CN1244551C - Process for separating and purifying phthalonitrile - Google Patents
Process for separating and purifying phthalonitrile Download PDFInfo
- Publication number
- CN1244551C CN1244551C CN 200410041027 CN200410041027A CN1244551C CN 1244551 C CN1244551 C CN 1244551C CN 200410041027 CN200410041027 CN 200410041027 CN 200410041027 A CN200410041027 A CN 200410041027A CN 1244551 C CN1244551 C CN 1244551C
- Authority
- CN
- China
- Prior art keywords
- separation
- tower
- distillation
- nitrile
- benzodiazepine
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to the improvement of an absorbing separation and purification method for separating phthalonitrile from gas generated by xylene, ammonia and oxygen-containing gas reacting in the presence of a catalyst, particularly to a distilling separation and purification method of phthalonitrile absorbing absorption liquid. The method is characterized in that the phthalonitrile absorbing absorption liquid is distilled and separated in a distilling separation tower, the absorption liquid is supplied from the middle of the distilling tower and discharged from the tower bottom through distilled high-boiling-point heavy constituents, small molecule light constituents and a solvent are distilled off from the tower top, and the phthalonitrile as the needed product is distilled off from the upper part of a stripping section of the tower. The distilling separation method of the present invention has the advantages of small energy consumption, low separation cost, separation and purification productivity improvement, and high separation efficiency. The distilling separation method can save distillation energy sources approximately 50% more or less and shorten the time for the distilling separation and the purification approximately 40% more or less. The product recovery rate of the gas generated in the reaction can reach 99%, and the product purity reaches 99.95%.
Description
Technical field
The invention relates to by dimethylbenzene and ammonia and oxygen-containing gas in the presence of catalyzer in the generated reactive gas, the improvement of Separation of Benzene dimethoxy nitrile method for absorbing and separating relates in particular to and makes the absorption liquid fractionation by distillation method of purification that absorbs benzene dicarbonitrile.
Background technology
Benzene dicarbonitrile is called different peptide nitrile (IPN) again, is the important source material of organic synthesis.In the benzene dicarbonitrile production method, be comparatively advanced production method of present stage by the oxidation proceses of ammonia of dimethylbenzene and ammonia and oxygen-containing gas reaction, promptly in gas-solid phase fluidized bed plant, make dimethylbenzene in the presence of high temperature and catalyzer with ammonia and oxygen reaction, generation benzene dicarbonitrile.Because oxidative ammonolysis produces a large amount of reaction heat, so temperature of reaction is very high, reaction product is discharged from reactor head with gas phase (be referred to as reaction and generate gas) usually.And generate in the gas in reaction; except that containing benzene dicarbonitrile; usually also contain ammonia, hydrogenation cyanogen, carbon monoxide, carbonic acid gas, water vapor, nitrogen, oxygen, dimethylbenzene, methyl benzonitrile, cyanobenzene etc., this separates with regard to needing that reaction is generated gas, to obtain highly purified benzene dicarbonitrile.
