A device for removing silicon organic matters in waste lubricating oil vacuum distillation waste gas

Abstract

This invention discloses a device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas. The device includes a scrubbing tower, an adsorption tower, exhaust gas pipelines, a solution pump, and a makeup pipe. The scrubbing tower contains at least two stages of packing layers. Each stage of packing layer is topped with a distribution plate, which consists of a plate sealed to the tower wall on all four sides and evenly distributed drain pipes on the plate. An inlet pipe, connected to the outlet of the solution pump via a valve, is located on one side of the tower wall above the distribution plate. The adsorbent layer in the adsorption tower has an inlet and an outlet on both sides of its upper end for adsorbent entry and exit. This invention divides a single-stage packing layer into multiple stages, reducing the load-bearing capacity of the packing layer support structure and increasing the scrubbing speed of the exhaust gas. Simultaneously, the distribution plate and the inlet pipes above each stage of packing layer work together to compensate for the loss in packing layer thickness, disperse the scrubbing liquid methylpyrrolidone, and increase the contact area between the scrubbing liquid methylpyrrolidone and the exhaust gas.

Description

Technical Field

[0001] This invention relates to the field of waste lubricating oil treatment technology, specifically to a device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas. Background Technology

[0002] Waste lubricating oil is treated by vacuum distillation to obtain regenerated base oil. During vacuum distillation, a large amount of waste gas at 200-300℃ is generated due to thermal pyrolysis. This waste gas requires further treatment before discharge. The silicon-based organic compounds in the waste gas are insoluble in water and must be burned in a combustion furnace for treatment. During the combustion process, a large amount of silica (white carbon black) generated from the silicone oil is found to be produced inside the furnace. This silica adheres to the heat transfer surfaces inside the furnace and forms scale, leading to reduced heating efficiency and malfunction of the combustion furnace. Therefore, the silicon-based organic compounds in the waste gas must be removed before it enters the combustion furnace to ensure the smooth progress of subsequent combustion treatment.

[0003] CN112619371A discloses a device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas, including a scrubbing tower and an adsorption tower. In the scrubbing tower, methylpyrrolidone is used to scrub the exhaust gas generated from waste lubricating oil vacuum distillation. Then, in the adsorption tower, an adsorbent is used to adsorb the scrubbed exhaust gas, effectively removing silicon-based organic compounds from the waste lubricating oil vacuum distillation exhaust gas. However, during use, it was found that the removal rate of silicon-based organic compounds gradually decreased from 95% to 62%. After overhauling the scrubbing tower and adsorption tower, the following reasons were found: One reason was that the packing layer thickness of the scrubbing tower was insufficient. Increasing the packing layer thickness resulted in a decrease in the scrubbing speed, and the load on the packing layer support plate was too large, causing the packing to fall from the support plate into the scrubbing liquid. Another reason was that the adsorbent at the bottom of the adsorption tower, after adsorbing siloxanes, became saturated and lost its adsorption effect, causing the adsorbate to exit and gradually lose its adsorption effect. Simultaneously, crystallization occurred, reducing the gaps between adsorbent particles and decreasing the adsorption speed. Summary of the Invention

[0004] The purpose of this invention is to provide a device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas, thereby solving the problems existing in the prior art.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] A device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas includes a scrubbing tower, an adsorption tower, an exhaust gas pipeline located between the top of the scrubbing tower and the bottom of the adsorption tower, and a solution pump and a makeup liquid pipe located on the pipeline between the bottom and top of the scrubbing tower.

[0007] The washing tower is provided with at least two packing layers. Each packing layer is provided with a liquid distribution plate above it. The liquid distribution plate is composed of a plate that is sealed and fixed to the tower wall on all four sides and a leakage pipe that is evenly distributed on the plate. A liquid inlet pipe is provided on one side of the tower wall above the liquid distribution plate, which is connected to the liquid outlet of the solution pump through a pipe valve.

[0008] The adsorbent layer inside the adsorption tower is provided with an inlet and an outlet on both sides of the upper end for the adsorbent to enter and exit.

