A biodiesel distillation device

Abstract

The invention discloses a biodiesel distillation device, which relates to the technical field of chemical equipment. The device comprises a heat exchanger, a flash tower, and a biodiesel distillation tower connected in sequence. The biodiesel is preheated by the heat exchanger, and then flash-evaporated by the flash tower to discharge low-boiling-point substances such as methanol and water in the biodiesel, thereby preventing the low-boiling-point substances from affecting the vacuum degree in the biodiesel distillation tower. The biodiesel distillation tower comprises a stripping section and a distillation section. The stripping section and the distillation section comprise a plurality of groups of tray heat and mass transfer components. The tray heat and mass transfer components can realize heat and mass transfer between a gas phase and a liquid phase. The stripping section can concentrate heavy components in the liquid phase of the biodiesel during the process of the liquid phase of the biodiesel moving from top to bottom. The distillation section can purify light components in the gas phase during the process of the gas phase of the biodiesel moving from bottom to top, thereby ensuring the quality stability of the biodiesel.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, in particular to a biodiesel distillation device. Background Art

[0002] Biodiesel is a typical "green energy" with the characteristics of wide raw material sources, good environmental performance, good engine starting performance and renewability. The development of biodiesel distillation technology is of great significance to promoting energy substitution and reducing environmental pressure. Biodiesel distillation is to separate the light and heavy components in biodiesel through a distillation device. Most of the existing distillation devices are composed of distillation towers, condensers, heat exchangers, reboilers, etc., and purifying the light components in biodiesel and concentrating the heavy components in biodiesel in the distillation tower are crucial issues in the biodiesel distillation process. The effect of biodiesel distillation directly affects the efficacy of biodiesel. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a biodiesel distillation device to improve the problems of purifying light components and concentrating heavy components of biodiesel in the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: a biodiesel distillation device, comprising:

[0005] a heat exchanger, wherein the biodiesel enters from an input end of the heat exchanger, and the heat exchanger is used to preheat the biodiesel;

[0006] A flash tower, wherein the output end of the heat exchanger is connected to the input end of the flash tower, and the flash tower discharges low-boiling-point substances such as methanol and water in the biodiesel to prevent the low-boiling-point substances from entering the biodistillation tower and affecting the vacuum degree in the distillation system, increasing the energy consumption of the distillation, and affecting the quality of the biodiesel;

[0007] A biodiesel distillation tower, wherein the output end of the flash tower is connected to the feed channel of the biodiesel distillation tower, a feed control valve is installed at one end of the feed channel, and the feed control valve can control the speed at which biodiesel enters the biodiesel distillation tower. The biodiesel distillation tower includes a stripping section and a rectifying section, wherein the stripping section is the portion below the feed channel, and the rectifying section is the portion above the feed channel. The stripping section can concentrate the heavy components in the liquid phase of the biodiesel as it moves from top to bottom, and the rectifying section can purify the light components in the gas phase as the biodiesel vapor moves from bottom to top, thereby ensuring the quality stability of the biodiesel. The stripping section and the rectifying section include several layers of tower plate heat and mass transfer components, and the tower plate heat and mass transfer components include several layers of tower plates, each of which contains the first A liquid channel, the biodiesel enters the input end of the first liquid channel from the feed channel, the shape of the first liquid channel is corrugated or broken line, a gas inlet channel is set at the bottom of each tower plate, the gas inlet channel is connected to the highest point of the first liquid channel, and a gas outlet channel is set at the top of the tower body, the gas outlet channel is connected to the lowest point of the first liquid channel, the biodiesel vapor is fully transferred with the liquid biodiesel through the gas inlet channel, and then discharged through the gas outlet channel, the corrugated or broken line first liquid channel can effectively increase the contact area and time of heat and mass transfer between the liquid biodiesel and the biodiesel vapor, can effectively purify the light components of the biodiesel, and concentrate the heavy components of the biodiesel.

