CN210974481U - Device for improving concentration of phosgenation reaction phosgene - Google Patents
Device for improving concentration of phosgenation reaction phosgene Download PDFInfo
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- CN210974481U CN210974481U CN201921552426.2U CN201921552426U CN210974481U CN 210974481 U CN210974481 U CN 210974481U CN 201921552426 U CN201921552426 U CN 201921552426U CN 210974481 U CN210974481 U CN 210974481U
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- degassing
- condenser
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- phosgene
- pipeline
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- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 title claims abstract description 50
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 36
- 238000007872 degassing Methods 0.000 claims abstract description 122
- 239000007788 liquid Substances 0.000 claims abstract description 26
- 238000000926 separation method Methods 0.000 claims abstract description 16
- 238000010521 absorption reaction Methods 0.000 claims abstract description 6
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 16
- 239000007789 gas Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 7
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical group ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 6
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000003786 synthesis reaction Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000002904 solvent Substances 0.000 description 3
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000012442 inert solvent Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- VOZKAJLKRJDJLL-UHFFFAOYSA-N 2,4-diaminotoluene Chemical compound CC1=CC=C(N)C=C1N VOZKAJLKRJDJLL-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
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Abstract
The utility model relates to a device for improving the concentration of phosgenation reaction phosgene, which comprises a degassing tower, a degassing first condenser and a degassing second condenser; a liquid outlet at the bottom of the degassing tower is communicated with a feed inlet pipeline of a degassing circulating pump; a feed inlet of a degassing reboiler is respectively communicated with a discharge port of the degassing circulating pump and a discharge port pipeline of the phosgenation reaction system; the discharge hole of the degassing reboiler is communicated with the middle part of the degassing tower; an exhaust port at the top of the degassing tower is communicated with a feed inlet pipeline at the top of the degassing first condenser; a liquid outlet at the bottom of the degassing first condenser is respectively communicated with the degassing tower and a phosgene separation system pipeline; a degassing first condensate pump is arranged on a pipeline which is communicated with the phosgene separation system by the degassing first condenser; an exhaust port in the middle of the degassing first condenser is communicated with a feed inlet pipeline at the top of the degassing second condenser; and an exhaust port in the middle of the degassing second condenser is communicated with a phosgene absorption system pipeline.
Description
Technical Field
The utility model relates to a technical field of toluene diisocyanate production, concretely relates to promote device of phosgenation reaction phosgene concentration.
Background
The production of Toluene Diisocyanate (TDI) by phosgenation is one of the main technological processes for the industrial production of toluene diisocyanate at home and abroad, and the method comprises the steps of mixing toluene diamine and a solvent, carrying out phosgenation reaction on the mixture and an excessive phosgene solution to generate toluene diisocyanate and hydrogen chloride, and conveying the material after the phosgenation reaction to degassing and other procedures to separate the hydrogen chloride, the phosgene and the solvent. The higher the concentration of the liquid phosgene solution participating in the reaction during the phosgenation reaction stage, the more favorable the reaction. In the existing production process, dissolved hydrogen chloride is separated in a degassing procedure, most of dissolved phosgene is desorbed, the desorbed phosgene solution can return to a phosgenation reaction stage to participate in TDI synthesis reaction, and the concentration of phosgene is greatly reduced (the concentration of phosgene is only 17 wt%) due to more solvents contained in the returned material flow, so that the performance of the phosgenation reaction is influenced, the energy consumption is increased, and the yield of TDI is influenced.
SUMMERY OF THE UTILITY MODEL
In order to overcome the problem, the utility model provides a promote device of phosgenation reaction phosgene concentration sets up first, second condenser at the degasification top of the tower, and the first condenser condensate that degasses does not return phosgenation reaction stage and participates in TDI synthetic reaction, but returns degassing tower, partly return light gas separator with its partly. The condensate of the second condenser is high-concentration phosgene solution which returns to the phosgenation reaction section to participate in TDI synthesis reaction.
The technical scheme of the utility model as follows:
a device for improving the concentration of phosgene in a phosgenation reaction comprises a degassing tower, a degassing first condenser and a degassing second condenser; a liquid outlet at the bottom of the degassing tower is communicated with a feed inlet pipeline of a degassing circulating pump; a feed inlet of a degassing reboiler is respectively communicated with a discharge port of the degassing circulating pump and a discharge port pipeline of the phosgenation reaction system; the discharge hole of the degassing reboiler is communicated with the middle part of the degassing tower; an exhaust port at the top of the degassing tower is communicated with a feed inlet pipeline at the top of the degassing first condenser; a liquid outlet at the bottom of the degassing first condenser is respectively communicated with the degassing tower and a phosgene separation system pipeline; a degassing first condensate pump is arranged on a pipeline which is communicated with the phosgene separation system by the degassing first condenser; an exhaust port in the middle of the degassing first condenser is communicated with a feed inlet pipeline at the top of the degassing second condenser; an exhaust port in the middle of the degassing second condenser is communicated with a phosgene absorption system pipeline; a liquid outlet at the bottom of the degassing second condenser is communicated with the phosgenation reaction system pipeline; a degassing second condensate pump is arranged on a pipeline which is communicated with the phosgenation reaction system by the degassing second condenser; the working temperature of the degassing first condenser is higher than that of the degassing second condenser.
