A recovery device and method for cyclohexanol

Abstract

This invention provides a cyclohexanol recovery device and method. The device includes a cyclohexanol evaporator, a first heat exchanger, a first cyclohexanol distillation and recovery assembly, a second heat exchanger, a ceramic membrane filter, a preheater, and a second cyclohexanol distillation and recovery assembly. The inlet of the cyclohexanol evaporator is connected to a cyclohexanol separation tower. The product outlet of the cyclohexanol evaporator is connected to the first cyclohexanol distillation and recovery assembly via the first heat exchanger. The discharge outlet of the cyclohexanol evaporator is connected to the inlet of the second heat exchanger. The discharge outlet of the second heat exchanger is connected to the inlet of the ceramic membrane filter. The product outlet of the ceramic membrane filter is connected to the second cyclohexanol distillation and recovery assembly via the preheater. This invention recovers cyclohexanol at the source, before waste oil mixing. Simultaneously, filtration of the catalyst before distillation avoids the risk of catalyst clogging in subsequent stages, thereby improving the simplicity and efficiency of cyclohexanol recovery.

Description

Technical Field

[0001] This invention relates to the field of chemical preparation technology, and in particular to a device and method for recovering cyclohexanol. Background Technology

[0002] Cyclohexanol is an important chemical raw material and a crucial intermediate in the production of cyclohexanone. Its production typically employs the cyclohexane oxidation method and the cyclohexene hydration method. Because the cyclohexane oxidation method generates large quantities of difficult-to-treat alcohol ester wastewater, an increasing number of manufacturers are now using the cyclohexene hydration method to produce cyclohexanol. This process uses ZSM-5 molecular sieves as a catalyst. After the reaction, the residue flows into a distillation section where unreacted cyclohexene is distilled off and returned to the hydration reactor. After the cyclohexanol is recovered, the remaining bottom material is discharged as effluent.

[0003] The main components of the discharged cyclohexanol are cyclohexanol, small amounts of cyclohexane, cyclohexene, methylcyclopentane, heavy components, and entrained catalyst. The cyclohexanol content in this cyclohexanol is as high as 98%. Currently, this cyclohexanol is directly fed into fuel oil for recycling. Taking a 200,000-ton / year cyclohexanol production unit as an example, approximately 1,000 tons of discharged cyclohexanol flow into fuel oil annually, of which more than 980 tons are cyclohexanol. Directly using cyclohexanol as fuel results in significant waste. Recovering the cyclohexanol would undoubtedly bring considerable economic benefits to the company.

[0004] Based on this, CN105669346 discloses a method for the comprehensive recovery and utilization of waste oil from cyclohexanone units. This process collects waste oil from all cyclohexanone units and uses a single-tower process for separation and recovery. The recovered product is sent back to the original cyclohexanone unit for comprehensive utilization, effectively reducing resource waste. However, when the various feed streams are mixed and flow into fuel oil before separation, the composition is complex and contains difficult-to-separate by-product impurities, increasing the difficulty of separation. Simple distillation recovery is only performed according to light and heavy components, and the recovery of the single component cyclohexanol is not achieved.

[0005] Therefore, there is an urgent need for a simple and efficient cyclohexanol recovery scheme. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, the present invention provides a cyclohexanol recovery device and method, which can improve the ease and efficiency of cyclohexanol recovery.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a cyclohexanol recovery device, comprising a cyclohexanol evaporator, a first heat exchanger, a first cyclohexanol distillation recovery assembly, a second heat exchanger, a ceramic membrane filter, a preheater, and a second cyclohexanol distillation recovery assembly.

[0009] The feed inlet of the cyclohexanol evaporator is used to connect with the cyclohexanol separation tower;

[0010] The product outlet of the cyclohexanol evaporator is connected to the first cyclohexanol distillation and recovery assembly via a first heat exchanger. The discharge outlet of the cyclohexanol evaporator is connected to the inlet of the second heat exchanger. The outlet of the second heat exchanger is connected to the inlet of the ceramic membrane filter. The product outlet of the ceramic membrane filter is connected to the second cyclohexanol distillation and recovery assembly via a preheater.

