A system for saving stripping steam in oil refining and Ve separation

Abstract

This application provides a system for saving stripping steam in oil refining and Ve separation. The system includes, in the direction of the oil path, a decolorized oil pipeline, a first heat exchanger, a deodorization plate tower, a second heat exchanger, a heater, a pre-deodorization packed tower, and a post-deodorization packed tower, connected in sequence. The first heat exchanger includes a first outlet for secondary steam, and the heater includes a second outlet for secondary steam. The first and second outlets for secondary steam are respectively connected to the pre-deodorization packed tower or the deodorization plate tower. The system of this utility model is more energy-efficient, has a simpler structure, lower cost, and lower maintenance costs, and is used to solve the problems in the prior art.

Description

Technical Field

[0001] This application relates to the technical field of oil refining and deodorization equipment, and in particular to a system for saving stripping steam in oil refining and Ve separation. Background Technology

[0002] The basic principle of the deodorization and Ve separation process in edible oil refining is that the decolorized oil in the first stage is heated to above 220+℃ through a high-temperature heat exchanger. Under a high vacuum of 1-3mbar, according to the partial pressure theorem, the partial pressure of water vapor in the system is increased to separate low-fraction products such as free fatty acids and tocopherols (Ve). Therefore, in terms of process principle, a certain amount of stripping steam needs to be added to the deodorization and Ve separation system during the operation of the separation process system. Currently, the common production process is to add a certain amount of stripping steam to the deodorization tower and the Ve distillation packed tower (regardless of whether this part of the steam is added directly to the packed distillation tower or added to the plate tower first through a channel and then enters the deodorization and Ve packed tower).

[0003] The decolorized oil entering the distillation system from the upstream stage usually has the opportunity to come into contact with moisture in the previous upstream processes. Although it has also undergone a heating and vacuum drying process to remove moisture, the temperature of vapor evolution during the upstream vacuum drying process does not exceed 120°C, and the vacuum residual pressure does not fall below 50 mbar. Therefore, through testing, we can confirm that the decolorized oil still contains a considerable amount of moisture, typically with a water and volatile matter content of 0.075%-0.1%. In typical deodorization and Ve separation processes, the deodorization temperature is between 230-255℃. To save energy, the decolorized oil is usually heated from 110℃ to above 200℃, such as 210℃, by a high-temperature oil-to-oil heat exchanger before directly entering the final heater. In the final heater, the decolorized oil is heated by high-pressure steam under the high vacuum of deodorization, raising the temperature by about 20℃ to the deodorization and Ve separation temperature (about 240℃). To improve the heating effect of the final heater, about 0.6-1.5 kg / ton of oil is usually added to the oil for stirring.

[0004] When the above-mentioned decolorizing oil is heated to above 200°C and subjected to deodorization under high vacuum conditions, the approximately 0.075-0.1% water and volatiles contained in the decolorizing oil will evaporate violently, producing "secondary steam" gas whose main component is water vapor. At the same time, it will cause a large amount of oil splashing, which usually accounts for about 0.1% of the oil volume. During single-temperature deodorization, this splashed oil and secondary steam are directly introduced into the fatty acid trap along with the stirring steam through the "final heater" and then into the vacuum system. During dual-temperature deodorization, this splashed oil and secondary steam are also introduced directly from the oil inlet of the pre-deacidification packed tower to the trap and then into the vacuum system.

[0005] As described above, under normal circumstances, in a 600tpd refinery, the stirring steam in the high-temperature heat exchanger is about 20kg / hour, so the total amount of overflowing secondary steam is about 32.5+25=57.5kg / hour, and the splashed oil is about 25kg / hour. For a 1000 tpd refinery: the inlet steam to the high-temperature heat exchanger is about 33.6 kg / hour, and the total amount of overflowing secondary steam is about 33.6 + 25.2 + 29.4 = 88.2 kg / hour, which is then used for the final heater; the splash oil is about 42 kg / hour.

[0006] Therefore, there is an urgent need to reuse "secondary" steam and provide a system that saves stripping steam in oil refining and Ve separation. Utility Model Content

[0007] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a system for saving stripping steam in oil refining and Ve separation. The system is more energy-efficient, has a simple structure, low cost, and low maintenance cost, thereby solving the problems in the prior art.

[0008] To achieve the above and other related objectives, this application provides a system for saving stripping steam in oil refining and Ve separation. The system includes, in the direction of the oil path, a decolorized oil pipeline, a first heat exchanger, a deodorization plate tower, a second heat exchanger, a heater, a pre-deodorization packed tower, and a post-deodorization packed tower connected in sequence. The first heat exchanger includes a first secondary steam outlet, and the heater includes a second secondary steam outlet. The first and second secondary steam outlets are respectively connected to the pre-deodorization packed tower or the deodorization plate tower.

[0009] In some embodiments of this utility model, the first heat exchanger further includes a decolorizing oil inlet, a first heat exchanger cold test oil outlet, a first stirring steam inlet, a first heat exchanger hot side oil inlet, and a first heat exchanger hot side oil outlet; the decolorizing oil inlet is connected to the decolorizing oil pipeline, the first heat exchanger cold test oil outlet is connected to the deodorizing plate tower, and the second heat exchanger hot side outlet is connected to the first heat exchanger hot side oil inlet.

