP.

From DOGP distilled stream 16 with a high content of npentane and output liquid stream 17, which is fed to the UCP. In the UCP and DOGP as the catalyst use complex obtained by the interaction of molybdenum with GPIB and ethanol. On the supply(s) of the UCP support total molar ratio MB and GPEB 4:1; in the filing(s) in DOGP their ratio of 0.3:1. The temperature in the UCP 100-110°in DOGP - 90-100°C.

The liquid stream 15 from the UCP is subjected to separation in the node ROHP. From AGP output stream 18 (mainly MB), recycled in the UCP, stream 20 containing predominantly oxide MB, stream 21 containing predominantly methylphenylcarbinol, DMFC, and the thread 22 (mainly benzene), preferably directed to oxidation to obtain gidroperekisi.

Oxide MB subjected to liquid-phase isomerization of unsaturated alcohol With5and dehydration with obtaining isoprene (pot) node IDR at 160-180°C.

In the stream 21 DMFC subjected to dehydration in the presence of an acidic solid catalyst and 30 display the styrene selectivity of transformation 97-98%).

The result is ˜660 kg/HR of isoprene and ˜1115 kg/h of styrene.

Example 8

Obtaining isoprene from isopentane carried out according to figure 3. Dehydrogenation of isopentane and receiving With5-mix Pro is W ill result analogously to example 1, obtaining 2-methyl-2-butane (MB) from C5-mixture analogously to example 3.

As gidroperekisi to interact with MB use hydrogen peroxide, which serves in the process (line 11) in aqueous solution at a molar amount of hydrogen peroxide relative to MB from 1:1 to 1.2. Stream MB (pot) and part of the hydrogen peroxide solution (pota) served in the node UCP (the rest of the hydrogen peroxide solution available on line 11b in the node DOGP), and the hydrogen peroxide solution with the introduction of the UCP and possibly DOGP thoroughly dispersed.

As the catalyst used mainly titanium on a porous carrier containing silicon. The total molar ratio MB and H2About2in the input streams is in the UCP 5:1, DOGP to 0.3:1. The temperature in the UCP 80-95°in DOGP - 75-90°C.

The resulting products hydro - and dihydroxypropane after distillation MB node ROGP served in aqueous solution by line 20 to the node GDR, where in the presence of a solid strong acid catalyst (sulfonic cation exchanger) digitalout with distillation of isoprene.

On line 27 deduce 670 kg/h of a stream containing predominantly isoprene.

1. The method of obtaining 2-methyl-2-butene from isopentane, including gas-phase dehydrogenation of isopentane in the dehydrogenation zone, removing from contact With gas5the fractions containing enhan the public isopentane, tert-pentene, impurities of isoprene and other hydrocarbons and receiving from it a stream containing predominantly 2-methyl-2-butene, using liquid-phase catalytic isomerization in C5-faction-2-methyl-1-butene 2-methyl-2-butene and rectification, characterized in that the specified C5-faction may additionally contain piperylene and 2-pentene, directly or after distillation from the greater part of 2-methyl-2-butene is subjected to liquid-phase hydroisomerization in the presence of a solid catalyst containing the metal(s) of group VIII of the Periodic system of Mendeleev's capable of(e) simultaneously catalyzing the hydrogenation of pentadiene, isoprene and possibly piperylene, and positional isomerization tert-pentanol preferably with subsequent isomerization of 2-methyl-1-butene 2-methyl-2-butene on sulfocationites catalyst, and a rectification output as distillate flow mainly isopentane containing not more than 1.0 wt.%, preferably not more than 0.2 wt.% pentadiene(s), which basically recycle to the dehydrogenation zone, and withdrawal from the bottom of the distillation stream is predominantly 2-methyl-2-butene mixed with npentane and possible 2-pentanol.

2. The method according to claim 1, characterized in that the conducting hydrogenation pentadiene and isomerization of 2-methyl-1-butene in p is outstay sulfocationites catalyst, containing the specified(s) metal(s).