Furthermore, a liquid separating device is also arranged in the degassing first condenser.
Further, the liquid separation device is a centrifuge.
The utility model discloses following beneficial effect has:
1. the utility model discloses simple structure, it is easy and simple to handle, carry out simple optimization on the device basis of original phosgenation reaction production toluene diisocyanate reform can, reduce the unit cost of product to the energy consumption has been reduced.
2. The top of the degassing tower is provided with a first degassing condenser and a second degassing condenser, condensate of the first degassing condenser is not returned to the phosgenation stage to participate in the TDI synthesis reaction, but a part of the condensate is returned to the degassing tower, and a part of the condensate is returned to the phosgene separation system. The condensate of the second condenser is high-concentration phosgene solution which returns to the phosgenation reaction section to participate in TDI synthesis reaction.
3. The utility model discloses can make degasification process return material participate in phosgenation's phosgene concentration promote 70% -85 wt% by 17 wt% to promote the going on of phosgenation, improve toluene diisocyanate product yield from 92% to more than 92.5%.
Drawings
Fig. 1 is a schematic view of the overall structure of the present invention.
The reference numbers in the figures denote:
1. a phosgenation reaction system; 2. a degassing tower; 3. a degassing circulation pump; 4. a degassing reboiler; 5. a degassing first condenser; 6. a degassed first condensate pump; 7. a liquid separating device; 8. a degassing second condenser; 9. a degassing second condensate pump; 10. a phosgene separation system; 11. a phosgene absorption system; 21. phosgenating the reacted material; 22. gas phase materials; 23. clear liquid; 24. turbid liquid; 25. a first-stage non-condensable gas phase; 26. a condensate containing phosgene in high concentration; 27. the second-stage noncondensable gas phase.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1, an apparatus for increasing the concentration of phosgene in a phosgenation reaction includes a degassing tower 2, a degassing first condenser 5, and a degassing second condenser 8; a liquid outlet at the bottom of the degassing tower 2 is communicated with a feed inlet pipeline of a degassing circulating pump 3; a feed inlet of a degassing reboiler 4 is respectively communicated with a discharge outlet of the degassing circulating pump 3 and a discharge outlet pipeline of the phosgenation reaction system 1; the discharge hole of the degassing reboiler 4 is communicated with the middle part of the degassing tower 2; the exhaust port at the top of the degassing tower 2 is communicated with the feed inlet pipeline at the top of the degassing first condenser 5; a liquid outlet at the bottom of the degassing first condenser 5 is respectively communicated with the degassing tower 2 and the phosgene separation system 10 through pipelines; a degassing first condensate pump 6 is arranged on a pipeline which is communicated with the degassing first condenser 5 and the phosgene separation system 10; an exhaust port in the middle of the degassing first condenser 5 is communicated with a feed inlet pipeline at the top of the degassing second condenser 8; an exhaust port in the middle of the degassing second condenser 8 is communicated with a phosgene absorption system 11 through a pipeline; a liquid outlet at the bottom of the degassing second condenser 8 is communicated with the phosgenation reaction system 1 through a pipeline; a degassing second condensate pump 9 is arranged on a pipeline of the degassing second condenser 8 communicated with the phosgenation reaction system 1; the operating temperature of the degassing first condenser 5 is higher than that of the degassing second condenser 8.
In the phosgenation reaction system 1, the material 21 after the phosgenation reaction enters the degassing reboiler 4 through a pipeline for heating and separation, and the gas phase material 22 enters the degassing first condenser 5 from the top of the degassing tower 2 for cooling. And one part of the condensate (mainly containing phosgene and inert solvent) is returned to the degassing tower 2 through a pipeline, and the other part of the condensate is returned to the phosgene separation system 10 through a pipeline for phosgene separation. In the degassing first condenser 5, the primary uncondensed gas phase 25 which is not condensed enters the degassing second condenser 8 for further cooling, the cooled condensate 26 containing high-concentration phosgene is sent to the phosgenation reaction system 1 to participate in the synthesis of TDI again, and the secondary uncondensed gas phase 27 which is not condensed is sent to the phosgene absorption system 11 to purify hydrogen chloride gas.
