Energy-saving device for separating refined phenol from tar crude phenol

Abstract

The utility model relates to an energy-saving device for separating refined phenol from tar crude phenol, and belongs to the field of tar crude phenol refining. The device comprises a separation device and an energy-saving thermal circulation loop device, the separation device comprises a first tower, a second tower, a third tower, a fourth tower, a fifth tower and matched cold exchange equipment, and the energy-saving thermal circulation loop device comprises a compressor, a throttling valve, a buffer tank and matched cold exchange equipment. According to the energy-saving device, high-purity products are obtained through dehydration, light component removal, phenol residue removal and phenol, o-cresol and m-cresol and p-cresol refining of tar crude phenol, the product purity is improved by dividing the area in the tower, low-grade waste heat is converted into a high-grade heat source through a compressor, traditional heating media and refrigerants are replaced, and the energy-saving purpose is achieved. According to the device, the tar crude phenol is separated and refined into high-purity phenol, o-cresol and m-cresol and p-cresol products, meanwhile, the purposes of saving energy and reducing consumption are achieved, and the device has important significance.

Description

Technical Field

[0001] This utility model relates to the refining of crude phenol from tar, and more specifically to an energy-saving device for separating refined phenol from crude phenol in tar. Background Technology

[0002] Crude phenol is a byproduct of industrial processes, commonly found in tar. It is a mixture of various phenols with highly diverse and complex components, resulting in low efficiency for direct utilization. Direct use of crude phenol degrades the performance and stability of downstream products. Therefore, it needs to be refined and purified to convert crude phenol into high-value-added products to meet the demands of high-end industries. Phenol and cresol, among other crude phenols, are key raw materials for synthetic resins, pharmaceuticals, and pesticides, with large market demand. However, industrial-grade phenols must have a purity of ≥99%.

[0003] The refining of crude phenol mainly employs distillation. Since the boiling points of various effective phenolic products in crude phenol are relatively close, batch distillation requires multiple batches and repeated distillations, resulting in extremely high energy consumption, significant phenol loss, and low yield. While continuous distillation improves the yield somewhat compared to batch distillation, it requires multiple columns and repeated purification to obtain a higher concentration, and the operating reflux ratio is consistently high, leading to a long production process and high energy consumption.

[0004] In summary, the refining of crude phenol from tar is complex and energy-intensive, reflecting multi-dimensional demands in terms of resources, environment, technology, and economy. The core challenge lies in achieving efficient separation and high-value conversion of complex mixtures of crude phenol through technological innovation. Therefore, developing efficient and low-cost energy-saving equipment for refining crude phenol from tar can enhance product competitiveness while reducing environmental pollution and achieving energy-saving goals. Patents CN102731264 and CN107721826 both disclose devices for continuous distillation separation of crude phenol from tar, but neither mentions energy-saving measures. Furthermore, to obtain high-purity phenol products, patent CN107721826 configures a pre-component tower before each product tower, further increasing operating energy consumption and the number of devices. Patents CN214088348U and CN114436782A disclose devices and methods for recovering phenol from tar using multi-effect distillation, but do not mention energy-saving measures for the production of other phenolic products. Utility Model Content

[0005] The purpose of this invention is to provide an energy-saving device for separating refined phenol from crude phenol in tar. By utilizing the heat from the overhead condenser in the recovery unit, it efficiently converts the heat into a heating source for the bottom reboiler, thus achieving energy savings. Further energy savings and improved product purity are achieved by separating the forefraction within a specific region of the column.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An energy-saving device for separating refined phenol from crude phenol in tar includes a first tower, a first tower condenser, a first tower reboiler, a second tower, a second tower condenser, a second tower reboiler, a third tower, a third tower condenser, a third tower reboiler, a fourth tower, a fourth tower condenser, a fourth tower reboiler, a fifth tower, a fifth tower condenser, a fifth tower reboiler, a compressor, a throttling valve, and a buffer tank.

[0008] Material pipelines connect Tower 1, the hot side of Tower 1 condenser, the cold side of Tower 1 reboiler, Tower 2, the hot side of Tower 2 condenser, the cold side of Tower 2 reboiler, Tower 3, the hot side of Tower 3 condenser, the cold side of Tower 3 reboiler, Tower 4, the hot side of Tower 4 condenser, the cold side of Tower 4 reboiler, and Tower 5, the hot side of Tower 5 condenser, and the cold side of Tower 5 reboiler, forming a separation device.

