CN1056823C - Method for separation of cracking C5 fraction by pre-removal process of alkyne - Google Patents
Method for separation of cracking C5 fraction by pre-removal process of alkyne Download PDFInfo
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- CN1056823C CN1056823C CN96102485A CN96102485A CN1056823C CN 1056823 C CN1056823 C CN 1056823C CN 96102485 A CN96102485 A CN 96102485A CN 96102485 A CN96102485 A CN 96102485A CN 1056823 C CN1056823 C CN 1056823C
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- 150000001345 alkine derivatives Chemical class 0.000 title claims abstract description 55
- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000000926 separation method Methods 0.000 title claims abstract description 21
- 238000005336 cracking Methods 0.000 title claims abstract description 20
- 239000002904 solvent Substances 0.000 claims abstract description 32
- XNMQEEKYCVKGBD-UHFFFAOYSA-N dimethylacetylene Natural products CC#CC XNMQEEKYCVKGBD-UHFFFAOYSA-N 0.000 claims abstract description 16
- 238000000605 extraction Methods 0.000 claims abstract description 13
- 150000001335 aliphatic alkanes Chemical class 0.000 claims abstract description 5
- 150000001336 alkenes Chemical class 0.000 claims abstract description 3
- -1 isoamylalkene Chemical class 0.000 claims abstract description 3
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 claims description 74
- ZSWFCLXCOIISFI-UHFFFAOYSA-N cyclopentadiene Chemical compound C1C=CC=C1 ZSWFCLXCOIISFI-UHFFFAOYSA-N 0.000 claims description 34
- 241000282326 Felis catus Species 0.000 claims description 28
- 239000000463 material Substances 0.000 claims description 24
- 238000000895 extractive distillation Methods 0.000 claims description 22
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 21
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 claims description 16
- 238000009835 boiling Methods 0.000 claims description 16
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 claims description 16
- 238000010992 reflux Methods 0.000 claims description 16
- HECLRDQVFMWTQS-RGOKHQFPSA-N 1755-01-7 Chemical compound C1[C@H]2[C@@H]3CC=C[C@@H]3[C@@H]1C=C2 HECLRDQVFMWTQS-RGOKHQFPSA-N 0.000 claims description 15
- BOFLDKIFLIFLJA-UHFFFAOYSA-N 2-methylbut-1-en-3-yne Chemical group CC(=C)C#C BOFLDKIFLIFLJA-UHFFFAOYSA-N 0.000 claims description 14
- 239000004215 Carbon black (E152) Substances 0.000 claims description 10
- 238000004821 distillation Methods 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 9
- 238000006471 dimerization reaction Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 229930195733 hydrocarbon Natural products 0.000 claims description 7
- 150000002430 hydrocarbons Chemical class 0.000 claims description 7
- HYBBIBNJHNGZAN-UHFFFAOYSA-N furfural Chemical compound O=CC1=CC=CO1 HYBBIBNJHNGZAN-UHFFFAOYSA-N 0.000 claims description 4
- KGWDUNBJIMUFAP-KVVVOXFISA-N Ethanolamine Oleate Chemical compound NCCO.CCCCCCCC\C=C/CCCCCCCC(O)=O KGWDUNBJIMUFAP-KVVVOXFISA-N 0.000 claims description 3
- 239000000470 constituent Substances 0.000 claims description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 2
- 238000005194 fractionation Methods 0.000 claims description 2
- LQNUZADURLCDLV-UHFFFAOYSA-N nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1 LQNUZADURLCDLV-UHFFFAOYSA-N 0.000 claims description 2
- 239000000376 reactant Substances 0.000 claims description 2
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 13
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 150000001993 dienes Chemical class 0.000 abstract description 6
- 238000004880 explosion Methods 0.000 abstract description 6
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 abstract 1
- 229910052799 carbon Inorganic materials 0.000 description 10
- QWTDNUCVQCZILF-UHFFFAOYSA-N isopentane Chemical compound CCC(C)C QWTDNUCVQCZILF-UHFFFAOYSA-N 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- AFABGHUZZDYHJO-UHFFFAOYSA-N dimethyl butane Natural products CCCC(C)C AFABGHUZZDYHJO-UHFFFAOYSA-N 0.000 description 5
- RGSFGYAAUTVSQA-UHFFFAOYSA-N pentamethylene Natural products C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 4
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 4
- 239000012141 concentrate Substances 0.000 description 4
- LPIQUOYDBNQMRZ-UHFFFAOYSA-N cyclopentene Chemical compound C1CC=CC1 LPIQUOYDBNQMRZ-UHFFFAOYSA-N 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- PMJHHCWVYXUKFD-UHFFFAOYSA-N piperylene Natural products CC=CC=C PMJHHCWVYXUKFD-UHFFFAOYSA-N 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 150000001941 cyclopentenes Chemical class 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003112 inhibitor Substances 0.000 description 3
- 125000004817 pentamethylene group Chemical group [H]C([H])([*:2])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[*:1] 0.000 description 3
- PMJHHCWVYXUKFD-SNAWJCMRSA-N (E)-1,3-pentadiene Chemical compound C\C=C\C=C PMJHHCWVYXUKFD-SNAWJCMRSA-N 0.000 description 2
- YHQXBTXEYZIYOV-UHFFFAOYSA-N 3-methylbut-1-ene Chemical compound CC(C)C=C YHQXBTXEYZIYOV-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000006837 decompression Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000012847 fine chemical Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- QGMRQYFBGABWDR-UHFFFAOYSA-N sodium;5-ethyl-5-pentan-2-yl-1,3-diazinane-2,4,6-trione Chemical compound [Na+].CCCC(C)C1(CC)C(=O)NC(=O)NC1=O QGMRQYFBGABWDR-UHFFFAOYSA-N 0.000 description 2
