System for reducing benzene content in hydrogenated gasoline
By combining heat exchange modules, pre-hydrogenation reaction modules, pre-fractionation modules, and benzene cutting modules, along with etherification and hydrodesulfurization treatments, the problem of high benzene content in stable gasoline during catalytic cracking was solved, effectively reducing the benzene content in hydrogenated gasoline and decreasing energy consumption.
Patent Information
- Application Number
- CN202423137063.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-18
AI Technical Summary
During catalytic cracking, the high benzene content in stabilized gasoline affects the quality of hydrogenated gasoline, making it difficult to meet stringent gasoline standards.
A combined system consisting of a heat exchange module, a pre-hydrogenation reaction module, a pre-fractionation module, a benzene cutting module, and a hydrodesulfurization module is adopted. The system cuts off benzene-rich gasoline components through pre-hydrogenation fractionation and a benzene cutting tower, and reduces the benzene content in hydrogenated gasoline by combining etherification and hydrodesulfurization treatments.
With lower investment and process modifications, it effectively reduces the benzene content in hydrogenated gasoline, improves benzene cutting efficiency, maintains temperature balance, and reduces energy consumption.
Smart Images
Figure CN223607220U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of petroleum chemical industry, concretely relates to a system for reducing benzene content in hydrogenated gasoline. BACKGROUND
[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the present utility model and does not necessarily constitute an admission that this information forms a prior art that is already known in this field.
[0003] Catalytic cracking is one of the main methods of secondary processing of petroleum distillates, which is a process of converting heavy distillate oil into diesel, gasoline and gas under the action of high temperature and catalyst.
[0004] Stable gasoline is the main product of catalytic cracking, and most of the gasoline is catalytic cracking stable gasoline. However, due to the enrichment of sulfur, nitrogen, olefins, aromatic hydrocarbons and the like, it cannot be directly used as a product and needs to be hydrotreated. Therefore, the conventional process is to send the stable gasoline from the catalytic cracking device to the hydrotreating device, remove the sulfur, nitrogen and other impurities in the stable gasoline under the action of a certain temperature and catalyst through a fixed bed hydrogenation reactor, and make the content of olefins and aromatic hydrocarbons qualified. Subsequently, the reaction oil enters the stripping tower (also known as the stabilizing tower), and after removing the acidic components formed in the hydrogenation process and C4 fraction, it is sent to the fractionation unit to obtain light and heavy gasoline.
[0005] However, due to the influence of factors such as reaction raw materials and reaction depth in the catalytic cracking process, the benzene content in stable gasoline is high, which further affects the benzene content in the final hydrogenated gasoline. With the strictness of gasoline standards, the benzene content in gasoline has become an important factor restricting the delivery of gasoline. CONTENT OF THE UTILITY MODEL
[0006] In order to solve the above problems, the utility model provides a system for reducing benzene content in hydrogenated gasoline.
[0007] In order to achieve the above technical purpose, the utility model adopts the following technical scheme:
[0008] A system for reducing benzene content in hydrogenated gasoline, comprising:
[0009] Heat exchange module, pre-hydrogenation reaction module, pre-fractionation module, benzene cutting module and hydrogenation desulfurization module;
[0010] The heat exchange module is connected with the pre-hydrogenation reaction module;
[0011] The pre-fractionation module comprises a pre-fractionation tower, the top of the pre-fractionation tower is connected with the pre-hydrogenation module, and the tank of the pre-fractionation tower is connected with the benzene cutting module through the heat exchange module;
[0012] The benzene cutting module comprises a benzene cutting column, the top of the benzene cutting column is connected with the reforming module, and the bottom of the benzene cutting column is connected with the hydrodesulfurization module.
[0013] In one or more embodiments, the heat exchange module comprises a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger and a fifth heat exchanger connected in sequence.
[0014] Preferably, the fourth heat exchanger is connected with the upper part of the pre-fractionation column.
[0015] Preferably, the bottom of the pre-fractionation column is connected with the second heat exchanger, and the second heat exchanger is connected with the upper part of the benzene cutting column.
[0016] In one or more embodiments, the pre-hydrogenation reaction module comprises a pre-hydrogenation reaction column, the top of the pre-hydrogenation reaction column is connected with the fifth heat exchanger, and the bottom of the pre-hydrogenation reaction column is connected with the fourth heat exchanger.
