Naphtha processing system

Abstract

The utility model discloses a naphtha processing system. The naphtha processing system at least comprises a continuous reforming device, the normal and isomerous separation device and the continuous reforming device are arranged in parallel; the naphtha hydrogenation device is connected with the continuous reforming device and the normal and isomerous separation device; the reformate fractionating tower is connected with the continuous reforming device; the p-xylene fractionating device is connected with the reformate fractionating tower; the aromatic hydrocarbon extraction device is connected with the reformate fractionating tower; the disproportionation device is connected with the aromatic hydrocarbon extraction device and the reformate fractionating tower; the input end of the buffer tank is connected with the aromatic hydrocarbon extraction device, and the output end of the buffer tank is connected with the isomerization separation device. According to the naphtha processing system provided by the utility model, benzene, p-xylene and hydrogen products with high added values can be increased, the utilization efficiency of naphtha is increased, and the economic benefit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of petrochemical industry, in particular to a naphtha processing system. Background Art

[0002] Raffinate oil is a by-product of naphtha continuous reforming to produce aromatics and hydrogen, including components such as normal alkanes, isoalkanes, aromatics, cycloalkanes and olefins. At present, in the downstream applications of raffinate oil, a small part of the raffinate oil is sent to the tank area as a gasoline blending component and a cracking raw material in the ethylene cracking unit, while most of the raffinate oil is sold as a product with low added value. Therefore, in the processing of naphtha, there are problems such as low product added value, low naphtha utilization efficiency and low economic benefits. Utility Model Content

[0003] The utility model aims to provide a naphtha processing system, which can increase the production of more high value-added benzene, paraxylene and hydrogen products, increase the utilization efficiency of naphtha and improve economic benefits.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the utility model is implemented through the following technical solutions.

[0005] The utility model provides a naphtha processing system, which at least comprises:

[0006] Continuous reforming unit;

[0007] a normal isomerization separation device, arranged in parallel with the continuous reforming device;

[0008] A naphtha hydrogenation unit connected to the continuous reforming unit and the normal-isomer separation unit;

[0009] a reformed oil fractionation tower connected to the continuous reforming device;

[0010] a paraxylene refining device connected to the reformed oil fractionation tower;

[0011] an aromatics extraction device connected to the reformed oil fractionation tower;

[0012] a disproportionation unit connected to the aromatics extraction unit and the reformate fractionation tower; and

[0013] A buffer tank, wherein the input end of the buffer tank is connected to the aromatics extraction device, and the output end of the buffer tank is connected to the normal isomerization separation device.

[0014] In one embodiment of the present invention, the normal isomerization separation device comprises a deisohexanizer, and the output port of the deisohexanizer is connected to the naphtha hydrogenation device.

[0015] In one embodiment of the present invention, the normal-isomerization separation device further comprises a de-normal pentane tower, and the output end of the de-normal pentane tower is connected to the de-isohexane tower.

[0016] In one embodiment of the present invention, the normal isomerization separation device further comprises a de-isopentanizer, and the output end of the de-isopentanizer is connected to the input end of the de-normal pentanizer.

[0017] In one embodiment of the utility model, the de-isohexanizer includes two input ports, one of which is connected to the output end of the buffer tank, and the other of which is connected to the de-normal pentanizer.

[0018] In one embodiment of the utility model, the naphtha hydrogenation device includes a naphtha hydrogenation tower, and the output end of the naphtha hydrogenation tower is connected to the continuous reforming device.

[0019] In one embodiment of the utility model, the naphtha hydrogenation device further comprises a raw material input pipeline, and the raw material input pipeline is connected to the input end of the naphtha hydrogenation tower.

[0020] In one embodiment of the present invention, the processing system comprises an alkane output pipeline, and the alkane output pipeline connects the output port of the deisohexanizer and the raw material input pipeline.

[0021] In one embodiment of the present invention, the processing system comprises a raffinate oil output pipeline, and the raffinate oil output pipeline is connected to the output end of the aromatics extraction device.

[0022] In an embodiment of the present invention, the raffinate oil output pipeline includes a first branch line, and the first branch line serves as an input end of the buffer tank.

[0023] In summary, the utility model proposes a naphtha processing system, which can circulate and process the raffinate oil, avoid selling a large amount of raffinate oil as a low-value-added product, increase the production of more high-value-added products such as benzene, paraxylene and hydrogen, increase the utilization efficiency of naphtha, and increase economic benefits.