[0011] The beneficial effects of this invention are as follows:

[0012] 1. After the hydration reaction, the product is first evaporated in an evaporator to recover most of the cyclohexanol. Then, the bottom liquid from the cyclohexanol evaporator is filtered with a solid catalyst, followed by distillation for recovery. This method reduces the ineffective separation and filtration of a large amount of cyclohexanol, alleviating the operating load and investment costs of subsequent filtration equipment. Simultaneously, separation and recovery occur before fuel oil mixing, recovering cyclohexanol at its source, thus improving the simplicity and efficiency of cyclohexanol recovery.

[0013] 2. The solid catalyst was filtered before distillation to avoid the risk of blockage of the second cyclohexanol distillation and recovery unit by the solid catalyst, which can further improve the simplicity and efficiency of cyclohexanol recovery.

[0014] Optionally, it also includes a catalyst buffer tank and a circulation pump, the circulation pump being disposed between the second heat exchanger and the ceramic membrane filter;

[0015] The discharge outlet of the ceramic membrane filter is connected to the top inlet of the catalyst buffer tank, and the catalyst buffer tank is connected to the inlet of the circulating pump through the discharge outlet in the middle side area.

[0016] As described above, solid catalyst is accumulated in a catalyst buffer tank, while other liquid feed is recycled to the ceramic membrane filter and the first cyclohexanol distillation and recovery unit for continuous filtration, distillation and recovery, thereby further improving the recovery efficiency of cyclohexanol.

[0017] Optionally, the first cyclohexanol distillation and recovery assembly includes a first cyclohexanol distillation column and a first cyclohexanol buffer tank, and the second cyclohexanol distillation and recovery assembly includes a second cyclohexanol distillation column and a second cyclohexanol buffer tank.

[0018] The feed inlet of the first cyclohexanol distillation column is connected to the product outlet of the cyclohexanol evaporator through a first heat exchanger, and the outlet is connected to the first cyclohexanol buffer tank.

[0019] The feed inlet of the second cyclohexanol distillation column is connected to the product outlet of the ceramic membrane filter via a preheater, and the outlet is connected to the second cyclohexanol buffer tank.

[0020] Optionally, the reaction temperature of the cyclohexanol evaporator is 150-170°C, the material temperature at the outlet of the first heat exchanger is 90-100°C, the liquid temperature at the outlet of the second heat exchanger is 50-60°C, and the material temperature at the outlet of the preheater is 90-100°C.

[0021] Alternatively, the ceramic membrane filter can be replaced by a bag filter containing submicron-sized filter cloth.

[0022] In a second aspect, the present invention provides a method for recovering cyclohexanol, using a cyclohexanol recovery apparatus according to the first aspect, comprising the following steps:

[0023] S1. The bottom liquid of the cyclohexanol separation tower is fed into the cyclohexanol evaporator for evaporation. The vaporized cyclohexanol is cooled by the first heat exchanger and then flows into the first cyclohexanol distillation and recovery component to recover the vaporized cyclohexanol. The unvaporized liquid accumulates at the bottom of the cyclohexanol evaporator and flows into the second heat exchanger.

[0024] S2. The second heat exchanger pumps the cooled liquid into the ceramic membrane filter. The filtered liquid from the ceramic membrane filter is heated by the preheater and then flows into the second cyclohexanol distillation and recovery unit.

[0025] Optionally, step S2 further includes:

[0026] The filtered liquid from the ceramic membrane filter flows into the catalyst buffer tank, where the solid catalyst accumulates. Once the preset concentration is reached, the catalyst is discharged from the recovery system for harmless treatment. The remaining liquid phase is circulated into the ceramic membrane filter by a circulation pump.

[0027] Optionally, in step S1, the vaporized cyclohexanol is cooled by a first heat exchanger and then flows into the first cyclohexanol distillation and recovery assembly, which includes:

[0028] After being cooled by the first heat exchanger, the vaporized cyclohexanol flows into the first cyclohexanol distillation column for distillation, and then is stored in the first cyclohexanol buffer tank.

[0029] The filtered liquid from the ceramic membrane filter flowing into the second cyclohexanol distillation and recovery unit in step S2 includes:

[0030] The filtered liquid from the ceramic membrane filter is heated by a preheater and then flows into the second cyclohexanol distillation column for distillation. After that, it is stored in the second cyclohexanol buffer tank and cooled by the first heat exchanger.