3. The method according to claim 1, characterized in that the said isomerization zone and/or hydroisomerization introduce additional amount of saturated(s) of hydrocarbon(s)may flow predominantly isopentane in an amount to provide a concentration of alkanes in the mixture of from 50 to 90 wt.%.

4. The method according to claim 1, characterized in that the output produced by distillation stream containing predominantly isopentane, is subjected to rectification in which output a distillate containing primarily 3-methyl-1-butene, and the VAT residue, preferably recycle to the dehydrogenation zone.

5. The method according to claim 1, characterized in that the output from the lower part of the specified rectification flow predominantly 2-methyl-2-butene additionally subjected to distillation from dimers may oligomers and resins.

6. A method of producing isoprene from isopentane, including gas-phase dehydrogenation of isopentane, removing from contact With gas5the fractions containing predominantly isopentane, tert-pentene, impurities of isoprene and other hydrocarbons, obtaining from it flow predominantly 2-methyl-2-butene using liquid-phase isomerization of 2-methyl-1-butene 2-methyl-2-butene and rectification catalyzed interaction of 2-methyl-2-butene with hydropredict and subsequent conversion forms(their)SJ acid is yodsoderjaschee(s) connection(s) C 5in isoprene, wherein the specified5-faction may additionally contain piperylene and 2-pentene, directly or after distillation from the greater part of 2-methyl-2-butene is subjected to liquid-phase hydroisomerization in the presence of a solid catalyst containing the metal(s) of group VIII of the Periodic system of Mendeleev's capable of(e) simultaneously catalyzing the hydrogenation of pentadiene, isoprene and possibly piperylene and positional isomerization tert-pentanol preferably with subsequent isomerization of 2-methyl-1-butene 2-methyl-2-butene on sulfocationites the catalyst and distillation, distilled stream predominantly isopentane, preferably recycled in the dehydrogenation zone, and is removed from the bottom of the distillation stream is predominantly 2-methyl-2-butene containing not more than 10%, preferably not more than 2%, npentane and possibly an admixture of 2-pentenol, in the specified thread 2-methyl-2-butene is subjected to interaction with hydropredict hydrocarbon and/or hydropredict hydrogen in the presence of a catalyst containing active at the specified interaction of metal ions of variable valence, IV, V or VI group of the Periodic system of Mendeleev, preferably molybdenum, tungsten or titanium, with recirculation stream containing predominantly 2-methyl-2-butene, with what vodom flow with a high content npentane, and the formed oxide 2-methyl-2-butene and/or products of its hydroxylation converted into isoprene removed from the mixture and formed from the gidroperekisi hydrocarbon alcohol may dehydration in the appropriate monomineralic monomer.

7. The method according to claim 6, characterized in that the flow is predominantly 2-methyl-2-butene, containing partially npentane are catalyzed interaction with hydropredict at least two zones, one of which supports the molar predominance of 2-methyl-2-butene over hydropredict, and at least part of the unreacted hydrocarbons are served in a reaction zone with molecular prevalence of gidroperekisi over 2-methyl-2-butene, output stream with a high content npentane and output a stream containing Gidropress, food interaction and possibly the catalyst that return in the first of these zones.

8. The method according to claim 7, characterized in that the first zone of interaction of 2-methyl-2-butene with hydropredict support the molar ratio of the incoming 2-methyl-2-butene and gidroperekisi from 1.4:1 to 10:1, and the second zone is from 0.1:1 to 0.85:1.

9. The method according to claim 6, characterized in that to interact with 2-methyl-2-butene use Gidropress(and), we get(s) the oxidation of hydrocarbon(s) from the group comprising isobutane, ethylbenzene, isopropylbenzene, and forming(e)camping at eisindisthe with 2-methyl-2-butene alcohol(s) preferably dehydration and receive respectively isobutene, styrene or α-methylsterol or alcohol(s) are recovered from the reaction mixture and used for other purposes.

