A device for recycling the heavy fraction waste liquid after desulfurization of MTBE products

Abstract

The present invention relates to a device for recycling heavy fraction waste liquid after desulfurization of MTBE products, which includes a desulfurization tower, a recovery tank and a reaction device. A heavy fraction waste liquid outlet is provided at the bottom of the desulfurization tower, and the heavy fraction waste liquid outlet communicates with the feed inlet of the recovery tank. An air outlet is provided at the top of the recovery tank, and the air outlet communicates with the air inlet of the desulfurization tower. There is also a discharge port at the bottom of the recovery tank, and the discharge port is connected to a hydrogenation reactor through a pipeline; the reaction device includes a heavy oil riser reactor, a gas-solid separation system and a circulation regeneration system; the gas-solid separation system includes a cyclone separator, a settler and a stripping device; the circulation regeneration system includes a spent catalyst standpipe, a regenerator and a regenerated catalyst standpipe. The present invention has the beneficial effects of simple structure, convenient use, avoiding the sulfur content of MTBE products exceeding the standard, reducing the treatment difficulty of oily sewage, realizing the recycling of heavy fraction waste liquid, saving energy and protecting the environment, etc.

Description

Technical Field

[0001] The present invention relates to a recycling device, in particular to a recycling device for heavy fraction waste liquid after desulfurization of MTBE products, and belongs to the technical field of petrochemical industry. Background Art

[0002] Methyl tert-butyl ether (MTBE) is an ideal blending component for producing unleaded, high-octane, oxygenated gasoline. It has good compatibility with gasoline, which can not only improve the combustion efficiency and anti-knock performance of gasoline, but also reduce the emissions of CO and other harmful substances (such as ozone, benzene, butadiene, etc.). MTBE can also be used as a solvent for paraffin, oil products, spices, alkaloids, resins, rubber, a reactant for organic synthesis, and can also be cracked to prepare high-purity isobutene.

[0003] With the rapid development of the automotive industry, the pollution of automobile exhaust has attracted increasing attention. To protect the environment, countries around the world have put forward more stringent requirements for the composition of vehicle fuels to reduce the emissions of harmful substances, and the limit on the sulfur content in vehicle gasoline is even more stringent. In recent years, China's vehicle gasoline standards have also been gradually tightened. For example, the sulfur content requirement for gasoline in National V is below 10 ppm. In the prior art, when producing MTBE products for desulfurization, in order to ensure the qualification of MTBE products, desulfurizing agents are often added, resulting in some high-sulfur heavy fraction waste liquid, which increases the difficulty of treating oily sewage. Moreover, the heavy fraction waste liquid will accumulate at the bottom of the desulfurization tower. Since the bottom temperature of the desulfurization tower is maintained at about 70 - 80 °C, if the heavy fraction waste liquid is not discharged in time, steam will be generated from the waste liquid at this high temperature, polluting the finished product, and then leading to an abnormal increase in the sulfur content of the finished MTBE product. Summary of the Invention

[0004] The present invention mainly aims at the above problems existing in the prior art, and provides a recycling device for heavy fraction waste liquid after desulfurization of MTBE products. The device has a simple structure, is easy to use, avoids the sulfur content of MTBE products exceeding the standard, reduces the difficulty of treating oily sewage, realizes the recycling of heavy fraction waste liquid, and is energy-saving and environmentally friendly.

[0005] The object of the present invention is mainly achieved by the following solution:

[0006] A device for recycling heavy fraction waste liquid after desulfurization of MTBE products, comprising a desulfurization tower, a recovery tank and a reaction device. The bottom of the desulfurization tower is provided with a heavy fraction waste liquid outlet, and the heavy fraction waste liquid outlet communicates with the feed inlet on the recovery tank through a first pipeline. The top of the recovery tank is provided with an air outlet, and the air outlet communicates with the air inlet in the middle of the desulfurization tower through a second pipeline. The bottom of the recovery tank is also provided with a discharge outlet, and the discharge outlet is connected to a hydrogenation reactor through a third pipeline. The reaction device includes a heavy oil riser reactor, a gas-solid separation system and a circulating regeneration system. The heavy oil riser reactor is composed of a lower riser, a middle riser and an upper riser connected in sequence from bottom to top. The bottom of the lower riser is provided with a lifting steam inlet, and the middle of the lower riser is provided with a catalyst inlet and an oil inlet above the catalyst inlet. The oil inlet is connected to the outlet of the hydrogenation reactor. The gas-solid separation system includes a cyclone separator, a settler and a stripping device. The port of the upper riser communicates with the inside of the settler. The cyclone separator and the settler are both located above the stripping device, and the upper end of the cyclone separator is connected to a collection chamber, and the lower end is connected to the stripping device. The circulating regeneration system includes a spent catalyst slant pipe, a regenerator and a regenerated catalyst slant pipe. The lower end of the stripping device is provided with a catalyst outlet, and the regenerator is connected to the catalyst outlet through the spent catalyst slant pipe. One end of the regenerated catalyst slant pipe communicates with the lower end of the regenerator, and the other end communicates with the catalyst inlet.