[0031] Optionally, the reaction temperature of the cyclohexanol evaporator is 150-170°C, the material temperature at the outlet of the first heat exchanger is 90-100°C, the liquid temperature at the outlet of the second heat exchanger is 50-60°C, and the material temperature at the outlet of the preheater is 90-100°C.

[0032] Alternatively, the ceramic membrane filter can be replaced by a bag filter containing submicron-sized filter cloth.

[0033] The technical effects of the cyclohexanol recovery method provided in the second aspect are described in the relevant description of the cyclohexanol recovery apparatus provided in the first aspect. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a cyclohexanol recovery device according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic flowchart of a method for recovering cyclohexanol according to an embodiment of the present invention.

[0036] [Explanation of Labels in the Attached Image]

[0037] E-901A, Cyclohexanol Evaporator; E-901B, First Heat Exchanger; T-901B, First Cyclohexanol Distillation Column; V-901B, First Cyclohexanol Buffer Tank; E-901C, Second Heat Exchanger; P-901, Circulation Pump; M-901, Ceramic Membrane Filter; V-901A, Catalyst Buffer Tank; E-901D, Preheater; T-901C, Second Cyclohexanol Distillation Column; V-901C, Second Cyclohexanol Buffer Tank;

[0038] R-901, hydration reactor; T-901A, cyclohexanol separation tower. Detailed Implementation

[0039] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0040] Example 1

[0041] Currently, the cyclohexanol-containing feed solution from cyclohexene hydration is directly fed into fuel oil for recycling, resulting in significant economic losses. Existing solutions involve separating the fuel oil, but these methods suffer from separation difficulties and low recovery efficiency. Therefore, this embodiment improves the traditional cyclohexanol recovery device as follows:

[0042] Please refer to Figure 1 A cyclohexanol recovery device includes a cyclohexanol evaporator E-901A, a first heat exchanger E-901B, a first cyclohexanol distillation recovery assembly, a second heat exchanger E-901C, a catalyst buffer tank V-901A, a circulating pump P-901, a ceramic membrane filter M-901, a preheater E-901D, and a second cyclohexanol distillation recovery assembly; wherein the first cyclohexanol distillation recovery assembly includes a first cyclohexanol distillation column T-901B and a first cyclohexanol buffer tank V-901B, and the second cyclohexanol distillation recovery assembly includes a second cyclohexanol distillation column T-901C and a second cyclohexanol buffer tank V-901C.

[0043] In this embodiment, the feed inlet of the cyclohexanol evaporator E-901A is used to connect with the cyclohexanol separation tower T-901A.

[0044] In this embodiment, the product outlet of the cyclohexanol evaporator E-901A is connected to the first cyclohexanol distillation and recovery assembly through the first heat exchanger E-901B. That is, the feed inlet of the first cyclohexanol distillation column T-901B is connected to the product outlet of the cyclohexanol evaporator E-901A through the first heat exchanger E-901B, and the discharge outlet is connected to the first cyclohexanol buffer tank V-901B.

[0045] In this embodiment, the discharge outlet of the cyclohexanol evaporator E-901A is connected to the inlet of the second heat exchanger E-901C. The outlet of the second heat exchanger E-901C is connected to the inlet of the circulating pump P-901. The outlet of the circulating pump P-901 is connected to the inlet of the ceramic membrane filter M-901. The product outlet of the ceramic membrane filter M-901 is connected to the second cyclohexanol distillation and recovery assembly via the preheater E-901D. Specifically, the inlet of the second cyclohexanol distillation column T-901C is connected to the product outlet of the ceramic membrane filter M-901 via the preheater E-901D, and its outlet is connected to the second cyclohexanol buffer tank V-901C. Simultaneously, the discharge outlet of the ceramic membrane filter M-901 is connected to the top inlet of the catalyst buffer tank V-901A, and the catalyst buffer tank V-901A is connected to the inlet of the circulating pump P-901 via the outlet in the middle side region.