[0010] In some embodiments of this utility model, a first oil pump is also included, and the hot-side oil outlet of the first heat exchanger is connected to the subsequent cooling inlet of the deodorized oil through the first oil pump.

[0011] In some embodiments of this utility model, the deodorization plate tower includes a plate tower oil inlet, a first fresh stripping steam inlet, a plate tower oil outlet, and a secondary stripping gas inlet. The plate tower oil inlet is connected to a first heat exchanger, the plate tower oil outlet is connected to a second heat exchanger, and the first secondary steam outlet and the second secondary steam outlet are respectively connected to the secondary stripping gas inlet.

[0012] In some embodiments of this utility model, the second heat exchanger includes a low-temperature oil inlet, a low-temperature oil outlet, a high-temperature oil inlet, and a high-temperature oil outlet. The low-temperature oil inlet is connected to the deodorization plate tower, the low-temperature oil outlet is connected to the heater, the high-temperature oil inlet is connected to the deodorized packed tower, and the high-temperature oil outlet is connected to the first heat exchanger.

[0013] In some embodiments of this utility model, a second oil pump is provided on the connecting pipeline between the deodorization plate tower and the second heat exchanger.

[0014] In some embodiments of this utility model, the heater further includes a heater oil inlet, a high-pressure heating steam inlet, a high-pressure condensate outlet, a second stirring steam inlet, and a heater oil outlet. The heater oil inlet is connected to the second heat exchanger, and the heater oil outlet is connected to the pre-deodorization packed tower.

[0015] In some embodiments of this utility model, the pre-deodorization packed tower includes a pre-packed tower oil inlet, a pre-packed tower oil outlet, a secondary steam inlet, and a pre-packed tower steam outlet. The pre-packed tower oil inlet is connected to a heater, the pre-packed tower oil outlet is connected to a post-deodorization packed tower, the first secondary steam outlet and the second secondary steam outlet are respectively connected to a secondary steam inlet, and the pre-packed tower steam outlet is connected to the inlet of the trap vacuum system.

[0016] In some embodiments of this utility model, the deodorized packing tower includes a packing tower oil inlet, a packing tower oil outlet, a fresh stripping gas second inlet, and a packing tower vacuum steam outlet. The packing tower oil inlet is connected to the deodorized packing tower, the packing tower oil outlet is connected to the second heat exchanger, and the packing tower vacuum steam outlet is connected to the vacuum system inlet of the trap.

[0017] In some embodiments of this utility model, the pre-deodorization packing tower is located above the deodorization plate tower and is connected through an internal flow channel.

[0018] This application provides a system for saving stripping steam in oil refining and Ve separation. The system includes, in the direction of the oil path, a decolorized oil pipeline, a first heat exchanger, a heater, a pre-deodorization packed tower, and a deodorization plate tower connected in sequence. The first heat exchanger includes a first secondary steam outlet, and the heater includes a second secondary steam outlet. The first and second secondary steam outlets are respectively connected to the pre-deodorization packed tower or the deodorization plate tower.

[0019] In some embodiments of this utility model, the first heat exchanger further includes a decolorizing oil inlet, a first heat exchanger cold test oil outlet, a first stirring steam inlet, a first heat exchanger hot side oil inlet, and a first heat exchanger hot side oil outlet; the decolorizing oil inlet is connected to the decolorizing oil pipeline, the first heat exchanger cold test oil outlet is connected to the heater, the deodorizing plate tower is connected to the first heat exchanger hot side oil inlet, and also includes a first oil pump, the first heat exchanger hot side oil outlet being connected to the deodorizing oil subsequent cooling inlet via the first oil pump.

[0020] In some embodiments of this utility model, the heater further includes a heater oil inlet, a high-pressure heating steam inlet, a high-pressure condensate outlet, a second stirring steam inlet, and a heater oil outlet. The heater oil inlet is connected to the first heat exchanger, and the heater oil outlet is connected to the pre-deodorization packed tower.

[0021] In some embodiments of this utility model, the pre-packed tower for deodorization includes a pre-packed tower oil inlet, a secondary steam inlet, and a pre-packed tower steam outlet. The pre-packed tower oil inlet is connected to a heater, the first secondary steam outlet and the second secondary steam outlet are respectively connected to the secondary steam inlet, and the pre-packed tower steam outlet is connected to the inlet of the vacuum system of the trap.

[0022] In some embodiments of this utility model, the pre-deodorization packing tower is located above the deodorization plate tower.

[0023] In some embodiments of this utility model, the deodorization plate tower includes a first fresh stripping steam inlet, a plate tower oil outlet, and a secondary stripping gas inlet. The plate tower oil outlet is connected to the first heat exchanger, and the secondary stripping gas inlet is connected to the first secondary steam outlet and the second secondary steam outlet, respectively.