[0009] The cold side of the second condenser, the cold side of the third condenser, the cold side of the fourth condenser, the cold side of the fifth condenser, the compressor, the hot side of the first reboiler, the hot side of the third reboiler, the hot side of the fourth reboiler, the hot side of the fifth reboiler, the throttle valve, and the buffer tank are connected by working fluid pipelines. The pipelines are filled with heat transfer working fluid to form an energy-saving heat cycle main loop device.

[0010] Furthermore, the cold side of the condenser in Tower 1 is connected to refrigerant circulating water or low-temperature water, while the hot side of the reboiler in Tower 2 is connected to heat transfer medium steam, heat transfer oil, or electric heating.

[0011] Furthermore, a partition plate is installed in the upper middle part of the fourth tower, dividing the tower into three areas: A, B, and C. The tops of areas A and B are connected to their respective condensers, while the bottom of area C is connected to the reboiler.

[0012] Furthermore, a partition plate is installed in the upper middle part of the tower to divide the tower into three areas: A, B, and C. The tops of areas A and B are connected to their respective condensers, and the bottom of area C is connected to the reboiler.

[0013] Furthermore, the buffer tank is equipped with heat exchange tubes connected to a heat medium or a cold medium. The buffer tank body is equipped with a supplementary working fluid inlet, and the bottom and top of the buffer tank are connected to working fluid pipes, forming an energy-saving heat circulation secondary loop device.

[0014] Furthermore, the heat transfer medium filled in the pipeline of the energy-saving heat circulation loop device is water, or R22, or R32, or R134, or R245, or R454, or R290, or R744, or CO2.

[0015] Furthermore, towers one, two, three, four, and five are equipped with mass transfer packing materials and tower internals or tower plates.

[0016] Furthermore, the hot side of the condenser at the top of Tower 4A is connected to the top of Tower 4 and the middle of Tower 3 by a material pipeline.

[0017] Furthermore, the hot side of the condenser at the top of Tower 5A is connected to the top of Tower 5 and the bottom of Tower 4B by material pipelines.

[0018] The energy-saving device for separating refined phenols from crude phenols in tar, as described in this utility model, has the following beneficial effects:

[0019] (1) The present invention discloses an energy-saving device for separating refined phenol from crude phenol in tar. The crude phenol is separated and refined in a fully continuous manner to obtain a variety of high-quality phenol products. The whole process has low energy consumption, simple operation, and is suitable for large-scale continuous production, with good social and economic benefits.

[0020] (2) The present invention discloses an energy-saving device for separating refined phenol from crude phenol in tar. The entire device only requires one heat supply on the hot side of the second reboiler and one cooling supply on the cold side of the first condenser, resulting in a significant reduction in overall energy consumption. The heat transfer medium is used to recover the heat from the hot side of the second, third, fourth, and fifth condensers. After the heat quality is improved by the compressor, it is used to heat the bottom material of the first, third, fourth, and fifth reboilers. This saves the heat originally required by the hot side of the first, third, fourth, and fifth reboilers, as well as the cooling originally required by the cold side of the second, third, fourth, and fifth condensers, achieving a significant energy-saving effect.

[0021] (3) The present invention discloses an energy-saving device for separating refined phenol from crude phenol in tar. Multiple devices in the whole device share a common energy-saving heat circulation loop device, which greatly reduces equipment investment.

[0022] (4) The present invention discloses an energy-saving device for separating refined phenol from crude phenol in tar. A partition plate is installed in the upper middle part of the four towers to further remove the fore-distillate, reduce the number of tower equipment and improve the quality of the product. This not only further achieves the energy-saving effect, but also reduces the investment cost of the device.

[0023] (5) The present invention discloses an energy-saving device for separating refined phenol from crude phenol in tar. A partition plate is installed in the upper middle part of the five-tower to further remove the fore-distillate, reduce the number of tower equipment and improve the quality of the product. This not only further achieves the energy-saving effect, but also reduces the investment cost of the device. Attached Figure Description

[0024] To further illustrate this utility model, the following figures are provided:

[0025] Figure 1 This is a schematic diagram of the device flow of Embodiment 1 of this utility model.