[0046] Therefore, the process flow of the present invention is as follows:

[0047] 1. The raw material cyclohexene enters the hydration reactor R-901 for reaction, and the product enters the cyclohexanol separation tower T-901A for separation. The separated and recovered cyclohexene is returned to the hydration reactor R-901.

[0048] The reaction temperature inside the cyclohexanol separation tower T-901A is 60-80℃, the top temperature is 50℃, the bottom temperature is 82℃, and the pressure is 40kPa.

[0049] 2. The liquid to be recovered in the cyclohexanol separation tower T-901A enters the cyclohexanol evaporator E-901A. After evaporation and vaporization, the gaseous components are cooled by the first heat exchanger E-901B and then flow into the first cyclohexanol distillation tower T-901B. After distillation, the cyclohexanol with the required purity flows into the first cyclohexanol buffer tank V-901B.

[0050] The reaction temperature of the first cyclohexanol distillation column T-901B is 150-170℃, the top temperature is 140℃, the bottom temperature is 160℃, and the pressure is atmospheric pressure or slightly negative pressure.

[0051] 3. At this point, the bottom of the cyclohexanol evaporator E-901A contains a feed liquid mainly composed of solid catalyst and cyclohexanol, with an internal temperature of 150–170°C. After entering the second heat exchanger E-901C and cooling to 50–60°C, it is pumped into the ceramic membrane filter M-901 via the circulation pump P-901. The ceramic membrane filter M-901 filters and separates the solid catalyst, which is then collected in the catalyst buffer tank V-901A. The remaining liquid feed liquid is circulated and filtered through the circulation pump P-901. The filtered clear liquid obtained from the ceramic membrane filter M-901 is heated by the preheater E-901D and then flows into the second cyclohexanol distillation column T-901C. The cyclohexanol with the required purity flows into the second cyclohexanol buffer tank V-901C, thus realizing the recovery of cyclohexanol from the feed liquid.

[0052] The clarified liquid filtered by the ceramic membrane filter M-901 is 50-60℃. After being heated to 90-100℃ by the preheater E-901D, it enters the second cyclohexanol distillation column T-901C. The reaction temperature of the second cyclohexanol distillation column T-901C is 160-180℃, the top temperature is 150℃, the bottom temperature is 170℃, and the pressure is atmospheric pressure or slightly negative pressure.

[0053] Because the composition of the substances entering the first cyclohexanol distillation column T-901B and the second cyclohexanol distillation column T-901C is different, the two cyclohexanol distillation columns cannot be used interchangeably.

[0054] It should be noted that in the bottom feed liquid of the cyclohexanol evaporator E-901A, cyclohexanol accounts for about 98%, catalyst accounts for about 0.4%, the remaining heavy components account for about 0.9%, and the rest consists of small amounts of light components, cyclohexane, cyclohexene, etc.

[0055] Among them, the bottom liquid of the E-901A cyclohexanol evaporator is filtered and distilled, and the cyclohexanol recovery rate reaches 96%. The purity of the recovered cyclohexanol is greater than the national requirement of 99.7%, so it can be directly used in the process flow.

[0056] In other embodiments, the ceramic membrane filter M-901 can be replaced by a bag filter containing submicron filter cloth, which can also achieve catalyst solid separation process, but the filter cloth needs to be replaced frequently, the operation is more cumbersome, and it is not suitable for continuous operation.

[0057] Example 2

[0058] Please refer to Figure 1 and Figure 2 A method for recovering cyclohexanol, using a cyclohexanol recovery apparatus as described in Example 1, includes the following steps:

[0059] S1. The bottom liquid of the cyclohexanol separation tower T-901A is fed into the cyclohexanol evaporator E-901A for evaporation. The vaporized cyclohexanol is cooled by the first heat exchanger E-901B and then flows into the first cyclohexanol distillation and recovery component. The unvaporized liquid accumulates at the bottom of the cyclohexanol evaporator E-901A and flows into the second heat exchanger E-901C.

[0060] In step S1, the vaporized cyclohexanol is cooled by the first heat exchanger E-901B and then flows into the first cyclohexanol distillation and recovery assembly, which includes:

[0061] After being cooled by the first heat exchanger E-901B, the vaporized cyclohexanol flows into the first cyclohexanol distillation column T-901B for distillation, and then is stored in the first cyclohexanol buffer tank V-901B.