10. The method according to claim 6, characterized in that, as specified gidroperekisi hydrocarbon use Gidropress tert-butyl and formed by the interaction of 2-methyl-2-butene tert-butanol receive an additional amount of isoprene by its interaction with formaldehyde and decomposition of the resulting intermediates.

11. The method according to claim 6, characterized in that the reaction mixture is extracted tert-butanol and get out of it and possibly isobutene additionally isoprene using it(them) interaction with formaldehyde and decay intermediates.

12. The method according to claim 6, characterized in that the products of hydroxylation of 2-methyl-2-butene is produced by its contact with water and/or alcoholic solution of hydrogen peroxide in the presence of water-soluble and/or solid catalyst containing the metal(s) of the variable valency selected(e) from the group comprising molybdenum, tungsten, titanium.

13. The method according to claim 10, characterized in that the products of hydroxylation and/or dihydroxypropane subjected to catalytic dehydration directly to the receiving water and/or aqueous-alcoholic solution.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention pertains to a catalyst and a method for selective increase in quality of paraffin raw material, with the aim of obtaining concentrated isoparaffin product as a benzine component. Description is given of the catalyst, which consists of a carrier from a sulphated oxide or hydroxide of group IVB (IUPAC 4) metals. The first component is, at least, from one lanthanide element or an yttric component, which is mainly ytterbium, and at least, one metal of the platinum group, which is mainly platinum, and a fireproof oxide binding substance, on which is dispersed at least, one metal of the platinum group. Description is given of the method of making the above mentioned catalyst, including a sulphated oxide or hydroxide of a group 1VB metal, depositing of the first component, mixing the sulphated carrier with the fireproof inorganic oxide of the oxide carrier, burning, depositing of the second component and subsequent burning. Description is given of the method of converting hydrocarbons through contacting with raw materials with the catalyst described above.

EFFECT: selective increase in quality of paraffin raw materials.

12 cl, 2 tbl, 2 dwg, 7 ex

FIELD: basic organic synthesis, chemical technology.

SUBSTANCE: invention relates to the improved method for isomerization reaction of pentane-hexane fraction with aim for preparing high-octane additive for gasoline. Pentane-hexane fraction is subjected for isomerization reaction in reaction-rectifying process using a low-temperature platinum-alumina catalyst. The parent raw is subjected for preliminary separation for pentane and hexane fractions. These fractions are subjected for separate isomerization that is carried out in vapor phase in reaction zone in bottom of reaction-rectifying column. Catalyst is placed under plates of zone and pressure in reaction zone in maintained in the range from 0.6 to 3.6 MPa, temperature - from 110.0oC to 200.0oC in the mole ratio hydrogen : hydrocarbons at inlet into column from 0.03:1 to 4:1. Method provides enhancing conversion of n-pentane, n-hexane and methylpentanes to high-octane isomers, elevating octane number of isomerizate and constructive simplifying the process.

EFFECT: improved preparing method.

1 dwg, 1 ex

The invention relates to the field of organic chemistry, namely, the method of production of Ala-4Z-ENES

The invention relates to catalytic methods hydroperiod hydrocarbons, and in particular to methods of hydroperiod oil fractions with a high content of normal paraffins in the environment of hydrogen to obtain products with a high content of ISO-paraffins

FIELD: industrial organic synthesis.

SUBSTANCE: production of styrene is effected via gas-phase dehydration of 1-phenylethanol at elevated temperature in presence of dehydration catalyst including molded particles of alumina-based catalyst having BET surface area 80 to 140 m2/g and pore volume (Hg) above 0.65 ml/g.

EFFECT: reduced amount of by-products and prolonged service cycle of catalyst.

3 cl, 1 tbl, 5 ex

FIELD: one-stage production of isoprene.

SUBSTANCE: proposed one-stage production method includes continuous or cyclic delivery of isobutylene and/or tert-butanol, formaldehyde and water to aqueous acid solution and interaction of reaction mixture at distillation of mixture containing isoprene to be produced, water, unreacted starting materials and other low-boiling components from reaction mixture beyond reaction system where said reaction is conducted at regulation of concentration of high-boiling byproducts which are accumulated in said reaction mixture at interval of from 0.5 to 40 mass-%.

