System and method for accelerating benzene product qualification in an aromatics complex

Abstract

The application belongs to the field of chemical industry and particularly relates to a reaction system and method for accelerating the qualification of benzene products after initial start-up of an aromatic hydrocarbon combined device or regeneration of a disproportionation catalyst, comprising a toluene line, a benzene product line and a mixed aromatic hydrocarbon line; the toluene line is connected with a toluene unqualified line at the outlet, the benzene product line is connected with a benzene unqualified line at the outlet, the toluene unqualified line and the benzene unqualified line are connected to a benzene-toluene unqualified line and connected to the mixed aromatic hydrocarbon line through the benzene-toluene unqualified line, and sent to the inlet of an extraction raw material tank through the mixed aromatic hydrocarbon line. The application has the advantages that a cross line is newly added between the benzene-toluene unqualified line and the non-aromatic mixed aromatic unqualified line, the unqualified benzene product is changed to the extraction raw material tank after start-up, so that the non-aromatic hydrocarbons in the unqualified benzene product cannot return to the benzene tower again, thereby shortening the time for the benzene product to reach the qualified standard.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical industry, and particularly relates to a reaction system and method for accelerating the qualification of benzene products after initial start-up of an aromatic hydrocarbon combination device or regeneration of a disproportionation catalyst. BACKGROUND

[0002] The aromatic hydrocarbon combination device is mainly a device for producing benzene, toluene and xylene, and in the aromatic hydrocarbon combination device, the disproportionation reaction is to produce xylene and by-product benzene with toluene and C9+A as raw materials under the action of a disproportionation catalyst. However, after the initial start-up of the aromatic hydrocarbon combination device or the regeneration of the disproportionation catalyst, the initial activity of the catalyst is very high, the disproportionation side reaction is more, the non-aromatic hydrocarbon content in benzene is high, and the production of qualified benzene products cannot be achieved in a short time. SUMMARY

[0003] In view of the defects in the prior art, the present application provides a reaction system and method for accelerating the qualification of benzene products in an aromatic hydrocarbon combination device, and particularly relates to a system and method for accelerating the qualification of benzene products after initial start-up of an aromatic hydrocarbon combination device or regeneration of a disproportionation catalyst, which aims to avoid the problem that after the initial start-up of the aromatic hydrocarbon combination device or the regeneration of the disproportionation catalyst, the activity of the catalyst is too high, and the production of qualified benzene products needs too long time.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a reaction system for accelerating the qualification of benzene products in an aromatic hydrocarbon combination device, comprising a toluene line, a benzene product line and a mixed aromatic hydrocarbon line; the outlet of the toluene line is connected with a toluene unqualified line, the outlet of the benzene product line is connected with a benzene unqualified line, the toluene unqualified line and the benzene unqualified line are connected to a benzene-toluene unqualified line and connected to the mixed aromatic hydrocarbon line through the benzene-toluene unqualified line, and sent to the inlet of an extraction raw material tank through the mixed aromatic hydrocarbon line.

[0005] Further, the inlet of the mixed aromatic hydrocarbon line is connected with the outlet of a mixed aromatic hydrocarbon reflux pump, the outlet of the mixed aromatic hydrocarbon line is connected with a mixed aromatic hydrocarbon qualified line and a mixed aromatic hydrocarbon unqualified line; the mixed aromatic hydrocarbon qualified line is connected to a disproportionation white clay feed tank, and the mixed aromatic hydrocarbon unqualified line is connected to the extraction raw material tank; the benzene-toluene unqualified line is connected to the mixed aromatic hydrocarbon unqualified line and connected to the inlet of the extraction raw material tank through the mixed aromatic hydrocarbon unqualified line.

[0006] Further, a first guide valve, a first valve, a second guide valve and a second valve are sequentially arranged on the benzene-toluene unqualified line, a branch pipeline is arranged on the outlet side of the first guide valve, the branch pipeline is connected with the mixed aromatic hydrocarbon qualified line and connected to the inlet of the disproportionation white clay feed tank through the mixed aromatic hydrocarbon qualified line, and a third valve is arranged on the branch pipeline.