[0009] A further improvement is that the adsorption tower body is a cuboid structure, the cross-section of the adsorbent layer is straight in the middle and semi-circular at both ends, and a vertical plate is provided inside the adsorbent layer. The vertical plate and the support device of the adsorbent layer divide the adsorbent layer into a closed loop channel. A magnetic pusher plate for moving the adsorbent particles is provided inside the adsorbent layer. The magnetic pusher plate moves along the closed loop channel to drive the adsorbent particles to move up and down. Limiting grooves for restricting the movement trajectory of the magnetic pusher plate are provided on both sides of the inner wall of the tower body.

[0010] A further improvement is that the adsorption tower has driving wheels and driven wheels on the opposite outer walls of the tower body, and a transmission component is provided between the driving wheels and driven wheels. An electromagnet is provided on the transmission component to drive the magnetic push plate to move when energized.

[0011] A further improvement is that the drive wheel is driven by a solution-driven structure, which is driven by the pumping flow of a solution pump.

[0012] A further improvement is that a magnetic gate is provided above the closed-loop channel, the support device is matched with the magnetic gate, and electromagnets and linear drives for driving the electromagnets to move up and down are provided on the opposite outer walls of the adsorption tower.

[0013] A further improvement is that the removal device also includes a regenerator for regenerating the detergent and adsorbent using the heat from the vacuum distillation exhaust gas.

[0014] A further improvement is that the regenerator's housing consists of a two-diameter cylindrical body and a tube sheet-type box body located at both ends of the cylindrical body and fixed by flanges;

[0015] The cylinder body is equipped with a straight tube bundle connecting the two tube sheet type boxes, a spiral tube bundle wrapped around the outside of the straight tube bundle, and several fixed tube sheets that fix the two tube bundles. The upper end of the cylinder body is equipped with a gas outlet pipe and a liquid inlet pipe connected to the washing liquid outlet of the washing tower. The lower end of the liquid inlet pipe is equipped with a spray pipe. The lower end of the cylinder body is equipped with a liquid outlet pipe connected to the liquid inlet of the solution pump.

[0016] One of the tube sheet-type boxes is provided with an adsorbent inlet pipe and a solvent inlet pipe. The other tube sheet-type box is provided with two partitions that divide the box into three areas. The tube sheet-type box in the middle area is provided with an adsorbent outlet pipe and a solvent outlet pipe. The upper and lower areas are respectively provided with an exhaust gas inlet pipe and an exhaust gas outlet pipe, and the exhaust gas inlet pipe and the exhaust gas outlet pipe are respectively connected to the beginning and end of the spiral tube bundle.

[0017] A further improvement is that vacuum lines are provided on both the cylinder and the tube sheet-type box with the adsorbent inlet pipe.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) Divide the single-stage packing layer into multiple-stage packing layers to reduce the load-bearing capacity of the packing layer support structure and increase the washing speed of the exhaust gas. At the same time, through the cooperation of the liquid distribution plate and the liquid inlet pipe above each packing layer, the loss in the thickness of the packing layer is compensated, the washing liquid methylpyrrolidone is dispersed, and the contact area between the washing liquid methylpyrrolidone and the exhaust gas is increased.

[0020] (2) The adsorption tower in this invention has a specific shape in the internal adsorbent layer. A closed-loop channel is formed by the vertical plate. Under the movement of the magnetic push plate, the adsorbent at the bottom can be slowly moved to the top. This cycle can prevent the adsorbent at the bottom of the adsorbent layer from contacting the waste gas first, causing oversaturation and loss of adsorption activity. It also prevents premature crystal growth, which would slow down or hinder the adsorption process.