[0008] Preferably, air pressure switch valves are installed at both ends of the gas inlet channel, and the air pressure switch valves include two groups of mutually symmetrical gaskets, springs, and wedges. The two groups of gaskets are respectively arranged on both sides of the gas inlet channel, and the gas inlet channel is integrated with the two groups of springs. The two groups of gaskets are respectively installed on the two groups of gaskets, and the wedges are respectively installed at one end of the two groups of gaskets. The hypotenuse of the wedge is close to the input end of the gas inlet channel. The air pressure switch valve is used to limit the leakage of the liquid biodiesel from the gas inlet channel before the biodiesel vapor reaches a predetermined air pressure.

[0009] Preferably, a gas ejection hood is installed at the outlet of the gas outlet channel, and a plurality of evenly distributed jet holes are provided on the surface of the gas ejection hood. The biodiesel vapor is evenly ejected from the jet holes, so that the biodiesel vapor can evenly transfer heat and mass with the liquid biodiesel.

[0010] Preferably, a downcomer is installed at the output end of the first liquid channel of each layer, and the downcomer is used to introduce liquid biodiesel into the tower plate of the lower layer. A first receiving plate is installed on one side of the tower plate of the lower layer close to the inner wall of the biodiesel distillation tower, and the first receiving plate is used to receive the liquid biodiesel of the upper layer and separate the liquid biodiesel of the upper layer from the liquid biodiesel of the lower layer.

[0011] Preferably, an overflow weir is installed at one end of the upper side of each layer of the tower plates, and a second liquid channel is set between each layer of the tower plates. The second liquid channel is connected to the overflow weir. The overflow weir is used to control the liquid level of the liquid biodiesel on the upper side of the tower plate and is used for buffering the liquid biodiesel. The gas outlet channel is connected to the second liquid channel. The biodiesel vapor in the gas outlet channel and the liquid biodiesel in the second liquid channel are fully transferred to the gas inlet channel of the tower plate on the upper layer after sufficient heat and mass transfer. The liquid biodiesel flows through the overflow weir to the tower plate on the lower layer after heat and mass transfer in the second liquid channel. A second receiving plate is installed at the bottom of one end of the tower plate on the lower layer. The second receiving plate is used to receive the liquid flowing out of the overflow weir.

[0012] Preferably, a top cooler is installed at the output end of the biodiesel distillation tower, and the top cooler is used to cool and liquefy the biodiesel vapor.

[0013] Preferably, a top reflux tank is installed at the output end of the top cooler, and the liquefied biodiesel is buffered in the top reflux tank. A portion of the liquid is extracted as the top product, and the other portion of the liquid is returned to the top of the bio-distillation tower as reflux liquid. The reflux liquid flows through the first liquid channel and the second liquid channel, and the biodiesel vapor is in countercurrent contact with the reflux liquid. The reflux liquid can increase the light component content in the biodiesel vapor, and the biodiesel vapor is distilled and separated in the distillation section to purify the biodiesel vapor.

[0014] Preferably, a reboiler is installed at the bottom of the biodiesel distillation tower, and the reboiler vaporizes the liquid at the bottom of the biodiesel distillation tower. The vaporized gas is used to provide a heat source for the biodiesel distillation tower, and the bottom sediment of the biodiesel distillation tower is discharged through the bottom of the tower.

[0015] Beneficial effects: The biodiesel distillation device of the present invention provides a tower plate heat and mass transfer component, the tower plate contains a wavy or broken line first liquid channel, the gas inlet channel is installed at the highest point of the first liquid channel, and the gas outlet channel is installed at the lowest point of the first liquid channel, which effectively increases the contact area and time of heat and mass transfer between liquid biodiesel and biodiesel vapor, constitutes the distillation of biodiesel in the first liquid channel, and improves the efficiency of purifying light components in biodiesel and concentrating heavy components in biodiesel. The second liquid channel is formed by the gap between the upper and lower tower plates, and the liquid biodiesel and gaseous biodiesel undergo secondary heat and mass transfer to constitute the biodiesel distillation of the second liquid channel, which can effectively purify the light components of biodiesel and concentrate the heavy components of biodiesel multiple times, thereby improving the efficiency of biodiesel distillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0017] In the attached figure:

[0018] Figure 1 It is the overall flow chart of the biodiesel distillation device of the present invention;

[0019] Figure 2 It is a partial schematic diagram of the heat and mass transfer component of the tower plate of the present invention;

[0020] Figure 3 is a schematic diagram of a gas ejection hood of the present invention;

[0021] Figure 4 Schematic diagram of the air pressure switch valve of the present invention.