[0007] Further, the inlet end of the mixed aromatic hydrocarbon qualified line is provided with a control valve group, and the control valve group is connected to a prepared defoaming agent line in the rear route, and the prepared defoaming agent line is connected to a defoaming agent tank; the inlet end of the mixed aromatic hydrocarbon unqualified line is provided with a control valve group, and the control valve group is connected to an unqualified mixed aromatic hydrocarbon goes to the underground tank line in the rear route, and the unqualified mixed aromatic hydrocarbon goes to the underground tank line is connected to a wet solvent tank.

[0008] Further, the reaction system further comprises an unqualified non-aromatic hydrocarbon line, the inlet of the unqualified non-aromatic hydrocarbon line is connected to the outlet of the non-aromatic hydrocarbon reflux pump, the outlet of the unqualified non-aromatic hydrocarbon line is connected to the mixed aromatic hydrocarbon unqualified line, and the mixed aromatic hydrocarbon unqualified line is connected to the inlet of the extraction raw material tank, and the unqualified non-aromatic hydrocarbon line is provided with a control valve group.

[0009] Further, the reaction system further comprises a top benzene line, the inlet of the top benzene line is connected to the outlet of the benzene reflux pump, the outlet of the top benzene line is connected to the mixed aromatic hydrocarbon unqualified line, and the mixed aromatic hydrocarbon unqualified line is connected to the inlet of the extraction raw material tank, and the top benzene line is provided with a control valve group.

[0010] Further, the inlet of the toluene line is connected to the outlet of the toluene reflux pump, the toluene line is connected with a toluene feeding pipeline and a toluene sending pipeline, the toluene feeding pipeline is connected to a disproportionation reaction feeding buffer tank, the toluene feeding pipeline is provided with a control valve group, and the toluene sending pipeline is provided with a toluene unqualified line.

[0011] Further, the toluene sending pipeline is sequentially connected with an air cooler, a water cooler, a control valve group and a fourth valve, the toluene unqualified line is connected to the rear route of the control valve group, the fourth valve is connected to the disproportionation white clay feeding heat exchanger through a first branch in the rear route, and the fourth valve is connected to a toluene storage tank through a second branch in the rear route.

[0012] Further, the benzene product line is provided with a control valve group, the rear route of the control valve group is connected to a benzene unqualified line and a storage tank feeding line, and the storage tank feeding line is connected to a benzene product storage tank.

[0013] The method for accelerating the qualification of benzene products of an aromatic hydrocarbon combined device, non-aromatic hydrocarbon content exceeding the standard benzene produced within a predetermined time after initial operation of the aromatic hydrocarbon device or regeneration of a disproportionation catalyst is sent to an extraction raw material tank, and the extraction raw material tank is sent to an extraction unit of the aromatic hydrocarbon combined device, and non-aromatic hydrocarbons in the benzene are removed through extraction distillation.

[0014] Further, the predetermined time is 3-5 days.

[0015] The method has the advantages that the unqualified benzene product is changed to the extraction raw material tank after operation through the newly added cross line between the benzene-toluene unqualified line and the non-aromatic mixed aromatic unqualified line, so that the non-aromatic hydrocarbons in the unqualified benzene product cannot return to the benzene tower again, and the time for the benzene product to reach the qualified standard is shortened. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the reaction system for accelerating benzene product qualification in the aromatic hydrocarbon complex of the present invention;

[0017] In the diagram: 1. Toluene line, 2. Benzene product line, 3. Mixed aromatics line, 4. Toluene non-compliant line, 5. Benzene non-compliant line, 6. Benzene and toluene non-compliant line, 7. Mixed aromatics compliant line, 8. Mixed aromatics non-compliant line, 9. First drain valve, 10. First valve, 11. Second drain valve, 12. Second valve, 13. Branch pipeline, 14. Third valve, 15. Defoamer preparation line, 16. Non-compliant mixed aromatics to underground tank line, 17. Non-compliant non-aromatics line, 18. Top-extraction benzene line, 19. Toluene feed pipeline, 20. Toluene external transmission pipeline, 21. Air cooler, 22. Water cooler, 23. Fourth valve, 24. Storage tank feed line;

[0018] A. Toluene reflux pump, B. Benzene product water cooler, C. Mixed aromatics reflux pump, D. Non-aromatics reflux pump, E. Benzene reflux pump, F. Disproportionating clay feed heat exchanger, G. Toluene storage tank, H. Benzene product storage tank, I. Defoamer tank, J. Disproportionating clay feed tank, K. Extraction raw material tank, L. Wet solvent tank, M. Disproportionation reaction feed buffer tank. Detailed Implementation

[0019] To make the structure and function of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0020] See appendix Figure 1 The aromatics complex is a reaction system that accelerates the qualification of benzene products, including toluene line 1, benzene product line 2 and mixed aromatics line 3; the outlet of toluene line 1 is connected to toluene non-qualified line 4, the outlet of benzene product line 2 is connected to benzene non-qualified line 5, the toluene non-qualified line 4 and benzene non-qualified line 5 are connected to benzene-toluene non-qualified line 6 and then connected to mixed aromatics line 3, and sent to the inlet of extraction feed tank K through mixed aromatics line 3.