[0021] (3) In the prior art, the methylpyrrolidone used in the washing process needs to be continuously circulated. After a period of operation, new methylpyrrolidone can be directly replaced, or a methylpyrrolidone regeneration device can be added to the circulation pipeline to regenerate the methylpyrrolidone and ensure a long-term high-efficiency washing effect. The adsorbent used in the adsorption process also needs to be replaced regularly. The replaced adsorbent can be regenerated to save raw materials. The regenerator in this invention improves the structure of the multi-stream heat exchanger and applies it to this field, integrating adsorbent regeneration and washing liquid regeneration into one device. It uses the waste lubricating oil vacuum distillation exhaust gas with a certain temperature as a heat source to distill and regenerate the waste adsorbent and waste washing liquid. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas in Example 1;

[0023] Figure 2 This is a schematic diagram of the internal structure of the adsorption tower of the waste lubricating oil vacuum distillation waste gas removal device in Example 2;

[0024] Figure 3 for Figure 2A top-view cross-section diagram of the adsorption tower;

[0025] Figure 4 for Figure 2 Schematic diagram of the external structure of the adsorption tower

[0026] Figure 5 This is a schematic diagram of the device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas in Example 3;

[0027] Figure 6 This is a schematic diagram of the internal structure of the regenerator in Example 3;

[0028] Figure 7 for Figure 6 A partial structural diagram of the regenerator.

[0029] Illustration: 100, Scrubber; 110, Packing layer; 120, Liquid distribution tray; 130, Inlet pipe;

[0030] 200. Adsorption tower; 210. Feed inlet; 220. Discharge outlet; 230. Adsorbent layer; 231. Support device; 232. Vertical plate; 233. Magnetic push plate; 234. Limiting groove; 235. Magnetic gate; 2351. Electromagnet II; 2352. Linear drive; 236. Driven wheel; 237. Transmission component; 238. Electromagnet I; 239. Drive wheel;

[0031] 300. Solution pump;

[0032] 400. Infusion tubing;

[0033] 500. Regenerator; 510. Straight tube bundle; 511. Adsorbent inlet; 512. Solvent inlet; 513. Adsorbent outlet; 514. Solvent outlet; 520. Spiral tube bundle; 521. Waste gas inlet; 522. Waste gas outlet; 530. Cylinder; 531. Liquid inlet; 532. Spray pipe; 533. Liquid outlet; 534. Gas outlet; 540. Fixed tube sheet; 550. Vacuum piping; 560. Baffle plate;

[0034] 600. Solution-driven structure. Detailed Implementation

[0035] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0036] Example 1

[0037] like Figure 1As shown, the device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas in this embodiment includes a scrubbing tower 100, an adsorption tower 200, an exhaust gas pipeline located between the top of the scrubbing tower 100 and the bottom of the adsorption tower 200, and a solution pump 300 and a replenishment pipe 400 located on the pipeline between the bottom and top of the scrubbing tower 100. Methylpyrrolidone, a scrubbing liquid, is introduced into the scrubbing tower 100, and the introduced methylpyrrolidone is continuously pumped out and returned by the solution pump 300 for circulation. The exhaust gas generated from the vacuum distillation of waste lubricating oil is then introduced into the scrubbing tower 100 from the bottom. The exhaust gas flows upward and comes into full contact with the methylpyrrolidone to complete the scrubbing. Simultaneously, new methylpyrrolidone is replenished through the replenishment pipe 400. Finally, the exhaust gas is discharged from the top of the scrubbing tower 100 and introduced into the adsorption tower 200 from the bottom through the exhaust gas pipeline. The exhaust gas flows upward and passes through the adsorbent to complete the adsorption, and finally, the exhaust gas is discharged from the top of the adsorption tower 200.

[0038] The scrubbing tower 100 has at least two levels of packing layers 110. Each packing layer 110 is equipped with a liquid distribution plate 120 above it. The liquid distribution plate 120 consists of a plate that is sealed and fixed to the tower wall on all four sides and a drain pipe that is evenly distributed on the plate. On one side of the tower wall above the liquid distribution plate 120, there is an inlet pipe 130 connected to the outlet end of the solution pump 300 through a pipe valve. The solution pump 300 draws methylpyrrolidone into the liquid distribution plate 120 through the inlet pipe 130. When the liquid level on the liquid distribution plate 120 exceeds the level of the drain pipe, the methylpyrrolidone overflows from the drain pipe and flows downward into the packing layer 110 below. It has excellent dispersion effect and fully contacts the upward flowing waste gas. While ensuring the scrubbing effect, it reduces the load-bearing capacity of the packing layer support structure and increases the scrubbing speed of the waste gas.