The separating and purifying method that generates Separation of Benzene dimethoxy nitrile the gas from reaction has multiple, and reported by a plurality of patents and document, wherein U.S. Pat 4134910, US6509490 and Chinese patent CN1397543A, report adopts the organic solvent absorption reaction to generate gas, making wherein, benzene dicarbonitrile is trapped in the lyosorption, separate for twice with rectifying through distillation through two fractionation by distillation towers again, obtain the high-purity benzene dimethoxy nitrile.Yet this absorption liquid that is absorbed with benzene dicarbonitrile separates high boiling point heavy constituent impurity (discharging at the bottom of the tower) by first distillation tower, and product, light constituent and solvent are steamed by cat head with gas phase; Product, light constituent and solvent gas separate through second rectifying tower again, solvent and light constituent are discharged by cat head, the second distillation separation method that the product benzene dicarbonitrile is discharged at the bottom of by tower, main deficiency is: separate solvent from the first distillation cat head, when benzene dicarbonitrile and light constituent, because selected solvent boiling point is lower than product, therefore can at first be steamed with other light constituents, next steams is only benzene dicarbonitrile, and whole still-process is again to carry out under vacuum condition, easily the benzene dicarbonitrile of distillation very likely can enter into vacuum system, not only cause product benzene dicarbonitrile partial loss, and it is malfunctioning also can to cause vacuum system to stop up when serious, causes vacuum system operation unstability.Secondly, be save energy, adopt the gas phase transmission between two towers, therefore the pipeline between two towers must be controlled at suitable size and length, and need have good heat insulation effect, otherwise also can cause benzene dicarbonitrile to condense in pipeline and blocking pipeline.The 3rd, double tower distil separates, and whole sepn process needs two vacuum systems, and quantity of solvent is generally all very big in the absorption liquid, and solvent needs to experience twice distillation through first tower and second tower, and separating energy consumption is higher, has strengthened separation costs.Therefore two towers, two steps fractionation by distillation exists: energy consumption height, product easily lose, the easy blocked three big defectives of vacuum system.And, think and to adopt twice separation of two towers because reaction generation gas exists product, solvent and light constituent, heavy constituent, and people are subjected to traditional thinking to influence the distillation separation method that can only follow conventional lines; Secondly, think the benzene dicarbonitrile that will obtain high yield as CN1397543A etc., must carry out high-boiling-point impurity as quickly as possible under alap temperature separates, so think that taking two tower second distillations to separate is a kind of effective ways.Report though therefore there are numerous separation to purify, fractionation by distillation still adopts two tower second distillations to separate so far.
Summary of the invention
The objective of the invention is to overcome the deficiency of above-mentioned prior art, provide a kind of fractionation by distillation simple, control is convenient, and the distillation cost is low, separates the high A Nitrile Benzodiazepine Separation And Purification Methods of purification efficiency.
The object of the invention realizes that mainly improving is two step fractionation by distillation to be purified change step fractionation by distillation purification in a tower into, thereby reduces the fractionation by distillation purification process, reaches save energy.Specifically, A Nitrile Benzodiazepine Separation And Purification Methods of the present invention, thereby comprise that reaction generation gas is contacted with organic solvent is trapped in the lyosorption expectation product benzene dicarbonitrile, absorption liquid is passed through fractionation by distillation, make product benzene dicarbonitrile and other separating substances, it is characterized in that said fractionation by distillation is to carry out in a distillation tower, said absorption liquid is introduced by the distillation tower middle part, at the bottom of the heavy constituent of distillation high boiling point are by tower, discharge, small molecules light constituent and solvent are steamed by cat head, and the product benzene dicarbonitrile is steamed by the middle part of tower.
For effectively avoiding the distillation of product benzene dicarbonitrile to enter vacuum system, a kind of better method of the present invention is that product is steamed from the top of stripping section.
Said distillation is suitably and makes the serious reciprocal of duty cycle≤50kPa of distillation tower, tower top temperature≤150 ℃, tower axe temperature≤225 ℃, 165-175 ℃ of benzene dicarbonitrile drop temperature.
For improving the product separation rate, the present invention generates product benzene dicarbonitrile absorption in the gas to reaction, a kind of better is to adopt the absorption liquid circulation to absorb, the absorption liquid of soon from the absorption tower, drawing, returning the absorption tower circulation again by a circulation groove absorbs, make that benzene dicarbonitrile reaches finite concentration (for example 15-30%) in the absorption liquid, draw fractionation by distillation again, and in circulation by control absorption liquid temperature (for example 105-155 ℃), make the more satisfactory state that is in that absorbs, to eliminate the deficiency that prior art single flow one way absorbs.
For reducing production costs, reach the detrimentally affect that may cause to environment, the cat head of fractionation by distillation of the present invention steams thing (light constituent and solvent), through the test para-Phthalonitrile good dissolving and absorptive character is arranged, and therefore a kind of better method is directly to return the do absorption without separation to replenish liquid.So not only improved the utilization ratio that steams by-product, but also can reduce the fractionation by distillation cost, and avoided distilling and steam thing discharging to the detrimentally affect of environment or reduce processing costs.
