CN1014057B - Rectification-recovery process of acrylonitrile - Google Patents
Rectification-recovery process of acrylonitrileInfo
- Publication number
- CN1014057B CN1014057B CN 87107558 CN87107558A CN1014057B CN 1014057 B CN1014057 B CN 1014057B CN 87107558 CN87107558 CN 87107558 CN 87107558 A CN87107558 A CN 87107558A CN 1014057 B CN1014057 B CN 1014057B
- Authority
- CN
- China
- Prior art keywords
- tower
- joint
- acetonitrile
- acrylonitrile
- collection
- 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
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to a novel process for recovering acrylonitrile from absorption liquid of ammoxidation effluence. The process of the present invention has the technical scheme that the integral technology is formed by combining corresponding operating conditions with a crosslinking tower system composed of a presteaming tower and an extraction steaming tower. Raw materials (the absorption liquid) enters the presteaming tower, solvent liquid enters the extraction steaming tower, and a mixture of the acrylonitrile, acidum hydrocyanicum and water is obtained at the top of the extraction steaming tower; acetonitrile distillates with the acetonitrile content larger than 55 wt% are directly extracted at the gas phase lateral line at the middle upper part or the middle part of the extraction steaming tower; the water with trace acetonitrile is obtained at the bottom of the extraction steaming tower. In order to obtain the results, the present invention provides corresponding requirements for the plate number of the presteaming tower and the extraction steaming tower and the current divider coefficient of crosslinking streams.
Description
The invention belongs to sepn process.
Vinyl cyanide is the important monomer of synthon (nitrile human relations), synthetic rubber (paracril) and plastics (ABS plastic).Vinyl cyanide is mainly produced by the ammoxidation of propylene method at present.Its main reaction is:
Most in the world now acrylonitrile process adopt this method.Absorb through over-quenching, pickling and solvent (water) from the effluent of ammonia oxidation reactor, obtaining acrylonitrile content is 2-7%(weight) solution, also have by products such as a spot of prussic acid, acetonitrile, acetaldehyde, propenal, acetone and vinylformic acid in this solution, must reclaim the vinyl cyanide in this solution with the method for extractive distillation.
Report about recovery and purification vinyl cyanide from the ammoxidation of propylene effluent is more.Through online information retrieval, search 163 pieces in document altogether, do not see similar content.19 pieces of close patents, but different with the present invention.
The invention provides the sepn process with extraction rectifying method recover acrylonitrile from ammonia oxidation reactor effluent absorption liquid, it steams tower and collection is steamed the cross-linked tower system configuration that tower is formed by giving, and the overall technology of forming in conjunction with corresponding operational condition.Its characteristics are shown in figure one.
The absorption liquid (raw material) that contains vinyl cyanide from head tank 1 through pump of constant delivery type 3B with give hot device 5 and be heated to certain temperature (as bubble point) and enter to give and steam the tower middle part of (forming) by 6 and 7 at tower joint.To introduce the bottom (along pipeline D) that collection is steamed tower (by tower joint 8,9,10 and 11 compositions) from giving the mixture that steams acetonitrile, water and partial impurities that tower bottom obtains; To introduce the top (along pipeline A) that collection is steamed tower from giving the mixture that steams prussic acid, vinyl cyanide, acetonitrile and less water that column overhead obtains.From the extraction water of aqueous solvent basin 2 through pump of constant delivery type 3A with give hot device 4 and give heat and enter the top that collection is steamed tower to certain temperature (as normal boiling point or be lower than a certain temperature of normal boiling point).The gas phase of coming out from collection steaming cat head enters return tank 13 entirely with fixed attention after certain temperature condenser 12, partial reflux is gone into collection and steamed column overhead, and part is gone further processing (purification) as product (vinyl cyanide, prussic acid and less water) extraction.After splitter (not marking) shunting, part flows into tower joint 6 through pipeline B in the junction of tower joint 8 and 9 for dirty liquid phase in tower joint 8, and part flows directly into tower and saves 9.Steam middle part or middle and upper part (junction of tower joint 9 and 10) of tower from collection and pay product by gas phase side line extraction weight concentration greater than 55% acetonitrile quantitatively, through condenser 15 full liquid phases of coagulating to certain temperature through extraction valve 14.Steaming tower bottom (tower joint 10 and 11 joins) from collection will save the 11 gas phase shuntings of rising from tower, and part enters tower joint 7 along pipeline C, and part enters tower joint 10.Save 11 dirty liquid phase part vaporizations reboiler from tower, part can be used as aqueous solvent in case of necessity and returns the top that collection is steamed tower (tower joint 8) as still raffinate (be essentially water, contain trace impurity) extraction.
Its operational condition is
Raw material gives hot temperature 50-100 ℃
Aqueous solvent is given hot temperature 50-75 ℃
The charge ratio of aqueous solvent and raw material (weight) 1/(2-8)
Collection is steamed 60-80 ℃ of tower top temperature
Collection is steamed 100-120 ℃ of column bottom temperature
40-75 ℃ of return tank temperature
Tower joint 11 is 0.1-0.95 to the gas phase current divider coefficient of tower joint 7
Collection is steamed tower reflux ratio 2-10
Required plate number is as follows in each tower joint
Tower saves 6789 10 11
Plate is counted 2-10 26-40 30-45 15-30 10-20 46-70
Plate number in the last table can be finished by corresponding packed height.
