CN101734997A - Combined method for joint production of aromatic hydrocarbon - Google Patents

Combined method for joint production of aromatic hydrocarbon Download PDF

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CN101734997A
CN101734997A CN200810043978A CN200810043978A CN101734997A CN 101734997 A CN101734997 A CN 101734997A CN 200810043978 A CN200810043978 A CN 200810043978A CN 200810043978 A CN200810043978 A CN 200810043978A CN 101734997 A CN101734997 A CN 101734997A
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toluene
strand
unit
xylol
aromatic hydrocarbons
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肖剑
钟禄平
卢咏琰
钟思青
顾军民
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China Petroleum and Chemical Corp
Sinopec Shanghai Research Institute of Petrochemical Technology
Sinopec Baling Co
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China Petroleum and Chemical Corp
Sinopec Shanghai Research Institute of Petrochemical Technology
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
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    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

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Abstract

The invention relates to a combined method for joint production of aromatic hydrocarbon, which mainly solves the problems of low concentration of p-xylene in mixed xylenes, high circulating load of aromatic hydrocarbon processing, rigorous requirement on reaction raw materials, high energy consumption and the like when p-xylene is produced in the prior art. The combined method adopts a combined reaction technical scheme of producing the mixed xylenes with high-concentration p-xylene by selective dismutation of toluene and producing benzene and the mixed xylenes in thermodynamic equilibrium through dismutation and transalkylation reaction by the aromatic hydrocarbon with 9 or more carbon atoms and a combined separation technical scheme of adopting crystallizing separation for the high-concentration p-xylene and adopting adsorptive separation and crystallizing separation for the low-concentration p-xylene, well solves the problems, and can be used for industrial production of the p-xylene.

Description

The combined method that is used for the aromatic hydrocarbons combination producing
Technical field
The present invention relates to a kind of combined method that is used for the aromatic hydrocarbons combination producing.
Background technology
P-Xylol is one of main basic organic of petrochemical industry, in numerous chemical production field such as chemical fibre, synthetic resins, agricultural chemicals, medicine, plastics purposes is widely arranged.Typical p-Xylol production method is that the dimethylbenzene that contains ethylbenzene of the thermodynamic(al)equilibrium that generates from the petroleum naphtha catalytic reforming is to separate or molecular sieve simulated moving bed adsorption separation (abbreviation fractionation by adsorption) technology by multistage cryogenic crystallization the C8 aronmatic, and p-Xylol is separated from the close with it isomer mixture of boiling point.And, often take C for the processing of the dimethylbenzene of an ortho position and a position 8A isomerization (abbreviation isomerization) technology makes it isomery and turns to p-Xylol.In order to increase production p-Xylol, utilize toluene disproportionation or toluene and carbon nine and above aromatic disproportion thereof and transalkylation (being called for short toluene disproportionation and transalkylation) reaction to generate benzene and C 8A, thereby volume increase C 8A is the operational path that effectively increases production p-Xylol.
Up to now, in the world more typically, also the technology relevant with toluene disproportionation of comparative maturity has sixties Mo industrialized Tatoray tradition toluene disproportionation process, the MTDP of late nineteen eighties release and S-TDT technology and the TransPlus technology of releasing in recent years.Selective disproportionation of toluene is a new way of producing p-Xylol.Because toluene is at the C that can carry out selective disproportionation generation benzene and high p-Xylol concentration on the ZSM-5 of modification catalyzer 8Therefore A only needs can isolate most p-Xylol through simple once the step subzero fractionation.In recent years, along with improving constantly of catalyst performance, this technology has obtained considerable progress.Its typical process has industrialized MSTDP selective disproportionation of toluene technology and the pX-Plus technology released in recent years the late nineteen eighties.
Industrialized selective disproportionation of toluene technology-MSTDP is the catalyst treatment methylbenzene raw material with treated ZSM-5 type mesoporous molecular sieve, can obtain the C of high p-Xylol concentration (85～90%, weight percent, identical except that indicating below) 8The benzene of A and nitration grade.Do not see the PX-plus technology of industrial application report as yet, its main technique index is that the selectivity of pX reaches 90% in the dimethylbenzene under toluene conversion 30% condition, and the mol ratio of benzene and pX is 1.37.
Yet, in the technology of this class selective disproportionation of toluene, in the harshness of the simultaneous with high para-selectivity to material choice.This type of technology can only be raw material with toluene, and C 9 +A does not have purposes in this technology, can not directly be utilized at least, causes the waste of aromatic hydrocarbon resource.In addition, this technology is a large amount of benzene of by-product also, causes the p-Xylol yield on the low side, and this is the fatal shortcoming of selective disproportionation technology.