[0024] Of course, any method of implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 The present invention is a schematic structural diagram of a naphtha processing system in one embodiment of the present invention.

[0027] Marking Description:

[0028] 11. First raw material input pipeline; 12. Continuous reforming unit; 13. Reforming oil fractionation tower; 14. Aromatics extraction unit; 15. Disproportionation unit; 16. Naphtha hydrogenation unit; 161. Raw material input pipeline; 162. Naphtha hydrogenation tower; 17. Buffer tank; 18. Second raw material input pipeline; 19. Deisopentanizer; 20. De-normal pentanizer; 21. Deisohexanizer; 22. Normal isomerization separation unit; 23. Paraxylene refining unit; 24. Raffinate oil output pipeline; 241. First branch line; 242. Second branch line; 25. Alkane output pipeline. DETAILED DESCRIPTION

[0029] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations. The details in the present invention can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0031] In the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, if the terms "first" and "second" appear, they are only used for description and distinction purposes, and cannot be understood as indicating or implying relative importance.

[0032] In the present utility model, it should be noted that C n + Refers to C n-1 Component, C n Components and Cn One or more of the above components, C n Component refers to organic matter with carbon number n. For example, C6 + It is one or more of the components of C5, C6 and above.

[0033] In the processing of naphtha, hydrogen and aromatics are produced by continuous reforming of naphtha, and the maximum output of raffinate oil byproducts reaches 160t / h, far exceeding the designed output of 120t / h of the device. In the downstream application of raffinate oil, the maximum demand for raffinate oil by the ethylene cracking unit is about 30t / h, and the amount of raffinate oil used for gasoline blending is at most 10% of the gasoline output, and most of the remaining raffinate oil is sold as low value-added products. The naphtha processing system provided by the utility model combines a continuous reforming unit, a naphtha hydrogenation unit and a normal isomerization separation unit to circulate and process the raffinate oil, which can increase the production of more high value-added benzene, paraxylene and hydrogen products and increase economic benefits.

[0034] See also Figure 1 As shown, the utility model provides a naphtha processing system, for example, including a continuous reforming device 12, a reforming oil fractionation tower 13, an aromatics extraction device 14, a naphtha hydrogenation device 16, a buffer tank 17 and a normal isomerization separation device 22. Among them, the continuous reforming device 12, the reforming oil fractionation tower 13 and the aromatics extraction device 14 are connected in sequence, the input end of the buffer tank 17 is connected to the output end of the aromatics extraction device 14, the output end of the buffer tank 17 is connected to the normal isomerization separation device 22, and the naphtha hydrogenation device 16 is connected to the normal isomerization separation device 22 and the continuous reforming device 12. The naphtha processing system provided by the utility model can increase the production of more high-value-added benzene, paraxylene and hydrogen products by successively introducing part of the raffinate oil at the output end of the aromatics extraction device 14 to the normal isomerization separation device 22, the naphtha hydrogenation device 16 and the continuous reforming device 12, and processing the raffinate oil, thereby increasing economic benefits.

[0035] See also Figure 1 As shown, in one embodiment of the present invention, the continuous reforming device 12 is used as a place for the raw material to undergo a reforming reaction. The raw material enters the continuous reforming device 12 and undergoes a reforming reaction to generate C6 + Reforming produces oil and reforming hydrogen, which is used to supply hydrogen to the whole plant. + The reformed oil enters the subsequent reformed oil fractionation tower 13 for separation and purification. + In the reforming oil, C5, C6, C7, C8, C9 and C 10The chain alkane content of C6, C7, C8, C9 and C 10 The cyclic alkane content of C6, C7, C8, C9, C 10 and C 11 + The aromatic content of C6 is 7wt%, 19.03wt%, 29.81wt%, 24.7wt%, 7.7wt% and 1.13wt%, respectively, and the chain alkane, cyclic alkane and aromatic content are 10.12wt%, 0.5wt% and 89.37wt%, respectively. + The components of the reformed oil are complex and need to be separated and reacted in the subsequent reformed oil fractionation tower 13, aromatics extraction unit 14, disproportionation unit 15 and paraxylene refining unit 23 to obtain high-purity benzene and paraxylene products.

[0036] See also Figure 1 As shown, in one embodiment of the present invention, the first raw material input pipeline 11 is connected to the input end of the continuous reforming device 12 to transport raw materials to the continuous reforming device 12. The first raw material input pipeline 11 transports raw materials such as heavy naphtha, for example.