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 description 2
- MJBPUQUGJNAPAZ-UHFFFAOYSA-N Butine Natural products O1C2=CC(O)=CC=C2C(=O)CC1C1=CC=C(O)C(O)=C1 MJBPUQUGJNAPAZ-UHFFFAOYSA-N 0.000 description 1
- KEAYESYHFKHZAL-UHFFFAOYSA-N Sodium Chemical compound [Na] KEAYESYHFKHZAL-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- WFYPICNXBKQZGB-UHFFFAOYSA-N butenyne Chemical group C=CC#C WFYPICNXBKQZGB-UHFFFAOYSA-N 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000012993 chemical processing Methods 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000000539 dimer Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- WFKAJVHLWXSISD-UHFFFAOYSA-N isobutyramide Chemical compound CC(C)C(N)=O WFKAJVHLWXSISD-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- QYZLKGVUSQXAMU-UHFFFAOYSA-N penta-1,4-diene Chemical compound C=CCC=C QYZLKGVUSQXAMU-UHFFFAOYSA-N 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000004230 steam cracking Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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Abstract
The present invention relates to a technological method for separating C5 diolefin and other components, such as alkane, olefin, etc., in cracking C5 fractions with an extractive rectification method, which is characterized in that before the C5 fractions are treated with extraction separation, firstly, alkyne, such as isoamylalkene, butyne-2, etc., are removed by rectification. Thus, by using the whole C5 separation technology, the explosion danger of alkyne is eliminated, and the safety in production is ensured. Simultaneously, the treatment load of subsequent technologies and the consumption of extracting solvents are reduced. Thereby, the treatment capability of the whole production flow is increased.
Description
The present invention relates to a kind of carbon five (C
5) extraction separating method of fraction, more particularly, relate to a kind of cracking C that adopts pre-removal process of alkyne
5The separation method of fraction.
As everyone knows, cracking C
5The alkynes that contains a small amount of four carbon atom and five carbon atoms in the fraction is as crotonylene, pentyne-1, pentyne-2, pseudoallyl acetylene (hereinafter to be referred as valylene) etc.Because differences such as cracking stock, cracking condition, separation process, wherein total alkynes content may change in 0.1～2wt% scope.The chemical property of alkynes is active, is C
5The main detrimental impurity of reaction of diolefin product and polymerization process, so effective elimination alkynes becomes cracking C
5The important step of fraction separating technology.
The explosion hazard of vinylacetylene in the butadiene extraction unit once taking place in history, caused tremendous loss, thereby caused people's great attention and concern.Study affirmation through us, at C
5The operation concentration of valylene and crotonylene, temperature, dividing potential drop should be controlled in certain scope and can guarantee production safety in the separating technology process.But the lesson as above-mentioned butadiene extraction unit blast shows that blast often occurs under the situation of abnormal operation, so C
5The alkynes explosion hazard is not sneezed at.
In existing C
5In the separating technology, generally adopt the method for chemical treatment, extraction or extracting rectifying to remove alkynes.Wherein more common is the method that adopts extracting rectifying, and the advantage of this method is when removing micro-cyclopentadiene the total alkynes in the isoprene finished product to be removed to below the 50ppm, and need not introduce chemical processing agent.Its shortcoming is to need higher energy consumption, and alkynes can concentrate at the tower still of some equipment such as extraction tower and the top of stripping tower in sepn process.Certainly when normal running, we can for example adopt the industrial chromatography monitoring, alarming by some means, prevent that in methods such as dangerous position adding suitable dilution agent alkynes concentration or dividing potential drop from reaching the explosion hazard degree.But when abnormal operation or accidental state, still might blast accident, the safety of harm operator and production equipment.
Nippon Zeon Co., Ltd. is in US Patent specification 3,510, discloses in 405 a kind of from C
5The processing method of separating high-purity isoprene in the fraction mixture, it comprises following process: the C that will obtain by hydrocarbon steam cracking or other high-temperature cracking method
5Fraction is also therefrom isolated dicyclopentadiene through overheated dimerization reaction; With DMF is that solvent carries out the extractive distillation first time in the presence of stopper, and solvent is by a stripping tower recycling use; Material carries out rectifying through a weight-removing column, therefrom separates the heavy constituent that contain cyclopentadiene and m-pentadiene; With DMF is that solvent carries out the extracting rectifying second time in the presence of stopper, and solvent reclaims by stripping tower and uses; Material obtains highly purified isoprene product after a dehydrogenation tower carries out rectifying.