[0026] Figure 2 This is a schematic diagram of the device flow of Embodiment 2 of this utility model.

[0027] Explanation of reference numerals in the attached diagram: 1 is Tower 1; 2 is Tower 2; 3 is Tower 3; 4 is Tower 4; 5 is Tower 5; 6 is Tower 1 condenser; 7 is Tower 2 condenser; 8 is Tower 3 condenser; 9 is Tower 4 condenser I; 10 is Tower 4 condenser II; 11 is Tower 5 condenser I; 12 is Tower 5 condenser II; 13 is Tower 1 reboiler; 14 is Tower 2 reboiler; 15 is Tower 3 reboiler; 16 is Tower 4 reboiler; 17 is Tower 5 reboiler; 18 is compressor; 19 is throttle valve; 20 is buffer tank; 21 is mass transfer packing and internal components of the tower or tower tray; 22 is partition plate; 23 is heat exchange tube; 24 is preheater; 25 is regulating valve; 26 is pump; A is partitioned area A in the tower; B is partitioned area B in the tower; C is partitioned area C in the tower; HWS is heat medium inlet; HWR is heat medium return; RWS is refrigerant inlet; RWR is refrigerant return. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example 1

[0029] Reference Figure 1 This embodiment provides an energy-saving device for separating refined phenol from crude phenol in tar. The device includes tower 1, tower 2, tower 3, tower 4, tower 5, tower 1 condenser 6, tower 2 condenser 7, tower 3 condenser 8, tower 4 condenser I 9, tower 4 condenser II 10, tower 5 condenser I 11, tower 5 condenser II 12, tower 1 reboiler 13, tower 2 reboiler 14, tower 3 reboiler 15, tower 4 reboiler 16, tower 5 reboiler 17, compressor 18, throttle valve 19, buffer tank 20, regulating valve 25, and pump 26.

[0030] Towers 1, 2, 3, 4, and 5 are all vertical towers, and each is equipped with mass transfer packing and internal components or trays 21. Towers 4 and 5 are equipped with partition plates 22, which divide the interior of the tower into three regions: A, B, and C.

[0031] The tower 1, tower 1 condenser 6 (hot side), tower 1 reboiler 13 (cold side), tower 2, tower 2 condenser 7 (hot side), tower 2 reboiler 14 (cold side), tower 3, tower 3 condenser 8 (hot side), tower 3 reboiler 15 (cold side), tower 4, tower 4 condenser I 9 (hot side), tower 4 condenser II 10 (hot side), tower 4 reboiler 16 (cold side), tower 5, tower 5 condenser I 11 (hot side), tower 5 condenser II 12 (hot side), and tower 5 reboiler 17 (cold side) are connected by material pipelines to form a separation device.

[0032] The cold side of the second condenser 7, the cold side of the third condenser 8, the cold side of the fourth condenser I 9, the cold side of the fourth condenser II 10, the cold side of the fifth condenser I 11, the cold side of the fifth condenser II 12, the compressor 18, the hot side of the first reboiler 13, the hot side of the third reboiler 15, the hot side of the fourth reboiler 16, the hot side of the fifth reboiler 17, the throttle valve 19, and the buffer tank 20 are connected by a working fluid pipeline, which is filled with heat transfer working fluid to form an energy-saving heat cycle main loop device; the buffer tank 20, the regulating valve 25, and the pump 26 form an energy-saving heat cycle secondary loop device.

[0033] The cold side of the first-stage condenser 6 is connected to a refrigerant, which can be either circulating water or low-temperature water; in this embodiment, circulating water is preferred. The hot side of the second-stage reboiler 14 is connected to a heat transfer medium, which can be either steam, thermal oil, or electric heating; in this embodiment, thermal oil is preferred.

[0034] The buffer tank 20 is equipped with a heat exchange tube 23, which is connected to the refrigerant circulating water. The buffer tank body is provided with a replenishment working fluid inlet. The heat transfer working fluid can be water, R22, R32, R134, R245, R454, R290, R744, or CO2. In this embodiment, water is preferred, and the corresponding working fluid liquid is liquid water, and the working fluid vapor is water vapor.