[0007] By adopting the above technical solution, the heavy fraction waste liquid can be discharged from the desulfurization tower in time, avoiding the excessive sulfur content in the MTBE product. The MTBE evaporated through the recovery tank enters the air inlet in the middle section of the desulfurization tower through the air outlet and is desulfurized again in the desulfurization tower, saving resources and avoiding waste of MTBE products. A heavy oil riser reactor is provided, and the waste liquid undergoes a catalytic cracking reaction, which not only reduces the treatment load of the oil sump, but also produces valuable combustible gas through the reaction, which is both energy-saving and environmentally friendly.

[0008] Preferably, saddle supports are symmetrically arranged at the bottom of the recovery tank, and a maintenance manhole and a liquid level gauge interface are arranged at the top of the recovery tank.

[0009] By adopting the above technical solution, the saddle supports ensure the stability of the recovery tank. The maintenance manhole facilitates the inspection by maintenance personnel, and the liquid level gauge interface is used to place a liquid level gauge to observe the liquid level in the recovery tank.

[0010] Preferably, a steam coil is arranged inside the recovery tank, and the lower end of the steam coil is a steam inlet and the upper end is a steam outlet. A temperature monitoring device is also arranged inside the recovery tank.

[0011] By adopting the above technical solution, the steam coil is used to heat the waste liquid, and MTBE evaporates and enters the desulfurization tower, avoiding waste of MTBE products.

[0012] Preferably, the middle riser is a diameter-expanded pipe, the upper riser and the lower riser have the same diameter, and the diameter of the middle riser is 2-5 times that of the upper riser or the lower riser.

[0013] By adopting the above technical solution, the diameter-expanded pipe makes the residence time of the oil agent longer and enables sufficient mixing and contact, fully completing the secondary reaction of the waste liquid (i.e., the reforming cracking with a long contact time).

[0014] Preferably, high-pressure nozzles are inserted into the upper side walls of the middle riser and the lower riser. One end of each high-pressure nozzle is connected to a nozzle arranged inside the middle riser and the lower riser, and the other end is communicated with the third pipeline through a fourth pipeline.

[0015] By adopting the above technical solution, the heavy fraction waste liquid raw material is used to clean the heavy oil riser reactor, preventing other impurities from entering.

[0016] Preferably, a recovery pipe is further connected to the lower riser. The recovery pipe is located between the oil inlet and the high-pressure nozzle on the lower riser. The recovery pipe is externally connected to a filtration tower, and the lower end of the filtration tower is communicated with the third pipeline through a fifth pipeline.

[0017] By adopting the above technical solution, molecular sieves are arranged in the filtration tower to filter coke lumps, ensuring that the recovered liquid is free of impurities.

[0018] Preferably, the distance between the connection of the fourth pipeline and the third pipeline and the hydrogenation reactor is greater than the distance between the connection of the fifth pipeline and the third pipeline and the hydrogenation reactor.

[0019] Preferably, a stop valve is further arranged on the lower riser. The stop valve is located below the connection of the recovery pipe and the lower riser and above the oil inlet.

[0020] By adopting the above technical solution, the cleaning liquid is prevented from flowing to the lower part of the lower riser.

[0021] Preferably, an oil-gas separation system is externally connected to the collection chamber.

[0022] Preferably, a pressure gauge port is arranged on the recovery tank, and the pressure gauge port is connected to a pressure monitoring device.

[0023] By adopting the above technical solution, the pressure monitoring device is used to detect the pressure inside the recovery tank, ensuring the normal operation of the device.