In above-mentioned separating technology process, have following shortcoming:
1, because alkynes mainly concentrates on the last and product of flow process removes; therefore; valylene is concentrated at the cat head of the stripping tower of second extracting rectifying; and crotonylene is concentrated at the cat head of lightness-removing column; so that whole flow process all has certain dangerous hidden danger; must take strict security measures, especially in particular cases danger is bigger operating undesired or parking maintenance etc.
2, in lightness-removing column with the crotonylene in the isoprene from removed overhead, dilute with isoprene at the cat head crotonylene, its concentration is remained on below the safe concentration, thereby causes the loss of isoprene.Equally, also needing when the first stripping tower top of second abstraction distillation system removes valylene with isoprene is that thinner surpasses safe concentration to avoid it, this has also caused the loss of isoprene, therefore makes the raising of isoprene yield be subjected to certain restriction.
3, because alkynes mainly concentrates on the last and product of flow process removes, therefore increased the load of whole flow process, made the processing power reduction of production equipment.
The objective of the invention is to the defective that exists in the above-mentioned prior art, proposed a kind of cracking C
5The separation method of fraction is characterized in that alkynes removes before extracting and separating, solved the problem of alkynes explosion hazard in the industrial production.
To describe the present invention in detail below.
The contriver has proposed a kind of cracking C that adopts pre-removal process of alkyne through for many years further investigation
5The separation method of fraction comprises following process:
Cracking C
5The fraction raw material carries out hot dimerization reaction in hot dipolymer reactor, make C
5Most of cyclopentadiene dimerization in the fraction generates dicyclopentadiene, and temperature of reaction is 60～150 ℃, and reaction pressure is 1.0～1.5MPa, and reactant removes dicyclopentadiene and other high boiling hydrocarbon through fractionation by distillation then;
The material that is obtained by said process enters first extractive distillation column by the middle part of tower, in the presence of solvent and stopper, carry out extracting rectifying, the tower internal pressure is 0.1～0.3MPa, tower still temperature is 100～140 ℃, the trim the top of column ratio is 4～10, get monoolefine, single alkane by cat head, must be rich in the solvent material of C 5 dienes such as isoprene by the tower still;
Above-mentioned tower still material enters a stripping tower by the top of tower, and stripping Tata still must reclaim solvent and return first extractive distillation column and recycle its cat head material C
5Component enters a weight-removing column and carries out rectifying separation, to be isolated dicyclopentadiene, m-pentadiene and other heavy constituent by the tower still, obtains thick isoprene by cat head;
Weight-removing column cat head material enters second extractive distillation column by the tower middle part, in the presence of solvent and stopper to the further extracting rectifying of thick isoprene, the tower internal pressure is 0.1～0.3MPa, tower still temperature is 100～150 ℃, the trim the top of column ratio is 4～8, get qualified isoprene product by cat head, its tower still material that contains a small amount of cyclopentadiene and other alkene and alkynes enters follow-up Analytic Tower, obtains the high purity isoprene product by precise distillation again;
It is characterized in that: according to alkynes energy and C such as valylene, crotonylenes
5Alkene etc. generate the minimum boiling point azeotrope, and the boiling point of azeotrope is lower than most of C
5The characteristic of fraction, cracking C
5The fraction raw material at first removes alkynes such as valylene, crotonylene by rectifying before carrying out extracting and separating; The tower top temperature of acetylene removal tower is controlled at 40～60 ℃, and the best is 45～55 ℃; Tower still temperature is 75～95 ℃, and the best is 80～90 ℃; Reflux ratio is 20～180, and the best is 50～150.
Stopper in first extracting rectifying and the employing of the second extracting rectifying process can be ONP, oil of mirbane, furfural, NMP, thanomin or NaNO
2Deng.
At above-mentioned C
5In the separation method of fraction, C
5Main alkynes such as alkynes energy and C such as valylene, crotonylene in the fraction
5Some alkane such as iso-pentane etc. generate the minimum boiling point azeotrope in the fraction, and the boiling point of its azeotrope is lower than most of C
5Fraction particularly is significantly less than isoprene, m-pentadiene and three kinds of diolefins of cyclopentadiene, thereby is easy to by the method for rectifying it be removed.Simultaneously, because C
5Contain a spot of C in the fraction
4The low component of boiling points such as fraction, 3-methyl butene-1, they will together steam from the cat head of rectifying tower with the azeotrope of alkynes.Therefore under normal circumstances, alkynes wherein can not be concentrated into the dangerous degree of may blasting.
At above-mentioned C
5In the separation method of fraction, before carrying out extracting and separating, at first make C
5Fraction enters a rectifying tower (acetylene removal tower), and tower bottoms enters next step extraction and separation technology again.Therefore, when adopting suitable stage number and reflux ratio, can make that alkynes content is reduced to tens to a hundreds of ppm in the tower bottoms of acetylene removal tower, thereby in technical process subsequently, also be difficult to be concentrated in the concentration range of explosion hazard.
At C of the present invention
5In the separation method, because main alkynes is removed at first isolating, therefore can be with in the prior art, the lightness-removing column in order to remove alkynes such as crotonylene that is provided with behind the extractive distillation column in the second time removes.Do not having under the situation of this lightness-removing column, in the product isoprene after separating by technology of the present invention, the total content＜50ppm of alkynes meets the quality index of polymerization-grade product.
