CN101367704A - System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid - Google Patents
System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid Download PDFInfo
- Publication number
- CN101367704A CN101367704A CNA2008101513485A CN200810151348A CN101367704A CN 101367704 A CN101367704 A CN 101367704A CN A2008101513485 A CNA2008101513485 A CN A2008101513485A CN 200810151348 A CN200810151348 A CN 200810151348A CN 101367704 A CN101367704 A CN 101367704A
- Authority
- CN
- China
- Prior art keywords
- tower
- toluene
- distillation column
- benzene
- column
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides a system of reclaiming pure benzene and pure toluene from crude benzene hydrogenation liquid and an operation method thereof. The system includes a pre-distillation column, an extractive distillation column, a solvent recovery column and a benzene toluene column. Light aromatic containing the benzene toluene, which is extracted from the pre-distillation column and non-aromatic vapor mixture goes into the extractive distillation column by a vapor feeding manner. Benzene toluene vapor mixture extracted from the solvent recovery column goes into the benzene toluene column by the vapor feeding manner. With the vapor feeding, not only the load of a condenser which is at the top of the pre-distillation column and the solvent recovery column is reduced, but also the load of a reboiler which is at the bottom of the extractive distillation column and the benzene toluene column is reduced. Compared with acid wash method, the invention has no product and no waste. The sulfur content of the product is less than 1ppm. Compared with the distillation process of Krupp-Koppes method or similar method, energy consumption is reduced by 20 to 30 percent and the manufacture cost is reduced.
Description
Technical field
The invention belongs to the distillation technology field, utilize benzene, toluene in the selective solvent extracting rectifying crude benzole hydrogenation liquid, propose system and working method that a kind of crude benzole hydrogenation liquid reclaims purified petroleum benzin and pure toluene especially.
Background technology
Separate acquisition aromatic hydrocarbons and mainly have two kinds of technologies from crude benzole hydrogenation liquid: a kind of is liquid liquid extraction process, and another is the extractive distillation method.Compare the extractive distillation method to have flow process simple, easy and simple to handle with liquid liquid extraction process, and characteristics such as facility investment is low, and energy consumption is low are particularly suitable for reclaiming aromatic hydrocarbons from the high hydrocarbon mixture of aromaticity content.And liquid liquid extracting rule is more suitable for reclaiming aromatic hydrocarbons from the content of stable hydrocarbon is 30%～40% hydrocarbon mixture.
Existing extractive distillation fado adopts following technology: raw material prefractionation-extractive distillation-solvent recuperation also comprises the regeneration of solvent, benzene, toluene separating unit certainly.The extraction agent of mainly selecting for use in the extracting rectifying process is: N-formylpyrrole alkane ketone, N-N-formyl morpholine N-or tetramethylene sulfone.N-formylpyrrole alkane ketone is because better to the solvability of alkane, and relatively poor to the selectivity of aromatic hydrocarbons, makes that the productive rate of benzene, toluene is not high, so be very restricted in the use.Then two kinds of solvents all have the characteristics high to arenes selectivity, and wherein industrial tetramethylene sulfone more is applicable to liquid liquid extraction process, and the N-N-formyl morpholine N-then more is used for extractive distillation technology, and are widely used on the technology of extraction rectification aromatic hydrocarbons.
German Patent 4586986 discloses the extractive distillation technology of a kind of NFM of utilization morpholine as solvent.This method is carried out pre-separation with raw material through pre-distillation column earlier, and the working pressure of this tower is up to 3MPa, and the cat head vapor phase temperature can reach 300 ℃, is used as extractive distillation column and recovery Tata still thermal source and is used for the preheating original feed with this steam then.Reflux as presorting column overhead in overhead product condensation rear section through heat exchange step by step, part enters the extracting rectifying unit and separates.Though purpose that this technology can arrive energy-conservation, it is too big to presort pressure tower, and temperature is too high, and to the equipment requirements height, operation easier is big, and security is not high, and operational condition is not gentle.The high temperature of presorting tower simultaneously need be with more high-grade heat transferring medium as thermal source.
German Patent 4776927 discloses a kind of technology that reclaims aromatic hydrocarbons with the extractive distillation method.The lean solvent that this technology is come out from solvent recovery tower is divided into the different sites that multiply enters tower respectively, wherein the main stream thigh that enters from cat head accounts for about 63% of whole solvents, remaining each burst total accounts for 37%, and the feeding temperature of each strand solvent can not be higher than the temperature of corresponding feed plate, but can not be lower than its 10 ℃.Though this technology can make throughput increase by 20%, has avoided the generation of cat head two liquid phase regions simultaneously, make that operation is more stable.The a large amount of solvents of this process using are from the cat head charging, make non-aromatic in solvent bigger, and each burst solvent feed temperature has very big influence to the operation of tower, how to realize that the feeding temperature that suits is a technological difficulties.