[0039] The adsorbent layer 230 in the adsorption tower 200 has an inlet 210 and an outlet 220 on both sides of the upper end for the adsorbent particles to enter and exit, which facilitates the replacement of adsorbent particles in the adsorbent layer 230.

[0040] Example 2

[0041] like Figure 2-4As shown, based on Example 1, the adsorption tower 200 in this example has a cuboid structure. The adsorbent layer 230 has a cross-section that is straight in the middle and semi-circular at both ends. That is, the adsorbent layer 230 is a whole composed of a cuboid and cylinders at both ends. The adsorbent layer 230 is provided with a vertical plate 232. The vertical plate 232 and the support device 231 of the adsorbent layer 230 divide the adsorbent layer 230 into a closed loop channel. The adsorbent layer 230 is provided with a magnetic push plate 233 for moving the adsorbent particles (activated carbon particles, silica gel balls and other light adsorbents). The magnetic push plate 233 moves along the closed loop channel to drive the adsorbent particles to move up and down. The inner walls of the tower are provided with limiting grooves 234 on both sides to limit the movement trajectory of the magnetic push plate 233. The two ends of the magnetic push plate 233 are limited in the limiting grooves 234, so that the magnetic push plate 233 remains vertical along the closed loop channel when it moves downward.

[0042] This embodiment also provides a driving method for the magnetic pusher plate 233. Driving wheels 239 and driven wheels 236 are provided on the opposite outer walls of the adsorption tower 200. A transmission component 237 is provided between the driving wheels 239 and driven wheels 236. The driving wheels 239 are driven to rotate by a motor or rotating structure, causing the driven wheels 236 to rotate, thereby driving the transmission component 237 to reciprocate. An electromagnet 238 is provided on the transmission component 237. When the transmission component 237 circulates, the electromagnet 238 also moves up and down. When energized, the magnetic pusher plate 233 is moved by magnetic force, thus slowly moving the adsorbent at the bottom to a higher position. Alternatively, driving wheels 239 and driven wheels 236 are provided on the opposite outer walls of the adsorption tower 200. Figure 5 The slide rail has the shape of a limiting groove 234 shown, and a movable pulley device on the slide rail drives the magnetic push plate 233 to move.

[0043] In this embodiment, the drive wheel 239 is driven by a solution-driven structure 600 (such as...). Figure 5 As shown, the solution drive structure 600 is driven by the pump flow of the solution pump 300. The solution drive structure 600 can be composed of a liquid wheel, a sprocket, a shaft, and a chain (not shown in the figure, but it is a conventional transmission structure). The liquid wheel is driven by the pump flow, which drives the first sprocket to rotate through the shaft. The first sprocket drives the second sprocket to rotate through the chain. The second sprocket drives the drive wheel 239 to rotate.

[0044] A magnetic gate 235 is provided above the closed-loop channel. The support device 231 is matched with the magnetic gate 235. A protrusion is provided at the upper end. During normal use, the magnetic gate 235 is located inside the protrusion. When the adsorbent needs to be replaced, the magnetic gate 235 is lowered to form a partition in the closed-loop channel. Then, the magnetic push plate 233 is moved to the position of the magnetic gate 235 to open the discharge port 220. The magnetic push plate 233 continues to move. Due to the obstruction of the magnetic gate 235, the adsorbent is discharged from the discharge port 220. After the magnetic push plate 233 passes the inlet 210, the inlet 210 is opened so that the new adsorbent refills the adsorbent layer 230. After it is full, the inlet 210 and the discharge port 220 are closed. In this embodiment, electromagnets 2351 and linear drive 2352 that drive electromagnets 2351 to move up and down are provided on the outer walls of opposite sides of the adsorption tower 200. When electromagnets 2351 are energized, they drive the magnetic gate 235 to rise and fall.