[0035] Using the energy-saving device provided in this embodiment, refined phenol can be separated from crude phenol tar through the following steps, achieving energy saving: The raw crude phenol enters the middle of column 1; the gas at the top of column 1 enters the hot side of column 1 condenser 6 and is liquefied by the circulating refrigerant water on the cold side; part of it flows back to the top of column 1, and part of it is collected as water and light components; the liquid at the bottom of column 1 enters the cold side of column 1 reboiler 13 and is heated and vaporized by the heat transfer medium water vapor on the hot side before returning to the bottom of column 1; part of the mixed phenol after water and light components are removed enters the middle of column 2; the liquid at the bottom of column 2 enters the cold side of column 2 reboiler 14 and is heated and vaporized by the heat transfer medium water vapor on the hot side. After the heat transfer oil is heated and vaporized, it returns to the bottom of column 2. Part of the residue phenol is collected. The gas at the top of column 2 enters the hot side of condenser 7 and is liquefied by the liquid water heat transfer medium on the cold side. Part of the liquefied gas flows back to the top of column 2, and part of the slag-removed mixed phenol enters the middle of column 3. The gas at the top of column 3 enters the hot side of condenser 8 and is liquefied by the liquid water heat transfer medium on the cold side. Part of the liquefied gas flows back to the top of column 3, and part of the phenol product is collected. The liquid at the bottom of column 3 enters the reboiler 15 and is vaporized by the steam heat transfer medium on the hot side, returning to the bottom of column 3. Part of the mixed phenol enters the middle of column 3. In Tower 4, section 4, the gas from the top of Tower 4, region A, enters the condenser I9 on the hot side. After being liquefied by the liquid water heat transfer medium on the cold side, a portion flows back into the top of Tower 4, region A, while a portion is collected as mixed phenol and enters the middle of Tower 3. In Tower 4, section B, the gas from the top of Tower 4, region B, enters the condenser II10 on the hot side. After being liquefied by the liquid water heat transfer medium on the cold side, a portion flows back into the top of Tower 4, region B, while a portion is collected as o-cresol product. The liquid from the bottom of Tower 4, region B, enters the reboiler 16 on the cold side. After being heated and vaporized by the steam heat transfer medium on the hot side, the liquid returns to the bottom of Tower 4, region B, while a portion is collected as mixed phenol and enters the middle of Tower 5. The gas at the top of section A of column 5 enters the hot side of condenser I11 of column 5 and is liquefied by the heat transfer medium liquid water on the cold side. Part of it flows back into the top of section A of column 5, and part of it is collected as mixed phenols and enters the bottom of section B of column 4. The gas at the top of section B of column 5 enters the hot side of condenser II12 of column 5 and is liquefied by the heat transfer medium liquid water on the cold side. Part of it flows back into the top of section B of column 5, and part of it is collected as m-p-cresol product. Part of the liquid in the bottom of column 5 enters the cold side of reboiler 17 of column 5 and is vaporized by the heat transfer medium water vapor on the hot side before returning to the bottom of column 5. Part of it is collected as mixed phenols product.

[0036] After passing through buffer tank 20, the working liquid water enters the cold side of condenser 7 in tower 2, the cold side of condenser 8 in tower 3, the cold side of condenser I 9 in tower 4, the cold side of condenser II 10 in tower 4, the cold side of condenser I 11 in tower 5, and the cold side of condenser II 12 in tower 5 to cool the hot side of the top gases from towers 2 2, 3, 4, and 5. The working liquid water itself is then heated and vaporized to form heat transfer working liquid water vapor. This heat transfer working liquid water vapor enters compressor 18 and is pressurized into high-pressure working liquid water vapor, which then enters tower 1 for further processing. The hot side of boiler 13, the hot side of reboiler 15, the hot side of reboiler 16, and the hot side of reboiler 17 heat the cold side of the bottom liquids of tower 1, tower 3, tower 4, and tower 5, producing working liquid water. After passing through throttling valve 19, the working liquid water enters buffer tank 20 for further cooling, forming the main loop of energy-saving thermal cycle. The working liquid in buffer tank 20 is pressurized by pump 26 and enters the top of buffer tank through regulating valve 25 to directly exchange heat with working steam, forming the secondary loop of energy-saving thermal cycle.