[0021] Furthermore, the inlet of the mixed aromatics line 3 is connected to the outlet of the mixed aromatics reflux pump C, and the outlet of the mixed aromatics line 3 is connected to the mixed aromatics qualified line 7 and the mixed aromatics unqualified line 8; the mixed aromatics qualified line 7 is connected to the disproportionated clay feed tank J, and the mixed aromatics unqualified line 8 is connected to the extraction raw material tank K; the benzene-toluene unqualified line 6 is connected to the mixed aromatics unqualified line 7, and is connected to the inlet of the extraction raw material tank K through the mixed aromatics unqualified line 7.

[0022] Further, the benzene-toluene unqualified line 6 is sequentially provided with a first guide valve 9, a first valve 10, a second guide valve 11, and a second valve 12, a branch line 13 is arranged on the rear side of the first guide valve 9, the branch line 13 is connected to the mixed aromatic hydrocarbon qualified line 7, and the mixed aromatic hydrocarbon qualified line 7 is connected to the entrance of the disulfuration white clay feeding tank J through the disulfuration white clay feeding tank J, and a third valve 14 is arranged on the branch line 13.

[0023] Further, the entrance of the mixed aromatic hydrocarbon qualified line 7 is provided with a control valve group, the control valve group is connected to the preparation defoaming agent line 15 on the rear side, the preparation defoaming agent line 15 is connected to the defoaming agent tank I, the entrance of the mixed aromatic hydrocarbon unqualified line 8 is provided with a control valve group, the control valve group is connected to the unqualified mixed aromatic hydrocarbon underground tank line 16 on the rear side, and the unqualified mixed aromatic hydrocarbon underground tank line 16 is connected to the wet solvent tank L.

[0024] Further, the reaction system further comprises an unqualified non-aromatic hydrocarbon line 17, the entrance of the unqualified non-aromatic hydrocarbon line 17 is connected to the outlet of the non-aromatic hydrocarbon reflux pump D, the outlet of the unqualified non-aromatic hydrocarbon line 17 is connected to the mixed aromatic hydrocarbon unqualified line 8, the mixed aromatic hydrocarbon unqualified line 8 is connected to the entrance of the extraction raw material tank K, and a control valve group is arranged on the unqualified non-aromatic hydrocarbon line 17.

[0025] Further, the reaction system further comprises a top benzene line 18, the entrance of the top benzene line 18 is connected to the outlet of the benzene reflux pump E, the outlet of the top benzene line 18 is connected to the mixed aromatic hydrocarbon unqualified line 8, the mixed aromatic hydrocarbon unqualified line 8 is connected to the entrance of the extraction raw material tank K, and a control valve group is arranged on the top benzene line 18.

[0026] Further, the entrance of the toluene line 1 is connected to the outlet of the toluene reflux pump A, the toluene line 1 is connected to a toluene feeding line 19 and a toluene delivery line 20, the toluene feeding line 19 is connected to the disulfuration reaction feeding buffer tank M, a control valve group is arranged on the toluene feeding line 19, and the toluene delivery line 20 is connected to the toluene unqualified line 4.

[0027] Further, the toluene delivery line 20 is sequentially connected to an air cooler 21, a water cooler 22, a control valve group, and a fourth valve 23, the toluene unqualified line 4 is connected to the rear side of the control valve group, the fourth valve 23 is connected to the disulfuration white clay feeding heat exchanger F through a first branch on the rear side, and the fourth valve 23 is connected to the toluene storage tank G through a second branch on the rear side.

[0028] Further, a control valve group is arranged on the benzene product line 2, the rear side of the control valve group is connected to the benzene unqualified line 5 and a storage tank feeding line 24, and the storage tank feeding line 24 is connected to the benzene product storage tank H.