The reactor feed of typical Tatoray technology is with toluene and C9 aromatic (C 9A) be reaction raw materials.The dimethylbenzene that is generated by Tatoray technology is to be in the isomer mixture that thermodynamic(al)equilibrium is formed, and has the p-Xylol content of industrial application value generally to have only about 24% most.For the xylol this point that selective disproportionation of toluene can obtain the p-Xylol concentration about 90%, Tatoray technology is in tangible inferior position undoubtedly, but Tatoray technology is exactly that Tatoray technology can be converted into benzene and dimethylbenzene to C9A with respect to one of selective disproportionation of toluene technology very big advantage.Document based on Tatoray technology has USP4341914, Chinese patent 98110859.8, USP2795629, USP3551510, Chinese patent 97106719.8 etc.The technical process that representative USP4341914 proposes is for to carry out the aromatic hydrocarbons fractionation with reformate, toluene that obtains and C 9A enters the Tatoray technique unit and carries out disproportionation and a heatable brick bed group-transfer reaction, and resultant of reaction is toluene and C after separating 9A and part carbon ten (C 10A) circulation, benzene is as the product extraction, C8 aronmatic and the C8 aronmatic from isomerization unit enter the pX tripping device together and isolate highly purified p-Xylol product, and other C8 aronmatic isomer carries out the xylol that xylene isomerization reaction obtains being in thermodynamic(al)equilibrium again to isomerization unit.
Heavy aromatics takes off alkyl and produces C 6～C 8Aromatic hydrocarbons technology caused people's attention gradually along with the rise of selective disproportionation of toluene technology in the last few years.USP5763721 and USP5847256 have proposed to be used for the catalyzer of heavy aromatics dealkylation respectively.Wherein, USP5847256 has announced a kind of mordenite catalyst of rhenium-containing, and this catalyzer is specially adapted to transform and contains the many raw materials of ethyl, can obtain products such as toluene, dimethylbenzene and benzene.
C 8The boiling point of each component of aromatic hydrocarbons is approaching: 136.2 ℃ in ethylbenzene, 138.4 ℃ of p-Xylol, 139.1 ℃ of m-xylenes, 144.4 ℃ of o-Xylols, the o-Xylol that its mid-boiling point is the highest can be separated by rectification method, need up to a hundred theoretical stages and bigger reflux ratio, the ethylbenzene that boiling point is minimum also can separate by rectification method, but much more difficult.C 8The fusing point of each component of aromatic hydrocarbons has bigger gap: 13.3 ℃ of p-Xylol, o-Xylol-25.2 ℃, m-xylene-47.9 ℃, ethylbenzene-94.95 ℃.Wherein the fusing point of p-Xylol is the highest, can adopt crystallization process that p-Xylol is wherein separated, and is not high as p-Xylol concentration in the raw material, for reaching the acceptable yield of industrial production, generally adopts two sections crystallizations.USP3177255, USP3467724 at first crystallize out most p-Xylol under-80～-60 ℃ low temperature and make productive rate reach theoretical maximum, this moment crystal purity between 65～85%, the crystallization second time is being carried out in the fusing back; Tc can obtain the p-Xylol of 99% above purity generally at-20～0 ℃ for the second time, and p-Xylol content is higher in the mother liquor, can return crystallized region recycle for the first time.
Utilize sorbent material to C 8Each component of aromatic hydrocarbons is difference optionally, can p-Xylol be separated by adsorption method of separation, after this method realizes industrialization in nineteen seventies for producing the main method of p-Xylol.USP2985589 has described the method for utilizing the simulation moving-bed separating paraxylene of adverse current; USP3686342, USP3734974, CN98810104.1 have described sorbent material that fractionation by adsorption uses X or the Y zeolite as barium type or barium potassium type; USP3558732, USP3686342 use toluene and the p-Diethylbenzene desorbing agent as fractionation by adsorption respectively.