[0022] Numbers in the figure: 1. heat exchanger; 2. flash tower; 3. biodiesel distillation tower; 4. top reflux tank; 5. reboiler; 6. distillation section; 7. stripping section; 8. feed channel; 9. feed control valve; 10. second receiving plate; 11. overflow weir; 12. downcomer; 13. first liquid channel; 14. first receiving plate; 15. gas inlet channel; 16. gas outlet channel; 17. tower plate; 18. second liquid channel; 19. gas ejection hood; 20. jet hole; 21. gasket; 22. spring; 23. wedge; 24. top cooler. DETAILED DESCRIPTION

[0023] The following, in conjunction with the accompanying drawings, provides a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments represent only a portion of the embodiments of the present invention, not all of them. The following text is intended only to describe an embodiment of a biodiesel distillation apparatus of the present invention and does not strictly limit the scope of protection claimed herein.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] Example: Figures 1-4 As shown, a biodiesel distillation device comprises:

[0026] Heat exchanger 1, the biodiesel enters from the input end of the heat exchanger 1, and the heat exchanger 1 is used to preheat the biodiesel;

[0027] Flash tower 2, the output end of the heat exchanger 1 is connected to the input end of the flash tower 2, and the flash tower 2 discharges low-boiling-point substances such as methanol and water in the biodiesel to prevent low-boiling-point substances from entering the biodistillation tower and affecting the vacuum degree in the distillation system, increasing the energy consumption of the distillation, and affecting the quality of the biodiesel;

[0028] The biodiesel distillation tower 3, the output end of the flash tower 2 is connected to the feed channel 8 of the biodiesel distillation tower 3, and a feed control valve 9 is installed at one end of the feed channel 8. The feed control valve 9 can control the speed of biodiesel entering the biodiesel distillation tower 3. The biodiesel distillation tower 3 includes a stripping section 7 and a distillation section 6. The stripping section 7 is the part below the feed channel 8, and the distillation section 6 is the part above the feed channel 8. The stripping section 7 can concentrate the heavy components in the liquid phase of the biodiesel in the process of moving from top to bottom, and the distillation section 6 can purify the light components in the gas phase in the process of moving the biodiesel vapor from bottom to top, thereby ensuring the quality stability of the biodiesel. The stripping section 7 and the distillation section 6 include several layers of tower plate heat and mass transfer components, and the tower plate heat and mass transfer components include several layers of tower plates 17, and each layer of the tower plate 17 contains a first Liquid channel 13, the biodiesel enters the input end of the first liquid channel 13 from the feed channel 8, the shape of the first liquid channel 13 is corrugated or broken line, a gas inlet channel 15 is provided at the bottom of each layer of the tower plate 17, the gas inlet channel 15 is connected to the highest point of the first liquid channel 13, a gas outlet channel 16 is provided at the top of the tower body, the gas outlet channel 16 is connected to the lowest point of the first liquid channel 13, the biodiesel vapor passes through the gas inlet channel 15 and performs sufficient heat and mass transfer with the liquid biodiesel, and is then discharged through the gas outlet channel 16, the corrugated or broken line first liquid channel 13 can effectively increase the contact area and time of heat and mass transfer between the liquid biodiesel and the biodiesel vapor, can effectively purify the light components of the biodiesel, and concentrate the heavy components of the biodiesel.

[0029] In an embodiment, air pressure switch valves are installed at both ends of the gas inlet channel 15. The air pressure switch valves include two groups of mutually symmetrical gaskets 21, springs 22, and wedges 23. The two groups of gaskets 21 are respectively arranged on both sides of the gas inlet channel 15. The gaskets 21 and the gas inlet channel 15 are integrated. The two groups of springs 22 are respectively installed on the two groups of gaskets 21. The wedges 23 are respectively installed at one end of the two groups of gaskets 21. The hypotenuse of the wedge 23 is close to the input end of the gas inlet channel 15. The air pressure switch valve is used to limit the leakage of the liquid biodiesel from the gas inlet channel before the biodiesel vapor reaches a predetermined air pressure.