[0024] Compared with the prior art, the beneficial effects of this application are as follows: The system for saving stripping steam in oil refining and Ve separation using this utility model, compared with the existing technology where secondary steam from high-temperature heat exchangers is directly discharged to the collector and then to the vacuum system, reduces the total amount of stripping steam added, completely recovers the splashed oil from the heater, reduces the total vacuum load, and the reduction in vacuum load leads to a reduction in power steam, saving electricity for the vacuum chiller and reducing the environmental pressure of vacuum condensate wastewater.

[0025] Specifically: (1) Turning waste into treasure saves energy and reduces consumption. By using waste gas “secondary steam” to replace part of the fresh “steam stripping”, under the premise that the total amount of “steam stripping” remains unchanged, the amount of fresh “steam stripping” used is reduced. Also, because the load on the subsequent vacuum system is reduced, the power steam consumption and the power consumption of the related refrigeration unit are greatly saved. (2) Reducing the amount of steam entering the subsequent vacuum channel reduces the load on the vacuum pipeline and collector, which is more conducive to reducing the load pressure drop of the vacuum system, optimizing the vacuum conditions in the deodorization tower, and helping to ensure product quality. (3) "Secondary steam" utilizes the complete recovery of splashed oil in the waste gas to improve the yield of product Ve; (4) Because it reduces power steam, reduces wastewater discharge, and is environmentally friendly, it improves the yield of deodorization and vacuum systems. Attached Figure Description

[0026] Figure 1 The diagram shown is a system schematic diagram of Embodiment 1 of this utility model; Figure 2 The diagram shown is a system schematic of Embodiment 2 of this utility model.

[0027] Component designation explanation: 1. Decolorizing oil pipeline 2 First heat exchanger 21. First steam inlet for stirring 22 Secondary steam first outlet 23 Imported decolorizing oil 24 First heat exchanger cold test oil outlet 25 First heat exchanger hot side oil inlet 26 First heat exchanger hot side oil outlet 3 Deodorization plate tower 31. Imported plate oil 32 Freshly Extracted Gasoline, First Import 33 Plate Oil Export 34 Secondary stripping gas import 4 Second heat exchanger 41. Imported low-temperature oil 42. Low-temperature oil outlet 43. High-temperature oil imports 44 High-temperature oil export 5 heaters 51. Stirring Steam Second Inlet 52 Secondary Steam Second Outlet 53 Heater oil inlet 54 Heater oil outlet 55 High-pressure heating steam inlet 56 High-pressure condensate outlet 6. Packed tower before deodorization 61. Oil inlet of the pre-packed tower 62. Oil outlet of the pre-packed tower 63 Secondary steam inlet 64 Steam outlet of the front packed tower 7. Deodorized packed tower 71 Post-packed tower oil inlet 72 Post-packed tower oil outlet 73 Fresh stripped gas second inlet 74 Vacuum steam outlet of the packed tower 8 First oil pump 9 Second oil pump 10 Deodorized oil subsequent cooling inlet 11. Vacuum system inlet of the trap. Detailed Implementation

[0028] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of this application.

[0029] The terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more. Example 1

[0032] like Figure 1 Embodiment 1 of this application provides a system comprising, in the direction of the oil path, a decolorized oil pipeline 1, a first heat exchanger 2, a deodorization plate tower 3, a second heat exchanger 4, a heater 5, a pre-deodorization packed tower 6, and a post-deodorization packed tower 7, which are connected in sequence.

[0033] The first heat exchanger 2 includes a first secondary steam outlet 22, and the heater 5 includes a second secondary steam outlet 52. The first secondary steam outlet 22 and the second secondary steam outlet 52 are respectively connected to the pre-deodorization packed tower 6 or the deodorization plate tower 3.

[0034] In the system provided in Embodiment 1 of this utility model, the first heat exchanger 2 further includes a decolorizing oil inlet 23, a first heat exchanger cold test oil outlet 24, a stirring steam first inlet 21, a first heat exchanger hot side oil inlet 25, and a first heat exchanger hot side oil outlet 26. The decolorizing oil inlet 23 is connected to the decolorizing oil pipeline 1, the first heat exchanger cold test oil outlet 24 is connected to the deodorizing plate tower 3, and the second heat exchanger 4 is connected to the first heat exchanger hot side oil inlet 25.

[0035] The first heat exchanger 2 may include more stages of heat exchange and may also include various forms, such as a horizontal floating head type, a plate heat exchanger during welding, or a high-temperature falling film heat exchanger, etc.

[0036] The system provided in Embodiment 1 of this utility model also includes a first oil pump 8, and the hot side oil outlet 26 of the first heat exchanger is connected to the subsequent cooling inlet 10 of the deodorized oil through the first oil pump 8.

[0037] In the system provided in Embodiment 1 of this utility model, the deodorization plate tower 3 includes a plate tower oil inlet 31, a fresh stripping steam first inlet 32, a plate tower oil outlet 33, and a secondary stripping gas inlet 34. The plate tower oil inlet 31 is connected to the first heat exchanger 2, specifically, the plate tower oil inlet 31 is connected to the cold test oil outlet 24 of the first heat exchanger. The plate tower oil outlet 33 is connected to the second heat exchanger 4. The secondary steam first outlet 22 and the secondary steam second outlet 52 are respectively connected to the secondary stripping gas inlet 34 (another embodiment is not shown).

