Discharged material separation and recovery system for improving BDO yield

Abstract

The utility model discloses a discharged material separation and recovery system capable of improving the yield of BDO (Butyl Dissolved Oxygen), which is characterized in that the flow of steam entering each steam heating section is controlled according to the actual temperature in a film evaporator corresponding to each steam heating section, so that a temperature difference is formed in the film evaporator from top to bottom, and the distillation efficiency is further improved. More light components are evaporated, so that the materials are better separated, and the content of BDO discharged from the bottom is reduced. The flow of the material entering the film evaporator is adjusted according to the tar content in the discharged material of the salt tower, so that the evaporation efficiency can be ensured, and BDO is fully separated from tar, salt and the like. The opening degree of the steam main valve is adjusted according to the discharging temperature of the film evaporator, it is guaranteed that BDO is fully evaporated and only recycled, and finally the effect of reducing the BDO discharge amount is achieved. According to the utility model, the concentration of BDO in heavy components delivered from inside to outside of the tar tank can be reduced to about 25% from the original 54.2%, so that the economic benefits of enterprises are effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of BDO recovery, in particular to an external discharge material separation and recovery system for improving the BDO yield. Background Art

[0002] 1,4-butanediol (BDO), as an important organic chemical raw material, has a wide range of applications in many fields such as chemical industry, textile, and medicine. During the production process of BDO, since a small part of tar and salt are contained in the BDO raw material, some impurities such as tar and salt will also be contained in the BDO product after the hydrogenation reaction. In order to obtain a high-purity BDO product, it needs to be separated and purified through processes such as rectification. The salt and tar in the system are discharged and removed from the bottom of the salt tower in the BDO rectification section. Since the BDO content (volume percentage) at the bottom of the salt tower is about 78%, a thin-film evaporator is added to separate the BDO in the material discharged from the bottom of the salt tower again. The feed of the salt tower comes from the bottom of the BDO concentration tower. After separation in the salt tower, the light components at the top are used as reflux to the feed of the low-boiling tower. The bottom heavy components, tar, salts, and BDO enter the thin-film evaporator again for separation. After separation, the light components at the top of the thin-film evaporator return to the salt tower, and the bottom tar, salts, and a small amount of BDO are discharged to the tar tank and sent to the incinerator for incineration. Among the heavy components sent for incineration, the BDO content (volume percentage) is about 54.2%, resulting in an increase in the BDO external discharge amount and affecting the BDO yield. Summary of the Utility Model

[0003] In order to solve the above problems, the purpose of the utility model is to provide an external discharge material separation and recovery system for improving the BDO yield.

[0004] The utility model is implemented by the following technical solutions:

[0005] An external discharge material separation and recovery system for improving the BDO yield, comprising a concentration tower, a salt tower, a thin-film evaporator and an incinerator; the bottom liquid discharge port of the concentration tower is communicated with the feed port of the salt tower through a pipeline, the bottom liquid discharge port of the salt tower is communicated with the feed port of the thin-film evaporator through a pipeline, the bottom liquid discharge port of the thin-film evaporator is communicated with the inlet of the discharge tank through a pipeline, the outlet of the discharge tank is communicated with the inlet of the tar tank through a pipeline, and the outlet of the tar tank is communicated with the inlet of the incinerator through a pipeline; the top gas outlet of the thin-film evaporator is communicated with the middle inlet of the salt tower through a pipeline, the top gas outlet of the salt tower is communicated with the feed port of the low-boiling tower through a pipeline, the bottom liquid discharge port of the low-boiling tower is communicated with the feed port of the high-boiling tower through a pipeline, and the side outlet of the high-boiling tower is communicated with the inlet of the BDO storage tank through a pipeline. Further, the thin-film evaporator is divided into a first steam heating section, a second steam heating section, a third steam heating section, a fourth steam heating section and a fifth steam heating section from top to bottom, and a first steam inlet, a second steam inlet, a third steam inlet, a fourth steam inlet and a fifth steam inlet are respectively arranged on the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section; the steam outlet end of the steam main pipe is divided into 5 paths and is respectively communicated with the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet and the fifth steam inlet through pipelines;

