A method and system for cracking and recovering phenol tar

Abstract

The invention discloses a method and system for cracking and recovering phenol tar, which comprises: 1) preheating phenol tar and an organic silver salt catalyst and performing cracking reaction to obtain light components and heavy components; 2) inputting the light components into a coarse fraction tower for rectification, and separating to obtain a cumylphenol mixture at the bottom of the tower and a first component at the top of the tower; 3) inputting the first component into an AMS product tower for rectification, and separating to obtain an AMS product, a phenol and acetophenone mixed solution, and a light component; 4) inputting the phenol and acetophenone mixed solution into a phenol product tower for rectification, and separating to obtain a phenol light component, a phenol product, and crude acetophenone. 5) inputting crude acetophenone into an acetophenone product tower for rectification, and separating to obtain an acetophenone light component, an acetophenone product, and an acetophenone heavy component. The invention can effectively recover phenol and acetophenone light components in tar, and significantly improve the recovery rate of phenol tar.

Description

Technical Field

[0001] The invention relates to the technical field of phenol tar recovery, and in particular to a method and system for phenol tar cracking and recovery. Background Art

[0002] Phenol is an important chemical raw material, which is widely used in the industrial production of plastics, synthetic fibers, medicines, pesticides and fuel intermediates. Cumene undergoes oxidation reaction to produce cumene hydroperoxide, which is decomposed into phenol and acetone using sulfuric acid as a catalyst. At the same time, heavy components such as acetophenone, cumylphenol and AMS dimer are generated during the reaction and eventually enter tar. The amount of phenol tar is large, usually between 30-70kg / t phenol, which not only affects the material consumption of phenol products, but also increases carbon emissions during incineration.

[0003] CN106675614A discloses a coking method, in which phenol tar enters a coke tower for coking, and the coking gas enters a fractionating tower to obtain naphtha, diesel, and wax oil fractions, thereby solving the problem of difficulty in recovering phenols in phenol-containing tar. The method uses a relatively high temperature (495°C-510°C), and the recovered products are primary raw materials such as naphtha. Although the method can realize the recycling of phenol tar resources, the path is long.

[0004] CN107298636A discloses a method for extracting cumylphenol from phenol tar, wherein cumylphenol is extracted by vacuum distillation and adding an amine solvent. However, there are still a lot of acetophenone and other heavy components in the tar that have not been effectively recycled. Summary of the invention

[0005] In view of the above-mentioned defects in the background technology, the present invention mainly provides a method and system for cracking and recovering phenol tar, which can effectively recover phenol and acetophenone light components in tar and can significantly improve the recovery rate of phenol tar.

[0006] To achieve the above-mentioned object of the invention, the first aspect of the present invention provides a method for cracking and recovering phenol tar, comprising the following steps:

[0007] 1) preheating phenol tar and an organic silver salt catalyst and performing a cracking reaction to obtain a light component and a heavy component;

[0008] 2) inputting the light component into a coarse fraction tower for rectification to separate and obtain a cumylphenol mixture at the bottom of the tower and a first component at the top of the tower;

[0009] 3) inputting the first component into an AMS product tower for distillation to separate and obtain an AMS product, a mixed solution of phenol and acetophenone, and a light component;

[0010] 4) The phenol and acetophenone mixed solution is input into a phenol product tower for rectification to separate and obtain phenol light components, phenol products and crude acetophenone.

[0011] 5) The crude acetophenone is input into an acetophenone product tower for rectification to separate and obtain an acetophenone light component, an acetophenone product and an acetophenone heavy component.

[0012] Furthermore, in the step 1), the phenol tar comes from a phenol and acetone production device using a cumene peroxidation process, and its components include, by mass content: 1%-10% phenol, 10%-20% acetophenone, 3%-10% dimethyl benzyl alcohol, 3%-10% α-methylstyrene dimer, and 20%-30% cumylphenol.