[0029] The method for accelerating the qualification of benzene product in an aromatic hydrocarbon combined device sends the benzene with non-aromatic hydrocarbon content exceeding the standard generated within the predetermined time after initial start-up of the aromatic hydrocarbon device or regeneration of the disproportionation catalyst to an extraction raw material tank, and sends the benzene from the extraction raw material tank to an extraction unit of the aromatic hydrocarbon combined device, and removes the non-aromatic hydrocarbon in the benzene through extraction distillation.

[0030] Based on the above technical solution, it is necessary to note that the benzene generated 3-5 days after start-up needs to be sent to the extraction raw material tank (this is the improved benzene product qualification time, and the previous benzene product qualification time is about 2 weeks), and the unqualified toluene needs to be sent to the extraction raw material tank K together with the unqualified benzene at the initial start-up stage, and the toluene is qualified soon, and then it can not be sent to the extraction raw material tank K, and the toluene is qualified and can directly participate in the reaction, and at this time, the benzene needs to be continuously sent to the extraction raw material tank K, and the benzene is qualified and is sent to the benzene product storage tank H. The main reason for the unqualified benzene is that the non-aromatic hydrocarbon content in the benzene exceeds the standard, and after being sent to the extraction raw material tank, the unqualified benzene needs to be sent to the extraction unit of the aromatic hydrocarbon combined device, and the non-aromatic hydrocarbon in the unqualified benzene is removed through extraction distillation.

[0031] The technical solution of the present application is improved on the basis of the existing technical process. In the original technical process, the benzene generated at the initial start-up stage is sent to the utility engineering public disproportionation white clay feed tank through the benzene-toluene unqualified line, the benzene tower overhead material is sent to the utility engineering extraction raw material tank through the benzene extraction, and the material is separated from the non-aromatic hydrocarbon in the benzene through the extraction unit of the aromatic hydrocarbon combined device, so that the benzene is gradually qualified. However, the problem is that after the unqualified benzene is sent to the disproportionation white clay feed tank, the material in the tank returns to the benzene tower, that is, the non-aromatic hydrocarbon in the benzene is brought into the benzene tower, and the qualification time of the benzene is prolonged.

[0032] The present application aims at the above-mentioned defects, shortens the time for benzene product to reach the qualified standard by reforming the on-site pipeline. The on-site reforming scheme is as follows: a head is cut on the benzene-toluene unqualified pipeline at the pipeline gallery of the aromatics combination device extraction unit, a new pipeline a is added, the pipeline is extended to the ground, a third valve 14 (DN150, 150LB) is added to the pipeline, a first guide valve 9 (DN20, 800LB) is added before the valve, and the pipeline after the valve is connected to the benzene-toluene unqualified post-line pipeline; a head is cut after the valve of the non-aromatic mixed aromatic unqualified pipeline from the device to the public extraction raw material tank pipeline, a new pipeline b is added, the pipeline is connected to the valve before the new pipeline a of the benzene-toluene unqualified pipeline, a first valve 10 (DN150, 150LB) and a second valve 12 (DN150, 150LB) are added between the pipelines, and a second guide valve 11 (DN20, 800LB) is added. The key point of the present application is to add a cross line and a valve between the benzene-toluene unqualified pipeline and the non-aromatic mixed aromatic unqualified pipeline to the disproportionation white clay feed tank pipeline in the aromatics combination device, at the initial start-up of the aromatics combination device and the initial start-up after the disproportionation catalyst regeneration, the unqualified benzene is sent to the public engineering extraction raw material tank directly by using the added cross line instead of being sent to the public engineering disproportionation white clay feed tank originally, so that the non-aromatic hydrocarbon in the disproportionation white clay feed tank is avoided to enter the benzene tower again, thereby shortening the time for the benzene product to reach the qualified standard.

[0033] The above-mentioned is only the best embodiment of the present application. Obviously, the present application is not limited to the above-mentioned embodiment, and there can be many variations. All the variations which can be directly derived or thought from the disclosed content by the ordinary skilled in the art should be considered as the protection scope of the present application.