[0038] In the system provided by Embodiment 1 of this utility model, in order to save energy and reduce the heating load of heater 5, a second heat exchanger 4 is added to the system. The second heat exchanger 4 includes a low-temperature oil inlet 41, a low-temperature oil outlet 42, a high-temperature oil inlet 43, and a high-temperature oil outlet 44. The low-temperature oil inlet 41 is connected to the deodorization plate tower 3, specifically, the low-temperature oil inlet 41 is connected to the plate tower oil outlet 33. The low-temperature oil outlet 42 is connected to the heater 5, and the high-temperature oil inlet 43 is connected to the deodorized packed tower 7. The high-temperature oil outlet 44 is connected to the first heat exchanger 2, specifically, the high-temperature oil outlet 44 is connected to the hot-side oil inlet 25 of the first heat exchanger.

[0039] The second heat exchanger 4 can take various forms, including welded plate heat exchangers or falling film heat exchangers.

[0040] A second oil pump 9 is installed on the connecting pipeline between the deodorization plate tower 3 and the second heat exchanger 4.

[0041] In the system provided in Embodiment 1 of this utility model, the heater 5 further includes a heater oil inlet 53, a high-pressure heating steam inlet 55, a high-pressure condensate outlet 56, a second stirring steam inlet 51, and a heater oil outlet 54. The heater oil inlet 53 is connected to the second heat exchanger 4, specifically, the heater oil inlet 53 is connected to the low-temperature oil outlet 42. The heater oil outlet 54 is connected to the pre-deodorization packed tower 6.

[0042] In the system provided in Embodiment 1 of this utility model, the pre-deodorization packed tower 6 includes a pre-packed tower oil inlet 61, a pre-packed tower oil outlet 62, a secondary steam inlet 63, and a pre-packed tower steam outlet 64. The pre-packed tower oil inlet 61 is connected to the heater 5, specifically, the pre-packed tower oil inlet 61 is connected to the heater oil outlet 54. The pre-packed tower oil outlet 62 is connected to the post-deodorization packed tower 7. The first secondary steam outlet 22 and the second secondary steam outlet 52 are respectively connected to the secondary steam inlet 63. The first secondary steam outlet 22 of the first heat exchanger 2 and the second secondary steam outlet 52 of the heater 5 can either be combined and connected together to the secondary steam inlet 63 of the pre-deodorization packed tower 6, or they can be separately connected to the pre-deodorization packed tower 6. The pre-packed tower steam outlet 64 is connected to the vacuum system inlet 11 of the trap.

[0043] In the system provided in Embodiment 1 of this utility model, the pre-deodorization packed tower 6 is located above the deodorization plate tower 3 and is connected through an internal flow channel. After the heat exchanged oil from the cold test oil outlet 24 of the first heat exchanger enters the oil inlet 31 of the plate tower, the "secondary steam" that flashes out is volatilized in the deodorization plate tower 3 and flows through the internal flow channel to the lower stripping steam inlet (not shown) of the pre-deodorization packed tower 6, and then enters the pre-deodorization packed tower 6.

[0044] In the system provided in Embodiment 1 of this utility model, the deodorized packed tower 7 includes a packed tower oil inlet 71, a packed tower oil outlet 72, a fresh stripping gas second inlet 73, and a packed tower vacuum outlet 74. The packed tower oil inlet 71 is connected to the pre-deodorized packed tower 6, specifically, it is connected to the pre-deodorized packed tower oil outlet 62. The packed tower oil outlet 72 is connected to the second heat exchanger 4, specifically, it is connected to the high-temperature oil outlet 44. The packed tower vacuum outlet 74 is connected to the trap vacuum system inlet 11.

[0045] In the system provided in Embodiment 1 of this utility model, the oil phase employs a dual-temperature distillation technique to separate Vitamin E (to ensure the quality indicators of the edible oil, such as low trans acid and low glycidyl esters, a low-temperature, long-time plate tower deodorization process must be used (high-temperature, long-time reactions are detrimental to the quality indicators of the finished oil); and a high-temperature, short-time distillation process is also used). To maximize the yield of tocopherol (Ve) during distillation, high-temperature steam stripping is necessary. Therefore, to balance oil quality and high tocopherol (Ve) yield, Embodiment 1 of this application employs a dual-temperature deodorization and separation distillation method. The working process of the system provided by this utility model is as follows: The system for saving stripping steam in oil refining and Ve separation provided in this embodiment is "a dual-temperature deodorization and Ve separation system. According to the process of the raw material decolorized oil, the first plate tower is used for low-temperature long-term deodorization, and the second high-temperature short-time deodorization and Ve separation is used in a double distillation packed tower".

[0046] For the sake of process convenience, dual-temperature deodorization usually follows a low-temperature-then-high-temperature process. Alternatively, it can be done by first using a low-temperature packed tower combined with a plate tower, followed by a high-temperature packed tower for a short time and then distillation separation.