German Patent 5107055 has proposed to be produced by the intermediates that contain aromatic hydrocarbons the another kind of method of aromatic hydrocarbons.Obtain pure toluene when obtaining high-purity benzene in order to be implemented in this technology, presort tower and adopt the side line extraction, cat head is that benzene fraction temperature is 75～85 ℃, and the side line extraction is the toluene fraction, temperature is 99～111 ℃, and the above heavy aromatics of dimethylbenzene is handled in addition again at the bottom of the tower.Benzene fraction and toluene fraction enter the bottom and the top of extraction distillation column respectively, can bring into play the effect that extractive distillation column removes the heavy non-aromatics to greatest extent like this, finish separating of aromatic hydrocarbons and non-aromatics in same tower.But the required extractive distillation column stage number of this technology is more, and the yield of benzene, toluene all do not have to surpass 99%, and yield is low excessively.
All propose novel process separately in the above-mentioned patent and reached purpose energy-conservation or the raising separation efficiency, but all exist a common ground to be exactly, the cut of pre-distillation column and solvent recuperation column overhead all adopts the mode of liquid phase feeding, here just there is a repeatedly vaporization, the process of multiple condensation makes energy consumption increase.At this deficiency, this patent proposes a brand-new technology, be the mode that all adopts the vapour phase charging between pre-distillation column and extractive distillation column, solvent recovery tower and the benzene toluene tower, simultaneously in order to reduce the requirement to equipment, whole exquisite sepn process is all carried out under the condition of gentleness.So, just can be issued to separation requirement and purpose of energy saving in the condition of existing liquid phase feeding equipment.
Summary of the invention
At the deficiencies in the prior art, in order to reduce the requirement to equipment, the present invention proposes system and the working method that crude benzole hydrogenation liquid reclaims purified petroleum benzin and pure toluene, can be issued to separation requirement and purpose of energy saving in the condition of existing liquid phase feeding equipment.
The present invention is realized by the following technical programs:
Crude benzole hydrogenation liquid of the present invention reclaims the system of purified petroleum benzin and pure toluene, comprises pre-distillation column 11, extractive distillation column 12, solvent recovery tower 13 and benzene toluene tower 14; It is characterized in that adopting the mode of vapour phase charging to enter extractive distillation column 12 from the light aromatic hydrocarbons that is rich in benzene toluene and the non-aromatic vapour mixture 2 of pre-distillation column 11 extraction, the benzene toluene vapour mixture 7 of solvent recovery tower 13 extraction adopts the mode of vapour phase charging to enter benzene toluene tower 14.
The operational condition of pre-distillation column of the present invention is a positive pressure operation, and tower top pressure is 0.085～0.10MPa (G), and tower top temperature is 100～130 ℃, and reflux ratio is 1.2～3.5, and the pre-distillation column theoretical stage is 40～60.
Extractive distillation column operational condition of the present invention is a positive pressure operation, tower top pressure is 0.07～0.085MPa (G), and tower top temperature is 85～115 ℃, and reflux ratio is 1.5～4.0, solvent ratio be 5.5～7.5 solvents to go into the tower temperature be 80～110 ℃, the extractive distillation column theoretical stage is 45～65.
Solvent recovery tower operational condition of the present invention is to be negative-pressure operation, tower top pressure is-0.08～-0.06MPa (G), tower top temperature is 40～65 ℃, and reflux ratio is 1.0～2.0, and the solvent recovery tower theoretical stage is 15～30.
Benzene toluene tower operational condition of the present invention is to operate under the negative pressure, tower top pressure is-0.09～-0.07MPa (G), tower top temperature is 30～45 ℃, and reflux ratio is 1.5～2.5, and benzene toluene tower theoretical stage is 40～60.
Described extraction agent is N-formyl morpholine, N-Methyl pyrrolidone, tetramethylene sulfone, glycol or the compounding substances between them.
With the coking crude benzene behind the hydrogenation is raw material, adopt the mode extraction rectifying method of vapour phase charging to produce high pure benzene, toluene and dimethylbenzene product, sepn process is finished under the mild condition of low temperature, low pressure, realized the purpose that cuts down the consumption of energy under the prerequisite of product requirement satisfying.Belong to the coking benzene purification techniques.