[0045] Example 3

[0046] like Figure 5-7 As shown, based on Example 1, Example 2, or a combination of both, the waste lubricating oil vacuum distillation exhaust gas removal device in this embodiment also includes a regenerator 500, which utilizes the heat from the vacuum distillation exhaust gas to regenerate the detergent and adsorbent, while simultaneously cooling the exhaust gas. According to on-site measurements, the temperature of the waste lubricating oil vacuum distillation exhaust gas is close to 200℃, and in some cases even reaches 250-300℃. However, existing waste lubricating oil or base oil production lines lack corresponding waste heat recovery devices, resulting in energy waste. Moreover, excessively high temperatures entering the removal device are detrimental to the treatment of silanes, sulfur-containing substances, and other contaminants in the exhaust gas.

[0047] In this embodiment, the regenerator 500 is designed by improving the structure of the multi-flow heat exchanger in the field of heat exchangers. The shell of the regenerator 500 is composed of a two-diameter section cylinder 530 (large diameter section and small diameter section) and a tube sheet box fixed at both ends of the cylinder 530 by flanges.

[0048] The interior of the cylinder 530 is provided with a straight tube bundle 510 connecting the two tube sheet type boxes, a spiral tube bundle 520 wound around the outside of the straight tube bundle 510, and several fixed tube sheets 540 fixing the two tube bundles. The upper end of the cylinder 530 is provided with a gas outlet pipe 534 and a liquid inlet pipe 531 connected to the washing liquid outlet of the washing tower 100. The lower end of the liquid inlet pipe 531 is provided with a spray pipe 532. The lower end of the cylinder 530 is provided with a liquid outlet pipe 533 connected to the liquid inlet of the solution pump 300.

[0049] One of the tube sheet-type boxes is equipped with an adsorbent inlet pipe 511 and a solvent inlet pipe 512. The adsorbent inlet pipe 511 can be directly connected to the outlet 220 of the adsorption tower 200. The other tube sheet-type box is equipped with two partitions 560 that divide the box into three areas. The tube sheet-type box in the middle area is equipped with an adsorbent outlet pipe 513 and a solvent outlet pipe 514. The upper and lower areas are respectively equipped with a waste gas inlet pipe 521 and a waste gas outlet pipe 522, and the waste gas inlet pipe 521 and the waste gas outlet pipe 522 are respectively connected to the beginning and end of the spiral tube bundle 520.

[0050] During operation, the vacuum distillation exhaust gas enters the spiral tube bundle 520 through the exhaust gas inlet pipe 521 and is then discharged from the exhaust gas outlet pipe 522. It is then introduced into the scrubbing tower 100 from the bottom. The circulating scrubbing liquid methylpyrrolidone in the scrubbing tower 100 enters through the liquid inlet pipe 531 and is then sprayed onto the spiral tube bundle 520 through the spray pipe 532. The heat of the exhaust gas is used to heat and distill the scrubbed methylpyrrolidone. The methylpyrrolidone is separated by its different boiling points. The high-boiling-point methylpyrrolidone is located at the bottom of the large-diameter section of the cylinder 530. When the circulating liquid level reaches a sufficiently high level, it is extracted and returned to the scrubbing tower 100.

[0051] When silica gel or other regenerable adsorbents are selected for the adsorbent layer 230 in the adsorption tower 200, when the adsorbent in the adsorption tower 200 needs to be replaced, the waste adsorbent is first introduced into the tube sheet box through the adsorbent inlet pipe 511, and then the desorption solvent is introduced through the solvent inlet pipe 512. After mixing through the straight tube bundle 510, the heat of the waste gas is used to heat the solvent and the waste adsorbent to mix them. First, the organic matter adsorbed in the silica gel is washed out by the solvent washing method, and then the silica gel is heated to remove the solvent. The silica gel is discharged from the adsorbent outlet pipe 513 through the suction device, and the solvent evaporates and is discharged and recovered from the solvent outlet pipe 514.