Summary of the invention
Technical problem to be solved by this invention be in the conventional art when producing p-Xylol, exist owing to p-Xylol concentration in the xylol is low, cause problems such as dimethylbenzene separating unit and isomerization unit internal circulating load are big, energy consumption height, a kind of new p-Xylol production method is provided.This method is with benzene, toluene, C 8A and C 9 +A is that raw material is produced p-Xylol, improves the concentration of p-Xylol in the xylol, reduces the scale of p-Xylol separating unit, isomerization unit and aromatic hydrocarbons fractionation unit greatly, thereby reduces the energy consumption of whole device.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of combined method that is used for the aromatic hydrocarbons combination producing may further comprise the steps:
A. separate the mixing raw material that contains benzene, toluene, C8 aronmatic, carbon nine and above aromatic hydrocarbons and non-aromatics from reformer unit, isolate first strand of benzene, first strand of toluene, first burst of C8 aronmatic, carbon nine and above aromatic hydrocarbons and non-aromatics;
B.a) first strand of toluene of isolated carbon nine of step and above aromatic hydrocarbons thereof and part enters toluene and carbon nine and above aromatic disproportion and alkyl transfering process unit, under hydro condition, carry out dealkylation, generate second strand of benzene, second strand of toluene and second strand of C8 aronmatic;
C. remaining first strand of toluene and second strand of toluene enter the selective disproportionation of toluene technique unit together, under hydro condition, carry out toluene selective disproportionation reaction, the reaction back generates C8 aronmatic and the benzene logistics that contains p-Xylol, after separating, obtain the 3rd strand of C8 aronmatic, the 3rd strand of toluene and the 3rd strand of benzene, wherein the 3rd strand of toluene turns back to the selective disproportionation of toluene technique unit;
D. send into adsorption separation unit after first strand of C8 aronmatic and second strand of C8 aronmatic mix, obtain first strand of p-Xylol product;
E. the 3rd strand of C8 aronmatic sent into the Crystallization Separation unit, obtains mother liquor and second strand of p-Xylol product, and mother liquor is sent into the benzenol hydrorefining unit.
In technique scheme, the used catalyzer in selective disproportionation of toluene unit is the type ZSM 5 molecular sieve catalyzer, type ZSM 5 molecular sieve contains at least a metal or its oxide compound that is selected from platinum, molybdenum or the magnesium, and its consumption is 0.005～5% by weight percentage; The operational condition of selective disproportionation of toluene technique unit is as follows: reaction pressure is 1～4Mpa, and temperature of reaction is 300～480 ℃, and hydrogen hydrocarbon mol ratio is 0.5～10, and the liquid weight air speed is 0.8～8 hour -1The used catalyzer in toluene and carbon nine and above aromatic disproportion thereof and alkyl transfering process unit is at least a molecular sieve that is selected among beta-zeolite, mordenite or the MCM-22, bismuthiferous metal or its oxide compound in the catalyzer, its consumption are 0.005～5% by weight percentage; Toluene and carbon nine and above aromatic disproportion thereof and the unitary operational condition of alkyl transfering process are as follows: reaction pressure is 1～5MPa, and temperature of reaction is 250～500 ℃, and hydrogen hydrocarbon mol ratio is 0.5～10, and weight space velocity is 0.8～10 hour -1The p-Xylol separating unit adopts fractionation by adsorption and the Crystallization Separation separating paraxylene that combines, and Crystallization Separation can adopt film-falling crystallization to separate or suspension crystallization separates; The isolating Tc of film-falling crystallization is-30～5 ℃; The isolating Tc of suspension crystallization is-30～5 ℃, and washings/crystal weight ratio is 0.05～0.5.The purity of p-Xylol product is weight concentration 〉=99.8%.
Among the present invention, in toluene and carbon nine and above aromatic disproportion and transalkylation, owing to use bismuthiferous zeolite to be catalyzer, under hydro condition, catalyzer has toluene and carbon nine and above aromatic hydrocarbons thereof is generated the function of dimethylbenzene and benzene, the C that reaction generates by disproportionation and transalkylation reaction 8A then enters fractionation by adsorption and isomerization unit is produced pure p-Xylol.All toluene in the Aromatic Hydrocarbon United Plant enter the selective disproportionation of toluene unit together, under the effect of platiniferous ZSM-5 catalyzer, toluene selective disproportionation reaction takes place, generate benzene and the xylol that contains the high density p-Xylol, p-Xylol concentration can reach 80～95%, this xylol is sent to the Crystallization Separation unit and obtains pure p-Xylol, and the residue xylol also enters fractionation by adsorption and isomerization unit is produced pure p-Xylol.As can be seen, such operational path can allow the concentration of producing p-Xylol in the xylol that obtains significantly improve, and has made full use of C again 9 +The A resource has reduced the treatment scale of isomerization unit and adsorption separation unit, has reduced energy consumption and facility investment scale effectively, and has reduced production cost, has obtained better technical effect.