[0006] A first steam flow regulating valve, a second steam flow regulating valve, a third steam flow regulating valve, a fourth steam flow regulating valve and a fifth steam flow regulating valve are respectively arranged at the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet and the fifth steam inlet;

[0007] A first condensate outlet, a second condensate outlet, a third condensate outlet, a fourth condensate outlet and a fifth condensate outlet are respectively arranged on the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section; the first condensate outlet, the second condensate outlet, the third condensate outlet, the fourth condensate outlet and the fifth condensate outlet are all communicated with the condensate system through pipelines.

[0008] Further, a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and a fifth temperature sensor are respectively arranged on the inner walls of the thin-film evaporator corresponding to the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section.

[0009] Further, a sampling port is provided at the bottom liquid discharge port of the salt tower, a sampling pipe is connected to the sampling port, and a sampling valve is provided at the sampling port.

[0010] Further, a feed flow regulating valve is provided at the feed port of the thin film evaporator.

[0011] Further, a discharge temperature sensor is provided at the bottom liquid discharge port of the thin film evaporator, and a steam main valve is provided at the steam outlet end of the steam main pipe.

[0012] Further, a pipeline booster pump is provided on the pipeline connecting the thin film evaporator and the discharge tank, a screw pump is provided on the pipeline connecting the discharge tank and the tar tank, and a tar pump is provided on the pipeline connecting the tar tank and the incinerator.

[0013] Advantages of the present utility model:

[0014] 1. Control the steam flow entering each steam heating section according to the actual temperature in the thin film evaporator corresponding to each steam heating section, so as to form a temperature difference from top to bottom in the thin film evaporator, thereby improving the distillation efficiency, enabling more light components to be evaporated, and better separating the materials, and reducing the BDO content in the bottom discharge.

[0015] 2. Adjust the flow rate of the material entering the thin film evaporator according to the tar content in the salt tower discharge, which can ensure the evaporation efficiency and fully separate BDO from tar, salts, etc.

[0016] 3. Adjust the opening degree of the steam main valve according to the discharge temperature of the thin film evaporator, ensuring that BDO is fully evaporated and only recovered, and finally achieving the effect of reducing the external discharge amount of BDO, and avoiding the evaporation of heavy components due to too high temperature, which affects the quality of BDO products.

[0017] 4. During the separation and purification of BDO, since the BDO concentration in the tar decreases, the viscosity of the separated tar material will increase, resulting in difficulties in discharging and transporting the tar; in the present utility model, a pipeline booster pump is added on the pipeline from the thin film evaporator to the discharge tank, which can smoothly discharge the heavy components in the thin film evaporator to the discharge tank; and by replacing the original discharge tank pump from an ordinary centrifugal pump with a screw pump, the problem of tar transportation can be solved, ensuring the stable operation of the system.

[0018] Through the present utility model, the BDO concentration in the heavy components sent out of the tar tank can be reduced from the original 54.2% to about 25%, which can effectively improve the economic benefits of the enterprise. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic diagram of the system connection for this embodiment.

