A distillation apparatus for biodiesel

Abstract

The utility model relates to a rectifying device for biodiesel, including esterificator, rectifying tower and condenser, rectifying tower includes reboiler and the rectifying column of solid connection in reboiler top, first heating pipe is solidly established in reboiler, the rectifying column includes the first rectifying section, secondary heating section and second rectifying section of solid connection from below to above in proper order, second heating pipe is solidly established in secondary heating section, the outlet of esterificator communicates with the import of reboiler through first pipeline, and the top outlet of second rectifying section communicates with the import of condenser through second pipeline, and the outlet of condenser communicates with the recovery mouth of esterificator, the outlet of first heating pipe communicates with the import of second heating pipe through third pipeline, the utility model improves the rectification effect and utilization ratio to methyl alcohol, and then improves methyl alcohol purity, and the methyl alcohol purity is conveniently detected, and it is more convenient to use.

Description

Technical Field

[0001] This utility model relates to the technical field of esterification reaction apparatus, specifically to a distillation apparatus for biodiesel. Background Technology

[0002] Currently, biodiesel is obtained through esterification. Conventional esterification technology involves simply refluxing methanol, with high-acid-value oil and methanol reacting under continuous stirring and a catalyst. High-acid-value oils require esterification to lower their acid value, a process commonly known as pre-esterification.

[0003] For example, patent CN201530814U discloses a distillation apparatus for producing biodiesel through distillation esterification. This apparatus consists of an esterifier, a distillation column, and a condenser. The distillation column includes a reboiler and a packed distillation column. The reboiler is equipped with a steam heating coil. The upper outlet of the distillation column is connected to the inlet of the condenser via a pipeline. The outlet of the condenser is connected to the inlet of the esterifier via a pipeline. The outlet of the esterifier is connected to the inlet of the distillation column via a pipeline. A drain outlet is located at the lower end of the distillation column. By using a distillation column to participate in the esterification reaction, not only is a continuous supply of high-concentration methanol required for the reaction provided, but also reaction water is smoothly removed. This completely solves the reverse reaction caused by water production during esterification, preventing the acid value reduction from rebounding and ensuring the complete esterification reaction, thus effectively reducing methanol consumption.

[0004] This patent addresses the issue that during distillation, the distillation column typically needs a certain height. As methanol vapor rises through the column, its temperature gradually decreases, causing some of the vapor to liquefy and fall back into the reboiler for reheating. This results in poor methanol distillation efficiency and low utilization. Furthermore, even after reboiling, the methanol vapor still contains a small amount of water vapor, reducing the purity of the distilled methanol. After cooling in the condenser, the methanol purity cannot be measured, making the process inconvenient. Therefore, this patent has significant room for improvement. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a distillation apparatus for biodiesel, which improves the distillation effect and utilization rate of methanol, thereby increasing methanol purity, and also facilitates methanol purity detection, making it more convenient to use.

[0006] This utility model is achieved through the following technical solution: a distillation device for biodiesel, comprising an esterifier, a distillation column, and a condenser. The distillation column includes a reboiler and a distillation column fixed to the top of the reboiler. A first heating tube is fixed in the reboiler. The distillation column includes a first distillation section, a secondary heating section, and a second distillation section fixed sequentially from bottom to top. A second heating tube is fixed in the secondary heating section. The outlet of the esterifier is connected to the inlet of the reboiler through a first pipeline. The top outlet of the second distillation section is connected to the inlet of the condenser through a second pipeline. The outlet of the condenser is connected to the recovery port of the esterifier. The outlet of the first heating tube is connected to the inlet of the second heating tube through a third pipeline.

[0007] This design shortens the methanol vapor distillation height by using a multi-segment combined structure for the distillation column. The methanol vapor first undergoes primary distillation in the first rectification section, then enters the secondary heating section where it is reheated by a second heating tube. This maintains the methanol in a vapor state, preventing it from liquefying upon cooling. Finally, the methanol vapor enters the second rectification section for secondary distillation. This design, through dual-stage distillation and reheating of the methanol vapor, ensures effective distillation while allowing more methanol vapor to enter the condenser, thus improving methanol vapor utilization.