Description of drawings
Fig. 1 is the technical process of traditional p-Xylol production equipment.
Fig. 2 is used for the combination process flow process of aromatic hydrocarbons combination producing for the present invention.
I is the reformer unit deheptanizer among Fig. 1 or Fig. 2; II is aromatic hydrocarbons extracting unit; III is the benzene toluene separating unit after the extracting; IV is the benzenol hydrorefining unit; V is toluene disproportionation and alkyl transfering process unit; VI is the selective disproportionation technique unit; VII is toluene and carbon nine and above aromatic disproportion and alkyl transfering process unit; VIII is the xylene isomerization process unit; IX is an adsorption separation unit; X is the aromatic hydrocarbons fractionation unit of selective disproportionation; XI is the Crystallization Separation unit.1 is the reformation de-pentane oil, and 2 is from deheptanizer cat head distilled C 7 -(comprising that benzene, toluene and carbon six carbon seven are non-aromatic), 3 is carbon eight and the above arene stream that deheptanizer tower still is extracted out, 4 for extracting benzene and the toluene logistics after non-aromatic, 5 is non-aromatic, 6 is the high purity product benzene that the benzene column overhead after the extracting is extracted, 7 for removing the unitary toluene of selective disproportionation, 8 C for the extraction of the toluene tower still after the extracting 8 +A, 9 is disproportionation and transalkylation product stream, 10 is C 8 +The C that heavy aromatics column overhead in the A fractionation unit is extracted out 9A and portion C 10A, 11 is the xylol of extracting out from the benzenol hydrorefining cat head, 12 is the C that heavy aromatics Tata still is extracted out 10A, 13 for heavy aromatics takes off the still liquid that alkyl unit benzene Tata still is extracted out, 14 small amount of toluene of separating for adsorption separation unit, the 15 pure p-Xylol of separating for adsorption separation unit, 16 for fractionation by adsorption goes out xylol behind the PX, and 17 is the C that isomerization unit deheptanizer tower still is discharged 8 +The A logistics, 18 logistics that contain benzene and toluene of extracting for isomerization unit deheptanizer cat head, 19 is the benzene logistics of disproportionation and transalkylation extraction, 20 for removing toluene and carbon nine and above aromatic disproportion thereof and the unitary toluene of alkyl transfering process, 21 is the benzene of toluene and carbon nine and above aromatic disproportion and the extraction of alkyl transfering process unit benzene tower, the 22 nitrated benzene of extracting for the benzene column overhead of selective disproportionation aromatic hydrocarbons fractionation unit, 23 toluene of extracting for the toluene tower cat head of selective disproportionation aromatic hydrocarbons fractionation unit, 24 mother liquors that come out for the Crystallization Separation unit, 25 is the still liquid that the toluene tower of selective disproportionation aromatic hydrocarbons fractionation unit is extracted out, the 26 pure p-Xylol of separating for the Crystallization Separation unit.
The technological process of tradition paraxylene process units as shown in Figure 1. Enter deheptanizer I from reformation depentanizer tower bottoms 1, cat head is told carbon seven and following aromatic hydrocarbons non-aromatics logistics 2 thereof and is entered Aromatics Extractive Project unit II and carry out separating of aromatic hydrocarbons and non-aromatics, isolated non-aromatic 5 discharge, unit III is removed in benzene toluene logistics 4, the benzene column overhead of products benzene 6 after the extracting sent, and the toluene tower tower reactor of mixed xylenes 8 after the extracting extracted out and entered benzenol hydrorefining unit IV. In addition, deheptanizer tower reactor logistics 3 also enters benzenol hydrorefining unit IV, mix carbon eight logistics 11 and distillate p-xylene separation unit IX from cat head, C9 aromatic 10 and from the raw material of the isolated toluene logistics 7 of toluene tower cat head as toluene disproportionation and transalkylation II, C10 +A logistics 12 is sent as byproduct; Disproportionation directly enters unit III with 9 of transalkylation product streams and separates; Adsorption separation unit IX isolates purpose product paraxylene 15, and a small amount of toluene 14 returns toluene disproportionation unit VI, and other mixed xylenes 16 enters xylene isomerization unit VIII and carries out isomerization reaction, the C that isomerization unit deheptanizer tower reactor is discharged8 +A logistics 17 is sent to benzenol hydrorefining unit IV, and the logistics that contains benzene and toluene 18 that the deheptanizer cat head is extracted is sent to the catalytic reforming unit.