[0021] In the figure: concentration tower 1, salt tower 2, thin-film evaporator 3, discharge tank 4, tar tank 5, incinerator 6, first steam heating section 7, second steam heating section 8, third steam heating section 9, fourth steam heating section 10, fifth steam heating section 11, steam main pipe 12, first steam flow regulating valve 13, second steam flow regulating valve 14, third steam flow regulating valve 15, fourth steam flow regulating valve 16, fifth steam flow regulating valve 17, first temperature sensor 18, second temperature sensor 19, third temperature sensor 20, fourth temperature sensor 21, fifth temperature sensor 22, sampling pipe 23, sampling valve 24, feed flow regulating valve 25, discharge temperature sensor 26, steam main valve 27, pipeline booster pump 28, screw pump 29, tar pump 30, low-boiling tower 31, high-boiling tower 32, BDO storage tank 33. Specific embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] Such as Figure 1An external discharge material separation and recovery system for improving the BDO yield is shown, including a concentration tower 1, a salt tower 2, a thin-film evaporator 3, and an incinerator 6; the bottom liquid discharge port of the concentration tower 1 is connected to the feed port of the salt tower 2 through a pipeline, the bottom liquid discharge port of the salt tower 2 is connected to the feed port of the thin-film evaporator 3 through a pipeline, the light component outlet at the top of the thin-film evaporator 3 is connected to the middle feed port of the salt tower 2 through a pipeline, the bottom liquid discharge port of the thin-film evaporator 3 is self-connected to the inlet of a discharge tank 4 through a pipeline, the outlet of the discharge tank 4 is connected to the inlet of a tar tank 5 through a pipeline, and the outlet of the tar tank 5 is connected to the inlet of the incinerator 6 through a pipeline; the top gas outlet of the thin-film evaporator 3 is connected to the middle inlet of the salt tower 2 through a pipeline, the top gas outlet of the salt tower 2 is connected to the feed port of a low-boiling tower 31 through a pipeline, the bottom liquid discharge port of the low-boiling tower 31 is connected to the feed port of a high-boiling tower 32 through a pipeline, and the side outlet of the high-boiling tower 32 is connected to the inlet of a BDO storage tank 33 through a pipeline. A pipeline booster pump 28 is provided on the pipeline connecting the thin-film evaporator 3 and the discharge tank 4, a screw pump 29 is provided on the pipeline connecting the discharge tank 4 and the tar tank 5, and a tar pump 30 is provided on the pipeline connecting the tar tank 5 and the incinerator 6.

[0025] The thin-film evaporator 3 is divided into a first steam heating section 7, a second steam heating section 8, a third steam heating section 9, a fourth steam heating section 10, and a fifth steam heating section 11 from top to bottom. A first steam inlet, a second steam inlet, a third steam inlet, a fourth steam inlet, and a fifth steam inlet are respectively provided on the first steam heating section 7, the second steam heating section 8, the third steam heating section 9, the fourth steam heating section 10, and the fifth steam heating section 11; the steam outlet end of a steam main pipe 12 is divided into 5 paths and is respectively connected to the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet, and the fifth steam inlet through pipelines;

[0026] At the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet, and the fifth steam inlet, there are respectively provided with a first steam flow regulating valve 13, a second steam flow regulating valve 14, a third steam flow regulating valve 15, a fourth steam flow regulating valve 16, and a fifth steam flow regulating valve 17; at the first steam heating section 7, the second steam heating section 8, the third steam heating section 9, the fourth steam heating section 10, and the fifth steam heating section 11, there are respectively provided with a first condensate outlet, a second condensate outlet, a third condensate outlet, a fourth condensate outlet, and a fifth condensate outlet; the first condensate outlet, the second condensate outlet, the third condensate outlet, the fourth condensate outlet, and the fifth condensate outlet are all connected to the condensate system through pipelines. On the inner walls of the thin film evaporator 3 corresponding to the first steam heating section 7, the second steam heating section 8, the third steam heating section 9, the fourth steam heating section 10, and the fifth steam heating section 11, there are respectively provided with a first temperature sensor 18, a second temperature sensor 19, a third temperature sensor 20, a fourth temperature sensor 21, and a fifth temperature sensor 22. At the bottom liquid discharge port of the thin film evaporator 3, there is provided a discharge temperature sensor 26, and at the steam outlet end of the steam main pipe 12, there is provided a steam main valve 27.

[0027] At the bottom liquid discharge port of the salt tower 2, there is provided a sampling port, at the sampling port, there is connected a sampling pipe 23, and at the sampling port, there is provided a sampling valve 24. At the feed inlet of the thin film evaporator 3, there is provided a feed flow regulating valve 25.