[0030] In the embodiment, a gas ejection hood 19 is installed at the outlet of the gas outlet channel 16, and a plurality of evenly distributed jet holes 20 are provided on the surface of the gas ejection hood 19. The biodiesel vapor is evenly ejected from the jet holes 20, so that the biodiesel vapor can evenly transfer heat and mass with the liquid biodiesel.

[0031] In an embodiment, a downcomer 12 is installed at the output end of each layer of the first liquid channel 13, and the downcomer 12 is used to introduce liquid biodiesel into the lower layer of the tower plate 17. A first receiving plate 14 is installed on one side of the lower layer of the tower plate 17 close to the inner wall of the biodiesel distillation tower 3. The first receiving plate 14 is used to receive the upper layer of liquid biodiesel and separate the upper layer of liquid biodiesel from the lower layer of liquid biodiesel.

[0032] In an embodiment, an overflow weir 11 is installed at one end of the upper side of the tower plate 17 of each layer, and a second liquid channel 18 is provided between the tower plates 17 of each layer. The second liquid channel 18 is connected to the overflow weir 11. The overflow weir 11 is used to control the liquid level of the liquid biodiesel on the upper side of the tower plate 17 and to buffer the liquid biodiesel. The gas outlet channel 16 is connected to the second liquid channel 18. The biodiesel vapor in the gas outlet channel 16 and the liquid biodiesel in the second liquid channel 18 are fully transferred to the gas inlet channel 15 of the tower plate 17 of the upper layer after sufficient heat and mass transfer. The liquid biodiesel flows through the overflow weir 11 to the tower plate 17 of the lower layer after heat and mass transfer in the second liquid channel 18. A second receiving plate 10 is installed at the bottom of one end of the tower plate 17 of the lower layer. The second receiving plate 10 is used to receive the liquid flowing out of the overflow weir 11.

[0033] In an embodiment, a tower top cooler 24 is installed at the output end of the biodiesel distillation tower 3 , and the tower top cooler 24 is used to cool and liquefy the biodiesel vapor.

[0034] In an embodiment, a top reflux tank 4 is installed at the output end of the top cooler 24, and the liquefied biodiesel is buffered in the top reflux tank 4. A portion of the liquid is extracted as the top product, and the other portion of the liquid is returned to the top of the bio-distillation tower as a reflux liquid. The reflux liquid flows through the first liquid channel 13 and the second liquid channel 18, and the biodiesel vapor is in countercurrent contact with the reflux liquid. The reflux liquid can increase the light component content in the biodiesel vapor, and the biodiesel vapor is distilled and separated in the distillation section 6 to purify the biodiesel vapor.

[0035] In an embodiment, a reboiler 5 is installed at the bottom of the biodiesel distillation tower 3, and the reboiler 5 vaporizes the liquid at the bottom of the biodiesel distillation tower 3. The vaporized gas is used to provide a heat source for the biodiesel distillation tower 3, and the bottom sediment of the biodiesel distillation tower 3 is discharged through the bottom of the tower.

[0036] When the present invention is in use, the biodiesel enters the input end of the heat exchanger 1 for preheating, and the biodiesel enters the flash tower 2 from the heat exchanger 1 to discharge low-boiling-point substances such as methanol and water in the biodiesel. After passing through the flash tower 2, the biodiesel enters the diesel distillation tower 3 for distillation, and the reboiler 5 vaporizes the liquid at the bottom of the biodiesel distillation tower 3 to provide a heat source for the biodiesel distillation tower 3. The biodiesel vapor enters the tower top cooler 24 and the tower top reflux tank 4 for cooling and reflux, and the bottom sediment of the biodiesel distillation tower 3 is discharged through the bottom of the tower.