[0013] Furthermore, in step 1), the organic silver salt catalyst may be a long-chain fatty acid silver salt, preferably C 14 -C 24 Silver salts of fatty acids;

[0014] Preferably, one or more of silver palmitate, silver stearate, silver caprate, silver dilaurate, etc. may be used.

[0015] Preferably, the addition amount of the long-chain fatty acid silver salt accounts for 0.05%-0.3% of the mass of the phenol tar, preferably 0.1%-0.2%.

[0016] Furthermore, the cumylphenol mixture obtained in step 2) is returned to step 1) to participate in the reaction.

[0017] Furthermore, the phenol light component obtained in step 4) is returned to the AMS product tower in step 3) for distillation.

[0018] Furthermore, the acetophenone light component obtained in step 5) is returned to the phenol product tower in step 4) for rectification.

[0019] A second aspect of the present invention provides a system for cracking and recovering phenol tar, comprising:

[0020] A heater, used for preheating a mixture of phenol tar and an organic silver salt catalyst to obtain a high-temperature material;

[0021] A reactor, used to receive high-temperature materials and perform cracking reactions on the high-temperature materials to obtain light components and heavy components;

[0022] A crude fraction tower, used for receiving the light component and performing distillation on the light component to separate the cumylphenol mixture at the bottom of the tower and the first component at the top of the tower;

[0023] An AMS product tower is used to receive the first component and distill the first component to separate and obtain an AMS product, a mixed solution of phenol and acetophenone, and a light component;

[0024] A phenol product tower is used to receive the phenol and acetophenone mixed solution and distill the mixed solution to separate and obtain phenol light components, phenol products and crude acetophenone;

[0025] The acetophenone product tower is used to receive the crude acetophenone and distill the crude acetophenone to separate and obtain the acetophenone light component, the acetophenone product and the acetophenone heavy component.

[0026] Furthermore, the heater is heated by an electric heating jacket, and the preheating temperature range is 350-400°C.

[0027] Further, the reactor is a tank reactor or a tubular reactor, preferably a tank reactor;

[0028] Preferably, the reaction temperature is 300-450°C, preferably 320-350°C;

[0029] Preferably, the reactor is made of one or two composite materials selected from carbon steel, 316L, nickel, 59 alloy, and Ha C, preferably nickel;

[0030] Preferably, the pressure of the reactor is 2-10 bar, preferably 3-4 bar;

[0031] Preferably, the residence time of the reactor is 0.5-3 h, preferably 0.8-1.2 h.

[0032] Furthermore, the crude fraction tower may be a packed tower or a plate tower, preferably a plate tower;

[0033] Preferably, the pressure of the crude fraction tower is 10-50 kPa, preferably 20-30 kPa;

[0034] Preferably, the number of theoretical plates of the crude fraction tower is 20-40, preferably 28-34;

[0035] Preferably, the reflux ratio of the crude fraction tower is 0.2-5, preferably 0.8-1.2.

[0036] Furthermore, the AMS product tower may be a plate tower or a packed tower, preferably a packed tower;

[0037] Preferably, the pressure of the AMS product column is 10-50 kPa, preferably 20-30 kPa;

[0038] Preferably, the reflux ratio of the AMS product column is 0.2-5, preferably 0.8-1.2;

[0039] Preferably, the packing height of the AMS product tower is 0.5-3 m, preferably 1-2 m;

[0040] Preferably, the purity of the AMS product is >99.8%.

[0041] Furthermore, the phenol product tower can be a plate tower or a packed tower, preferably a packed tower;

[0042] Preferably, the pressure of the phenol product column is 10-50 kPa, preferably 20-30 kPa;

[0043] Preferably, the reflux ratio of the phenol product column is 0.2-5, preferably 0.8-1.2;

[0044] Preferably, the packing height of the phenol product tower is 0.5-3 m, preferably 1-2 m;

[0045] Preferably, the purity of the phenol product is >99.9%.