[0008] As an optimization, the second heating tube has a serpentine bend structure. This optimization increases the heating area of ​​the second heating tube, allowing the methanol vapor to fully contact the second heating tube, thereby ensuring the heating effect.

[0009] As an optimization, a steam-water separator is also fixedly installed within the secondary heating section, located above the second heating tube. This optimized solution further filters water vapor from the methanol vapor through the steam-water separator, thereby further improving the purity of the methanol vapor.

[0010] As an optimization, the distillation unit also includes a four-way reversing valve. The outlet of the condenser is connected to the first port of the four-way reversing valve via a fourth pipe. The second port of the four-way reversing valve is connected to the recovery port of the reboiler via a fifth pipe. The third port of the four-way reversing valve is connected to the recovery port of the esterifier via a sixth pipe. In this optimized design, the four-way reversing valve facilitates control of the methanol delivery direction. The condensed methanol enters the four-way reversing valve through the fourth pipe. By controlling the four-way reversing valve, the methanol can either flow back to the esterifier via the sixth pipe for reuse, or flow back to the reboiler for re-distillation via the fifth pipe, making it flexible and convenient to use.

[0011] As an optimization, the fourth port of the four-way reversing valve is connected to a sampler via a seventh pipeline, and the sampler is equipped with a methanol concentration meter. In this optimized scheme, methanol enters the sampler through the seventh pipeline, and the methanol purity is detected by the methanol concentration meter, allowing personnel to select the direction of methanol delivery.

[0012] As an optimization, a balancing valve is installed on the fourth pipeline. This optimization scheme improves safety by balancing the output pressure through the balancing valve.

[0013] As an optimization, a flow meter is installed on the sixth pipeline. This optimization scheme uses the flow meter to calculate the amount of methanol entering the esterifier, making it easier for personnel to calculate the methanol utilization rate.

[0014] As an optimization, the outlet of the first heating tube is connected to the inlet of the second heating tube via a third pipe. In this optimized scheme, the heating steam first enters the first heating tube to heat the reboiler, and then flows through the third pipe to the second heating tube to heat the secondary heating section, thus saving energy.

[0015] The beneficial effects of this invention are as follows: By arranging the distillation column in a multi-segment combined structure, the distillation height of methanol vapor is shortened. The methanol vapor first undergoes primary distillation in the first distillation section, then enters the secondary heating section where it is reheated by a second heating tube, thus maintaining the methanol in a vapor state and preventing it from liquefying upon cooling. Finally, the methanol vapor enters the second distillation section for secondary distillation. This design, through distillation on both sides and reheating of the methanol vapor, ensures effective distillation while allowing more methanol vapor to enter the condenser, thereby improving methanol vapor utilization.

[0016] The four-way reversing valve allows for easy control of the methanol delivery direction. The condensed methanol enters the sampler through the seventh pipeline, and the purity of the methanol is detected by the methanol concentration detector. This allows personnel to choose whether to return the methanol to the esterifier or the reboiler, making it more convenient and flexible to use. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the present invention;

[0018] Figure 2 for Figure 1 Enlarged view of part A;

[0019] As shown in the figure:

[0020] 1. Esterifier, 2. Reboiler, 3. Distillation column, 31. First distillation section, 32. Secondary heating section, 33. Second distillation section, 4. Condenser, 5. Four-way reversing valve, 6. Sampler, 7. First heating tube, 8. Second heating tube, 9. Methanol concentration meter, 10. First pipeline, 11. Third pipeline, 12. Second pipeline, 13. Fourth pipeline, 14. Balance valve, 15. Fifth pipeline, 16. Seventh pipeline, 17. Flow meter, 18. Sixth pipeline, 19. Gas-water separator. Detailed Implementation

[0021] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0022] like Figure 1 , 2 As shown, a distillation apparatus for biodiesel includes an esterifier 1, a distillation column, and a condenser 4. The distillation column includes a reboiler 2 and a distillation column 3 fixed to the top of the reboiler 2, and a first heating tube 7 is fixed in the reboiler 2.