[0047] The process flow of the oil circuit is as follows: 110℃ decolorizing oil enters the first heat exchanger 2 from the decolorizing oil pipeline 1 through the decolorizing cleaning oil inlet 23. After passing through the first heat exchanger, the oil temperature reaches 220℃ at the cold test oil outlet 24 and enters the deodorizing plate tower 3 for low-temperature deodorization, with an absolute pressure of approximately 1-2 mbar. The oil after low-temperature deodorization in the deodorizing plate tower 3 enters the second heat exchanger 4 from the plate tower oil outlet 33 through the second oil pump 9. The low-temperature oil outlet 42 reaches a temperature of 245℃, and then enters the heater 5 through the heater oil inlet 53. In the heater 5, the oil temperature is heated to 268℃, with an absolute pressure of approximately 2-4 mbar. To improve the heat exchange effect, approximately 0.06% stirring steam is added to the heater 5. 268℃ high-temperature oil enters the pre-deodorizing packed tower 6 from the heater oil outlet 54 through the pre-packed tower oil inlet 61, and then the hot oil exits from the pre-packed tower oil outlet 6. 2. The oil enters the deodorized packed tower 7 through the oil inlet 71 of the packed tower (the oil flows downward in the space of the pre-deodorized packed tower 6, is collected and separated by a special collection tray, and then leads to the pre-packed tower oil outlet 62 through the oil pipe). The high-temperature oil enters the second heat exchanger 4 through the high-temperature oil inlet 43 after passing through the oil outlet 72 of the packed tower. The high-temperature oil is heated to about 244°C and flows out from the high-temperature oil outlet 44. It then enters the first heat exchanger 2 through the hot side oil inlet 25 of the first heat exchanger. In order to enhance the heat exchange effect, about 0.08% of the oil volume of stirring steam is added to the first heat exchanger 2 through the first stirring steam inlet 21. After passing through the first heat exchanger 2, the hot oil temperature drops to 136°C. The deodorized oil comes out from the hot side oil outlet 26 of the first heat exchanger and is pumped to the subsequent finished oil cooling stage through the outlet of the first oil pump 8.

[0048] This first example uses a 1000tpd refining line with a dual-temperature deodorization process, featuring double packed towers and an intermediate plate tower before and after the process: (Channel A) Stirring steam (gauge pressure 0.1-0.2MPa) is added to the second stirring steam inlet 51 of heater 5. The amount of waste gas (secondary steam) coming out from the second secondary steam outlet 52 to the secondary steam inlet 63 of the pre-deodorization packed tower 6 is about 42,000 kg / h * (0.01 + 0.06)% = 29.4 kg / h. (Channel B) The deodorized high-temperature oil at approximately 268°C enters the shell of the second heat exchanger 4 from the oil outlet 72 of the post-deodorization packed tower 7 for heat exchange. To increase the heat exchange effect, stirring steam (gauge pressure 0.1-0.2MPa) needs to be added to the first stirring steam inlet 21 of the first heat exchanger 2. The amount of stirring steam added is approximately 0.06% of the oil volume. The amount of waste gas (secondary steam) from the first secondary steam outlet 22 of the first heat exchanger 2 to the secondary steam inlet 63 of the pre-deodorization packed tower 6 is approximately 42,000 kg / hour * 0.08% = 33.6 kg / hour. (Channel C) After the heat exchanged oil from the cold test oil outlet 24 of the first heat exchanger enters the oil inlet 31 of the plate tower, the "secondary steam" that flashes out is volatilized in the deodorization plate tower 3 and flows through the internal flow channel (steam channel) to the lower stripping steam inlet of the packing tower 6 before deodorization. The water vapor in this part of the flash waste gas is about 42,000 kg / h * 0.06% = 25.2 kg (secondary steam) / h; the splashed oil is about 42,000 kg / h * 0.1% = 42 kg / h.

[0049] The three channels A, B, and C above enter the deodorization packed tower, which is the steam generated by the "stripping steam" of the packed tower: 29.4 + 33.6 + 25.2 = 88.2 kg + splashed oil 25 kg) / hour. At the same time, about 25 kg / hour of splashed oil from this secondary steam enters the packed tower and is fully recovered.

[0050] Fresh stripping steam: In this example, the total amount of stripping steam required for the deodorization Ve separation process is about 150 kg / hour; at the first fresh stripping steam inlet 32 ​​of the deodorization plate tower 3, fresh stripping steam needs to be supplemented by 150-88.2=61.8 kg / hour.

[0051] Because the deodorization and Ve separation processes require a certain quantity of "stripping steam", this patent provides a partial alternative to the "stripping steam" through the aforementioned channels, saving a large amount of fresh "stripping steam" and reducing a large amount of waste gas emissions; the "stripping steam" used for deodorization and Ve separation is provided by secondary steam inlet 63, and other insufficient fresh stripping steam is supplemented by first inlet 32, etc.