Describe cracking C of the present invention in detail below in conjunction with accompanying drawing
5The separation method of fraction.
Accompanying drawing 1 cracking C of the present invention
5The process flow sheet of the separation method of fraction
As shown in Figure 1, raw material C5Fraction at first enters acetylene removal tower 1, and with the removed overhead of alkynes from the acetylene removal tower, the number of plates of this tower is 80～140, and tower top temperature is 40～60 ℃, and the tower reactor temperature is 75～95 ℃, reflux ratio 20～180, and pressure is 0.11～0.13MPa. Remove the C of most of alkynes5Fraction enters hot dipolymer reactor 2, carries out the dimerization reaction of cyclopentadiene, generates dicyclopentadiene, and reaction temperature is 60～150 ℃, and reaction pressure is 1.0～1.5MPa, and the time of staying is 20～200 minutes. C through dimerization reaction5Fraction gives weight-removing column 3 entering, and removes dicyclopentadiene and C6The above restructuring of fraction divides, and the number of plates of this tower is 30～50, and charging aperture is between the 15th～20 block of column plate, and its technological parameter is: 50～70 ℃ of tower top temperatures, and 88～95 ℃ of tower reactor temperature, pressure is 0.11～0.2MPa, reflux ratio is 1.5～3.5.
The component that obtains from the cat head that gives weight-removing column 3 enters the first extractive distillation column 4, the number of plates of the first extracting rectifying is 90～140, charging aperture is between the 50th～60 block of column plate, its technological parameter is: the tower internal pressure is 0.1～0.3MPa, the tower reactor temperature is 100～140 ℃, and overhead reflux is than 4～10. Extractant can be selected a kind of in dimethyl formamide, the dimethylacetylamide, or their mixture, and the concentration of body of the tower solvent is controlled at 50～80%, and optimum value is 65～70%, can obtain larger relative volatility like this. In extraction separation process, the tower reactor temperature is higher, and diolefin is easy to polymerization reaction take place, causes the feed blocking e-quipment and pipe, makes loss of material, therefore must add polymerization inhibitor. In the present invention, used binary inhibition system, be preferably natrium nitrosum-monoethanolamine, weight ratio is 1: 2～1: 10, and the concentration expressed in percentage by weight in solvent is respectively 0.05～0.1wt% and 0.5～1wt%.
Be divided into single alkane, monoolefine from the cat head of the first extractive distillation column, the tower bottoms that has absorbed diolefin, alkynes enters two strippers 6,7, the water that accumulates in the circulating solvent and dimer are removed, steam diolefin, alkynes etc. from the cat head of stripper 7, obtain containing C from the tower reactor of stripper 65Hydrocarbon circulating solvent seldom returns the extraction part and recycles.
The C that the second stripper 7 cats head steam5Hydrocarbon enters the first extracting rectifying weight-removing column 5, removes boiling point greater than restructuring such as cyclopentadiene, pentadiene, cyclopentene and the pentamethylene of isoprene minute with rectification method, and the tower temperature is 45～65 ℃, and pressure is 0.1～0.2Mpa.
Thick isoprene product introduction the second extractive distillation column 8 that obtains from the first extracting rectifying weight-removing column 5 cats head, carry out again one-time extractive rectification with the solvent identical with the first extractive distillation column and polymerization inhibitor, remove the restructuring such as cyclopentadiene minute, the number of plates of the second extracting rectifying is 132～182, charging aperture is between the 100th～120 block of column plate, its technological parameter is: the tower internal pressure is 0.1～0.3MPa, and the tower reactor temperature is 100～150 ℃, and overhead reflux is than 4～8.
From the isoprene of the cat head of the second extractive distillation column 8, the C such as the isoprene containing of tower reactor extraction, cyclopentadiene, pentone5The solvent of hydrocarbon enters normal pressure Analytic Tower 9,100～170 ℃ of tower reactor temperature, and the overhead reflux ratio is 1～3, and its number of plates is 35～50, and charging aperture is between the 10th～20. At Ben Tanei with C5Hydrocarbon steams, and wherein a part of extraction obtains purity and be the isoprene product more than 99.3%, and a part is returned the second extractive distillation column.
The circulating solvent that normal pressure Analytic Tower 9 tower reactors obtain enters decompression Analytic Tower 10 further to remove the cyclopentadiene in the circulating solvent, its cat head material can partly send the solvent refining part except refluxing, refining solvent send the second extractive distillation column to recycle, its technological parameter is: the tower internal pressure is 0.01～0.03MPa, temperature is 80～130 ℃, the overhead reflux ratio is 70～90, and its number of plates is 30～50, and charging aperture is between the 5th～10 block of column plate.
We can be with the material that gives weight-removing column 3 and the first extracting rectifying weight-removing column 5 tower reactors the method by rectifying again, remove other carbon five hydrocarbon components and carbon six hydrocarbon components, obtain highly purified pentadiene and dicyclopentadiene product, this part equipment can not put into main flow.