[0037] See also Figure 1 As shown, in one embodiment of the present invention, the normal isomerization separation device 22 is arranged in parallel with the continuous reforming device 12. In this embodiment, the normal isomerization separation device 22, for example, includes a second raw material input pipeline 18, a deisopentanizer 19, a deisopentanizer 20, and a deisohexanizer 21, etc., which are connected in sequence. Among them, the second raw material input pipeline 18 is used to transport raw materials for the normal isomerization separation device 22, and the second raw material input pipeline 18, for example, transports raw materials such as cracked light naphtha.

[0038] See also Figure 1 As shown, in one embodiment of the present invention, the input end of the deisopentanizer 19 is connected to the second raw material input pipeline 18, and the output end of the deisopentanizer 19 is connected to the input end of the depentanizer 20. In the deisopentanizer 19, isopentane in the raw material is separated.

[0039] See also Figure 1 As shown, in one embodiment of the present invention, the input end of the depentanizer 20 is connected to the output end of the deisopentanizer 19, and the output end of the depentanizer 20 is connected to the input end of the deisohexanizer 21. In the depentanizer 20, the normal pentane in the raw material is separated.

[0040] See also Figure 1 As shown, in one embodiment of the present invention, the input end of the deisohexanizer 21 is connected to the output end of the depentanizer 20, and the output end of the deisohexanizer 21 is connected to the alkane output pipeline 25. In the deisohexanizer 21, isohexane in the feedstock is separated.

[0041] See also Figure 1 As shown, in one embodiment of the utility model, the naphtha hydrogenation unit 16 is connected to the continuous reforming unit 12 and the deisohexane tower 21. Wherein, the naphtha hydrogenation unit 16, for example, includes a raw material input pipeline 161 and a naphtha hydrogenation tower 162, etc., the output end of the naphtha hydrogenation tower 162 is connected to the continuous reforming unit 12, and the raw material input pipeline 161 is connected to the input end of the naphtha hydrogenation tower 162. Wherein, the raw material input pipeline 161, for example, transports straight-run naphtha. In this embodiment, the raw material is hydrorefined in the naphtha hydrogenation tower 162 to remove olefins in the raw material, and then enters the continuous reforming unit 12 for reforming reaction to avoid coking of olefins in the continuous reforming unit 12.

[0042] See also Figure 1 As shown, in one embodiment of the present invention, the reformed oil fractionation tower 13 is connected to the continuous reforming device 12. In this embodiment, the reformed oil fractionation tower 13 is connected to the output end of the continuous reforming device 12, and the C6 + The reformed oil enters the reformed oil fractionation tower 13 for fractionation, and is separated according to different boiling points. + The C8 aromatics in the reformed oil enter the subsequent p-xylene refining unit 23 to wait for the purification of p-xylene, C6 + C9 in reforming oil + Aromatics enter the subsequent disproportionation unit 15. + The C6-C7 fraction mixture in the reformed oil is evaporated to the top of the tower and enters the subsequent aromatics extraction device 14 to wait for benzene purification.

[0043] See also Figure 1 As shown, in one embodiment of the present invention, the p-xylene refining device 23 is connected to the reforming oil fractionation tower 13. In this embodiment, the C8 aromatics separated by the reforming oil fractionation tower 13 enter the p-xylene refining device 23 for separation and purification, and the separated p-xylene is sold as a product or used as a chemical raw material for re-production. Among them, the p-xylene refining device 23 includes, for example, separation devices such as a distillation tower and a centrifugal device.

[0044] See also Figure 1As shown, in one embodiment of the utility model, the aromatic extraction device 14 is connected to the reformed oil fractionation tower 13. In this embodiment, the aromatic extraction device 14 is connected to the top of the reformed oil fractionation tower 13, for example. The C6-C7 fraction at the top of the reformed oil fractionation tower 13 enters the aromatic extraction device 14 to separate the raffinate oil and C6-C7 aromatics, and the C6-C7 aromatics enter the subsequent disproportionation device 15 to wait for benzene purification. Among them, in the raffinate oil, the contents of ethane, propane, butane and aromatics account for 0.35, 0.3, 0.3 and 0.29 wt% respectively, the contents of C5 non-aromatics, C6 non-aromatics, C7 non-aromatics and C8 non-aromatics account for 8.07, 44.06, 44.11 and 2.52 wt% respectively, and the contents of normal alkanes, isoalkanes, cycloalkanes and olefins account for 24.86, 65.73, 7.41 and 1.64 wt% respectively. The normal alkanes, isoalkanes and cycloalkanes in the raffinate oil are good reforming reaction raw materials with high conversion rate and can be processed and utilized.