[0052] Furthermore, vacuum lines 550 are provided on both the cylinder 530 and the tube sheet housing with the adsorbent inlet pipe 511, which can provide a vacuum decompression environment when necessary.

[0053] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas, comprising a scrubbing tower, an adsorption tower, an exhaust gas pipeline located between the top of the scrubbing tower and the bottom of the adsorption tower, and a solution pump and a makeup liquid pipe located on the pipeline between the bottom and top of the scrubbing tower, characterized in that: The washing tower is provided with at least two packing layers. Each packing layer is provided with a liquid distribution plate above it. The liquid distribution plate is composed of a plate that is sealed and fixed to the tower wall on all four sides and a leakage pipe that is evenly distributed on the plate. A liquid inlet pipe is provided on one side of the tower wall above the liquid distribution plate, which is connected to the liquid outlet of the solution pump through a pipe valve. The adsorbent layer inside the adsorption tower is provided with an inlet and an outlet on both sides of the upper end for the adsorbent to enter and exit. The adsorption tower has a rectangular parallelepiped structure. The cross-section of the adsorbent layer is straight in the middle and semi-circular at both ends. The adsorbent layer is equipped with a vertical plate. The vertical plate and the support device of the adsorbent layer divide the adsorbent layer into a closed loop channel. The adsorbent layer is equipped with a magnetic pusher plate for moving the adsorbent particles. The magnetic pusher plate moves along the closed loop channel to drive the adsorbent particles to move up and down. The inner walls of the tower are equipped with limiting grooves on both sides to restrict the movement trajectory of the magnetic pusher plate. The adsorption tower has a driving wheel and a driven wheel on the opposite outer walls of the tower body, and a transmission component is provided between the driving wheel and the driven wheel. The transmission component is equipped with an electromagnet that matches the magnetic push plate. A magnetic gate is provided above the closed-loop channel, and electromagnets and linear actuators for driving the electromagnets to move up and down are provided on the opposite outer walls of the adsorption tower.

2. The device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas according to claim 1, characterized in that: The drive wheel is driven by a solution-driven structure, which is driven by the pumping flow of a solution pump.

3. The device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas according to claim 1, characterized in that: The removal device also includes a regenerator for regenerating the detergent and adsorbent using the heat from the vacuum distillation exhaust gas.

4. The device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas according to claim 3, characterized in that: The regenerator's housing consists of a two-diameter cylindrical body and a tube sheet-type box body located at both ends of the cylindrical body and fixed by flanges; The cylinder body is equipped with a straight tube bundle connecting the two tube sheet type boxes, a spiral tube bundle wrapped around the outside of the straight tube bundle, and several fixed tube sheets that fix the two tube bundles. The upper end of the cylinder body is equipped with a gas outlet pipe and a liquid inlet pipe connected to the washing liquid outlet of the washing tower. The lower end of the liquid inlet pipe is equipped with a spray pipe. The lower end of the cylinder body is equipped with a liquid outlet pipe connected to the liquid inlet of the solution pump. One of the tube sheet-type boxes is provided with an adsorbent inlet pipe and a solvent inlet pipe. The other tube sheet-type box is provided with two partitions that divide the box into three areas. The tube sheet-type box in the middle area is provided with an adsorbent outlet pipe and a solvent outlet pipe. The upper and lower areas are respectively provided with an exhaust gas inlet pipe and an exhaust gas outlet pipe, and the exhaust gas inlet pipe and the exhaust gas outlet pipe are respectively connected to the beginning and end of the spiral tube bundle.

5. The device for removing silicon-based organic compounds from waste lubricating oil vacuum distillation exhaust gas according to claim 4, characterized in that: Vacuum lines are provided on both the cylinder and the tube sheet box with the adsorbent inlet pipe.

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