[0037] In this embodiment, the crude phenol raw material processing capacity is 30,000 tons / year, and the mass content of the crude phenol raw material components is as follows: water 0.473%, light phenols 0.473%, phenol 48.424%, o-cresol 10.315%, p-cresol 11.262%, m-cresol 16.4%, o-ethylphenol 0.653%, 2,4-xylenol 1.968%, and slag phenol 10.031%. After processing by the device described in this invention, phenol, o-cresol, and m-p-cresol with a mass concentration of 99.5% and 99.5% respectively are stably produced.

[0038] In this embodiment, the operating pressure of column 1 is 17 kPaA, the operating temperature at the top of column 1 is 57.4°C, and the operating temperature at the bottom of column 1 is 135.7°C. The operating pressure of column 2 is 11 kPaA, the operating temperature at the top of column 2 is 121.7°C, and the operating temperature at the bottom of column 2 is 160.1°C. The operating pressure of column 3 is 12.5 kPaA, the operating temperature at the top of column 3 is 119.2°C, and the operating temperature at the bottom of column 3 is 135.5°C. The operating pressure of column 4 is 10.5 kPaA, the operating temperature in region A of the top of column 4 is 118.1°C, the operating temperature in region B of the top of column 4 is 121.0°C, and the operating temperature at the bottom of column 4 is 135.1°C. The operating pressure of column 5 is 8 kPaA, the operating temperature in region A of the top of column 5 is 124.6°C, the operating temperature in region B of the top of column 5 is 125.8°C, and the operating temperature at the bottom of column 5 is 135.7°C.

[0039] In this embodiment, the heat transfer working fluid circulation makes full use of the waste heat. The heat transfer working fluid liquid water absorbs the heat from the hot side of the second condenser 7, the third condenser 8, the fourth condenser I 9, the fourth condenser II 10, the fifth condenser I 11, and the fifth condenser II 12. The working fluid liquid water itself is vaporized to form working fluid water vapor. After the working fluid water vapor is pressurized to 600 kPaA water vapor by the compressor 18, it is used to heat the materials on the cold side of the first reboiler 13, the third reboiler 15, the fourth reboiler 16, and the fifth reboiler 17. This system saves on the heat transfer medium required for the hot side of reboilers 13, 15, 16, and 17 in Tower 1, as well as the refrigerant required for the cold side of condensers 7, 8, 9, 10, 11, and 12 in Tower 5. Only the hot side of reboiler 14 in Tower 2 requires heat transfer medium, while the cold side of condenser 6 in Tower 1 and the heat exchange tubes 23 in buffer tank 20 require refrigerant. Compared to traditional systems, this system saves 409.8 tons of heat transfer oil (83.9% reduction) and 444.3 tons of circulating refrigerant water (82.3% reduction) per ton of crude phenol feedstock produced. The power consumption of compressor 18 per ton of crude phenol feedstock produced is only 73.4 kWh, resulting in a significant reduction in overall energy consumption.

[0040] In this embodiment, towers 4 and 5 are equipped with partition plates 22, dividing the tower interior into three regions: A, B, and C. Region A achieves further removal of light mixed phenols, saving two towers compared to conventional devices, reducing equipment investment, and also lowering energy consumption. Example 2

[0041] Reference Figure 2 This embodiment provides an energy-saving device for separating refined phenol from crude phenol in tar. The device includes tower 1, tower 2, tower 3, tower 4, tower 5, condenser 6 for tower 1, condenser 7 for tower 2, condenser 8 for tower 3, condenser I for tower 4, condenser II for tower 4, condenser I for tower 5, condenser II for tower 5, reboiler 13 for tower 1, reboiler 14 for tower 2, reboiler 15 for tower 3, reboiler 16 for tower 4, reboiler 17 for tower 5, compressor 18, throttle valve 19, buffer tank 20, preheater 24, regulating valve 25, and pump 26.

[0042] Similar to Example 1, towers 1, 2, 3, 4, and 5 are all vertical towers, and mass transfer packing and internal components or trays 21 are installed inside each tower. Towers 4 and 5 are equipped with partition plates 22, dividing the interior of the tower into three regions: A, B, and C.

[0043] Material pipelines connect the preheater 24 (cold side), tower 1, tower 1 condenser 6 (hot side), tower 1 reboiler 13 (cold side), tower 2, tower 2 condenser 7 (hot side), tower 2 reboiler 14 (cold side), tower 3, tower 3 condenser 8 (hot side), tower 3 reboiler 15 (cold side), tower 4, tower 4 condenser I 9 (hot side), tower 4 condenser II 10 (hot side), tower 4 reboiler 16 (cold side), tower 5, tower 5 condenser I 11 (hot side), tower 5 condenser II 12 (hot side), and tower 5 reboiler 17 (cold side), forming a separation device.