[0045] See also Figure 1 As shown, in one embodiment of the present invention, the disproportionation device 15 is connected to the aromatics extraction device 14 and the reformed oil fractionation tower 13. + Aromatics and C6-C7 aromatics from the aromatics extraction unit 14 enter the disproportionation unit 15, and toluene and C9 + C9C in aromatics 10 Aromatics undergo disproportionation to produce benzene and C8 + Aromatics, benzene are sold as products, while C8 + Aromatic hydrocarbons are successively returned to the reforming oil fractionation tower 13 and the para-xylene refining unit 23, and are converted into para-xylene through reactions such as distillation, centrifugal separation or isomerization.

[0046] See also Figure 1 As shown, in one embodiment of the utility model, the input end of the buffer tank 17 is connected to the aromatic extraction device 14, and the output end of the buffer tank 17 is connected to the deisohexanizer 21. The raffinate oil separated by the aromatic extraction device 14 enters the buffer tank 17 and the deisohexanizer 21 in sequence. By providing the buffer tank 17, the feed flow rate and pressure of the deisohexanizer 21 can be stabilized to ensure the smooth operation of the deisohexanizer 21.

[0047] See also Figure 1As shown, in one embodiment of the utility model, the raffinate oil output pipeline 24 is connected to the output end of the aromatics extraction device 14, and is used to output the raffinate oil separated by the aromatics extraction device 14. The raffinate oil output pipeline 24 includes, for example, a first branch line 241 and a second branch line 242, and the first branch line 241 is used as the input end of the buffer tank 17 to input the raffinate oil into the buffer tank 17. The second branch line 242 and the first branch line 241 are arranged in parallel at the output end of the aromatics extraction device 14, and the raffinate oil extracted by the second branch line 242 is used in gasoline blending and ethylene cracking devices.

[0048] See also Figure 1 As shown, in one embodiment of the utility model, the deisohexane tower 21 includes two input ports, one of which is connected to the depentane tower 20 and is used to remove isohexane from the raw material in the second raw material input pipeline 18. The other input port is connected to the output end of the buffer tank 17, and the raffinate oil output from the buffer tank 17 enters the deisohexane tower 21. - Non-aromatics (mainly pentane, n-hexane and isohexane), C6 - Non-aromatic hydrocarbons will undergo cracking reactions in the continuous reforming unit 12 and consume hydrogen. Therefore, the C6 - Removal of non-aromatics and removal of C6 from raffinate oil - After dearomatic hydrocarbons are extracted, the remaining residue is mainly C7 + Hydrocarbons, then C7 + The hydrocarbons are successively sent to the subsequent naphtha hydrogenation unit 16 and the continuous reforming unit 12 for processing.

[0049] See also Figure 1 As shown, in one embodiment of the present invention, the alkane output pipeline 25 connects the output port of the deisohexanizer 21 and the raw material input pipeline 161 to transfer the C7 separated by the deisohexanizer 21 to the raw material input pipeline 161. + The hydrocarbons are successively sent to the naphtha hydrogenation unit 16 and the continuous reforming unit 12 for cyclic processing to utilize C7 + The normal alkanes, isoalkanes and cycloalkanes of hydrocarbons are used as raw materials for reforming reactions and are further processed to increase the production of high value-added hydrogen, paraxylene and benzene products.

[0050] See also Figure 1 As shown, in one embodiment of the present invention, the raw material input pipeline 161 is connected to the alkane output pipeline 25. The C7 + The hydrocarbons contain olefins. If the C7 + Hydrocarbons directly enter the continuous reforming unit 12, and olefins are easily coked during the reforming reaction. Therefore, the alkane output pipeline 25 is connected to the raw material input pipeline 161, C7 +The hydrocarbons will pass through the naphtha hydrogenation tower 162 and then enter the continuous reforming unit 12. The naphtha hydrogenation tower 162 will + Hydrogenation of hydrocarbon olefins to prevent C7 + The olefins of the hydrocarbons are coked in the continuous reforming unit 12 .