Be used for the group technology flow process of paraxylene production among the present invention as shown in Figure 2. Be that with the improvements of traditional handicraft technique of the present invention changes the toluene disproportionation process unit in the traditional handicraft into C9 aromatic and takes off the alkyl technique unit, in addition, a cover selective disproportionation of toluene unit VI, corresponding aromatic hydrocarbons fractionation unit X and Crystallization Separation unit XI have been increased. The place that Fig. 2 is identical with Fig. 1 is no longer narrated, and the below only elaborates with regard to difference. Handle all was divided into two strands as the toluene of toluene disproportionation and transalkylation raw material originally in the technique of the present invention, one logistics 7 is as the raw material of selective disproportionation of toluene unit VI, another burst logistics 20 is as the raw material of toluene and carbon nine and above aromatic disproportion and alkyl transfering process unit, in addition the former carbon nine that is used as toluene disproportionation and transalkylation raw material and above aromatic hydrocarbons 10 thereof also as the raw material of toluene and carbon nine and above aromatic disproportion and alkyl transfering process unit, selective disproportionation unit product logistics 9 enters the aromatic hydrocarbons fractionation unit X of selective disproportionation, from the nitrated benzene 22 of benzene column overhead extraction, toluene tower overhead extraction toluene 23 turns back to selective disproportionation unit VI, Crystallization Separation unit XI is sent in the still liquid logistics 25 that selective disproportionation aromatic hydrocarbons fractionation unit toluene tower is extracted out, isolate pure paraxylene 26, the mother liquor 24 of crystalline element is delivered to benzenol hydrorefining unit IV.
The present invention is further illustrated below by specific embodiment, and still, scope of the present invention has more than and is limited to the scope that embodiment covers.
Embodiment
[embodiment 1]
By flow process shown in Figure 2, with C in the typical reformation de-pentane oil 6A～C 10 +Each material of hydrocarbon consist of basic data, investigate ability and each unitary treatment scale situation that the present invention produces p-Xylol and benzene.Typical reformer is sent the composition distribution of aromatic hydrocarbons and the flow rate of each component that present embodiment adopted sees Table 1.
Toluene and carbon nine and above aromatic disproportion thereof and alkyl transfering process unit adopt fixed-bed reactor, and the filling bismuth-containing is 0.05% beta-zeolite catalyzer in the reactor, and reaction conditions is: 385 ℃ of temperature of reaction, pressure are 3.0MPa, and weight space velocity is 2.0 hours -1, hydrogen/hydrocarbon mol ratio is 3.0.Aroamtic hydrocarbon raw material with after hydrogen mixes from top to bottom by beds, carry out C 9 +The dealkylation of A.
The selective disproportionation of toluene technique unit adopts fixed-bed reactor, and filling contains 0.05% platinum ZSM-5 molecular sieve catalyst in the reactor, and reaction conditions is: 385 ℃ of temperature of reaction, pressure are 3.0MPa, and weight space velocity is 2.0 hours -1, hydrogen/hydrocarbon mol ratio is 3.0.Toluene with after hydrogen mixes from top to bottom by beds, carry out toluene selective disproportionation reaction, generate the C of benzene and high p-Xylol concentration 8A.
24 grades of adsorption separation unit employings are simulation moving-bed, filling sorbent material in the moving-bed, and the fractionation by adsorption service temperature is 130 ℃.
The Crystallization Separation unit adopts film-falling crystallization to separate, and Crystallization Separation is divided crystallization, sweating and three steps of fusion, and wherein Tc is-20 ℃, and sweating temperature is 15 ℃, and melt temperature is 30 ℃.
Table 1 reformation de-pentane oil aromatic hydrocarbons is formed and flow rate
Form ??Ben ??Tol ??C 8A ??C 9A ??C 10 + ??∑
Form weight % ??14.41 ??26.79 ??33.53 ??24.02 ??1.25 ??100.00
Flow, kilogram/hour ??12673 ??23560 ??29482 ??21122 ??1095 ??87932
Wherein: NA is a non-aromatics, and Ben is a benzene, and Tol is a toluene, C 8A is a C8 aronmatic, C 9A is a C9 aromatic,
C 10 +A is carbon ten and above aromatic hydrocarbons thereof, below identical.