[0044] The cold side of the second condenser 7, the cold side of the third condenser 8, the cold side of the fourth condenser I 9, the cold side of the fourth condenser II 10, the cold side of the fifth condenser I 11, the cold side of the fifth condenser II 12, the buffer tank 20, the compressor 18, the hot side of the first reboiler 13, the hot side of the third reboiler 15, the hot side of the fourth reboiler 16, the hot side of the fifth reboiler 17, the hot side of the preheater 24, and the throttling valve 19 are connected by a working fluid pipeline, which is filled with heat transfer working fluid to form an energy-saving heat cycle main loop device; the buffer tank 20, the regulating valve 25, and the pump 26 form an energy-saving heat cycle secondary loop device.

[0045] The cold side of the first-stage condenser 6 is connected to a refrigerant, which can be either circulating water or low-temperature water; in this embodiment, circulating water is preferred. The hot side of the second-stage reboiler 14 is connected to a heat medium, which can be either steam, thermal oil, or electric heating; in this embodiment, steam is preferred.

[0046] The buffer tank 20 is equipped with a heat exchange tube 23, which is connected to the heat transfer medium steam. The buffer tank body is provided with a replenishment working fluid inlet. The heat transfer medium can be water, R22, R32, R134, R245, R454, R290, R744, or CO2. In this embodiment, water is preferred, and the corresponding working liquid is liquid water, and the working steam is water vapor.

[0047] Using the energy-saving device provided in this embodiment, refined phenol can be separated from crude phenol tar through the following steps, achieving energy saving: The crude phenol raw material, after heat exchange between the cold and hot sides of the preheater 24, enters the middle of column 1. The gas at the top of column 1 enters the hot side of column 1 condenser 6 and is liquefied by the circulating refrigerant water on the cold side. Part of the liquefied gas flows back to the top of column 1, and part of it is collected as water and light components. Part of the liquid at the bottom of column 1 enters the cold side of column 1 reboiler 13 and is heated and vaporized by the steam heat transfer medium on the hot side before returning to the bottom of column 1. Part of the mixed phenol after water and light components are removed enters the middle of column 2; the liquid at the bottom of column 2... Part of the gas entering the reboiler 14 of column 2 is heated and vaporized by the hot-side heat transfer medium steam and then returned to the bottom of column 2. Part of the gas is collected as slag phenol. The gas at the top of column 2 enters the condenser 7 of column 2 and is liquefied by the cold-side heat transfer medium liquid water. Part of the gas flows back to the top of column 2, and part of the slag-removed mixed phenol is collected and enters the middle of column 3. The gas at the top of column 3 enters the condenser 8 of column 3 and is liquefied by the cold-side heat transfer medium liquid water. Part of the gas flows back to the top of column 3, and part of the phenol product is collected. The liquid at the bottom of column 3 enters the reboiler 15 of column 3 and is heated and vaporized by the hot-side heat transfer medium water steam and then returned to the bottom of column 3. Part of the mixed phenols is collected and enters the middle of column 4 (section 4). The gas at the top of column 4 (section 4) enters the hot side of condenser I (section 4) and is liquefied by the cold side heat transfer medium, liquid water. Part of the liquefied gas flows back into the top of column 4 (section 4) (section 4), and part of the mixed phenols are collected and enter the middle of column 3 (section 3). The gas at the top of column 4 (section 4) (section 4) enters the hot side of condenser II (section 4) and is liquefied by the cold side heat transfer medium, liquid water. Part of the liquefied gas flows back into the top of column 4 (section 4) (section 4), and part of the o-cresol product is collected. The liquid in the bottom of column 4 (section 4) enters the cold side of reboiler 16 and is vaporized by the hot side heat transfer medium, water vapor, before returning to the bottom of column 4 (section 4). Part of the mixed phenols are collected and enters the middle of column 3 (section 3). The gas from the top of column 5 (section 5) enters the middle section of column 5. The gas from the top of column 5 (section 5) enters the hot side of condenser I (section 11) and is liquefied by the liquid water heat transfer medium on the cold side. Part of the liquefied gas flows back into the top of column 5 (section 5), while part of the mixed phenols is collected and enters the bottom of section B of column 4 (section 4). The gas from the top of column 5 (section 5) (section 5) enters the hot side of condenser II (section 12) and is liquefied by the liquid water heat transfer medium on the cold side. Part of the liquefied gas flows back into the top of column 5 (section 5), while part of the m-p-cresol product is collected. The liquid from the bottom of column 5 (section 5) enters the cold side of reboiler 17 and is vaporized by the steam heat transfer medium on the hot side before returning to the bottom of column 5. Part of the mixed phenols product is collected.