[0028] Working description:

[0029] After the material at the bottom of the concentration tower 1 enters the salt tower 2, the light components are separated from the top and enter the low-boiling tower 31, and then the low-boiling components are separated out. The bottom liquid then enters the high-boiling tower 32, and the BDO product is taken out from the side line of the high-boiling tower 32. Since the bottom liquid of the salt tower 2 still contains BDO, after entering the thin film evaporator 3 for evaporation, most of the BDO contained therein will be evaporated from the top of the thin film evaporator 3 as light components and returned to the salt tower 2 to participate in the separation again. Finally, the BDO in the material returned to the salt tower 2 is discharged from the top of the salt tower 2 and then enters the BDO storage tank 33 through the low-boiling tower 31 and the high-boiling tower 32 in sequence, realizing the recovery of BDO and thus improving the recovery rate of BDO.

[0030] In this embodiment, first, the steam flow rates entering each steam heating section of the thin-film evaporator 3 are adjusted in real time according to the actual temperature inside the thin-film evaporator 3. Specifically: In the initial stage of system operation, the valves of the first steam flow rate regulating valve 13, the second steam flow rate regulating valve 14, the third steam flow rate regulating valve 15, the fourth steam flow rate regulating valve 16, and the fifth steam flow rate regulating valve 17 are all fully open. After the system has been running for 48 hours, the temperatures inside the thin-film evaporator 3 corresponding to the first steam heating section 7, the second steam heating section 8, the third steam heating section 9, the fourth steam heating section 10, and the fifth steam heating section 11 are monitored respectively by the first temperature sensor 18, the second temperature sensor 19, the third temperature sensor 20, the fourth temperature sensor 21, and the fifth temperature sensor 22. And preset normal range values are set for the temperatures inside the thin-film evaporator 3 corresponding to each steam heating section in advance. When it is detected that the real-time temperature value of a certain section exceeds the preset corresponding range, the opening degree of the corresponding steam flow rate regulating valve is reduced by 5%; when it is detected that the real-time temperature value of a certain section is lower than the preset corresponding range, the opening degree of the corresponding steam flow rate regulating valve is increased by 5%. In order to improve the distillation efficiency, make more light components be evaporated, so as to better separate the materials and reduce the BDO content discharged at the bottom, different preset range values are set for the temperatures inside the thin-film evaporator 3 corresponding to each steam heating section in this embodiment, and the preset range values corresponding from top to bottom gradually decrease. In this way, a temperature difference will be formed from top to bottom inside the thin-film evaporator 3. During the actual operation process, the staff obtained through statistical analysis of the data that when the first steam flow rate regulating valve 13 and the second steam flow rate regulating valve 14 are fully closed, the opening degree of the third steam flow rate regulating valve 15 is adjusted to 50%, and the fourth steam flow rate regulating valve 16 and the fifth steam flow rate regulating valve 17 are fully open, a stable temperature difference can be formed inside the thin-film evaporator 3.

[0031] Meanwhile, during the system operation process, the tar content in the discharge of the salt tower 2 is monitored regularly through the sampling pipe 23, and the tar content in the sampled samples is detected. When it is detected that the tar in the sample exceeds 15%, the opening degree of the feed flow rate regulating valve 25 is increased to make more materials enter the thin-film evaporator 3. On the one hand, it improves the evaporation efficiency, and on the other hand, it avoids the temperature at the bottom of the salt tower 2 from being too high, thereby avoiding the heavy components from being distilled out and affecting the product quality of BDO. When it is detected that the tar in the sample is lower than 10%, the opening degree of the feed flow rate regulating valve 25 is reduced to reduce the amount of materials entering the thin-film evaporator 3, so that BDO can be fully separated from tar, salts, etc.

[0032] In addition, in this embodiment, the discharge temperature sensor 26 is also used to detect the discharge temperature of the thin-film evaporator 3. When the temperature is higher than 176 °C, the opening degree of the total steam valve 27 is adjusted to be smaller to reduce the steam volume, so as to avoid the evaporation of heavy components due to excessive temperature and affect the quality of the BDO product; when the temperature is lower than 168 °C, the opening degree of the total steam valve 27 is adjusted to be larger to increase the steam volume, so as to ensure that BDO is fully evaporated and only recovered, and finally achieve the effect of reducing the external discharge amount of BDO.