EFFECT: enhanced efficiency.

10 cl, 2 dwg, 1 tbl, 13 ex

FIELD: chemical industry; methods of production of the pure isobutene out of the isobutene-containing mixture.

SUBSTANCE: the invention is pertaining to the method of production of the pure isobutene out of the isobutene-containing mixture predominantly - out of hydrocarbon С4 with usage of the catalysis by the strong-acid cationite(s) including the liquid-phase interaction of the isobutene with the water at the temperature of from 60 up to 130°С in one or several sections at the stage of hydration, delamination of the being withdrawn from it stream(s), distillation of the unreacted hydrocarbons С4 from the hydrocarbon layer, decomposing of the tret-butanol in the section(s) at the stage of dehydration, separation of the formed isobutene from the water and its) purification and characterized by that isobutene and the total amount of the returned from the stage of dehydration fresh water is fed in the section of hydration in the total molar ratio from 1:0.4 up to 1:20, and it is preferential from 1:1 up to 1:5, in the straight-flow or bubbling mode in the absence of the emulsifier hydrate from 30 up to 97 % of isobutene. From the stage of the hydration in the stage of the dehydration at least one-third of the produced tret-butanol is fed in the stream, separated by the rectification from the layer of the unreacted hydrocarbons and containing from 5 up to 30 mass % of the water, and, possibly, the rest amount - in the stream of the water layer, at the total content of the different, than the isobutene, the hydrocarbons not exceeding their admissible quantity in the target isobutene, and from the stage of the dehydration the water at least partially is returned into the stage of the hydration. The presented method requires the low power input and the low metal input.

EFFECT: the invention ensures the low power input and the low metal input.

14 cl, 2 dwg, 4 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of styrene. At the first step the method involves interaction of ethylbenzene hydroperoxide with propene in the presence of catalyst to yield propylene oxide and 1-phenylethanol followed by separate treatment of reaction flow and removing propylene oxide. At the second step the method involves interaction of 1-phenylethanol-containing distillate with a heterogenous dehydration catalyst at temperature 150-320°C to obtain styrene. Distillate contains 0.30 wt.-%, not above, compounds of molecular mass at least 195 Da. Invention provides decreasing the content of by-side compounds in styrene and to enhance it's the conversion degree.

EFFECT: improved method of synthesis.

3 cl, 3 tbl

FIELD: industrial organic synthesis and catalysts.

SUBSTANCE: invention provides a method for processing methanol into dimethyl ether and liquid hydrocarbons, the latter being used as high-octane components of gasolines Ai-92, 95. Processing comprises contacting of raw material, in at least one step, in at least one reactor containing catalyst: Pentasil-type zeolite and binder, followed by cooling resulting products, condensation and separation thereof to isolate methanol conversion hydrocarbon gases, water, and desired products, after which cooled hydrocarbon gases are recycled to methanol conversion stage in at least one reactor. Catalyst is characterized by SiO2/Al2O3 molar ratio 20-100, content of sodium oxide not higher than 0.2%, and additionally contained silicon dioxide and zirconium dioxide at following proportions of components: 1.0-15.0% silicon dioxide, 1.0-5.0% zirconium dioxide, 20-70% zeolite, and binder - the balance.

EFFECT: increased yield of desired products and improved performance characteristics of catalyst.

4 cl, 5 tbl, 18 ex

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to production of alkylaryl hydroperoxides useful as starting material in production of propylene oxide and alkenylaryl. Process of invention comprises following stages: oxidation of alkylaryl compound to form reaction product containing alkylaryl hydroperoxide; contacting at least part of reaction product with basic aqueous solution; separation of hydrocarbon phase containing alkylaryl hydroperoxide from aqueous phase; containing at least part of above hydrocarbon phase with aqueous solution containing waste water, said aqueous solution containing less than 0.2% alkali metal and/or salt (determined as ratio of metal component to total amount of solution); and separation of hydrocarbon phase from aqueous phase. By bringing at least part of above hydrocarbon phase containing alkylaryl hydroperoxide into interaction with propylene and catalyst, alkylaryl hydroxide and propylene oxide are obtained. At least part of propylene oxide is then separated from alkylaryl hydroxide. Dehydration of at least part of alkylaryl hydroxide results in formation of alkenylaryl.