[0023] In this embodiment, the esterifier 1, condenser 4, and reboiler 2 all use the same equipment as described in patent CN201530814U.

[0024] The distillation column 3 comprises a first distillation section 31, a secondary heating section 32, and a second distillation section 33, which are sequentially fixed from bottom to top. The first distillation section 31 is fixed to the reboiler 2 by bolts, the second distillation section 33 is fixed to the secondary heating section 32 by bolts, and the distillation column 3 adopts a multi-segment modular structure for easy assembly.

[0025] By arranging the distillation column 3 into a multi-segment combined structure, the distillation height of methanol vapor is shortened. The methanol vapor first undergoes primary distillation in the first distillation section 31, then enters the secondary heating section 32 for secondary heating, thus maintaining the methanol in a vapor state and preventing it from liquefying upon cooling. Finally, the methanol vapor enters the second distillation section 33 for secondary distillation. Through two distillations and secondary heating of the methanol vapor, the distillation column ensures distillation efficiency while allowing more methanol vapor to enter the condenser 4, improving methanol vapor utilization.

[0026] Both the first rectification section 31 and the second rectification section 33 are filled with corrugated packing for rectification, which is a conventional setting in existing rectification structures and will not be described in detail here.

[0027] Specifically, a second heating tube 8 is fixedly installed within the secondary heating section 32. The second heating tube 8 has a serpentine bend structure. This increases the heating area of ​​the second heating tube, allowing the methanol vapor to fully contact the tube and thus ensuring the heating effect.

[0028] The first heating tube 7 is the steam heating coil as described in patent CN201530814U. The outlet of the first heating tube 7 is connected to the inlet of the second heating tube 8 through the third pipe 11. The heating steam first enters the first heating tube 7 to heat the reboiler 2, and then flows through the third pipe 11 to the second heating tube 8 to heat the secondary heating section 32, thus saving energy.

[0029] Preferably, a steam-water separator 19 is also fixedly installed within the secondary heating section 32, and the steam-water separator 19 is located above the second heating tube 8. The steam-water separator 19 is conventional equipment and can be directly purchased. The steam-water separator 19 further filters the water vapor in the methanol vapor, thereby further improving the purity of the methanol vapor.

[0030] The outlet of the esterifier 1 is connected to the inlet of the reboiler 2 via the first pipe 10. The top outlet of the second rectification section 33 is connected to the inlet of the condenser 4 via the second pipe 12, and the outlet of the condenser 4 is connected to the recovery port of the esterifier 1.

[0031] Specifically, the distillation apparatus also includes a four-way directional valve 5. In this embodiment, the four-way directional valve 5 is an electrically operated four-way switching valve, which realizes the electric switching of the valve, making it more labor-saving.

[0032] The outlet of the condenser 4 is connected to the first port of the four-way reversing valve 5 via the fourth pipe 13. The second port of the four-way reversing valve 5 is connected to the recovery port of the reboiler 2 via the fifth pipe 15. The third port of the four-way reversing valve 5 is connected to the recovery port of the esterifier 1 via the sixth pipe 18. The fourth port of the four-way reversing valve 5 is connected to a sampler 6 via the seventh pipe 16, and a methanol concentration detector 9 is installed on the sampler 6.

[0033] In this embodiment, the sampler 6 is a Lyman LMC-A model automatic online sampler, which is convenient for sampling.

[0034] The four-way reversing valve 5 facilitates the control of methanol delivery direction. The valve first controls methanol to enter the sampler 6 via the seventh pipeline 16, where the methanol purity is detected by the methanol concentration detector 9, allowing personnel to select the appropriate delivery direction. Methanol can be returned to the esterifier 1 via the sixth pipeline 18 for reuse, or returned to the reboiler 2 via the fifth pipeline 15 for re-distillation, offering flexibility and convenience.