The present invention has following advantage: 1. sepn process is compared with acid wash does not have by product, does not have waste discharge, and product sulphur nitrogen content is lower than 1ppm; 2. course of processing benzene aromatic hydrocarbon product yield and purity are very high, and for example, benzaldehyde product purity can reach more than 99.9%, the rate of recovery can reach more than 99.5%, and the toluene product purity can reach more than 99.5%, the rate of recovery can reach more than 99.0%; 3. rectifying tower process conditions gentleness, generally below 0.1MPa (G), the process-stream temperature is below 200 ℃ for pressure; 4. the extracting rectifying unit extracts than low, the rectification efficiency height; 5. rectification process turndown ratio height is insensitive to the change in concentration of raw material treatment capacity and crude benzol composition, the distillation process of 6. relative Krupp-Koppes method or similar approach, and energy consumption reduces by 20～30%.
Description of drawings
Fig. 1: the schematic flow sheet of crude benzene refining.
Embodiment
Below in conjunction with embodiment and accompanying drawing the present invention is described in further detail, but the present invention is not limited to this.
Adopt the mode of connection of accompanying drawing, presort the tower middle part and establish opening for feed, crude benzole hydrogenation liquid raw material 1 is entered (comprising C8) the high boiling point heavy aromatics component that removes in the pre-distillation column 11 more than the C8 by pipeline, heavy aromatics 3 is discharged system by pipeline, cat head obtains is rich in benzene, the light constituent partial condensation of toluene is as trim the top of column liquid, part enters extractive distillation column 12 for light aromatic hydrocarbons and the non-aromatic vapour mixture 2 that is rich in benzene toluene by pipeline, the non-aromatic chemical industry light oil 10 of the removed overhead of extractive distillation column is derived as chemical industry light oil through pipeline, the rich solvent 4 that is rich in aromatic hydrocarbons enters solvent recovery tower 13 by pipeline from the extraction of extracting rectifying Tata still, aromatic hydrocarbons separates in recovery tower with solvent, obtain containing the lean solvent 5 of higher-grade heat energy at the bottom of the tower through pipeline importing interchanger, lead via pipeline and get back in the extractive distillation column through obtaining solvent 6 behind the condensing heat-exchange step by step, the benzene toluene vapour mixture fraction 7 that cat head obtains is led into benzene toluene tower 14 by pipeline, the benzene toluene fraction separates in the benzene tower, cat head passes through pipeline extraction pure toluene 9 by pipeline extraction purified petroleum benzin 8 at the bottom of the tower.Concrete operation method according to this system is as follows:
Embodiment 1:
Process 50,000 tons of/year crude benzol raw materials, benzene content 75%, toluene level 13%, choosing N-Methyl pyrrolidone is solvent, solvent ratio is 7.5:1.
Pre-rectifying tower tower top pressure 0.1MPa (G), temperature are 115～130 ℃, and reflux ratio is 2.0～3.5, and 40～50 theoretical stages are arranged;
Extractive distillation column tower top pressure 0.085MPa (G), temperature are 100～115 ℃, and reflux ratio is 2.5～4.0, and 45～55 theoretical stages are arranged, and adopt the vapour phase charging, and solvent is by the 10th plate charging, and temperature is 110 ℃;
Recovery tower tower top pressure-0.08MPa (G), temperature are 40～55 ℃, and reflux ratio is 1.0～1.5, and 20～30 theoretical stages are arranged;
Benzene toluene column overhead pressure-0.09MPa (G), temperature are 30～35 ℃, and adopting vapour phase charging reflux ratio is 1.5～2.0, and 40～50 theoretical stages are arranged.
Through behind the said process, main products benzene meets the country-level standard of coking benzene, and purity is 99.95%, the rate of recovery is 99.5%, and major product toluene meets the coking toluene national grade ii standard, and purity is 99.1%, the rate of recovery is 99.0%.
Before and after transforming, presort tower and extractive distillation column and must load and be compared as follows shown in the table (table one):
Table one
Can obviously find out by table one, adopt the vapour phase charging can reduce the load of presorting the column overhead condenser greatly, reduce the thermal load at the bottom of the extractive distillation column simultaneously, can reduce energy consumption 24%.
Embodiment 2:
Process 100,000 tons of/year crude benzol raw materials, benzene content 74%, toluene level 14%, choosing the N-N-formyl morpholine N-is solvent, solvent ratio is 5:1.