EFFECT: reduced amount of contaminating by-products in alkylaryl hydroperoxide preparation stage.

8 cl, 4 ex

FIELD: industrial organic synthesis.

SUBSTANCE: embodiments of invention are accomplished via liquid-phase dehydration of methyl phenyl carbinol-containing feedstock in presence of acid-type catalyst in column-type reactor-rectifier comprising still portion, built-in heat-exchanger, and rectification portion, volume of still portion constituting 80% of built-in heat-exchanger volume. Temperature of till portion of reactor-rectifier is 140-205°C and temperature in rectification portion 130-180°C. Advantageously, methyl phenyl carbinol-containing feedstock is supplied to and/or under built-in heat-exchanger and catalyst or mixture of catalyst with feedstock and/or still product is supplied to still portion at mixing. Linear velocity of reaction mass vapors within free cross-section of reactor is 0.05 to 0.9 m/s, residence time of styrene in reaction zone 0.05 to 50 sec, and residence time of still product in reactor 5 to 500 h.

EFFECT: increased conversion of feedstock and final product formation selectivity.

5 cl, 14 ex

The invention relates to a method for producing olefin vapor-phase dehydration of alcohols in the presence of a catalyst at elevated temperature

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 petrochemical industry and can be used to obtain propylene oxide (OP) and styrene

FIELD: one-stage production of isoprene.

SUBSTANCE: proposed one-stage production method includes continuous or cyclic delivery of isobutylene and/or tert-butanol, formaldehyde and water to aqueous acid solution and interaction of reaction mixture at distillation of mixture containing isoprene to be produced, water, unreacted starting materials and other low-boiling components from reaction mixture beyond reaction system where said reaction is conducted at regulation of concentration of high-boiling byproducts which are accumulated in said reaction mixture at interval of from 0.5 to 40 mass-%.

EFFECT: enhanced efficiency.

10 cl, 2 dwg, 1 tbl, 13 ex

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to an isoprene production process involving dehydrogenation of isoamylene fraction in presence of overheated steam and iron oxide-based catalyst and is characterized by that catalyst has loose density at least 1.0 g/cc and not higher than 2.00 g/cc, apparent density at least 2.0 g/cc and not higher than 3.5 g/cc, and following composition. wt %: potassium compound 5-30, magnesium oxide 0.5-10, cerium(IV) oxide 5-20, calcium carbonate 1-10, molybdenum oxide 0.5-5, and ferric oxide - the rest.

EFFECT: improved selectivity of dehydrogenation process and increased activity and service cycle of catalyst.

2 cl, 1 tbl, 7 ex

FIELD: petrochemical processes.

SUBSTANCE: isoprene is obtained from isobutylene-containing stream and formaldehyde. Process comprises at least zones for chemical conversion in presence of strong-acid catalyst(s) and water and zone(s) for separating resulting mixtures. At least one of zones is used to carry out liquid-phase synthesis of intermediates suitable to be converted into isoprene, in which process unconverted C4-hydrocarbons are preferably separated and stream containing these intermediates are subjected to joint processing in vertical intermediate conversion zone(s) to produce isoprene preferably at ascending travel of stream(s). Converted vapor stream picked from the top of the conversion zone chiefly contains isoprene and isobutylene, and partially water. The stream is separated to remove at least one liquid stream containing chiefly water and optionally acid and organic impurities. This stream freed of high-boiling by-products (capable of being densified) is recycled to synthesis zone(s) and/or intermediate conversion zone(s). Resulting liquid organic stream contains high-boiling by-products, major part of which are separated inside intermediate conversion zone(s) and/or in a separate outer zone by way of extraction at 65 to 170°C with organic solvent containing essentially no alkadienes and components forming azeotropes with isoprene, which solvent is unable of forming homogeneous mixture with the above stream supplied in amount large enough to extract most part of high-boiling by-products. After extraction and settling, low layer is recycled to intermediate conversion zone(s) and optionally partially to intermediate synthesis zone(s).