[0035] A balancing valve 14 is installed on the fourth pipeline 13. The balancing valve 14 balances the output pressure and improves safety.

[0036] A flow meter 17 is installed on the sixth pipeline 18. The amount of methanol entering the esterifier is calculated by the flow meter 17, which facilitates the calculation of methanol utilization rate.

[0037] Working principle: When in use, the solvent vapor evaporated by the esterifier 1 carries water into the reboiler 2. The low-boiling-point methanol is heated by the first heating tube 7, causing it to rise into the distillation column 3 for distillation.

[0038] Methanol vapor first enters the first rectification section 31 for primary rectification, then enters the secondary heating section 32 where it is reheated by the second heating tube 8, thus keeping the methanol in a vapor state and preventing it from liquefying back into the cold. Finally, the methanol vapor enters the second rectification section 33 for secondary rectification.

[0039] After distillation, methanol vapor enters the condenser 4 through the outlet at the upper end of the second distillation section 33, where it is condensed and then enters the four-way reversing valve 5. First, the four-way reversing valve 5 is switched to the fourth valve port, allowing methanol to enter the sampler 6 for sampling. The methanol concentration is then detected by the methanol concentration detector 9, and the conveying direction is selected based on the methanol purity.

[0040] When the purity reaches the set value, the four-way reversing valve 5 switches to the third valve port, allowing methanol to flow back into the esterifier 1 to participate in the esterification reaction again.

[0041] When the purity does not reach the set value, the four-way reversing valve 5 switches to the second valve port, so that the methanol flows back into the reboiler 2 for re-distillation.

[0042] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A distillation apparatus for biodiesel, comprising an esterifier (1), a distillation column, and a condenser (4), the distillation column comprising a reboiler (2) and a distillation column (3) fixed to the top of the reboiler, wherein a first heating tube (7) is fixed in the reboiler (2), characterized in that: The distillation column (3) includes a first distillation section (31), a secondary heating section (32), and a second distillation section (33) that are fixedly connected from bottom to top. A second heating tube (8) is fixedly installed in the secondary heating section (32). The outlet of the esterifier (1) is connected to the inlet of the reboiler (2) through the first pipeline (10). The top outlet of the second distillation section (33) is connected to the inlet of the condenser (4) through the second pipeline (12). The outlet of the condenser (4) is connected to the recovery port of the esterifier (1).

2. The distillation apparatus for biodiesel according to claim 1, characterized in that: The second heating tube (8) has a serpentine curved structure.

3. The distillation apparatus for biodiesel according to claim 1, characterized in that: A steam-water separator (19) is also fixedly installed in the secondary heating section (32), and the steam-water separator is located above the second heating tube (8).

4. The distillation apparatus for biodiesel according to claim 1, characterized in that: The distillation apparatus also includes a four-way reversing valve (5). The outlet of the condenser (4) is connected to the first valve port of the four-way reversing valve (5) through the fourth pipeline (13). The second valve port of the four-way reversing valve (5) is connected to the recovery port of the reboiler (2) through the fifth pipeline (15). The third valve port of the four-way reversing valve (5) is connected to the recovery port of the esterifier (1) through the sixth pipeline (18).

5. The distillation apparatus for biodiesel according to claim 4, characterized in that: The fourth valve port of the four-way reversing valve (5) is connected to a sampler (6) via a seventh pipeline (16), and a methanol concentration detector (9) is installed on the sampler.

6. The distillation apparatus for biodiesel according to claim 4, characterized in that: A balancing valve (14) is installed on the fourth pipeline (13).

7. The distillation apparatus for biodiesel according to claim 4, characterized in that: A flow meter (17) is installed on the sixth pipeline (18).

8. The distillation apparatus for biodiesel according to claim 1, characterized in that: The outlet of the first heating tube (7) is connected to the inlet of the second heating tube (8) through the third pipe (11).

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