Sometimes the isoprene product (chemical grade) that uses as fine chemical material, be not so good as such height of polymer grade product for the requirement of isoprene purity, but the requirement for the content of alkynes is then stricter, in the present invention owing to main alkynes is removed at the initial stage of separating, therefore only need carry out one-time extractive rectification can reach requirement in above-mentioned separation method, and it mainly comprises following process:
According to alkynes energy and C such as pentone, crotonylenes5Alkene etc. generate the minimum boiling point azeotropic mixture, and the boiling point of azeotropic mixture is lower than most of C5The characteristic of fraction, cracking C5The fraction raw material at first removes the alkynes such as pentone, crotonylene by rectifying before carrying out extract and separate, also therefrom isolates dicyclopentadiene and other high boiling hydrocarbon through hot dimerization reaction again;
In the presence of polymerization inhibitor, carry out extracting rectifying take dimethyl formamide (DMF) solvent as solvent, solvent is by the stripper recycling use, material removes wherein high-boiling components such as cyclopentadiene, cyclopentene, pentamethylene and pentadiene-1,3 through precise distillation, obtains the thick isoprene product of chemical grade.
In concrete technological process, the flow process after the first extractive distillation column then can be stopped.
The present invention compared with prior art has the following advantages:
(1) among the present invention owing to remove the technology of alkynes before having adopted, initial at separating technology, most of alkynes is removed, the concentration of main alkynes valylene, crotonylene all can be lower than 200ppm, therefore makes whole C
5Separating technology has been got rid of the danger of alkynes blast, has guaranteed safety in production.Need not to be provided with security measuress such as expensive plant chromatograph.
(2) give when lightness-removing column removes alkynes in setting, can be with C
5Contained C in the fraction
4Component, 3-methyl butene-1, pentadiene-1, major parts such as 4 remove, and components such as iso-pentane, amylene-1 partly remove.With the variation of feed composition, give lightness-removing column removed overhead inventory and can account for 10～20% of charging total amount.Therefore reduce the processing load of post-order process and the usage quantity of extraction solvent, improved the processing power of whole production flow process.
(3) work as C
5Raw material is formed when changing to some extent, through the C behind the acetylene removal tower
5The composition of fraction is stable, thereby has strengthened whole C
5Separating technology is for C
5The adaptability that material component changes has improved the quality of product.
(4) among the present invention, because alkynes one motion device promptly is removed, therefore the concentration of weight-removing column cat head isoprene in first abstraction distillation system can be reached more than 99%, wherein the content of alkynes can reduce below the 200ppm.So when isoprene is used for fine chemical material, need not the requirement that second abstraction distillation system can satisfy its purity is set, thereby saved the expense of investing greatly.And in the prior art, because main alkynes all concentrates on removing at last in the technology, therefore the said products is still needed just can meet the demands by second abstraction distillation system.
Embodiment
Example 1: with C
5Raw material enters acetylene removal tower (T101) from the position of the 28th block of column plate, tower still temperature is 83 ℃, 50 ℃ of tower top temperatures, reflux ratio 35, the tower bottoms that removes most of alkynes enters hot dipolymer reactor (R101) and gives weight-removing column (T102) to remove high boiling point components such as dicyclopentadiene, enter the 56th block of column plate (by upwards counting at the bottom of the tower) of first extractive distillation column (T201) then with the flow of 0.53kg/h, contain 1500ppmNaNO with 114 column plates
2With the solvent of the dimethylformamide of 1.0wt% thanomin the 104th block of column plate and 56 blocks of column plates, flow from top to bottom with the flow of 3.34kg/hr from tower.This tower is operated under following condition, tower still pressure 0.118MPa, and 125 ℃ of tower still temperature, trim the top of column 2.03kg/hr tower bottoms enters first stripping tower (T202).Enter the T203 tower by the second stripping tower T202 overhead product, the overhead product that obtains 0.48kg/hr is delivered to the weight-removing column (T204) with 120 blocks of column plates and is removed high boiling material.The operational condition of T204 tower: tower still pressure 0.102MPa, 62.5 ℃ of tower still temperature, reflux ratio 44.5.The overhead product of T204 tower enters second extractive distillation column (T301) with the flow of 0.29kg/hr by the 22nd block of column plate of tower, this tower has 132 blocks of column plates, add the solvent that contains with the same stopper of first extractive distillation column by the 122 blocks of column plates in tower top, mobile from top to bottom with the flow of 2.85kg/hr.The operational condition of this tower is: tower still pressure 0.10MPa, and 140 ℃ of tower still temperature, trim the top of column 1.18kg/hr obtains qualified isoprene product by cat head.In order to remove cyclopentadiene and the alkynes in the circulating solvent, the second extractive distillation column T301 tower bottoms enters normal pressure Analytic Tower (T303) and the decompression Analytic Tower (T304) with 52 blocks of column plates, and the cyclopentadiene in the circulating solvent is dropped to below the 1ppm.The analytical results of each tower is listed in table 1.