The present invention's distillation, a kind of better is preferentially to be chosen in the packing tower to carry out, and filler in the tower, a kind of better is to select levels to adopt the different fillers of proterties, wherein adopts high-density packing with the upper strata especially, lower floor adopts low density high porosity filler.Filler vapour lock in upper strata is little like this, helps steaming of light constituent and solvent, simultaneously because packing density is big, and macromolecular product benzene dicarbonitrile is difficult for being inhaled into vacuum system, thereby can avoid causing the product loss and to the disadvantageous effect of vacuum system; Lower floor's low density high porosity filler more helps the heavy constituent material and sinks to separating, and can obtain well to separate purification efficiency, and reaction generates the gas product rate of recovery can reach 99%, and product purity can reach 99.95%.
The present invention is owing to adopt a tower single flash to separate, therefore only need a vacuum system, not only reduced facility investment, and, make distillation work amount and energy consumption reduce greatly owing to only need to have avoided twice distillation of lyosorption through single flash, also significantly reduced separation purification running cost, it is about about 50% that the inventive method can be saved the distillation energy, and it is about about 40% also can to reduce fractionation by distillation time of purifying, and has improved separation purification production capacity.Especially product benzene dicarbonitrile design steams from the stripping section top of tower, can also effectively avoid the distillation of product benzene dicarbonitrile to enter unfavorable that vacuum system brings.The absorption liquid circulation absorbs, and can make to absorb to be in more satisfactory state, has also improved the ability that generates separated product the gas from reaction.Cat head steams thing and replenishes liquid without separating directly to return to do to absorb, and has not only improved the utilization ratio that steams by-product, but also can reduce the fractionation by distillation cost, and avoided distilling and steam the thing discharging to the detrimentally affect of environment or reduce processing costs.Distillation tower is selected packing tower for use, and high-density packing is selected on the upper strata for use, lower floor selects low density high porosity filler for use, not only has the separation efficiency height, reaction generates the gas product rate of recovery can reach 99%, product purity reaches 99.95%, but also can avoid product to enter vacuum system, causes product loss and to the vacuum system disadvantageous effect.
Below in conjunction with an embodiment, further specify the present invention, but the inventive method is not limited to illustrated embodiment.
Description of drawings
Fig. 1 is a part process flow sheet of the present invention.
Fig. 2 is a preferred embodiment of the present invention process flow sheet.
Embodiment
Embodiment: is example with m-xylene as raw material, referring to Fig. 2.
Oxidative ammonolysis
In φ 38mm * 1800mm stainless steel fluidized-bed reactor 1, add fine particle ammoxidation catalyst 550g (the said V of Chinese patent CN1123385C for example
10Cr
aA
bB
cC
dO
xCatalyzer), feed m-xylene, ammonia and oxygen-containing gas (air) respectively, control raw material charging proportioning is: m-xylene: ammonia: air=1: 8: 41, carry out oxidative ammonolysis, about 425 ℃ of control reaction temperature, reaction generates gas and is drawn by reactor head.
The generation aspiration is received
To react and generate gas to introduce internal diameter be φ 150mm, highly be 800mm, in be filled with the stainless steel absorption tower 2 of 450mm Pall ring packing layer, spiral coil cooling tube, absorption liquid distribution pipe are housed in the absorption tower.One φ 500mm * 280mm is arranged behind the absorption tower, the stainless steel circulation groove 5 of tensimeter, thermometer, stirring rake, electric heater 4, spiral coil cooling tube 3 (water quench), safety valve is housed.Add 40 liter 1 in the circulation groove, 3,5-trimethylbenzene organic solvent, pumping enters the reaction generation circulation of vital energy in the wrong direction stream that enters with lower bottom part by top, absorption tower and contacts absorption, absorption liquid is drawn at the bottom of by tower and is pumped to circulation groove 5 and returns circulation and absorb, do not formed as ammonia, hydrogenation cyanogen, carbon monoxide, carbonic acid gas, water vapor, nitrogen, oxygen etc., draw from the top on absorption tower, after treatment emptying by the gas phase of solvent absorbing.Control Circulation groove absorption liquid temperature is 105-155 ℃ in the circulation absorption process, the concentration of product in the continuous sampling analysis absorption liquid, in circulation groove, add as required by the distillation cat head and steam thing (light constituent and solvent), product benzene dicarbonitrile concentration reaches 15-30% (preferred 20%-25%) in circulation groove, send back distillation tower fractionation by distillation with absorption liquid.