[0048] After passing through buffer tank 20, the heat transfer working fluid steam enters compressor 18 and is pressurized into high-pressure working fluid steam. It then enters the hot side of reboiler 13 of column 1, the hot side of reboiler 15 of column 3, the hot side of reboiler 16 of column 4, and the hot side of reboiler 17 of column 5 to heat the cold side of the bottom liquids of column 11, column 3, column 4, and column 5. The working fluid steam condenses itself into working fluid liquid water. The working fluid liquid water enters the hot side of preheater 24 to heat the cold side of the crude phenol raw material. After cooling itself, it enters the cold side of condenser 7 of column 2, the cold side of condenser 8 of column 3, the cold side of condenser I of column 4, and the cold side of condenser I of column 4. The cold side of condenser II 10, the cold side of condenser I 11 of tower 5, and the cold side of condenser II 12 of tower 5 cool the top gases of tower 2, tower 3, tower 4, and tower 5 on the hot side. The working liquid water is heated and vaporized to form heat transfer working liquid water vapor. The working liquid water vapor enters the buffer tank 20 for further heating and then goes to the compressor 18 to form the main loop of the energy-saving heat cycle. The working liquid in the buffer tank 20 is pressurized by pump 26 and, after being controlled by regulating valve 25 through the pipeline after throttle valve 19, enters the top of the buffer tank 20 to directly exchange heat with the working liquid vapor, forming the secondary loop of the energy-saving heat cycle.

[0049] In this embodiment, the crude phenol raw material processing capacity is 10,000 tons / year, and the mass content of the crude phenol raw material components is as follows: water 3.31%, light phenols 0.23%, phenol 35.47%, o-cresol 12.5%, p-cresol 12.53%, m-cresol 23.09%, o-ethylphenol 0.69%, 2,4-xylenol 5.47%, and slag phenol 6.71%. After processing by the device described in this invention, phenol, o-cresol, and m-p-cresol with a mass concentration of 99.5% and 98.5% respectively are stably produced.

[0050] In this embodiment, the operating pressure of column 1 is 18 kPaA, the operating temperature at the top of column 1 is 57.8°C, and the operating temperature at the bottom of column 1 is 139.6°C. The operating pressure of column 2 is 11 kPaA, the operating temperature at the top of column 2 is 124.5°C, and the operating temperature at the bottom of column 2 is 155.5°C. The operating pressure of column 3 is 14.5 kPaA, the operating temperature at the top of column 3 is 122.9°C, and the operating temperature at the bottom of column 3 is 139.8°C. The operating pressure of column 4 is 12.5 kPaA, the operating temperature in region A at the top of column 4 is 122.2°C, the operating temperature in region B at the top of column 4 is 125.1°C, and the operating temperature at the bottom of column 4 is 139.5°C. The operating pressure of column 5 is 10 kPaA, the operating temperature of zone A at the top of column 5 is 122.8℃, the operating temperature of zone B at the top of column 5 is 131.2℃, and the operating temperature of the bottom of column 5 is 140.2℃.