[0033] Through the technical transformation of this embodiment, the BDO concentration in the externally transported heavy components inside and outside the tar tank 5 can be reduced to about 25%, and then the BDO recovery rate can be increased from the original 88.9% to 91%. It is calculated that the annual increased income is expected to be 28.191 million yuan.

[0034] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for separating and recovering effluent materials for improving the yield of BDO, characterized in that: It includes a concentration tower, a salt tower, a thin film evaporator and an incinerator; the bottom liquid discharge port of the concentration tower is connected to the feed port of the salt tower through a pipeline, the bottom liquid discharge port of the salt tower is connected to the feed port of the thin film evaporator through a pipeline, the bottom liquid discharge port of the thin film evaporator is self-connected to the inlet of the discharge tank through a pipeline, the outlet of the discharge tank is connected to the inlet of the tar tank through a pipeline, and the outlet of the tar tank is connected to the inlet of the incinerator through a pipeline; the top gas outlet of the thin film evaporator is connected to the middle inlet of the salt tower through a pipeline, the top gas outlet of the salt tower is connected to the feed port of the low boiling tower through a pipeline, the bottom liquid discharge port of the low boiling tower is connected to the feed port of the high boiling tower through a pipeline, and the side outlet of the high boiling tower is connected to the inlet of the BDO storage tank through a pipeline; The thin film evaporator is divided into a first steam heating section, a second steam heating section, a third steam heating section, a fourth steam heating section and a fifth steam heating section from top to bottom, respectively, and a first steam inlet, a second steam inlet, a third steam inlet, a fourth steam inlet and a fifth steam inlet are respectively opened in the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section; the steam outlet end of the steam main pipe is divided into 5 routes, which are connected with the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet and the fifth steam inlet through pipelines respectively.

2. The effluent material separation and recovery system for improving BDO yield according to claim 1, characterized in that: A first steam flow regulating valve, a second steam flow regulating valve, a third steam flow regulating valve, a fourth steam flow regulating valve and a fifth steam flow regulating valve are respectively provided at the first steam inlet, the second steam inlet, the third steam inlet, the fourth steam inlet and the fifth steam inlet; A first condensate outlet, a second condensate outlet, a third condensate outlet, a fourth condensate outlet and a fifth condensate outlet are respectively provided on the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section; the first condensate outlet, the second condensate outlet, the third condensate outlet, the fourth condensate outlet and the fifth condensate outlet are all connected to the condensate system through pipelines.

3. The effluent material separation and recovery system for improving BDO yield according to claim 1, characterized in that: A first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and a fifth temperature sensor are respectively provided on the inner walls of the thin film evaporator corresponding to the first steam heating section, the second steam heating section, the third steam heating section, the fourth steam heating section and the fifth steam heating section.

4. The effluent material separation and recovery system for improving BDO yield according to claim 1, characterized in that: A sampling port is provided at the bottom liquid discharge port of the salt tower, a sampling tube is connected to the sampling port, and a sampling valve is provided at the sampling port.

5. The effluent material separation and recovery system for improving BDO yield according to claim 4, characterized in that: A feed flow regulating valve is provided at the feed inlet of the thin film evaporator.

6. The effluent material separation and recovery system for improving BDO yield according to claim 1, characterized in that: A discharge temperature sensor is provided at the discharge port of the tower bottom liquid of the thin film evaporator, and a steam main valve is provided at the steam outlet end of the steam main pipe.

7. The effluent material separation and recovery system for improving BDO yield according to claim 1, characterized in that: A pipeline booster pump is provided on the pipeline connecting the thin film evaporator and the discharge tank, a screw pump is provided on the pipeline connecting the discharge tank and the tar tank, and a tar pump is provided on the pipeline connecting the tar tank and the incinerator.

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