According to aromatic hydrocarbons flow rate (fresh feed) in accompanying drawing 2 described technical process of the present invention and the table and the operation of the parameter among the embodiment, the material charging and the discharging data of selective disproportionation of toluene unit, toluene and carbon nine and above aromatic disproportion thereof and transalkylation and isomerization unit are listed in table 2.Each unitary treatment scale of p-Xylol production equipment sees Table 3, and the output of product p-Xylol and benzene sees Table 4.
Table 2 embodiment 1 process stream table
Figure G2008100439780D0000071
Annotate: C 8A *Be meant other C8 aronmatic except that PX, as follows.
Table 3 embodiment 1 each cell processing scale table
The unit title Disproportionation and transalkylation Isomerization unit Adsorption separation unit The Crystallization Separation unit The dimethylbenzene fractionation unit
Scale, kilogram/hour ??47505 ??161209 ??210658 ??54731 ??235861
Table 4 embodiment 1 product production and purity table
Product P-Xylol Benzene Summation
Output, kilogram/hour ??49258 ??28066 ??77328
Purity, % ??99.80 ??99.94
The result shows, utilization the technology of the present invention, and with the listed aroamtic hydrocarbon raw material of table 1, the ultimate production that technology of the present invention can be produced p-Xylol and benzene is 78324 kilograms/hour.The treatment scale of xylene isomerization unit, adsorption separation unit and dimethylbenzene fractionation unit has descended 26%, 23% and 27% respectively, and this has obviously reduced the Design of device scale.Plant energy consumption is 21263 * 10 6Joule/ton (p-Xylol+benzene) is with respect to 26579 * 10 of Comparative Examples 6Joule/ton (p-Xylol+benzene), energy consumption has reduced by 20%.Therefore, problems such as xylol concentration was low when patent of the present invention had overcome the production p-Xylol that exists in the conventional art, internal circulating load is big, energy consumption height, the method that provides a kind of brand-new more economical being used to produce p-Xylol.
[embodiment 2]
By flow process shown in Figure 2, with C in the typical reformation de-pentane oil 6A～C 10 +Each material of hydrocarbon consist of basic data, investigate ability and each unitary treatment scale situation that the present invention produces p-Xylol and benzene.Typical reformer is sent the composition distribution of aromatic hydrocarbons and the flow rate of each component that present embodiment adopted sees Table 1.
Toluene and carbon nine and above aromatic disproportion thereof and alkyl transfering process unit adopt fixed-bed reactor, the Hydrogen MCM-22 zeolite catalyst of filling bismuth-containing 0.30% in the reactor, reaction conditions is: 460 ℃ of temperature of reaction, pressure are 41.0MPa, and weight space velocity is 3.0 hours -1, hydrogen/hydrocarbon mol ratio is 8.0.Aroamtic hydrocarbon raw material with after hydrogen mixes from top to bottom by beds, carry out C 9 +The dealkylation of A.
The selective disproportionation of toluene technique unit adopts fixed-bed reactor, filling platiniferous 0.2% and 0.5% magnesium ZSM-5 molecular sieve catalyst in the reactor, and reaction conditions is: 450 ℃ of temperature of reaction, pressure are 6.0MPa, weight space velocity is 6.0 hours -1, hydrogen/hydrocarbon mol ratio is 8.0.Toluene with after hydrogen mixes from top to bottom by beds, carry out toluene selective disproportionation reaction, generate the C of benzene and high p-Xylol concentration 8A.
30 grades of adsorption separation unit employings are simulation moving-bed, filling sorbent material in the moving-bed, and the fractionation by adsorption service temperature is 130 ℃.
The Crystallization Separation unit adopts suspension crystallization to separate, and Tc is-15 ℃.
Operate according to the parameter that provides in accompanying drawing 2 described technical process of the present invention and the example, each unitary treatment scale of p-Xylol production equipment sees Table 5, and the output of product p-Xylol and benzene sees Table 6.
Table 5 embodiment 2 each cell processing scale table
The unit title Disproportionation and transalkylation Isomerization unit Adsorption separation unit The Crystallization Separation unit The dimethylbenzene fractionation unit
Scale, kilogram/hour ??47505 ??161209 ??205929 ??14411 ??239219
Table 6 embodiment 2 product productions and purity table
Product P-Xylol Benzene Summation
Output, kilogram/hour ??49258 ??29066 ??78328
Purity, % ??99.80 ??99.94
The result shows, utilization the technology of the present invention, and with the listed aroamtic hydrocarbon raw material of table 1, the ultimate production that technology of the present invention can be produced p-Xylol and benzene is 78324 kilograms/hour.The treatment scale of xylene isomerization unit, adsorption separation unit and dimethylbenzene fractionation unit has descended 26%, 25% and 26% respectively, and this has obviously reduced the Design of device scale.Plant energy consumption is 20200 * 10 6Joule/ton (p-Xylol+benzene) is with respect to 26579 * 10 of Comparative Examples 6Joule/ton (p-Xylol+benzene), energy consumption has reduced by 24%.