The analytical results of each tower in table 1 example 1
| Form wt% | T-101 advances | The T-101 top | At the bottom of the T-101 | T-201 advances | The T-201 top | The T-203 top | The T-204 top | At the bottom of the T-204 | T-301 advances | The T-301 top |
| Total carbon 4 | 11.46 | 0.06 | ||||||||
| Iso-pentane | 3.02 | 15.86 | 0.02 | 0.03 | 0.26 | |||||
| The trimethylammonium butene-1 | 3.91 | 15.09 | ||||||||
| Skellysolve A | 1.99 | 0.17 | 2.44 | 3.08 | 10.33 | |||||
| Amylene-1 | 6.88 | 25.20 | 1.91 | 4.82 | 22.96 | |||||
| Neohexene-1 | 4.71 | 11.20 | 2.85 | 5.81 | 21.19 | |||||
| Pentadiene-1,4 | 8.93 | 13.47 | 7.99 | 10.14 | 33.50 | |||||
| Neohexene-2 | 2.54 | 3.32 | 4.37 | 11.46 | 0.05 | 6.06 | 0.01 | |||
| Pentamethylene | 1.04 | 0.69 | 0.06 | 1.77 |
| Isoprene | 21.04 | 3.36 | 26.17 | 33.49 | 0.02 | 47.15 | 99.86 | 99.86 | 99.93 | |
| * crotonylene | 0.60 | 3.38 | 9.6ppm | |||||||
| Cyclopentenes | 4.50 | 5.73 | 6.54 | 9.12 | 17.68 | 0.03 | ||||
| Sow distrust among one's enemies pentadiene-1,3 | 12.10 | 14.45 | 17.80 | 24.30 | 45.18 | 0.02 | ||||
| Along m-pentadiene-1,3 | 6.03 | 8.39 | 9.31 | 13.31 | 24.43 | |||||
| Cyclopentadiene | 5.95 | 0.04 | 8.62 | 3.72 | 4.64 | 0.08 | 2.30 | 0.08 | 0.2ppm | |
| Total carbon six | 0.38 | 0.08 | 1.32 | 0.17 | 1.50 | 0.04 | 2.11 | 0.04 | ||
| Valylene | 0.11 | 0.64 | ||||||||
| X0 | 0.49 | 0.74 | 0.06 | 0.03 | ||||||
| X 1 | 0.18 | 0.08 | 0.20 | 0.02 | 0.07 | 0.03 | ||||
| X 2 | 0.04 | 0.04 | ||||||||
| X 3 | 0.60 | 0.85 | 1.01 | |||||||
| Dicyclopentadiene | 11.62 | 14.90 | 0.23 | 0.04 | 5.32 |
From last table data as can be seen, the content of butine is 9.6ppm in the T-301 cat head gained isoprene product, and valylene does not have substantially, meets the requirement of polymerization-grade product to alkynes content.
Example 2: the preceding acetylene removal tower T-101 in the example 1 is removed, acetylene removal tower T-302 after second extractive distillation column (T-301) back increases by, other flow process and operation steps are with example 4, and the analytical results of each tower is listed in table 3.
The analytical results of each tower in table 2 example 2
| Form wt% | T-102 advances | The T-102 top | T-204 advances | The T-204 top | The T-301 top | At the bottom of the T-302 | The T-302 top | The T-303 top |
| Total carbon 4 | 2.68 | 4.03 | 0.08 | |||||
| Iso-pentane | 6.81 | 4.21 | 0.17 | |||||
| The trimethylammonium butene-1 | ||||||||
| Skellysolve A | 5.36 | 1.70 | 0.009 | 0.08 | ||||
| Amylene-1 | 8.78 | 6.73 | 0.06 | 0.01 | 0.05 | 0.005 | 0.88 | |
| Neohexene-1 | 5.80 | 8.94 | 0.02 | 0.03 | 0.09 | 0.040 | 0.49 | |
| Anti-amylene-2 | 7.62 | 9.38 | 0.03 | 0.05 | 0.10 | 0.050 | 0.80 | |
| Along amylene-2 | 3.59 | 3.58 | 0.03 | 0.02 | 0.06 | 0.040 | 0.08 | |
| Neohexene-2 | 2.58 | 3.88 | 0.18 | 0.04 | 0.08 | 0.050 | 0.02 | |
| Isoprene | 19.30 | 28.56 | 54.83 | 97.17 | 98.07 | 99.81 | 89.97 | 96.53 |
| * crotonylene | 0.29 | 0.43 | 0.73 | 2.01 | 1.48 | 1.1ppm | 8.64 | 1.96 |
| Cyclopentenes | 4.49 | 2.61 | 5.54 |
| Sow distrust among one's enemies pentadiene-1,3 | 10.83 | 12.38 | 20.18 | 0.01 | 35ppm | 2.2ppm | 0.53 | |
| Along m-pentadiene-1,3 | 6.00 | 5.71 | 10.15 | 0.2ppm | 0.1ppm | 0.12 | ||
| Cyclopentadiene | 0.84 | 4.32 | 6.04 | 0.08 | 0.4ppm | 0.11 | ||
| Total carbon six | 6.16 | 1.96 | 1.75 | |||||
| Valylene | 0.05 | 0.023 | 0.04 | 0.49 | 0.4ppm | 0.76 | ||
| Dicyclopentadiene | 8.82 | 1.54 | 1.11 | |||||
| X | 0.07 | 0.05 |
Data from example 1 and example 2 find out that relatively during the cat head material of T-204 (i.e. the charging of second extractive distillation column) was formed, the content of isoprene was respectively 99.86wt% and 97.17%.Find out that thus the present invention has compared with prior art improved the processing power of equipment.