The pressure of pre-distillation column is that 0.085MPa (G), temperature are 100～115 ℃, and reflux ratio is 1.2～2.0, and number of theoretical plate is 50～60;
Extractive distillation column tower top pressure 0.07MPa (G), temperature are 85～100 ℃, and reflux ratio is 1.5～2.5, and 55～65 theoretical stages are arranged, and adopt the vapour phase charging, and the solvent feed temperature is 80 ℃, by the 8th plate charging;
Recovery tower tower top pressure-0.06MPa (G), temperature are 55～65 ℃, and reflux ratio is 1.5～2.0, and 15～25 theoretical stages are arranged;
Benzene toluene column overhead pressure-0.07MPa (G), temperature are 35～45 ℃, adopt the vapour phase charging, and reflux ratio is 2.0～2.5, and 50～60 theoretical stages are arranged.
Through behind the said process, main products benzene meets the country-level standard of coking benzene, and purity is 99.93%, the rate of recovery is 99.55%, and major product toluene meets the coking toluene national grade ii standard, and purity is 99.2%, the rate of recovery is 99.2%.
Before transforming is liquid phase feeding, and transforming the back is the vapour phase charging, and both are compared as follows shown in the table (table two) the load of presorting tower and extractive distillation column:
Table two
Can significantly find out by last table, transform the back and adopt the vapour phase charging can reduce the load of condenser greatly, reduce energy consumption 26%.
Embodiment 3:
Process 50,000 tons of/year crude benzol raw materials, benzene content 73%, toluene level 15%, choosing the N-N-formyl morpholine N-is solvent, solvent ratio is 5.8:1.
Pre-distillation column tower top pressure 0.09MPa (G), temperature are 111 ℃, and reflux ratio is 1.35, and number of theoretical plate is 42;
Extractive distillation column tower top pressure 0.074MPa (G), temperature are 91 ℃, and reflux ratio is 1.65, and 46 theoretical stages are arranged, and adopt the vapour phase charging, the solvent feed temperature be 90 ℃ by the 8th plate charging;
Recovery tower tower top pressure-0.06MPa (G), temperature are 63 ℃, and reflux ratio is 1.2, and 23 theoretical stages are arranged;
Benzene toluene column overhead pressure-0.08MPa (G), temperature are 35 ℃, adopt the vapour phase charging, and reflux ratio is 1.6, and 46 theoretical stages are arranged.
Through behind the said process, main products benzene meets the country-level standard of coking benzene, and purity is 99.92%, the rate of recovery is 99.75%, and major product toluene meets the coking toluene national grade ii standard, and purity is 99.3%, the rate of recovery is 99.1%.
Before transforming is liquid phase feeding, and transforming the back is the vapour phase charging, and both are compared as follows shown in the table (table three) the load of presorting tower and extractive distillation column:
Table three
Can significantly find out by last table, transform the back and adopt the vapour phase charging can reduce the load of condenser greatly, reduce energy consumption 25.8%.
Claims (5)
1. a crude benzole hydrogenation liquid reclaims the system of purified petroleum benzin and pure toluene, comprises pre-distillation column 11, extractive distillation column 12, solvent recovery tower 13 and benzene toluene tower 14; It is characterized in that adopting the mode of vapour phase charging to enter extractive distillation column (12) from the light aromatic hydrocarbons that is rich in benzene toluene and the non-aromatic vapour mixture (2) of pre-distillation column (11) extraction, the benzene toluene vapour mixture (7) of solvent recovery tower (13) extraction adopts the mode of vapour phase charging to enter benzene toluene tower (14).
2. the crude benzole hydrogenation liquid of claim 1 reclaims the working method of the system of purified petroleum benzin and pure toluene, it is characterized in that the direct draught operation of pre-distillation column at 0.085～0.1MPa (G), tower top temperature is 100～130 ℃, and control of reflux ratio is 1.2～3.5, and presorting the tower theoretical stage is 40～60.
3. the crude benzole hydrogenation liquid of claim 1 reclaims the working method of the system of purified petroleum benzin and pure toluene, it is characterized in that extractive distillation column is a positive pressure operation, tower top pressure is 0.07～0.085M (G) Pa, tower top temperature is 85～115 ℃, reflux ratio is 1.5～4.0, solvent ratio is 5.0～7.5, and it is 80～110 ℃ that solvent is gone into the tower temperature, and the extractive distillation column theoretical stage is 45～65.