[embodiment 3]
By flow process shown in Figure 2, with C in the typical reformation de-pentane oil 6A～C 10 +Each material of hydrocarbon consist of basic data, investigate ability and each unitary treatment scale situation that the present invention produces p-Xylol and benzene.Typical reformer is sent the composition distribution of aromatic hydrocarbons and the flow rate of each component that present embodiment adopted sees Table 1.
Toluene and carbon nine and above aromatic disproportion thereof and alkyl transfering process unit adopt fixed-bed reactor, the h-mordenite catalyzer of filling bismuth-containing 0.10% in the reactor, reaction conditions is: 320 ℃ of temperature of reaction, pressure are 1.0MPa, and weight space velocity is 0.8 hour -1, hydrogen/hydrocarbon mol ratio is 2.0.Aroamtic hydrocarbon raw material with after hydrogen mixes from top to bottom by beds, carry out C 9 +The dealkylation of A.
The selective disproportionation of toluene technique unit adopts fixed-bed reactor, and filling contains 0.3% molybdenum and 0.8% magnesium ZSM-5 molecular sieve catalyst in the reactor, and reaction conditions is: 320 ℃ of temperature of reaction, pressure are 1.0MPa, and weight space velocity is 0.8 hour -1, hydrogen/hydrocarbon mol ratio is 1.0.Toluene with after hydrogen mixes from top to bottom by beds, carry out toluene selective disproportionation reaction, generate the C of benzene and high p-Xylol concentration 8A.
18 grades of adsorption separation unit employings are simulation moving-bed, filling sorbent material in the moving-bed, and the fractionation by adsorption service temperature is 130 ℃.
The Crystallization Separation unit adopts suspension crystallization to separate, and Tc is 5 ℃.
Operate according to the parameter that provides in accompanying drawing 2 described technical process of the present invention and the example, each unitary treatment scale of p-Xylol production equipment sees Table 7, and the output of product p-Xylol and benzene sees Table 8.
Table 7 embodiment 3 each cell processing scale table
The unit title Heavy aromatics takes off alkyl unit Isomerization unit Adsorption separation unit The Crystallization Separation unit The dimethylbenzene fractionation unit
Scale, kilogram/hour ??38750 ??161532 ??203754 ??15201 ??252150
Table 8 embodiment 3 product productions and purity table
Product P-Xylol Benzene Summation
Output, kilogram/hour ??49273 ??29067 ??78340
Purity, weight % ??99.80 ??99.94
The result shows, utilization the technology of the present invention, and with the listed aroamtic hydrocarbon raw material of table 1, the ultimate production that technology of the present invention can be produced p-Xylol and benzene is 78340 kilograms/hour.The treatment scale of xylene isomerization unit, adsorption separation unit and dimethylbenzene fractionation unit has descended 26%, 26% and 22% respectively, has obviously reduced the Design of device scale.Plant energy consumption is 20465 * 10 6Joule/ton (p-Xylol+benzene) is with respect to 26579 * 10 of Comparative Examples 6Joule/ton (p-Xylol+benzene), energy consumption has reduced by 23%.
[comparative example 1]
By flow process shown in Figure 1, still with typical reformation de-pentane oil C in the table 1 6A～C 10 +The flow rate of A logistics is a basic data, investigates traditional ability that contains toluene disproportionation and unitary Aromatic Hydrocarbon United Plant production p-Xylol of alkyl transfering process and benzene as shown in Figure 1.The material charging and the extraction situation of its disproportionation and transalkylation, isomerization unit see Table 9, and each unitary treatment scale sees Table 10, and the output of product p-Xylol and benzene sees Table 11.
Table 9 comparative example 1 process stream table
Table 10 comparative example 1 each cell processing scale table
The unit title Disproportionation and transalkylation Isomerization unit Adsorption separation unit The dimethylbenzene fractionation unit
Scale, kilogram/hour ??111988 ??219438 ??274572 ??323269
Table 11 comparative example 1 product production and purity table
Product P-Xylol Benzene Summation
Output, kilogram/hour ??54316 ??22751 ??77067
Purity, % ??99.80 ??99.94
The result shows, traditional aromatic hydrocarbons production technique reaction aroamtic hydrocarbon raw material listed as table 1, and the total amount that the worker has produced p-Xylol and benzene is 77067 kilograms/hour, plant energy consumption is 26579 * 10 6Kilojoule/ton (p-Xylol+benzene).