Example 3: with C
5Raw material enters the acetylene removal tower with the feed rate of 0.2154kg/hr, the control tower top temperature is 45 ℃, tower still temperature is 73 ℃, reflux ratio 150, tower bottoms enters first abstraction distillation system with the flow of 0.2051kg/hr, other testing sequence is investigated the removal effect of alkynes with example 1, sees Table 1 analytical data.
From the data of table 3 as can be seen, valylene charging content is 0.025%, and the tower still reduces to 0.009%, and cat head rises to 0.22%; Same crotonylene charging content is 0.20%, and the tower still reduces to 0.0064%, and cat head rises to 1.90%, and as seen these two kinds of main alkynes can be told from cat head.
Example 4: experimental procedure is with example 3, and the experiment condition of acetylene removal tower changes feed rate 0.2356kg/h into, and tower top temperature is 48 ℃, and tower still temperature is 76 ℃, reflux ratio 80～120, and tower bottoms is with the flow discharging of 0.2195kg/hr, and its acetylene removal effect sees Table 3.
Example 5: experimental procedure is with example 3, and the experiment condition of acetylene removal tower changes feed rate 0.2154kg/h into, and tower top temperature is 48 ℃, and tower still temperature is 78.5 ℃, reflux ratio 50, and tower bottoms is with the flow discharging of 0.1983kg/hr, and its acetylene removal effect sees Table 3.
Material compositional analysis data under table 3 different experimental conditions
| Example 3 | Example 4 | Example 5 | |||||||
| Reflux ratio | 150 | 80 ～ 100 | 50 | ||||||
| Temperature ℃ | 45 | 57 | 73 | 48 | 57 | 76 | 48 | 56 | 78.5 |
| Flow kg/h | 0.00651 | 0.2154 | 0.2051 | 0.00614 | 0.2356 | 0.2195 | 0.01842 | 0.2154 | 0.1983 |
| Form wt% | Eject | Charging | Still goes out | Eject | Charging | Still goes out | Eject | Charging | Still goes out |
| Carbon 4 | 21.52 | 2.78 | 17.61 | 2.71 | 13.65 | 2.60 | |||
| Iso-pentane | 34.63 | 6.19 | 0.709 | 34.51 | 6.43 | 1.47 | 30.53 | 5.90 | 0.62 |
| Skellysolve A | 0.09 | 5.15 | 6.167 | 0.72 | 5.51 | 6.33 | 0.73 | 5.41 | 6.55 |
| Amylene-1 | 15.21 | 9.07 | 7.67 | 17.65 | 9.20 | 7.28 | 23.67 | 9.26 | 5.61 |
| Neohexene-1 | 5.11 | 5.95 | 6.64 | 7.79 | 6.00 | 5.58 | 11.83 | 6.15 | 4.99 |
| Anti-amylene-2 | 16.89 | 8.12 | 6.406 | 12.73 | 8.09 | 7.27 | 11.74 | 8.09 | 7.03 |
| Along amylene-2 | 3.71 | 4.333 | 3.63 | 4.35 | 3.81 | 5.06 | |||
| Neohexene-2 | 2.72 | 2.809 | 0.02 | 2.76 | 3.20 | 0.04 | 2.54 | 3.08 | |
| Isoprene | 28.3 | 20.35 | 23.707 | 6.07 | 20.29 | 24.12 | 5.57 | 20.73 | 24.29 |
| * crotonylene | 1.90 | 0.20 | 0.0064 | 1.69 | 0.19 | 0.021 | 1.26 | 0.21 | Little |
| Cyclopentenes | 1.06 | 4.41 | 4.344 | 0.58 | 4.43 | 4.80 | 0.43 | 4.12 | 5.09 |
| Sow distrust among one's enemies pentadiene-1,3 | 10.81 | 10.896 | 0.011 | 0.17 | 12.26 | 11.01 | 12.64 | ||
| Along m-pentadiene-1,3 | 5.99 | 6.045 | 0.003 | 5.62 | 6.44 | 0.01 | 6.01 | 5.77 | |
| Cyclopentadiene | 0.86 | 0.867 | 0.01 | 0.80 | 0.95 | 0.004 | 0.83 | 1.07 | |
| Total carbon six | 0.54 | 5.225 | 8.22 | 0.43 | 5.22 | 5.21 | 0.37 | 4.63 | 7.92 |
| Valylene | 0.22 | 0.025 | 0.009 | 0.17 | 0.03 | 0.016 | 0.16 | 0.03 | Little |
| X 1 | 0.49 | 0.6 | 0.52 | 0.58 | 0.46 | 0.55 | |||
| X 2 | 0.29 | 0.38 | 0.31 | 0.34 | 0.28 | 0.32 | |||
| X 3 | 0.81 | 1.08 | 0.86 | 1.00 | 0.69 | 0.88 | |||
| Dicyclopentadiene | 6.84 | 9.11 | 7.44 | 8.77 | 7.22 | 8.54 | |||
Claims (3)
1, a kind of cracking C that adopts pre-removal process of alkyne
5The separation method of fraction comprises following process:
Cracking C
5The fraction raw material carries out hot dimerization reaction in hot dipolymer reactor, make C
5Most of cyclopentadiene dimerization in the fraction generates dicyclopentadiene, and temperature of reaction is 60～150 ℃, and reaction pressure is 1.0～1.5MPa, and reactant removes dicyclopentadiene and other high boiling hydrocarbon through fractionation by distillation then;
The material that is obtained by said process enters first extractive distillation column by the middle part of tower, in the presence of solvent and stopper, carry out extracting rectifying, the tower internal pressure is 0.1～0.3MPa, tower still temperature is 100～140 ℃, the trim the top of column ratio is 4～10, get monoolefine, single alkane by cat head, must be rich in the solvent material of C 5 dienes such as isoprene by the tower still;
Above-mentioned tower still material enters a stripping tower by the top of tower, and stripping Tata still must reclaim solvent and return first extractive distillation column and recycle its cat head material C