Absorption liquid separates
The absorption liquid that meets concentration requirement is entered by filler distillation tower 6 middle parts by the circulation groove pumping, and the distillation tower upper strata is a high-density packing, and lower floor is a low density high porosity filler.Distillation control tower serious reciprocal of duty cycle≤50kPa, tower top temperature≤150 ℃, tower axe temperature≤225 ℃, 165-175 ℃ of product drop temperature.Light constituent and solvent are steamed to be directly used in to replenish by the distillation cat head makes absorption liquid, and then by discharging at the bottom of the tower, the product benzene dicarbonitrile is steamed by stripping section top in heavy constituent.
In the inventive method, organic solvent absorbs and also can adopt common single flow one way absorption pattern.
Lyosorption of the present invention replenishes, and also can adopt to add fresh lyosorption.
The inventive method is equally applicable to produce para-Phthalonitrile and phthalonitrile with p-Xylol or o-Xylol as raw material.
Dimethylbenzene of the present invention comprises p-Xylol, m-xylene, o-Xylol.
Claims (9)
1, a kind of A Nitrile Benzodiazepine Separation And Purification Methods, thereby comprise that reaction generation gas is contacted with organic solvent is trapped in the lyosorption expectation product benzene dicarbonitrile, absorption liquid is passed through fractionation by distillation, make product benzene dicarbonitrile and other separating substances, it is characterized in that said fractionation by distillation is to carry out in a distillation tower, said absorption liquid is introduced by the distillation tower middle part, at the bottom of the heavy constituent of distillation high boiling point are by tower, discharge, small molecules light constituent and solvent are steamed by cat head, and the product benzene dicarbonitrile is steamed by the middle part of tower.
2,, it is characterized in that said benzene dicarbonitrile is steamed by stripping section top according to the described A Nitrile Benzodiazepine Separation And Purification Methods of claim 1.
3, according to the described A Nitrile Benzodiazepine Separation And Purification Methods of claim 2, it is characterized in that top vacuum degree≤50kPa, tower top temperature≤150 ℃, tower still temperature≤225 ℃, 165-175 ℃ of benzene dicarbonitrile drop temperature.
4,, it is characterized in that said absorption liquid circulation absorbs according to claim 1,2 or 3 described A Nitrile Benzodiazepine Separation And Purification Methods.
5,, it is characterized in that said circulating absorption solution temperature is 105-155 ℃ according to the described A Nitrile Benzodiazepine Separation And Purification Methods of claim 4.
6,, when it is characterized in that benzene dicarbonitrile concentration reaches 15-30% in the said circulating absorption solution, send into follow-up fractionation by distillation according to the described A Nitrile Benzodiazepine Separation And Purification Methods of claim 4.
7,, it is characterized in that said fractionation by distillation tower adopts packing tower according to claim 1,2 or 3 described A Nitrile Benzodiazepine Separation And Purification Methods.
8, according to the described A Nitrile Benzodiazepine Separation And Purification Methods of claim 7, it is characterized in that said inner-tower filling material upper strata is a high-density packing, lower floor is a low density high porosity filler.
9,, it is characterized in that said cat head steams thing and makes to absorb additional liquid without separating directly to return according to claim 1,2 or 3 described A Nitrile Benzodiazepine Separation And Purification Methods.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410041027 CN1244551C (en) | 2004-06-18 | 2004-06-18 | Process for separating and purifying phthalonitrile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410041027 CN1244551C (en) | 2004-06-18 | 2004-06-18 | Process for separating and purifying phthalonitrile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1594289A CN1594289A (en) | 2005-03-16 |
| CN1244551C true CN1244551C (en) | 2006-03-08 |
Family
ID=34664843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410041027 Expired - Fee Related CN1244551C (en) | 2004-06-18 | 2004-06-18 | Process for separating and purifying phthalonitrile |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1244551C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106892840B (en) * | 2015-12-18 | 2019-04-05 | 上海泰禾国际贸易有限公司 | A method of purification para-Phthalonitrile |