[0017] In one or more embodiments, the system for reducing the benzene content in hydrogasoline also comprises an etherification module.
[0018] Preferably, the top of the pre-fractionation column is connected with a first air cooler, a first reflux tank and a first reflux pump in sequence, and the first reflux pump is connected with the upper part of the pre-fractionation column and the etherification module respectively.
[0019] In one or more embodiments, the top of the benzene cutting column is connected with a second air cooler, a second reflux tank and a second reflux pump in sequence, the second reflux pump is connected with the upper part of the benzene cutting column through a first pipeline, the second reflux pump is connected with the reforming module through a second pipeline, and the second reflux pump is connected with the hydrodesulfurization module through a third pipeline.
[0020] In one or more embodiments, the bottom of the benzene cutting column is connected with a sixth heat exchanger, and the sixth heat exchanger is connected with the hydrodesulfurization module.
[0021] Preferably, one end of the second pipeline is connected with a pipeline between the sixth heat exchanger and the hydrodesulfurization module.
[0022] The utility model discloses the beneficial effect lies in:
[0023] (1) The utility model discloses, the medium heavy gasoline after prehydrogenation fractionation is cut to the top benzene rich distillate and the bottom benzene poor distillate in benzene cutting tower, wherein the benzene rich distillate is divided into three, wherein the first stock distillate refluxes to the benzene cutting tower, not only can improve the efficiency of benzene cutting, can also maintain the temperature balance in the tower, the second stock distillate enters the reforming module, and the third stock distillate is combined with the bottom benzene poor component and enters the hydrogenation desulfurization module and carries out hydrogenation desulfurization. By increasing the benzene cutting tower after prehydrogenation fractionation, part of benzene rich gasoline component can be cut off, and then the benzene content in the final hydrogenation gasoline is reduced.
[0024] (2) The utility model discloses can realize the effective control to the benzene content in gasoline under the condition of lower investment or process flow change. BRIEF DESCRIPTION OF DRAWINGS
[0025] The accompanying drawings, which form a part of this document, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this document. The drawings illustrate one or more exemplary embodiments of the present application and, together with the description, serve to explain the application.
[0026] Figure 1 It is a system structure diagram for the utility model, wherein, 1 - raw material storage tank, 2 - raw material pump, 3 - first heat exchanger, 4 - second heat exchanger, 5 - third heat exchanger, 6 - fourth heat exchanger, 7 - fifth heat exchanger, 8 - prehydrogenation reaction tower, 9 - pre-fractionation tower, 10 - medium heavy gasoline pump, 11 - first air cooler, 12 - first reflux tank, 13 - first reflux pump, 14 - etherification module, 15 - benzene cutting tower, 16 - second air cooler, 17 - second reflux tank, 18 - second reflux pump, 19 - heavy gasoline pump, 20 - sixth heat exchanger, 21 - reforming module, 22 - hydrogenation desulfurization module. DETAILED DESCRIPTION
[0027] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0028] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further noted that the singular forms "a," "an," and "the" are intended to include the plural referents, unless the context clearly dictates otherwise. It is to be understood that the terms "comprising," "including," and "having" can be used interchangeably.
[0029] The utility model will be made further detailed explanation in combination with specific embodiment, it should be pointed out that the specific embodiment is the explanation of the utility model but not limit.
[0030] Embodiment 1
[0031] Referring to Figure 1 A system for reducing benzene content in hydrogas oil, comprising:
[0032] The heat exchange module, the pre-hydrogenation reaction module, the pre-fractionation module, the benzene cutting module and the hydrodesulfurization module are connected in sequence.
[0033] The heat exchange module is connected with the pre-hydrogenation reaction module.
[0034] The pre-fractionation module comprises a pre-fractionation column 9, the top of the pre-fractionation column 9 is connected with the pre-hydrogenation module, and the bottom of the pre-fractionation column 9 is connected with the benzene cutting module through the heat exchange module.
[0035] The benzene cutting module comprises a benzene cutting column 15, the top of the benzene cutting column 15 is connected with the reforming module, and the bottom of the benzene cutting column 15 is connected with the hydrodesulfurization module.
[0036] The system for reducing benzene content in hydrogas oil further comprises a raw material storage tank 1, the raw material storage tank 1 is connected with a raw material pump 2 and the heat exchange module in sequence.