[0024] Therefore, the present invention has the following advantages: (1) The structure of the present invention is simple and convenient to use. The recycling tank is used to distill the heavy fraction waste liquid again and reflux MTBE, improving the utilization rate of MTBE; (2) The present invention adopts hydrocatalytic cracking. All high-sulfur waste liquids pass through the residual liquid recovery process of the catalytic workshop and undergo the reaction in the heavy oil riser pipe. This not only reduces the treatment load of the sewage oil tank, but also produces combustible oil and gas with beneficial value through the reaction, which is both energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of the present invention;

[0026] Figure 2 is a schematic structural diagram of the recycling tank of the present invention;

[0027] Figure 3 is a schematic structural diagram of the reaction device of the present invention.

[0028] Illustration: 1 - desulfurization tower, 2 - recycling tank, 3 - heavy fraction waste liquid outlet, 4 - first pipeline, 5 - feed inlet, 6 - gas outlet, 7 - second pipeline, 8 - air inlet, 9 - discharge outlet, 10 - third pipeline, 11 - hydrocracking reactor, 12 - lower riser pipe, 13 - middle riser pipe, 14 - upper riser pipe, 15 - lifting steam inlet, 16 - catalyst inlet, 17 - oil inlet, 18 - cyclone separator, 19 - settler, 20 - stripping device, 21 - spent catalyst inclined pipe, 22 - regenerator, 23 - regenerated catalyst inclined pipe, 24 - catalyst outlet, 25 - saddle, 26 - maintenance manhole, 27 - liquid level gauge interface, 28 - steam coil, 29 - steam inlet, 30 - steam outlet, 31 - temperature monitoring device, 32 - high-pressure nozzle, 33 - nozzle, 34 - fourth pipeline, 35 - recovery pipe, 36 - filtration tower, 37 - fifth pipeline, 38 - check valve, 39 - collection chamber, 40 - pressure gauge port, 41 - pressure monitoring device. DETAILED DESCRIPTION OF THE INVENTION

[0029] The technical solution of the present invention will be further specifically described below through examples in combination with the drawings.

[0030] As Figure 1 、 2As shown in the figure, the present invention provides a technical solution, a device for recycling heavy fraction waste liquid after MTBE product desulfurization, which includes a desulfurization tower 1, a recovery tank 2 and a reaction device. A heavy fraction waste liquid outlet 3 is provided at the bottom of the desulfurization tower. The heavy fraction waste liquid outlet 3 communicates with a feed inlet 5 on the recovery tank 2 through a first pipeline 4. An air outlet 6 is provided at the top of the recovery tank 2. The air outlet 6 communicates with an air inlet 8 in the middle of the desulfurization tower 1 through a second pipeline 7. A discharge outlet 9 is further provided at the bottom of the recovery tank 2. The discharge outlet 9 is connected to a hydrogenation reactor 11 through a third pipeline 10. Saddle supports 25 are symmetrically provided at the bottom of the recovery tank 2. A maintenance manhole 26 and a liquid level gauge interface 27 are provided at the top of the recovery tank 2. A steam coil 28 is provided inside the recovery tank 2. The lower end of the steam coil 28 is a steam inlet 29, and the upper end is a steam outlet 30. A temperature monitoring device 31 is further provided inside the recovery tank 2. A pressure gauge port 40 is provided on the recovery tank 2. The pressure gauge port 40 is connected to a pressure monitoring device 41.