[0052] The sources of “secondary steam” are: (a) the moisture generated by the evaporation of decolorized oil from the first heat exchanger 2 or heater 5, either alone or together; (b) the stirring steam added to the first heat exchanger 2 and the second heat exchanger 4 to improve heat exchange efficiency; (c) the “secondary steam” that is desorbed in the low-temperature deodorization plate tower 3 after passing through the first heat exchanger 2 to reduce oil splashing in the dual-temperature deodorization process; and (d) the secondary steam that enters the pre-deodorization packed tower 6 from the deodorization plate tower 3.

[0053] Because "secondary steam" turns waste into treasure, it recovers splashed oil, improves product yield, and replaces part of the fresh "stripping steam." This reduces the total load on the total fatty acid trap and vacuum system. The reduction in total load will reduce the power consumption of the power steam and refrigeration unit, and also reduce the amount of wastewater discharged.

[0054] It should be noted that the field used is dual-temperature deodorization system, which also includes dual-temperature deodorization systems, in addition to those used in tocopherol (Ve) distillation systems, as well as deodorization systems with distillation deacidification functions.

[0055] The oil circuit adopts a dual-temperature deodorization system, which first involves a low-temperature, long-duration plate tower reaction, followed by a high-temperature, short-duration dual-packed distillation tower. Oil circuits with similar functions, such as a low-temperature pre-packed tower and low-temperature plate tower followed by a high-temperature simple post-packed tower, are also considered energy-saving methods protected by this utility model, as long as the gas circuit method is consistent with the overall scheme. Example 2

[0056] like Figure 2 The second embodiment of the present invention provides a system for saving stripping steam in oil refining and Ve separation. The system includes, in the direction of the oil path, a decolorized oil pipeline 1, a first heat exchanger 2, a heater 5, a pre-deodorization packed tower 6, and a deodorization plate tower 3 connected in sequence.

[0057] The first heat exchanger 2 includes a first secondary steam outlet 22, and the heater 5 includes a second secondary steam outlet 52. The first secondary steam outlet 22 and the second secondary steam outlet 52 are respectively connected to the pre-deodorization packed tower 6 or the deodorization plate tower 3.

[0058] In the system provided by this utility model embodiment, the first heat exchanger 2 further includes a decolorizing oil inlet 23, a first heat exchanger cold test oil outlet 24, a stirring steam first inlet 21, a first heat exchanger hot side oil inlet 25, and a first heat exchanger hot side oil outlet 26. The decolorizing oil inlet 23 is connected to the decolorizing oil pipeline 1, the first heat exchanger cold test oil outlet 24 is connected to the heater 5, and the deodorizing plate tower 3 is connected to the first heat exchanger hot side oil inlet 25.

[0059] The first heat exchanger 2 may include more stages of heat exchange and may also include various forms, such as a horizontal floating head type, a plate heat exchanger during welding, or a high-temperature falling film heat exchanger, etc.

[0060] The system provided in this embodiment of the present invention also includes a first oil pump 8, and the hot side oil outlet 26 of the first heat exchanger is connected to the subsequent cooling inlet 10 of the deodorized oil through the first oil pump 8.

[0061] In the system provided by this embodiment of the present invention, the heater 5 further includes a heater oil inlet 53, a high-pressure heating steam inlet 55, a high-pressure condensate outlet 56, a second stirring steam inlet 51, and a heater oil outlet 54. The heater oil inlet 53 is connected to the first heat exchanger 2, specifically, the heater oil inlet 53 is connected to the cold test oil outlet 24 of the first heat exchanger. The heater oil outlet 54 is connected to the pre-deodorization packed tower 6.

[0062] In the system provided by this embodiment of the utility model, the pre-packed tower 6 for deodorization includes a pre-packed tower oil inlet 61, a secondary steam inlet 63, and a pre-packed tower steam outlet 64. The pre-packed tower oil inlet 61 is connected to the heater 5, specifically, the pre-packed tower oil inlet 61 is connected to the heater oil outlet 54. The pre-packed tower oil outlet 62 is connected to the deodorization plate tower 3, the first secondary steam outlet 22 and the second secondary steam outlet 52 are respectively connected to the secondary steam inlet 63, and the pre-packed tower steam outlet 64 is connected to the trap vacuum system inlet 11.

[0063] In the system provided by this utility model embodiment, the pre-deodorization packed tower 6 is located above the deodorization plate tower 3. After the oil enters from the oil inlet of the pre-packed tower, it further enters the deodorization plate tower 3 through the internal oil pipeline.

[0064] In the system provided by this embodiment of the present invention, the deodorization plate tower 3 includes a first fresh stripping steam inlet 32, a plate tower oil outlet 33, and a secondary stripping gas inlet 34. The plate tower oil outlet 33 is connected to the first heat exchanger 2, specifically, the plate tower oil outlet 33 is connected to the hot-side oil inlet 25 of the first heat exchanger. The secondary stripping gas inlet 34 is connected to the first secondary steam outlet 22 and the second secondary steam outlet 52 respectively (another embodiment is not shown).