| CN107540572B (en) * | 2016-06-28 | 2024-01-30 | 江苏新河农用化工有限公司 | Equipment for refining m/p-phthalonitrile |
| CN109593051B (en) * | 2018-12-29 | 2021-07-16 | 江阴苏利化学股份有限公司 | Refining method of chlorothalonil raw material isophthalonitrile |
| CN110256291B (en) * | 2019-07-26 | 2022-02-22 | 江阴苏利化学股份有限公司 | Method for separating phthalonitrile from high-temperature mixed gas generated by ammoxidation |
| CN111100012B (en) * | 2019-12-16 | 2021-01-22 | 上海交通大学 | Method for preparing m-phenylenediamine |
| CN113429318A (en) * | 2021-06-22 | 2021-09-24 | 四川金象赛瑞化工股份有限公司 | Method for producing phthalonitrile by gas-phase quenching method |
-
2004
- 2004-06-18 CN CN 200410041027 patent/CN1244551C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1594289A (en) | 2005-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101546464B1 (en) | Process for continuous recovering (meth)acrylic acid and apparatus for the process | |
| CN1039315C (en) | Process for the production of purified terephthalic acid | |
| CN1202072C (en) | Prodn. process of high pureness xylylene amine | |
| CN102558113B (en) | An improved process for recovery of maleic anhydride by using organic solvent | |
| US8212067B2 (en) | Method for recovering (meth)acrylonitrile | |
| US20220410028A1 (en) | Process and system for heat integration in ethanol production | |
| HUE026209T2 (en) | Improved ethylene oxide recovery process | |
| CN106631759A (en) | System and method for simultaneously producing methacrylic acid and methacrolein | |
| CN1910142A (en) | Process for the purification of olefinically unsaturated nitriles | |
| JP2009079036A (en) | Method for producing dimethyl ether | |
| CN1907943A (en) | Process for isolating vinyl acetate | |
| CN1244551C (en) | Process for separating and purifying phthalonitrile | |
| KR102355059B1 (en) | Method and apparatus for treating offgases in a acetic acid production unit | |
| KR102309236B1 (en) | Fluidized bed apparatus and method for the simultaneous production of low-carbon olefins and the production of para-xylene with methanol and/or dimethyl ether and benzene | |
| JP2008540492A5 (en) | ||
| JP4463330B2 (en) | Purification method of acrylonitrile | |
| CN109134217B (en) | Oxidation device and oxidation process improvement method in cyclohexanone production process by cyclohexane oxidation method | |
| CN109761940A (en) | Crude maleic anhydride continuous rectification apparatus and process | |
| CN114307214A (en) | Rectification recovery device and method for rectifying and recovering acetone in acetone aqueous solution | |
| CN1176636A (en) | Process for producing acrylonitrile | |
| CN116337837A (en) | Component detection and separation device and method in maleic anhydride production process | |
| CN100473636C (en) | Method for purifying (meth)acrylic acid by oxidising a gaseous substrate | |
| US11007452B2 (en) | Process and system for dehydrating a product stream in ethanol production | |
| CN209619244U (en) | Crude maleic anhydride continuous rectification apparatus | |
| CN1244552C (en) | Process for absorbing and separating phthalonitrile gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Dynamic (Nanjing) Chemical Indusrty Co., Ltd. Assignor: Jiangsu Tianying Chemical Industrial Co., Ltd. Contract fulfillment period: 2004.1.18 to 2014.1.18 contract change Contract record no.: 2008320000169 Denomination of invention: Process for separating and purifying phthalonitrile Granted publication date: 20060308 License type: Exclusive license Record date: 2008.9.22 |
|
| LIC | Patent licence contract for exploitation submitted for record |
Free format text: EXCLUSIVE LICENCE; TIME LIMIT OF IMPLEMENTING CONTACT: 2004.1.18 TO 2014.1.18 Name of requester: DANA (NANJING) CHEMICAL CO., LTD. Effective date: 20080922 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20081219 Address after: The concept of village of Jiangsu Province, Yixing Zhoutie town before Patentee after: Jiangsu Tianyin Chemical Industry Co., Ltd. Address before: The concept of village of Jiangsu Province, Yixing Zhoutie town before Patentee before: Jiangsu Tianying Chemical Industrial Co., Ltd. |
|
| ASS | Succession or assignment of patent right |
Owner name: JIANGSU TIANYIN CHEMICAL CO., LTD. Free format text: FORMER OWNER: JIANGSU TIANYIN CHEMICAL INDUSTRY CO., LTD. Effective date: 20081219 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20060308 Termination date: 20150618 |
|
| EXPY | Termination of patent right or utility model |