[0031] As Figure 3As shown in the figure, the reaction device includes a heavy oil riser reactor, a gas-solid separation system, and a recycle regeneration system. The heavy oil riser reactor consists of a lower riser 12, a middle riser 13, and an upper riser 14 that are connected in sequence from bottom to top. The middle riser 13 is a diameter-expanded pipe. The diameters of the upper riser 14 and the lower riser 12 are equal, and the diameter of the middle riser 13 is 3 times the diameter of the upper riser 14 or the lower riser 12. A lifting steam inlet 15 is provided at the bottom of the lower riser 12, and a catalyst inlet 16 and an oil inlet 17 above the catalyst inlet 16 are provided in the middle of the lower riser 12. The oil inlet 17 is connected to the outlet of the hydrogenation reactor 11. The gas-solid separation system includes a cyclone separator 18, a settler 19, and a stripping device 20. The port of the upper riser 14 is connected to the inside of the settler 19. The cyclone separator 18 and the settler 19 are both located above the stripping device 20. A collection chamber 39 is connected to the upper end of the cyclone separator 18. The collection chamber 39 is externally connected to an oil-gas separation system, and the lower end is connected to the stripping device 20. The recycle regeneration system includes a spent catalyst inclined pipe 21, a regenerator 22, and a regenerated catalyst inclined pipe 23. A catalyst outlet 24 is opened at the lower end of the stripping device 20. The regenerator 22 is connected to the catalyst outlet 24 through the spent catalyst inclined pipe 21. One end of the regenerated catalyst inclined pipe 23 communicates with the lower end of the regenerator 22, and the other end communicates with the catalyst inlet 16. High-pressure nozzles 32 are inserted into the upper side walls of the middle riser 13 and the lower riser 12. One end of the high-pressure nozzle 32 is connected to a nozzle 33 provided inside the middle riser 13 and the lower riser 12, and the other end is connected to the third pipe 10 through a fourth pipe 34. A check valve 38 is also provided on the lower riser 12. The check valve 38 is located below the connection between the recovery pipe 35 and the lower riser 12 and above the oil inlet 17. A recovery pipe 35 is also connected to the lower riser 12. The recovery pipe 35 is located between the oil inlet 17 and the high-pressure nozzle 32 on the lower riser 12. The recovery pipe 35 is externally connected to a filtration tower 36. The lower end of the filtration tower 36 is connected to the third pipe 10 through a fifth pipe 37. The distance between the connection of the fourth pipe 34 and the third pipe 10 and the hydrogenation reactor 11 is greater than the distance between the connection of the fifth pipe 37 and the third pipe 10 and the hydrogenation reactor 11.

[0032] During the production process of the desulfurization tower 1, the heavy fraction waste liquid is collected into the recovery tank 2. The recovery tank is used to distill the heavy fraction waste liquid again and reflux MTBE, improving the utilization rate of MTBE. The heated heavy fraction waste liquid flows out from the discharge port 9, and then flows into the heavy oil riser reactor after reacting in the hydrogenation reactor 11. The lifting steam enters the lower riser 12 through the lifting steam inlet 15, and the hot regenerated catalyst enters the lower riser 12 through the regeneration dipleg 23 and is lifted by the lifting steam; the hydrogenated waste liquid enters the lower riser 12 through the oil inlet 17, mixes with the hot catalyst, and undergoes a high-temperature thermal shock cracking reaction under certain conditions, and enters the middle riser 13 from the lower riser 12, that is, the expanded riser. Due to the expansion of the expanded riser, the residence time of the oil and agent becomes longer and they are fully mixed and contacted, and the secondary reaction (i.e., the reforming cracking with a long contact time) is fully completed; the oil gas and catalyst lifted from the middle riser 13 enter the upper riser 14, and then the reaction stream quickly enters the settler 19 and the cyclone separator 18. The reaction product goes to the separation system through the pipeline of the oil gas separation system. The spent catalyst with carbon after the reaction enters the stripper, is stripped by the steam from the steam pipeline, and then enters the regenerator 22 through the spent catalyst dipleg 21. The hot catalyst after air burning regeneration returns to the lower riser 12 through the regeneration dipleg 23 for recycling; during cleaning, the stop valve 38 is closed, the heavy fraction waste liquid is sprayed into the middle riser 13 and the lower riser 12 through the high-pressure nozzle 32, and then flows into the recovery pipe 35, and is filtered in the filter tower 36. The heavy fraction waste liquid is refluxed to the third pipeline 10 to achieve recycling. All the high-sulfur heavy fraction waste liquid of the present invention passes through the catalytic workshop residual liquid recovery process and undergoes heavy oil riser reaction, which not only reduces the treatment load of the dirty oil tank, but also produces valuable combustible oil gas through the reaction, which is both energy-saving and environmentally friendly.