Claims

1. A system for expediting the qualification of benzene product in an aromatics complex, characterized by: The benzene product line is connected with a benzene unqualified line, and the benzene unqualified line is connected with the benzene-toluene unqualified line and the mixed aromatic hydrocarbon line through the benzene-toluene unqualified line, and is sent to the extraction raw material tank inlet through the mixed aromatic hydrocarbon line; the mixed aromatic hydrocarbon line inlet is connected with the mixed aromatic hydrocarbon reflux pump outlet, the mixed aromatic hydrocarbon line outlet is connected with a mixed aromatic hydrocarbon qualified line and a mixed aromatic hydrocarbon unqualified line; the mixed aromatic hydrocarbon qualified line is connected with the bleaching clay feed tank, and the mixed aromatic hydrocarbon unqualified line is connected with the extraction raw material tank; the benzene-toluene unqualified line is connected with the mixed aromatic hydrocarbon unqualified line, and is connected with the extraction raw material tank inlet through the mixed aromatic hydrocarbon unqualified line; the benzene-toluene unqualified line is sequentially provided with a first guide valve, a first valve, a second guide valve and a second valve, a branch pipeline is arranged on the rear route of the first guide valve, the branch pipeline is connected with the mixed aromatic hydrocarbon qualified line, and is connected with the bleaching clay feed tank inlet through the mixed aromatic hydrocarbon qualified line, and a third valve is arranged on the branch pipeline.

2. The system for expediting the qualification of benzene product of the aromatics complex of claim 1, wherein: The inlet end of the mixed aromatic hydrocarbon qualified line is provided with a control valve group, the rear route of the control valve group is connected with a prepared defoaming agent line, the prepared defoaming agent line is connected with a defoaming agent tank; the inlet end of the mixed aromatic hydrocarbon unqualified line is provided with a control valve group, the rear route of the control valve group is connected with an unqualified mixed aromatic hydrocarbon goes to underground tank line, and the unqualified mixed aromatic hydrocarbon goes to underground tank line is connected with a wet solvent tank.

3. The system for expediting the qualification of benzene product of the aromatics complex of claim 1, wherein: The unqualified non-aromatic hydrocarbon line is also included, the inlet of the unqualified non-aromatic hydrocarbon line is connected with a non-aromatic hydrocarbon reflux pump outlet, the outlet of the unqualified non-aromatic hydrocarbon line is connected with the mixed aromatic hydrocarbon unqualified line, and is connected with the extraction raw material tank inlet through the mixed aromatic hydrocarbon unqualified line, and the unqualified non-aromatic hydrocarbon line is provided with a control valve group.

4. The system for expediting the qualification of benzene product of the aromatics complex of claim 1, wherein: The overhead benzene line is also included, the inlet of the overhead benzene line is connected with a benzene reflux pump outlet, the outlet of the overhead benzene line is connected with the mixed aromatic hydrocarbon unqualified line, and is connected with the extraction raw material tank inlet through the mixed aromatic hydrocarbon unqualified line, and the overhead benzene line is provided with a control valve group.

5. The system for expediting qualification of benzene product of the aromatics complex of claim 1, wherein: The inlet of the toluene line is connected with the outlet of a toluene reflux pump, the toluene line is connected with a toluene feed pipeline and a toluene external delivery pipeline, the toluene feed pipeline is connected with a bleaching reaction feed buffer tank, the toluene feed pipeline is provided with a control valve group, and the toluene external delivery pipeline is provided with a toluene unqualified line.

6. The system for expediting qualification of benzene product of the aromatics complex of claim 5, wherein: The toluene external delivery pipeline is sequentially connected with an air cooler, a water cooler, a control valve group and a fourth valve, the toluene unqualified line is connected behind the control valve group, the rear route of the fourth valve is connected with a bleaching clay feed heat exchanger through a first branch, and the rear route of the fourth valve is connected with a toluene storage tank through a second branch.

7. The system for expediting qualification of benzene product of the aromatics complex of claim 1, wherein: The benzene product line is provided with a control valve group, and the rear route of the control valve group is connected with a benzene unqualified line and a storage tank feed line, and the storage tank feed line is connected with a benzene product storage tank.

8. A method for expediting the qualification of benzene product in an aromatics complex using a system as claimed in any one of claims 1 to 7, characterized in that: The benzene produced within a predetermined time after initial start-up of the aromatic hydrocarbon device or regeneration of the disproportionation catalyst and exceeding the standard of non-aromatic hydrocarbon content is sent to the extraction raw material tank, and is sent into the extraction unit of the aromatic hydrocarbon combined device from the extraction raw material tank, and is removed from the non-aromatic hydrocarbon in the benzene through extraction distillation.

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