[0051] See also Figure 1 As shown, in one embodiment of the utility model, the utility model introduces part of the raffinate oil output from the aromatic extraction device 14 to the deisohexanizer 21, the raw material input pipeline 161 and the naphtha hydrogenation tower 162, the continuous reforming device 12, the reforming oil fractionation tower 13 and the paraxylene refining device 23 in sequence, and introduces the fractions output from the reforming oil fractionation tower 13 to the aromatic extraction device 14 and the disproportionation device 15 respectively, so as to realize the recycling processing and utilization of the raffinate oil, convert the normal alkanes, isoalkanes and cycloalkanes in the raffinate oil into high value-added products such as benzene, paraxylene and hydrogen, and increase the economic benefits. The system provided by the utility model can process 100 t / h of raffinate oil, can increase the raw materials of the continuous reforming device 12 by 45 t / h, and increase the output of reforming hydrogen, paraxylene and benzene products by 2.75 t / h, 17 t / h and 6.5 t / h respectively, thus avoiding a large amount of raffinate oil from being sold as a low value-added product, increasing the output of high value-added products and improving economic benefits.

[0052] In summary, the utility model proposes a naphtha processing system, which combines a continuous reforming device, a naphtha hydrogenation device and a normal isomerization separation device, and introduces the by-product raffinate oil of the continuous reforming to prepare aromatics and hydrogen into the normal isomerization separation device, the naphtha hydrogenation device and the continuous reforming device in turn, and the normal alkanes, isoalkanes and cycloalkanes in the raffinate oil are recycled and processed, which can increase the production of high value-added products such as benzene, paraxylene and hydrogen, increase the utilization efficiency of naphtha, and increase economic benefits.

[0053] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that the specific features, structures, or characteristics described in conjunction with the embodiment are included in at least one embodiment of the utility model, and not necessarily in all embodiments. Thus, the various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics of any specific embodiment of the utility model may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the utility model embodiments described and shown herein may be based on the teachings herein and will be considered part of the spirit and scope of the utility model.

[0054] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the concept of the utility model, such as the technical solution formed by replacing the above-mentioned features with the technical features with similar functions disclosed in this application (but not limited to). In addition to the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present utility model, the remaining technical features will not be repeated here.

Claims

1. A naphtha processing system, characterized in that: At least: Continuous reforming unit; a normal isomerization separation device, arranged in parallel with the continuous reforming device; A naphtha hydrogenation unit connected to the continuous reforming unit and the normal-isomer separation unit; a reformed oil fractionation tower connected to the continuous reforming device; a paraxylene refining device connected to the reformed oil fractionation tower; an aromatics extraction device connected to the reformed oil fractionation tower; a disproportionation device connected to the aromatics extraction device and the reformed oil fractionation tower; as well as A buffer tank, wherein the input end of the buffer tank is connected to the aromatics extraction device, and the output end of the buffer tank is connected to the normal isomerization separation device.

2. The processing system according to claim 1, characterized in that: The normal isomerization separation device comprises a deisohexanizer, and the output port of the deisohexanizer is connected to the naphtha hydrogenation device.

3. The processing system according to claim 2, characterized in that: The normal isomerization separation device further comprises a depentanizer, and an output end of the depentanizer is connected to the deisohexanizer.

4. The processing system according to claim 3, characterized in that: The normal isomerization separation device further comprises a de-isopentanizer, and the output end of the de-isopentanizer is connected to the input end of the de-normal pentanizer.

5. The processing system according to claim 3, characterized in that: The deisohexanizer includes two input ports, one of which is connected to the output end of the buffer tank, and the other is connected to the depentanizer.

6. The processing system according to claim 2, characterized in that: The naphtha hydrogenation device comprises a naphtha hydrogenation tower, and the output end of the naphtha hydrogenation tower is connected to the continuous reforming device.

7. The processing system according to claim 6, characterized in that: The naphtha hydrogenation device further comprises a raw material input pipeline, and the raw material input pipeline is connected to the input end of the naphtha hydrogenation tower.

8. The processing system according to claim 7, characterized in that: The processing system comprises an alkane output pipeline, and the alkane output pipeline connects the output port of the deisohexanizer and the raw material input pipeline.

9. The processing system according to claim 1, characterized in that: The processing system further comprises a raffinate oil output pipeline, and the raffinate oil output pipeline is connected to the output end of the aromatics extraction device.

10. The processing system according to claim 9, characterized in that: The raffinate oil output pipeline includes a first branch line, and the first branch line serves as an input end of the buffer tank.

Images