[0037] In order to stably improve the temperature of the raw material stable gasoline, fully recover various heat energy in the reaction process and reduce the energy consumption of the reaction, the heat exchange module comprises a first heat exchanger 3, a second heat exchanger 4, a third heat exchanger 5, a fourth heat exchanger 6 and a fifth heat exchanger 7 connected in sequence.
[0038] The pre-hydrogenation reaction module comprises a pre-hydrogenation reaction column 8, the top of the pre-hydrogenation reaction column 8 is connected with the fifth heat exchanger 7, the bottom of the pre-hydrogenation reaction column 8 is connected with the fourth heat exchanger 6, the fourth heat exchanger 6 is connected with the upper part of the pre-fractionation column 9, and the material after pre-hydrogenation reaction in the pre-hydrogenation reaction column 8 has high temperature and exchanges heat with the raw material without hydrogenation reaction in the fourth heat exchanger 6, so that the heat energy is fully recovered and the energy consumption of the reaction is reduced.
[0039] In order to further recover heat energy and reduce the energy consumption of the reaction, the bottom of the pre-fractionation column 9 is connected with the second heat exchanger 4 through a middle heavy gasoline pump 10. The material flowing out of the bottom of the pre-fractionation column 9 has high temperature and exchanges heat with the raw material without hydrogenation reaction in the second heat exchanger 4.
[0040] In the heat exchange module, the second heat exchanger 4 and the fourth heat exchanger 6 recycle and utilize the heat source in the reaction, in order to stably improve the temperature of the raw material stable gasoline, in addition to utilizing the heat energy in the reaction process, the first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, the fourth heat exchanger 6 and the fifth heat exchanger 7 are all provided with a heat medium inlet and a heat medium outlet.
[0041] The system for reducing the benzene content in hydrogenated gasoline provided by the application further comprises an etherification module 14. The top of the prefractionating column 9 is sequentially connected with a first air cooler 11, a first reflux tank 12 and a first reflux pump 13, the first reflux pump 13 is connected with the upper part of the prefractionating column through a fourth pipeline, and the first reflux pump 13 is connected with the etherification module 14 through a fifth pipeline. The material is refluxed to the prefractionating column through the fourth pipeline, which can not only improve the fractionation efficiency, but also maintain the temperature balance in the column. The etherification module 14 comprises an etherification reactor, and the light gasoline after the prehydrogenation reaction and fractionation is introduced into the etherification reactor to perform etherification reaction with methanol.
[0042] The second heat exchanger 4 is connected with the upper part of a benzene cutting column 15, the top of the benzene cutting column 15 is sequentially connected with a second air cooler 16, a second reflux tank 17 and a second reflux pump 18, the second reflux pump 18 is connected with the upper part of the benzene cutting column 15 through a first pipeline, the second reflux pump 18 is connected with a reforming module 21 through a second pipeline, and the second reflux pump 18 is connected with a hydrodesulfurization module 22 through a third pipeline. The bottom of the benzene cutting column 15 is sequentially connected with a heavy gasoline pump 19 and a sixth heat exchanger 20, the sixth heat exchanger 20 is connected with the hydrodesulfurization module 22. One end of the second pipeline is connected with the pipeline between the sixth heat exchanger 20 and the hydrodesulfurization module 22. The medium-heavy gasoline after the prehydrogenation and fractionation is cut into a benzene-rich fraction at the top of the benzene cutting column 15 and a benzene-lean fraction at the bottom of the benzene cutting column 15 through the benzene cutting column 15; the benzene-rich fraction is divided into three streams, the first stream is refluxed into the benzene cutting column 15, which can not only improve the benzene cutting efficiency, but also maintain the temperature balance in the column; the second stream is introduced into the reforming module 21, and the third stream is combined with the benzene-lean component at the bottom and introduced into the hydrodesulfurization module 22 to perform hydrodesulfurization. By adding the benzene cutting column after the prehydrogenation and fractionation, part of the gasoline component rich in benzene can be removed, and thus the benzene content in the final hydrogenated gasoline can be reduced.
[0043] The reforming module 21 comprises a prehydrogenation unit, a continuous reforming unit, a catalyst regeneration unit and an aromatic extraction unit which are sequentially connected.