[0065] like Figure 2 It is "a combined tower structure consisting of a single-temperature deodorization system, an upper pre-deodorization packed tower (6 towers), and a lower deodorization plate tower (3 towers)"; the case study uses a 600 tpd refining line as an example: In this case, the oil flow is as follows: 108℃ decolorizing oil enters the first heat exchanger 2, where it exchanges heat with the high-temperature deodorizing oil (shell side), raising the temperature of the decolorizing oil (tube side) to 215℃. The 215℃ decolorizing oil then enters the heater 5. In the heater 5, the hot phase high-pressure steam flows through the tube side, while the cold phase decolorizing oil flows through the shell side. Stirring steam is added to the shell side to increase the heat exchange effect (approximately 0.06% of the oil volume). The decolorizing oil is heated to approximately 238℃ in the heater 5, and the hot oil exits from the heater oil outlet 54 into the pre-deodorization packed tower. 6. The oil further enters the pre-deodorization packed tower 6 for stripping and separation, and then passes through the deodorization plate tower 3 for deodorization (the oil falls downward in the space (gas chamber) of the pre-deodorization packed tower 6, is collected and separated by a special collection tray, and then leads to the plate tower oil outlet 33 through the oil pipe of the deodorization plate tower 3). The deodorized oil enters the hot side oil inlet 25 of the first heat exchanger from the plate tower oil outlet 33. After heat exchange in the first heat exchanger 2, the deodorized hot oil is cooled to about 133°C, and then is transported to the subsequent deodorized oil cooling system through the pump outlet of the first oil pump 8.

[0066] The main components involved in this case are gas phase flow channel equipment, which are described as follows: (Channel A): Stirring steam (gauge pressure 0.1-0.2MPa) is added to the second stirring steam inlet 51 of heater 5. The exhaust gas exits from the second secondary steam outlet 52 and passes through the pipeline to the secondary steam inlet 63 at the bottom of the packing tower 6 before deodorization. The exhaust gas (secondary steam) from heater 5 contains approximately 32.5 kg / hour of water vapor and approximately 20 kg / hour of splashed oil. (Channel B) Stirring steam (gauge pressure 0.1-0.2MPa) is added to the first stirring steam inlet 21 of the first heat exchanger 2. Waste gas (secondary gas) is discharged from the steam outlet of the first secondary steam outlet 22 of the first heat exchanger 2. The waste gas exits from the first secondary steam outlet 22 and passes through the pipeline to the secondary steam inlet 63 at the bottom of the packing tower 6 before deodorization. The water vapor in the waste gas (secondary steam) from the high temperature intermediate heat exchanger is about 20kg / hour. The two channels A and B above enter the pre-deodorization packed tower 6, and the total amount of secondary steam for the "stripping steam" of the pre-deodorization packed tower 6 is approximately 32.5 + 20 = 52.5 kg / hour. At the same time, about 25 kg / hour of splashed oil in this secondary steam enters the pre-deodorization packed tower 6 and is recovered.

[0067] Fresh stripping steam: In this example, the total stripping steam required for the deodorization process is about 100 kg / hour; at the steam inlet 61 of the deodorization plate tower 3, fresh stripping steam needs to be added by 100-32.5-20=47.5 kg / hour.

[0068] Because "secondary steam" turns waste into treasure, it recovers splashed oil, improves product yield, and replaces part of the fresh "stripping steam." This reduces the total load on the total fatty acid trap and vacuum system. The reduction in total load will reduce the power consumption of the power steam and refrigeration unit, and also reduce the amount of wastewater discharged.

[0069] In summary, this application effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0070] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A system for saving stripping steam in oil refining and Ve separation, characterized in that, The system includes, in the direction of the oil path, a decolorized oil pipeline (1), a first heat exchanger (2), a deodorization plate tower (3), a second heat exchanger (4), a heater (5), a pre-deodorization packed tower (6), and a post-deodorization packed tower (7), which are connected in sequence. The first heat exchanger (2) includes a first outlet (22) of secondary steam, and the heater (5) includes a second outlet (52) of secondary steam. The first outlet (22) and the second outlet (52) of secondary steam are respectively connected to the pre-deodorization packed tower (6) or the deodorization plate tower (3).

2. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, The first heat exchanger (2) further includes a decolorizing oil inlet (23), a first heat exchanger cold test oil outlet (24), a stirring steam first inlet (21), a first heat exchanger hot side oil inlet (25), and a first heat exchanger hot side oil outlet (26); the decolorizing oil inlet (23) is connected to the decolorizing oil pipeline (1), the first heat exchanger cold test oil outlet (24) is connected to the deodorizing plate tower (3), and the second heat exchanger (4) is connected to the first heat exchanger hot side oil inlet (25).

3. The system for saving stripping steam in oil refining and Ve separation according to claim 2, characterized in that, It also includes a first oil pump (8), and the hot side oil outlet (26) of the first heat exchanger is connected to the subsequent cooling inlet (10) of the deodorized oil through the first oil pump (8).

4. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, The deodorization plate tower (3) includes a plate tower oil inlet (31), a fresh stripping steam first inlet (32), a plate tower oil outlet (33), and a secondary stripping gas inlet (34). The plate tower oil inlet (31) is connected to the first heat exchanger (2), the plate tower oil outlet (33) is connected to the second heat exchanger (4), and the secondary steam first outlet (22) and secondary steam second outlet (52) are respectively connected to the secondary stripping gas inlet (34).

5. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, It also includes one or more of the following conditions: A1) The second heat exchanger (4) includes a low-temperature oil inlet (41), a low-temperature oil outlet (42), a high-temperature oil inlet (43), and a high-temperature oil outlet (44). The low-temperature oil inlet (41) is connected to the deodorization plate tower (3), the low-temperature oil outlet (42) is connected to the heater (5), the high-temperature oil inlet (43) is connected to the deodorized packed tower (7), and the high-temperature oil outlet (44) is connected to the first heat exchanger (2). A2) The deodorization plate tower (3) and the second heat exchanger (4) are connected by a second oil pump (9).

6. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, The heater (5) also includes a heater oil inlet (53), a high-pressure heating steam inlet (55), a high-pressure condensate outlet (56), a second stirring steam inlet (51), and a heater oil outlet (54). The heater oil inlet (53) is connected to the second heat exchanger (4), and the heater oil outlet (54) is connected to the deodorization pre-packed tower (6).

7. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, The pre-deodorization packed tower (6) includes a pre-packed tower oil inlet (61), a pre-packed tower oil outlet (62), a secondary steam inlet (63), and a pre-packed tower steam outlet (64). The pre-packed tower oil inlet (61) is connected to the heater (5), the pre-packed tower oil outlet (62) is connected to the post-deodorization packed tower (7), the first secondary steam outlet (22) and the second secondary steam outlet (52) are respectively connected to the secondary steam inlet (63), and the pre-packed tower steam outlet (64) is connected to the vacuum system inlet (11) of the trap.

8. The system for saving stripping steam in oil refining and Ve separation according to claim 1, characterized in that, It also includes one or more of the following conditions: B1) The deodorized packed tower (7) includes a packed tower oil inlet (71), a packed tower oil outlet (72), a fresh stripping gas second inlet (73), and a packed tower vacuum outlet (74). The packed tower oil inlet (71) is connected to the deodorized packed tower (6), the packed tower oil outlet (72) is connected to the second heat exchanger (4), and the packed tower vacuum outlet (74) is connected to the trap vacuum system inlet (11). B2) The pre-deodorization packed tower (6) is located above the deodorization plate tower (3) and is connected through an internal flow channel.

9. A system for saving stripping steam in oil refining and Ve separation, characterized in that, The system includes, in the direction of the oil path, a decolorized oil pipeline (1), a first heat exchanger (2), a heater (5), a pre-deodorization packed tower (6), and a deodorization plate tower (3) connected in sequence. The first heat exchanger (2) includes a first outlet (22) of secondary steam, and the heater (5) includes a second outlet (52) of secondary steam. The first outlet (22) and the second outlet (52) of secondary steam are respectively connected to the pre-deodorization packed tower (6) or the deodorization plate tower (3).

10. The system for saving stripping steam in oil refining and Ve separation according to claim 9, characterized in that, It also includes one or more of the following conditions: C1) The first heat exchanger (2) further includes a decolorizing oil inlet (23), a first heat exchanger cold test oil outlet (24), a stirring steam first inlet (21), a first heat exchanger hot side oil inlet (25), and a first heat exchanger hot side oil outlet (26); the decolorizing oil inlet (23) is connected to the decolorizing oil pipeline (1), the first heat exchanger cold test oil outlet (24) is connected to the heater (5), and the deodorizing plate tower (3) is connected to the first heat exchanger hot side oil inlet (25); it also includes a first oil pump (8), and the first heat exchanger hot side oil outlet (26) is connected to the deodorizing oil subsequent cooling inlet (10) through the first oil pump (8); C2) The heater (5) further includes a heater oil inlet (53), a high-pressure heating steam inlet (55), a high-pressure condensate outlet (56), a second stirring steam inlet (51), and a heater oil outlet (54). The heater oil inlet (53) is connected to the first heat exchanger (2), and the heater oil outlet (54) is connected to the deodorization pre-packed tower (6). C3) The deodorization pre-packed tower (6) includes a pre-packed tower oil inlet (61), a secondary steam inlet (63), and a pre-packed tower steam outlet (64). The pre-packed tower oil inlet (61) is connected to the heater (5). The first secondary steam outlet (22) and the second secondary steam outlet (52) are respectively connected to the secondary steam inlet (63). The pre-packed tower steam outlet (64) is connected to the trap vacuum system inlet (11). C4) The pre-deodorization packed tower (6) is located above the deodorization plate tower (3); C5) The deodorization plate tower (3) includes a fresh stripping steam first inlet (32), a plate tower oil outlet (33), and a secondary stripping gas inlet (34). The plate tower oil outlet (33) is connected to the first heat exchanger (2), and the secondary stripping gas inlet (34) is connected to the secondary steam first outlet (22) and the secondary steam second outlet (52) respectively.

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