EFFECT: alleviated clogging of equipment and reduced power consumption.

14 cl, 1 dwg, 7 ex

FIELD: industrial organic synthesis.

SUBSTANCE: in two-stage isoprene production process via dehydration of isopentane, contact gas produced in each stage is condensed and non-condensed hydrocarbons are absorbed and then desorbed. Hydrocarbon condensate is separated by rectification to give low-boiling hydrocarbon distillate fraction and bottom product. The latter is separated with the aid of extractive rectification to give isopentane and isoamylene fractions after the first dehydration stage and isoprene and isoamylene fractions after the second dehydration stage. Non-condensed low-boiling hydrocarbon vapors recovered after rectification are combined with non-condensed hydrocarbons from the first dehydration stage, preliminarily compressed, separated, and subjected to absorption.

EFFECT: maximized utilization of C5-hydrocarbons leading to reduced consumption of isopentane.

2 dwg, 4 tbl

FIELD: industrial organic synthesis.

SUBSTANCE: isoprene is produced from isobutene contained in C4-hydrocarbon fraction and formaldehyde in presence of water acid catalyst corrosive or moderately corrosive toward alloyed steel. Process is accomplished in at least two stages of liquid-phase chemical conversion to form, in the intermediates synthesis stage, isoprene precursors and withdrawing them with organic and essentially water stream followed by distillation of at least C4-hydrocarbons from organic stream and joint processing of the rest of organic stream and above-mentioned essentially water stream in intermediates decomposition stage. Decomposition of intermediates is accompanied by continuous withdrawal of vapor stream containing isoprene, isobutene, and a part of water, which stream is further subjected to separation and removal of liquid stream containing essentially water and acid and, preferably, removal of liquid organic stream containing high-boiling by-products. At least part of isobutene isolated from decomposition stage products is recycled into the beginning of this stage in such an amount that, in this stage, input streams contain summary molar amount of isobutene and tert-butanol exceeding by 1.1 times, preferably by 1.4 times, summary molar amount of formaldehyde and 4,4-dimethyl-1,3-dioxane. Organic stream obtained after condensation and stratification of vapor stream from decomposition stage is brought into contact with liquid stream from decomposition stage containing mainly water and acid and then subjected to separation involving at least rectification step, and stream containing mainly water and acid is recycled into the beginning of decomposition and/or synthesis stage.

EFFECT: simplified technology and reduced formation of high-boiling by-products.

2 cl, 2 dwg, 3 ex

FIELD: technology of petroleum chemistry, organic chemistry.

SUBSTANCE: invention relates to a method for preparing isoprene, isobutylene and formaldehyde from by-side products in the process for producing isoprene. Methyldihydropyrane and/or high-boiling products are heated in the presence of steam up to temperature 400-550°C followed by their contacting with alumosilicate-containing catalyst in the presence of steam at temperature 400-480°C. Method provides enhancing the selectivity of process, to enhance the conversion of heavy residue and to reduce the coke deposition. Invention can be used in industry of synthetic rubber and the organic synthesis.

EFFECT: improved processing method.

2 cl, 1 tbl, 4 ex

FIELD: petroleum chemistry, chemical technology.

SUBSTANCE: invention relates to dehydrogenation of isoamylenes to isoprene on iron oxide self-regenerating catalysts. Method involves addition of piperylenes in the concentration up to 4 wt.-% representing a by-side product in manufacturing process of isoprene by the indicated method to the parent isoamylenes before their dehydrogenation. Method provides enhancing selectivity of method for isoamylenes dehydrogenation to isoprene in the presence of iron oxide self-regenerating catalysts.

EFFECT: improved preparing method.

1 tbl, 6 ex

Up!