[0044] The hydrodesulfurization module 22 comprises a hydrodesulfurization reactor, which can perform deep hydrodesulfurization on the gasoline obtained by combining the third stream cut from the top of the benzene cutting column 15 and the benzene-lean component at the bottom.
[0045] The process flow of the system for reducing the benzene content in hydrogenated gasoline provided by the application is as follows:
[0046] The raw material stable gasoline enters into the first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5, the fourth heat exchanger 6 and the fifth heat exchanger 7 in sequence through the raw material pump 2 for heat exchange; the raw material after heat exchange enters into the pre-hydrogenation reaction tower 8 from the inlet at the top of the pre-hydrogenation reaction tower 8 for pre-hydrogenation, the gasoline after pre-hydrogenation flows out from the bottom of the pre-hydrogenation reaction tower 8 and enters into the fourth heat exchanger 6 for heat exchange with the raw material without hydrogenation reaction, and the heat energy is recovered; the gasoline after pre-hydrogenation enters into the pre-fractionating tower 9 for pre-fractionation, the light gasoline is obtained at the top of the pre-fractionating tower 9, the light gasoline enters into the etherification reactor for etherification reaction with methanol, the medium and heavy gasoline is obtained at the bottom of the pre-fractionating tower 9, the medium and heavy gasoline is heat exchanged with the raw material without hydrogenation reaction in the second heat exchanger 4, and the heat energy is recovered; the medium and heavy gasoline after heat exchange enters into the benzene cutting tower 15 for cutting, the top benzene-rich fraction and the bottom benzene-lean fraction are obtained, wherein the benzene-rich fraction is divided into three streams, the first stream returns to the benzene cutting tower 15, the second stream enters into the reforming module 21, and the third stream is combined with the bottom benzene-lean component and enters into the hydrogenation desulfurization module 22 for hydrogenation desulfurization.
[0047] Finally, it should be noted that the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing embodiments, for those skilled in the art, it can still be modified, or part of the equivalent replacement. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the scope of protection of the present application.
Claims
1. A system for reducing the benzene content of hydrotreated gasoline, characterized in that, The system comprises a heat exchange module, a pre-hydrogenation reaction module, a pre-fractionation module, a benzene cutting module, and a hydrodesulfurization module. The heat exchange module is connected with the pre-hydrogenation reaction module. The pre-fractionation module comprises a pre-fractionation column, the top of which is connected with the pre-hydrogenation module, and the column bottom of which is connected with the benzene cutting module through the heat exchange module. The benzene cutting module comprises a benzene cutting column, the top of which is connected with the reforming module, and the bottom of which is connected with the hydrodesulfurization module. The heat exchange module comprises a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, and a fifth heat exchanger connected in sequence.
2. The system of claim 1, wherein, The fourth heat exchanger is connected with the upper part of the pre-fractionation column.
3. The system of claim 2, wherein, The column bottom of the pre-fractionation column is connected with the second heat exchanger, and the second heat exchanger is connected with the upper part of the benzene cutting column.
4. The system of claim 2, wherein, The pre-hydrogenation reaction module comprises a pre-hydrogenation reaction column, the top of which is connected with the fifth heat exchanger, and the column bottom of which is connected with the fourth heat exchanger.
5. The system of claim 2, wherein, The system for reducing the benzene content in hydrogasoline further comprises an etherification module.
6. The system of claim 1, wherein, The top of the pre-fractionation column is connected with a first air cooler, a first reflux tank, and a first reflux pump in sequence, and the first reflux pump is connected with the upper part of the pre-fractionation column and the etherification module respectively.
7. The system of claim 6, wherein, The top of the benzene cutting column is connected with a second air cooler, a second reflux tank, and a second reflux pump in sequence, the second reflux pump is connected with the upper part of the benzene cutting column through a first pipeline, the second reflux pump is connected with the reforming module through a second pipeline, and the second reflux pump is connected with the hydrodesulfurization module through a third pipeline.
8. The system of claim 1, wherein, The bottom of the benzene cutting column is connected with a sixth heat exchanger, and the sixth heat exchanger is connected with the hydrodesulfurization module.
9. The system of claim 8, wherein, One end of the second pipeline is connected with the pipeline between the sixth heat exchanger and the hydrodesulfurization module.
10. The system of claim 9, wherein,