Claims (8)

1. combined method that is used for the aromatic hydrocarbons combination producing may further comprise the steps:
A. separate the mixing raw material that contains benzene, toluene, C8 aronmatic, carbon nine and above aromatic hydrocarbons and non-aromatics from reformer unit, isolate first strand of benzene, first strand of toluene, first burst of C8 aronmatic, carbon nine and above aromatic hydrocarbons and non-aromatics;
B.a) first strand of toluene of isolated carbon nine of step and above aromatic hydrocarbons thereof and part enters toluene and carbon nine and above aromatic disproportion and alkyl transfering process unit, under hydro condition, carry out dealkylation, generate second strand of benzene, second strand of toluene and second strand of C8 aronmatic;
C. remaining first strand of toluene and second strand of toluene enter the selective disproportionation of toluene technique unit together, under hydro condition, carry out toluene selective disproportionation reaction, the reaction back generates C8 aronmatic and the benzene logistics that contains p-Xylol, after separating, obtain the 3rd strand of C8 aronmatic, the 3rd strand of toluene and the 3rd strand of benzene, wherein the 3rd strand of toluene turns back to the selective disproportionation of toluene technique unit;
D. send into adsorption separation unit after first strand of C8 aronmatic and second strand of C8 aronmatic mix, obtain first strand of p-Xylol product;
E. the 3rd strand of C8 aronmatic sent into the Crystallization Separation unit, obtains mother liquor and second strand of p-Xylol product, and mother liquor is sent into the benzenol hydrorefining unit.
2. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, it is characterized in that the used catalyzer in selective disproportionation of toluene unit is the type ZSM 5 molecular sieve catalyzer, type ZSM 5 molecular sieve contains at least a metal or its oxide compound that is selected from platinum, molybdenum or the magnesium, and its consumption is 0.005～5% by weight percentage.
3. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, the operational condition that it is characterized in that the selective disproportionation of toluene technique unit is as follows: reaction pressure is 1～4MPa, temperature of reaction is 300～480 ℃, and hydrogen hydrocarbon mol ratio is 0.5～10, and the liquid weight air speed is 0.8～8 hour -1
4. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, it is characterized in that the used catalyzer in toluene and carbon nine and above aromatic disproportion thereof and alkyl transfering process unit is at least a molecular sieve that is selected among beta-zeolite, mordenite or the MCM-22, bismuthiferous metal or its oxide compound in the catalyzer, its consumption are 0.005～5% by weight percentage.
5. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, it is characterized in that toluene and carbon nine and above aromatic disproportion thereof and the unitary operational condition of alkyl transfering process are as follows: reaction pressure is 1～5MPa, temperature of reaction is 250～500 ℃, hydrogen hydrocarbon mol ratio is 0.5～10, and weight space velocity is 0.8～10 hour -1
6. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, it is characterized in that the p-Xylol separating unit adopts fractionation by adsorption and the Crystallization Separation separating paraxylene that combines, Crystallization Separation can adopt film-falling crystallization to separate or suspension crystallization separates.
7. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, it is characterized in that the isolating Tc of film-falling crystallization is-30～5 ℃; The isolating Tc of suspension crystallization is-30～5 ℃, and washings/crystal weight ratio is 0.05～0.5.
8. according to the described combined method that is used for the aromatic hydrocarbons combination producing of claim 1, the purity that it is characterized in that the p-Xylol product is weight concentration 〉=99.8%.
CN200810043978A 2008-11-21 2008-11-21 Combined method for joint production of aromatic hydrocarbon Pending CN101734997A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108250014A (en) * 2016-12-28 2018-07-06 中国石油天然气股份有限公司 Method for preparing p-xylene through isomerization
CN108290110A (en) * 2015-11-13 2018-07-17 埃克森美孚研究工程公司 The separation of mixed xylenes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108290110A (en) * 2015-11-13 2018-07-17 埃克森美孚研究工程公司 The separation of mixed xylenes
CN108290110B (en) * 2015-11-13 2021-12-07 埃克森美孚研究工程公司 Separation of mixed xylenes
CN108250014A (en) * 2016-12-28 2018-07-06 中国石油天然气股份有限公司 Method for preparing p-xylene through isomerization

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