[0062] S2, the second heat exchanger E-901C pumps the cooled feed liquid into the ceramic membrane filter M-901. The filtered liquid from the ceramic membrane filter M-901 is heated by the preheater E-901D and then flows into the second cyclohexanol distillation and recovery unit.

[0063] Step S2 further includes:

[0064] The filtered liquid from the ceramic membrane filter M-901 flows into the catalyst buffer tank V-901A. The solid catalyst accumulates in the catalyst buffer tank V-901A. After reaching the preset concentration, it is discharged from the recovery system for harmless treatment. The remaining liquid phase is circulated into the ceramic membrane filter M-901 through the circulation pump P-901.

[0065] The preset concentration is 20%-30%.

[0066] In step S2, the filtered liquid from the ceramic membrane filter M-901 is heated by the preheater E-901D and then flows into the second cyclohexanol distillation and recovery assembly, including:

[0067] The filtered liquid from the ceramic membrane filter M-901 is heated by the preheater E-901D and then flows into the second cyclohexanol distillation column T-901C for distillation, and then stored in the second cyclohexanol buffer tank V-901C.

[0068] In this embodiment, the reaction temperature of the cyclohexanol evaporator E-901A is 150-170°C, the material temperature at the outlet of the first heat exchanger E-901B is 90-100°C, the liquid temperature at the outlet of the second heat exchanger E-901C is 50-60°C, and the material temperature at the outlet of the preheater is 90-100°C. For example, if the reaction temperature of the cyclohexanol evaporator E-901A is 160°C, the material temperature at the outlet of the first heat exchanger is 96°C, the liquid temperature at the outlet of the second heat exchanger E-901C is 56°C, and the material temperature at the outlet of the preheater is 100°C.

[0069] In this embodiment, the ceramic membrane filter M-901 can be replaced by a bag filter containing submicron filter cloth.

[0070] For other descriptions of this second embodiment, please refer to the first embodiment.

[0071] In summary, Embodiments 1 and 2 have the following beneficial effects:

[0072] 1. In this embodiment, the separation and recovery device operates at the top and bottom of the cyclohexanol evaporator E-901A. Therefore, this embodiment treats the waste oil during the production process, rather than separating and recovering it after all the waste oil is collected. This is equivalent to reducing the total waste oil content and composition complexity from the source. At the same time, the cyclohexanol component in this waste oil has a high concentration and accounts for the largest proportion of the total waste oil source. Therefore, this embodiment can improve the simplicity and efficiency of cyclohexanol recovery.

[0073] 2. In this embodiment, cyclohexanol was first evaporated using an E-901A evaporator before filtration and separation of the solid catalyst, recovering most of the cyclohexanol product. The feed solution was then filtered using the solid catalyst, followed by distillation to recover the cyclohexanol. This method reduces the separation and filtration of a large amount of ineffective products, thus alleviating the operating load and investment costs of subsequent filtration equipment.

[0074] 3. In this embodiment, before separating and recovering the bottom liquid of the cyclohexanol evaporator E-901A, the solid catalyst is first filtered through the ceramic membrane filter M-901. This avoids the risk of the solid catalyst clogging the circulating pump, circulating pipeline and recovery components of the cyclohexanol distillation section, and can further improve the simplicity and efficiency of cyclohexanol recovery.

[0075] 4. In terms of economic benefits, recovering and utilizing cyclohexanol that would otherwise end up in fuel oil, for example, a 200,000-ton / year cyclohexanone plant can generate nearly ten million yuan in economic benefits annually from cyclohexanol recovery. Therefore, it can increase the company's economic efficiency.

[0076] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0077] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0078] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0079] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0080] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for recovering cyclohexanol, characterized in that, It includes a cyclohexanol evaporator, a first heat exchanger, a first cyclohexanol distillation and recovery assembly, a second heat exchanger, a ceramic membrane filter, a preheater, and a second cyclohexanol distillation and recovery assembly; The feed inlet of the cyclohexanol evaporator is used to connect with the cyclohexanol separation tower; The product outlet of the cyclohexanol evaporator is connected to the first cyclohexanol distillation and recovery assembly via a first heat exchanger. The discharge outlet of the cyclohexanol evaporator is connected to the inlet of the second heat exchanger. The outlet of the second heat exchanger is connected to the inlet of the ceramic membrane filter. The product outlet of the ceramic membrane filter is connected to the second cyclohexanol distillation and recovery assembly via a preheater.