[0033] It should be understood that this embodiment is only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A device for recycling the heavy fraction waste liquid after desulfurization of MTBE products, characterized in that: The recycling device includes a desulfurization tower (1), a recovery tank (2) and a reaction device. A heavy fraction waste liquid outlet (3) is provided at the bottom of the desulfurization tower. The heavy fraction waste liquid outlet (3) communicates with a feed inlet (5) on the recovery tank (2) through a first pipeline (4). An air outlet (6) is provided at the top of the recovery tank (2). The air outlet (6) communicates with an air inlet (8) in the middle of the desulfurization tower (1) through a second pipeline (7). A discharge outlet (9) is also provided at the bottom of the recovery tank (2). The discharge outlet (9) is connected to a hydrogenation reactor (11) through a third pipeline (10). The reaction device includes a heavy oil riser reactor, a gas-solid separation system and a circulation regeneration system. The heavy oil riser reactor is composed of a lower riser (12), a middle riser (13) and an upper riser (14) which are connected in sequence from bottom to top. A lifting steam inlet (15) is provided at the bottom of the lower riser (12). A catalyst inlet (16) and an oil inlet (17) located above the catalyst inlet (16) are provided in the middle of the lower riser (12). The oil inlet (17) is connected to the outlet of the hydrogenation reactor (11). The gas-solid separation system includes a cyclone separator (18), a settler (19) and a stripping device (20). The port of the upper riser (14) communicates with the inside of the settler (19). Both the cyclone separator (18) and the settler (19) are located above the stripping device (20). The upper end of the cyclone separator (18) is connected to a collection chamber (39), and the lower end is connected to the stripping device (20). The circulation regeneration system includes a spent catalyst inclined pipe (21), a regenerator (22) and a regeneration inclined pipe (23). A catalyst outlet (24) is opened at the lower end of the stripping device (20). The regenerator (22) is communicated with the catalyst outlet (24) through the spent catalyst inclined pipe (21). One end of the regeneration inclined pipe (23) communicates with the lower end of the regenerator (22), and the other end communicates with the catalyst inlet (16). The middle riser (13) is a diameter-expanded pipe, and the diameters of the upper riser (14) and the lower riser (12) are equal. High-pressure spray nozzles (32) are inserted into the upper side walls of the middle riser (13) and the lower riser (12).

2. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 1, characterized in that: Saddle supports (25) are symmetrically provided at the bottom of the recovery tank (2). A maintenance manhole (26) and a liquid level gauge interface (27) are provided at the top of the recovery tank (2).

3. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 2, wherein: A steam coil (28) is provided inside the recovery tank (2). The lower end of the steam coil (28) is a steam inlet (29), and the upper end is a steam outlet (30). A temperature monitoring device (31) is also provided inside the recovery tank (2).

4. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 1, wherein: One end of the high-pressure spray nozzle (32) is connected to a nozzle (33) provided inside the middle riser (13) and the lower riser (12), and the other end is communicated with the third pipeline (10) through a fourth pipeline (34).

5. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 4, wherein: A recovery pipe (35) is also connected to the lower riser pipe (12). The recovery pipe (35) is located between the oil inlet (17) and the high-pressure nozzle (32) on the lower riser pipe (12). The recovery pipe (35) is externally connected to a filtration tower (36). The lower end of the filtration tower (36) is communicated with the third pipe (10) through a fifth pipe (37).

6. The device for recycling the heavy fraction waste liquid after desulfurization of MTBE product according to claim 5, wherein: The distance between the connection of the fourth pipe (34) and the third pipe (10) and the hydrogenation reactor (11) is greater than the distance between the connection of the fifth pipe (37) and the third pipe (10) and the hydrogenation reactor (11).

7. A device for recycling the heavy fraction waste liquid after desulfurization of MTBE products according to claim 6, characterized in that: A stop valve (38) is also provided on the lower riser pipe (12). The stop valve (38) is located below the connection of the recovery pipe (35) and the lower riser pipe (12) and above the oil inlet (17).

8. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 1, characterized in that: The collection chamber (39) is externally connected to an oil-gas separation system.

9. The device for recycling the heavy fraction waste liquid after desulfurization of MTBE product according to claim 3, characterized in that: A pressure gauge port (40) is provided on the recovery tank (2), and the pressure gauge port (40) is connected to a pressure monitoring device (41).

10. The recycling device for the heavy fraction waste liquid after desulfurization of MTBE products according to claim 1, wherein: The diameter of the middle riser pipe (13) is 2 - 5 times the diameter of the upper riser pipe (14) or the lower riser pipe (12).

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