Using the water absorption liquid products obtained therefrom purity of process separation of ammonia oxidation reactor effluent provided by the invention compares as follows with U.S. SOHIO company technology (coming from the whole process material balance table from SOHIO company patent of introduction technology):
Index SOHIO of the present invention
Acrylonitrile content in the overhead product, % 95 84
(weight)
Acetonitrile is paid the ethane nitrile content in the product, %＞55 50
(weight)
Acetonitrile is paid the HCN in the product content, and % 0.017 2.10
(weight)
Acetonitrile is paid the acrylonitrile content in the product, and 0.183 0.51
% (weight)
Embodiments of the invention are as follows:
Example one, will consist of HCN0.395%(weight); H
2O93.92%(weight); Acetonitrile 0.227%(weight) and vinyl cyanide 5.457%(weight) absorption liquid as raw material, in diameter is the stainless head tower of 20mm, be placed with the triangle helical packing that granularity is 1.5mm, corresponding to packed height in each tower joint shown in Figure 1 be
Tower saves 6789 10 11
The filler height, mm 20-70 100-200 50-200 50-200 50-150 100-300
The inlet temperature of extraction solvent (water) is 55 ℃, and inlet is 75g/h.The inlet temperature of raw material is 75 ℃, and inlet is 95g/h.Advancing to give the liquid phase flow rate mark that steams tower is 0.2-0.8, and reflux ratio is 4-6, and full tower working pressure is reduced to 10-40mmH
2During O, when the water absorption liquid of ammonia oxidation reactor effluent is carried out the rectifying recover acrylonitrile, acrylonitrile concentration is greater than 85%(weight in collection steaming column overhead overhead product), at the acetonitrile concentration of tower joint 9 and 10 junction gas phase extraction greater than 55%(weight) and at the bottom of the tower in the liquid content of water greater than 99.9%(weight), acetonitrile is a tracer level.
Example two, will consist of HCN0.395%(weight); H
2O93.92%(weight); Acetonitrile 0.227%(weight) and vinyl cyanide 5.457%(weight) ammonia oxidation reactor effluent water absorption liquid as raw material, send in the used tray column of flow process shown in Figure 1, the stage number in each tower joint is:
Tower saves 6789 10 11
The feeding temperature of extraction solvent water is 55-60 ℃, and inlet amount is 2.61 kilograms/hour, and the material inlet temperature is 75-80 ℃, and inlet amount is 5.94kg/h.It is normal pressure that collection is steamed cat head, and temperature is 64-66 ℃, is 1.52 * 10 at the bottom of the tower
5Pa.Reflux ratio is 2-3.Collection is steamed the column overhead acrylonitrile content and is about 82%(weight), in or the gas phase extraction of middle and upper part acetonitrile cut separate be about 0.1-0.2 wherein acetonitrile concentration greater than 60%(weight).Water-content is a 99.927%(weight at the bottom of the tower), all the other are acetonitrile.
Claims (1)
1, from ammonia oxidation reactor effluent absorption liquid, uses the sepn process of extractive distillation recover acrylonitrile, it is characterized in that by cross-linked tower system configuration that giving shown in the figure one steamed tower and the steaming tower that comes together is formed and the overall technology of forming in conjunction with following operational condition.
(a) raw material that contains vinyl cyanide, acetonitrile, prussic acid and water enters and gives the middle part or the middle and upper part of steaming tower, and feeding temperature is 50-100 ℃.
(b) aqueous solvent enters the top that collection is steamed tower, and feeding temperature is 50-75 ℃.
(c) at the middle part or the middle and upper part gas phase side line extraction acetonitrile cut of collection steaming tower, wherein ethane nitrile content is 55-70%, and prussic acid content is less than 0.1%, and acrylonitrile content is less than 0.2% (weight).
(d) give steaming tower (tower joint 6 and 7) and contain the 28-50 plate; Collection is steamed tower (tower joint 8-11) and is contained the 80-140 plate.
(e) current divider coefficients of introducing the liquid phase of towers joint 6 from tower joint 8 are 0.1-0.9, and the gas phase current divider coefficients of introducing towers joint 7 from tower joint 1.1 are 0.1-0.95.
(f) draw vinyl cyanide from the top of tower joint 8, its concentration is 82～95% (weight).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87107558 CN1014057B (en) | 1987-11-07 | 1987-11-07 | Rectification-recovery process of acrylonitrile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87107558 CN1014057B (en) | 1987-11-07 | 1987-11-07 | Rectification-recovery process of acrylonitrile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1033045A CN1033045A (en) | 1989-05-24 |
| CN1014057B true CN1014057B (en) | 1991-09-25 |
Family
ID=4816137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 87107558 Expired CN1014057B (en) | 1987-11-07 | 1987-11-07 | Rectification-recovery process of acrylonitrile |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1014057B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6284196B1 (en) * | 1999-04-01 | 2001-09-04 | Bp Corporation North America Inc. | Apparatus for monitor and control of an ammoxidation reactor with a fourier transform infrared spectrometer |
| CN104027994B (en) * | 2014-05-30 | 2017-10-20 | 英尼奥斯欧洲股份公司 | The separation of crude acetonitrile and acrylonitrile |
-
1987
- 1987-11-07 CN CN 87107558 patent/CN1014057B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CN1033045A (en) | 1989-05-24 |
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| C13 | Decision | ||
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