5Component enters a weight-removing column and carries out rectifying separation, to be isolated dicyclopentadiene, m-pentadiene and other heavy constituent by the tower still, obtains thick isoprene by cat head;
Weight-removing column cat head material enters second extractive distillation column by the tower middle part, in the presence of solvent and stopper to the further extracting rectifying of thick isoprene, the tower internal pressure is 0.1～0.3MPa, tower still temperature is 100～150 ℃, the trim the top of column ratio is 4～8, get qualified isoprene product by cat head, its tower still material that contains a small amount of cyclopentadiene and other alkene and alkynes enters follow-up Analytic Tower, obtains the high purity isoprene product by precise distillation again;
It is characterized in that: according to alkynes energy and C such as valylene, crotonylenes
5Alkene etc. generate the minimum boiling point azeotrope, and the boiling point of azeotrope is lower than most of C
5The characteristic of fraction, cracking C
5The fraction raw material at first removes alkynes such as valylene, crotonylene by rectifying before carrying out extracting and separating; The tower top temperature of acetylene removal rectifying tower is 40～60 ℃, and tower still temperature is 75～95 ℃, and reflux ratio is 20～180.
2, the cracking C of employing pre-removal process of alkyne according to claim 1
5The separation method of fraction is characterized in that: the extraction solvent that adopts in first extracting rectifying and the second extracting rectifying process can be selected a kind of in dimethyl formamide, the N,N-DIMETHYLACETAMIDE or their mixture.
3, the cracking C of employing pre-removal process of alkyne according to claim 1
5The separation method of fraction is characterized in that: the stopper in first extracting rectifying and the employing of the second extracting rectifying process can be ONP, oil of mirbane, furfural, NMP, thanomin, NaNO
2In a kind of or their mixture.
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| CN100593530C (en) * | 2007-07-19 | 2010-03-10 | 中国石油化工集团公司 | Separation method of diolefins in C5 fraction of petroleum cracking |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1077561C (en) * | 1998-11-09 | 2002-01-09 | 化学工业部北京化工研究院 | Method for separating diolefin from carbon five fraction |
| TW583178B (en) | 2001-09-29 | 2004-04-11 | China Petrochemical Corp | Process for separating C5 cuts obtained from a petroleum cracking process |
| CN101113366B (en) * | 2007-07-17 | 2011-05-11 | 华东理工大学 | Hydrocarbons pyrolysis coking judgment pilot experimental device |
| CN101798255B (en) * | 2009-02-11 | 2013-04-24 | 中国石油天然气股份有限公司 | A method for acetonitrile separation of diolefins in petroleum cracking carbon five cuts |
| CN103086822B (en) * | 2011-11-02 | 2016-03-30 | 中国石油化工股份有限公司 | A kind of separation method of m-pentadiene |
| CN110950732A (en) * | 2019-12-31 | 2020-04-03 | 淄博鲁华同方化工有限公司 | Large-scale carbon five separation method |
| CN114684953B (en) * | 2020-12-31 | 2024-05-07 | 中国石油化工股份有限公司 | Method and device for treating ethylene waste alkali liquor |
| CN114276834B (en) * | 2021-12-24 | 2023-03-14 | 宁波甬华树脂有限公司 | Preparation method of refined C5 fraction |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3705204A (en) * | 1967-05-18 | 1972-12-05 | Nippon Oil Co Ltd | Process for recovering conjugated diolefins selectively from a c5 fraction |
| US4134795A (en) * | 1978-04-05 | 1979-01-16 | The Goodyear Tire & Rubber Company | Acetylenes removal from diolefin streams by extractive distillation |
| JPS6439645A (en) * | 1987-08-05 | 1989-02-09 | Fuji Electric Co Ltd | Optical recording medium |
-
1996
- 1996-03-20 CN CN96102485A patent/CN1056823C/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3705204A (en) * | 1967-05-18 | 1972-12-05 | Nippon Oil Co Ltd | Process for recovering conjugated diolefins selectively from a c5 fraction |
| US4134795A (en) * | 1978-04-05 | 1979-01-16 | The Goodyear Tire & Rubber Company | Acetylenes removal from diolefin streams by extractive distillation |
| JPS6439645A (en) * | 1987-08-05 | 1989-02-09 | Fuji Electric Co Ltd | Optical recording medium |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100593530C (en) * | 2007-07-19 | 2010-03-10 | 中国石油化工集团公司 | Separation method of diolefins in C5 fraction of petroleum cracking |
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