4. the crude benzole hydrogenation liquid of claim 1 reclaims the working method of the system of purified petroleum benzin and pure toluene, it is characterized in that solvent recovery tower is a negative-pressure operation, tower top pressure is-0.08～-0.06MPa (G), tower top temperature is 40～65 ℃, reflux ratio is 1.0～2.0, and the solvent recovery tower theoretical stage is 15～30.
5. the crude benzole hydrogenation liquid of claim 1 reclaims the working method of the system of purified petroleum benzin and pure toluene, it is characterized in that the benzene toluene tower is to operate under the negative pressure, tower top pressure is-0.09～-0.07MPa (G), tower top temperature is 30～45 ℃, reflux ratio is 1.5～2.5, and benzene toluene tower theoretical stage is 40～60.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008101513485A CN101367704A (en) | 2008-09-17 | 2008-09-17 | System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008101513485A CN101367704A (en) | 2008-09-17 | 2008-09-17 | System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101367704A true CN101367704A (en) | 2009-02-18 |
Family
ID=40411735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008101513485A Pending CN101367704A (en) | 2008-09-17 | 2008-09-17 | System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101367704A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107213666A (en) * | 2016-03-22 | 2017-09-29 | 河南永大化工有限公司 | The separator of benzene in a kind of alkylation of toluene methanol reaction product |
| CN114470834A (en) * | 2020-10-27 | 2022-05-13 | 湖南中岭化工有限责任公司 | Crude benzene hydrogenation extraction device |
-
2008
- 2008-09-17 CN CNA2008101513485A patent/CN101367704A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107213666A (en) * | 2016-03-22 | 2017-09-29 | 河南永大化工有限公司 | The separator of benzene in a kind of alkylation of toluene methanol reaction product |
| CN107213666B (en) * | 2016-03-22 | 2023-10-31 | 河南永大化工科技有限公司 | Separation device for benzene in toluene methanol alkylation reaction product |
| CN114470834A (en) * | 2020-10-27 | 2022-05-13 | 湖南中岭化工有限责任公司 | Crude benzene hydrogenation extraction device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103520945B (en) | The refining plant of crude benzole hydrogenation product and method | |
| TWI794402B (en) | Method for separating aromatics by extractive distillation | |
| CN103664446A (en) | Technology for separating n-hexane-methylcyclopentane through extractive distillation | |
| CN101250079A (en) | Heat-exchange network device for refining crude benzene and method of operation | |
| CN101759520B (en) | Method for extracting, rectifying and separating phenylethylene from hydrocarbon mixture | |
| CN105837394A (en) | Purifying method of highly-pure 1,2,3-trimethylbenzene | |
| CN102190555B (en) | Method for recovering styrene | |
| CN103086823A (en) | Method and device for separating n-hexane, isohexane and benzene | |
| CN103073383A (en) | Method and device for separating isohexane, n-hexane and benzene | |
| CN1085646C (en) | Method for separating arene from hydrocarbons mixture by use of extraction and rectification | |
| CN101081993B (en) | Method for recovering aromatic hydrocarbons from hydrocarbons mixture with high content of aromatic hydrocarbons | |
| CN114989856B (en) | Method and device for separating aromatic hydrocarbon or sulfur-containing compound from gasoline fraction | |
| CN204509216U (en) | Catalytically cracked gasoline extracting rectifying desulfurizer | |
| CN100378048C (en) | Method of extracting, rectifying and separating aromatic hydrocarbons and extracting and rectifying apparatus | |
| CN103664489A (en) | Rectifying method for producing paraxylene products | |
| CN1262264A (en) | Process for recovering arylhydrocarbon by combination of extracting distillation with liquid-liquid extraction | |
| CN101367704A (en) | System and operation method for recycling benezene and pure methylbenzene from crude benzole hydrogenation liquid | |
| CN104591952A (en) | Method for refining mesitylene by virtue of differential pressure thermal coupling rectification | |
| CN101671225A (en) | Method and equipment thereof for rectifying methylbenzene | |
| CN111004079B (en) | Separation method and device for reaction gas for preparing ethylene by oxidative coupling of methane | |
| CN1083819C (en) | Method for separating arene by using extraction and rectification | |
| CN100460373C (en) | Method for extracting rectifying and separating benzene | |
| US4401560A (en) | Process for the separation of aromatic hydrocarbons from petroleum fractions with heat recovery | |
| CN1304343C (en) | Method and device for separating 1,2,3-trimethylbenzene | |
| CN105085152A (en) | Novel extraction process for aromatic hydrocarbons |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Open date: 20090218 |