2. The cyclohexanol recovery device according to claim 1, characterized in that, It also includes a catalyst buffer tank and a circulation pump, the circulation pump being disposed between the second heat exchanger and the ceramic membrane filter; The discharge outlet of the ceramic membrane filter is connected to the top inlet of the catalyst buffer tank, and the catalyst buffer tank is connected to the inlet of the circulating pump through the discharge outlet in the middle side area.

3. The cyclohexanol recovery device according to claim 2, characterized in that, The first cyclohexanol distillation and recovery assembly includes a first cyclohexanol distillation column and a first cyclohexanol buffer tank, and the second cyclohexanol distillation and recovery assembly includes a second cyclohexanol distillation column and a second cyclohexanol buffer tank. The feed inlet of the first cyclohexanol distillation column is connected to the product outlet of the cyclohexanol evaporator through a first heat exchanger, and the outlet is connected to the first cyclohexanol buffer tank. The feed inlet of the second cyclohexanol distillation column is connected to the product outlet of the ceramic membrane filter via a preheater, and the outlet is connected to the second cyclohexanol buffer tank.

4. The cyclohexanol recovery device according to claim 1, characterized in that, The reaction temperature of the cyclohexanol evaporator is 150~170℃, the material temperature at the outlet of the first heat exchanger is 90~100℃, and the liquid temperature at the outlet of the second heat exchanger is 50~60℃.

5. The cyclohexanol recovery device according to claim 1, characterized in that, The ceramic membrane filter can be replaced by a bag filter containing submicron-sized filter cloth.

6. A method for recovering cyclohexanol, using the cyclohexanol recovery apparatus according to claim 3, characterized in that, Includes the following steps: S1. The bottom liquid of the cyclohexanol separation tower is fed into the cyclohexanol evaporator for evaporation. The vaporized cyclohexanol is cooled by the first heat exchanger and then flows into the first cyclohexanol distillation and recovery unit. The unvaporized liquid accumulates at the bottom of the cyclohexanol evaporator and flows into the second heat exchanger. S2. The second heat exchanger pumps the cooled liquid into the ceramic membrane filter. The filtered liquid from the ceramic membrane filter is heated by the preheater and then flows into the second cyclohexanol distillation and recovery unit.

7. The method for recovering cyclohexanol according to claim 6, characterized in that, Step S2 further includes: The filtered liquid from the ceramic membrane filter flows into the catalyst buffer tank, where the solid catalyst accumulates. Once the preset concentration is reached, the catalyst is discharged from the recovery system for harmless treatment. The remaining liquid phase is circulated into the ceramic membrane filter by a circulation pump.

8. The method for recovering cyclohexanol according to claim 6, characterized in that, In step S1, the vaporized cyclohexanol is cooled by the first heat exchanger and then flows into the first cyclohexanol distillation and recovery assembly, which includes: After being cooled by the first heat exchanger, the vaporized cyclohexanol flows into the first cyclohexanol distillation column for distillation, and then is stored in the first cyclohexanol buffer tank. The clarified liquid from the ceramic membrane filter in step S2 is heated by a preheater and then flows into the second cyclohexanol distillation and recovery assembly, including: The filtered liquid from the ceramic membrane filter is heated by a preheater and then flows into the second cyclohexanol distillation column for distillation, and then stored in the second cyclohexanol buffer tank.

9. The method for recovering cyclohexanol according to claim 6, characterized in that, The reaction temperature of the cyclohexanol evaporator is 150~170℃, the material temperature at the outlet of the first heat exchanger is 90~100℃, the liquid temperature at the outlet of the second heat exchanger is 50~60℃, and the material temperature at the outlet of the preheater is 90~100℃.

10. The method for recovering cyclohexanol according to claim 6, characterized in that, The ceramic membrane filter can be replaced by a bag filter containing submicron-sized filter cloth.

Images