Furthermore, a liquid separating device 7 is also arranged in the degassing first condenser 5. The condensate in the degassing first condenser 5 can be separated by means of a separating device 7 into a clear liquid 23 containing phosgene at a relatively high concentration and a turbid liquid 24 containing phosgene at a relatively low concentration, the clear liquid 23 being returned to the degassing column 2 via a pipe, and the turbid liquid 24 being returned to the phosgene separation system 10 via a pipe. Thus, the turbid liquid 24 containing phosgene at a relatively low concentration does not participate in the TDI synthesis reaction, and the problem of packing blockage of the degassing tower 2 can be avoided.
Further, the liquid separation device 7 is a centrifuge.
In particular, the working temperature of the degassing first condenser 5 is between 40 and 100 ℃ and the working temperature of the degassing second condenser 8 is between-30 and-10 ℃. The inert solvent is o-dichlorobenzene or chlorobenzene.
In particular, the operating temperature of the gaseous feed 22 is 163 ℃ and the flow rate is 29656kg/h, consisting essentially of: 57.7 wt% of o-dichlorobenzene, 33.2 wt% of phosgene, 5.6 wt% of hydrogen chloride and the like.
In particular, the condensation temperature and the composition in the degassing first condenser 5 are mainly shown in table 1.
Table 1:
| unit of | 1 | 2 | 3 | |
| Temperature of | ℃ | 40 | 80 | 100 |
| Operating pressure | kPaA | 108 | 108 | 108 |
| Ortho-dichlorobenzene | wt％ | 80.5 | 87.7 | 89.9 |
| Phosgene | wt％ | 14.58 | 7.1 | 5.2 |
| HCl | wt％ | 0.22 | 0.13 | 0.08 |
| Flow rate | kg/h | 21200 | 18600 | 17100 |
In the embodiment, after the primary uncondensed gas phase 25 in the degassing first condenser 5 is condensed to-10 to-12 ℃ by the degassing second condenser 8, the concentration of phosgene in the condensate 26 containing high-concentration phosgene in the degassing second condenser 8 can reach 70 to 85 weight percent, so that the concentration of phosgene returned in the degassing process and participating in the phosgenation reaction can be increased from 17 weight percent to 70 to 85 weight percent, the progress of the phosgenation reaction is improved, and the yield of TDI is increased.
The above only is the embodiment of the present invention, not limiting the patent scope of the present invention, all the equivalent structures or equivalent processes that are used in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.
Claims (3)
1. The utility model provides a promote device of phosgenation reaction phosgene concentration which characterized in that: comprises a degassing tower (2), a degassing first condenser (5) and a degassing second condenser (8); a liquid outlet at the bottom of the degassing tower (2) is communicated with a feed inlet pipeline of a degassing circulating pump (3); a feed inlet of a degassing reboiler (4) is respectively communicated with a discharge outlet of the degassing circulating pump (3) and a discharge outlet pipeline of the phosgenation reaction system (1); the discharge hole of the degassing reboiler (4) is communicated with the middle part of the degassing tower (2); an exhaust port at the top of the degassing tower (2) is communicated with a feed inlet pipeline at the top of the degassing first condenser (5); a liquid outlet at the bottom of the degassing first condenser (5) is respectively communicated with the degassing tower (2) and the phosgene separation system (10) through pipelines; a degassing first condensate pump (6) is arranged on a pipeline of the degassing first condenser (5) communicated with the phosgene separation system (10); an exhaust port in the middle of the degassing first condenser (5) is communicated with a feed port pipeline at the top of the degassing second condenser (8); an exhaust port in the middle of the degassing second condenser (8) is communicated with a phosgene absorption system (11) through a pipeline; a liquid outlet at the bottom of the degassing second condenser (8) is communicated with the pipeline of the phosgenation reaction system (1); a degassing second condensate pump (9) is arranged on a pipeline which is communicated with the phosgenation reaction system (1) by the degassing second condenser (8); the working temperature of the degassing first condenser (5) is higher than that of the degassing second condenser (8).
2. The apparatus for increasing the concentration of phosgene in phosgenation according to claim 1, wherein: a liquid separating device (7) is also arranged in the degassing first condenser (5).
3. The apparatus for increasing the concentration of phosgene in phosgenation according to claim 2, wherein: the liquid separating device (7) is a centrifugal machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921552426.2U CN210974481U (en) | 2019-09-18 | 2019-09-18 | Device for improving concentration of phosgenation reaction phosgene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921552426.2U CN210974481U (en) | 2019-09-18 | 2019-09-18 | Device for improving concentration of phosgenation reaction phosgene |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210974481U true CN210974481U (en) | 2020-07-10 |
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ID=71460945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921552426.2U Expired - Fee Related CN210974481U (en) | 2019-09-18 | 2019-09-18 | Device for improving concentration of phosgenation reaction phosgene |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210974481U (en) |
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2019
- 2019-09-18 CN CN201921552426.2U patent/CN210974481U/en not_active Expired - Fee Related
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| Date | Code | Title | Description |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200710 |