[0037] Finally, it should be noted that the above is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A biodiesel distillation device, characterized in that: include: a heat exchanger, wherein the biodiesel enters from an input end of the heat exchanger, and the heat exchanger is used to preheat the biodiesel; A flash tower, wherein the output end of the heat exchanger is connected to the input end of the flash tower, and the flash tower discharges low-boiling-point substances in the biodiesel; A biodiesel distillation tower, wherein the output end of the flash tower is connected to the feed channel of the biodiesel distillation tower, a feed control valve is installed at one end of the feed channel, and the feed control valve is used to control the speed at which biodiesel enters the biodiesel distillation tower. The biodiesel distillation tower includes a stripping section and a rectifying section, wherein the stripping section is the portion below the feed channel, and the rectifying section is the portion above the feed channel. The stripping section and the rectifying section include several layers of tower plate heat and mass transfer components, and the tower plate heat and mass transfer components include several layers of tower plates, and each layer of the tower plate contains There is a first liquid channel, the biodiesel enters the input end of the first liquid channel from the feed channel, the shape of the first liquid channel is corrugated or broken line, the output end of each layer of the first liquid channel is installed with a downcomer, the downcomer is used to introduce the liquid biodiesel into the lower layer of the tower plate, the top of one end of the lower layer of the tower plate is close to the inner wall of the biodiesel distillation tower. The first receiving plate is used to receive the upper layer of liquid biodiesel and separate the upper layer of liquid biodiesel from the lower layer of liquid biodiesel. The bottom of each layer of the tower plate is provided with a first receiving plate. A gas inlet channel is provided, which is connected to the highest point of the first liquid channel. A gas outlet channel is provided at the top of the tower body, which is connected to the lowest point of the first liquid channel. The biodiesel vapor undergoes sufficient heat and mass transfer with the liquid biodiesel through the gas inlet channel and is then discharged through the gas outlet channel. An overflow weir is installed at one end of the upper side of each tower plate. A second liquid channel is provided between each tower plate, which is connected to the overflow weir. The overflow weir is used to control the liquid level of the liquid biodiesel on the upper side of the tower plate and to buffer the liquid biodiesel. The gas outlet channel is connected to the second liquid channel. After sufficient heat and mass transfer, the biodiesel vapor in the gas outlet channel flows to the gas inlet channel of the upper tower plate. After heat and mass transfer in the second liquid channel, the liquid biodiesel flows through the overflow weir to the lower tower plate. A second receiving plate is installed at the bottom of one end of the lower tower plate, which is used to receive the liquid flowing out of the overflow weir.

2. A biodiesel distillation device according to claim 1, characterized in that: Air pressure switch valves are installed at both ends of the gas inlet channel. The air pressure switch valves include two groups of mutually symmetrical gaskets, springs, and wedges. The two groups of gaskets are respectively arranged on both sides of the gas inlet channel. The gaskets are integrated with the gas inlet channel. Two groups of springs are respectively installed on the two groups of gaskets. The wedges are respectively installed at one end of the two groups of gaskets. The hypotenuse of the wedge is close to the input end of the gas inlet channel. The air pressure switch valve is used to limit the leakage of the liquid biodiesel from the gas inlet channel before the biodiesel vapor reaches a predetermined air pressure.

3. A biodiesel distillation device according to claim 1, characterized in that: A gas ejection cover is installed at the outlet of the gas outlet channel. A plurality of evenly distributed ejection holes are arranged on the surface of the gas ejection cover, and the biodiesel vapor is evenly ejected from the ejection holes.

4. A biodiesel distillation device according to claim 1, characterized in that: A tower top cooler is installed at the output end of the biodiesel distillation tower, and the tower top cooler is used to cool and liquefy the biodiesel vapor.

5. A biodiesel distillation device according to claim 4, characterized in that: A top reflux tank is installed at the output end of the top cooler, and the liquefied biodiesel is buffered in the top reflux tank. A portion of the liquid is extracted as the top product, and the other portion of the liquid is returned to the top of the bio-distillation tower as reflux liquid. The reflux liquid flows through the first liquid channel and the second liquid channel, and the biodiesel vapor is in countercurrent contact with the reflux liquid, and the biodiesel vapor is distilled and separated in the distillation section.

6. A biodiesel distillation device according to claim 1, characterized in that: A reboiler is installed at the bottom of the biodiesel distillation tower, and the reboiler vaporizes the liquid at the bottom of the biodiesel distillation tower. The vaporized gas is used to provide a heat source for the biodiesel distillation tower, and the bottom sediment of the biodiesel distillation tower is discharged through the bottom of the tower.

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