[0051] In this embodiment, the heat transfer working fluid circulation makes full use of the waste heat. The heat transfer working fluid liquid water absorbs the heat from the hot side of the second condenser 7, the third condenser 8, the fourth condenser I 9, the fourth condenser II 10, the fifth condenser I 11, and the fifth condenser II 12. The working fluid liquid water itself is vaporized to form working fluid water vapor. After passing through the buffer tank 20, the working fluid water vapor is pressurized to 650 kPaA water vapor by the compressor 18 and then used to heat the materials on the cold side of the first reboiler 13, the third reboiler 15, the fourth reboiler 16, and the fifth reboiler 17. This system saves on the heat transfer medium required for the hot side of reboilers 13, 15, 16, and 17 in Tower 1, as well as the refrigerant required for the cold side of condensers 7, 8, 9, 10, 11, and 12 in Tower 5. Only the hot side of reboiler 14 in Tower 2 and the heat exchange tubes 23 in buffer tank 20 require heat transfer medium, while the cold side of condenser 6 in Tower 1 requires refrigerant. Compared to traditional systems, this system saves 4.65 tons of heat transfer medium steam (79.1%) and 426.2 tons of refrigerant circulating water (81.5%) per ton of crude phenol feedstock produced. The power consumption of compressor 18 per ton of crude phenol feedstock produced is only 51.3 kWh, resulting in a significant reduction in overall energy consumption.

[0052] Similar to Example 1, in this example, towers 4 and 5 are equipped with partition plates 22, dividing the tower interior into three regions: A, B, and C. Region A achieves further removal of light mixed phenols, saving two towers compared to conventional devices, reducing equipment investment, and also lowering energy consumption.

[0053] The preferred embodiments of this utility model have been described in detail above. However, the content described is only a preferred embodiment of this utility model and should not be considered as limiting the scope of implementation of this utility model. All equivalent changes and improvements made within the scope of the claims of this utility model should still fall within the scope of this utility model patent.

Claims

1. An energy saving device for separating refined phenol from tar crude phenol, characterized by: The column one, the column one condenser, the column one reboiler, the column two, the column two condenser, the column two reboiler, the column three, the column three condenser, the column three reboiler, the column four, the column four condenser, the column four reboiler, the column five, the column five condenser, the column five reboiler, the compressor, the throttle valve, the buffer tank are connected by the material pipeline. The column two condenser cold side, the column three condenser cold side, the column four condenser cold side, the column five condenser cold side, the compressor, the column one reboiler hot side, the column three reboiler hot side, the column four reboiler hot side, the column five reboiler hot side, the throttle valve, the buffer tank are connected by the working medium pipeline, the pipeline is filled with the heat transfer working medium, and the energy-saving heat cycle main loop device is formed. The column one condenser cold side is connected with the refrigerant circulating water or low temperature water, and the column two reboiler hot side is connected with the heat medium steam or heat conducting oil or electric heating.

2. An energy efficient apparatus for separating refined phenol from tar crude phenol as claimed in claim 1, wherein: The middle and upper parts of the column four are provided with the partition plates, so that the column four is divided into three regions A, B and C, the top of the regions A and B is connected with the respective condensers, and the bottom of the region C is connected with the reboiler.

3. The energy-saving device for separating refined phenols from crude phenols in tar as described in claim 1, characterized in that: The middle and upper parts of the column five are provided with the partition plates, so that the column five is divided into three regions A, B and C, the top of the regions A and B is connected with the respective condensers, and the bottom of the region C is connected with the reboiler.

4. An energy efficient apparatus for separating refined phenol from tar crude phenol as claimed in claim 1, wherein: The buffer tank is provided with the heat exchange pipe, the heat exchange pipe is connected with the heat medium or the refrigerant, the tank body of the buffer tank is provided with the supplementary working medium inlet, the bottom and the top of the buffer tank are connected with the working medium pipeline, and the energy-saving heat cycle auxiliary loop device is formed.

5. An energy efficient apparatus for separating refined phenol from tar crude phenol as claimed in claim 1, wherein: The heat transfer working medium filled in the pipeline of the energy-saving heat cycle loop device is water or R22 or R32 or R134 or R245 or R454 or R290 or R744 or CO2.

6. An energy efficient apparatus for separating refined phenol from tar crude phenol as claimed in claim 1, wherein: The columns one, two, three, four and five are provided with the mass transfer filler and the column internals or the column plate.

7. The energy-saving device for separating refined phenols from crude phenols in tar as described in claim 1, characterized in that: The column four A region top condenser hot side is connected with the column four top and the column three middle part by the material pipeline.

8. An energy efficient apparatus for separating refined phenol from tar crude phenol as claimed in claim 3, wherein: The column five A region top condenser hot side is connected with the column five top and the column four B region bottom by the material pipeline.

9. An energy efficient apparatus for separating fine phenol from tar crude phenol as claimed in claim 4, wherein: ​

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