[0046] Furthermore, the acetophenone product tower may be a plate tower or a packed tower, preferably a packed tower;

[0047] Preferably, the pressure of the acetophenone product column is 10-50 kPa, preferably 20-30 kPa;

[0048] Preferably, the reflux ratio of the acetophenone product column is 0.2-5, preferably 0.8-1.2;

[0049] Preferably, the packing height of the acetophenone product tower is 0.5-3 m, preferably 1-2 m;

[0050] Preferably, the purity of the acetophenone product is >99.5%.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] The inventors of the present invention have found that by using the method of cracking and recycling phenol tar, not only can the phenol and acetophenone light components in the tar be recovered, but also the AMS dimer, cumylphenol and other recombinant components can be cracked and decomposed into phenol and AMS for recovery. However, AMS will generate heavy components during the cracking process due to its high activity, which will reduce the reaction yield. Silver ions are weakly acidic and can promote the decomposition of AMS dimer and cumylphenol by bond breaking. The electronic structure on the silver ions is easily combined with the isopropenyl group, which serves the purpose of dispersing the double bond electron cloud of AMS and reducing the polymerization activity of AMS. If an inorganic silver salt is used as a catalyst, it and the tar are recombined into solid-liquid two phases, the contact is insufficient, and the catalytic and anti-polymerization effects are poor. Therefore, the present invention adopts an organic silver salt catalyst with both catalytic effect and AMS polymerization effect, ensures that the silver ions are fully in contact with the tar, and adopts a reactive distillation reactor to remove the generated AMS in time, improve the yield of the cracking process, and effectively reduce the amount of side reactions.

[0053] Other features and advantages of the present invention will be described in detail through the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A flow chart of a method for cracking and recovering phenol tar provided in an embodiment of the present invention.

[0055] The labels are as follows: 1. Heater, 2. Reactor, 3. Crude fraction tower, 4. AMS product tower, 5. Phenol product tower, 6. Acetophenone product tower, 7. Phenol tar, 8. High-temperature phenol tar, 9. Heavy components, 10. Reactor light components, 11. First component, 12. Cumylphenol mixture, 13. Light components, 14. AMS, 15. Phenol and acetophenone mixture, 16. Phenol light components, 17. Phenol, 18. Phenol heavy components, 19 Acetophenone light components, 20. Acetophenone, 21. Acetophenone heavy components. DETAILED DESCRIPTION

[0056] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0057] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0058] Unless otherwise specified, the raw materials involved in the present invention can be obtained from commercial channels.

[0059] The first aspect of the present invention provides a method for cracking and recovering phenol tar, comprising the following steps:

[0060] 1) preheating phenol tar and an organic silver salt catalyst and then performing a high temperature cracking reaction, so that the AMS dimer is decomposed into AMS again, and the cumylphenol is decomposed into AMS and phenol, so as to obtain light components and heavy components;

[0061] 2) inputting the light component into a coarse fraction tower for rectification to separate and obtain a cumylphenol mixture at the bottom of the tower and a first component at the top of the tower;

[0062] 3) inputting the first component into an AMS product tower for distillation to separate and obtain an AMS product, a mixed solution of phenol and acetophenone, and a light component;

[0063] 4) The phenol and acetophenone mixed solution is input into a phenol product tower for rectification to separate and obtain phenol light components, phenol products and crude acetophenone.

[0064] 5) The crude acetophenone is input into an acetophenone product tower for rectification to separate and obtain an acetophenone light component, an acetophenone product and an acetophenone heavy component.

[0065] In the present invention, in the step 1), the phenol tar comes from a phenol and acetone production device using a cumene peroxidation process, and the components thereof include, by mass content, 1%-10% phenol, 10%-20% acetophenone, 3%-10% dimethyl benzyl alcohol, 3%-10% α-methylstyrene dimer, and 20%-30% cumylphenol.

[0066] In the present invention, in step 1), the organic silver salt catalyst may be a long-chain fatty acid silver salt, preferably C 14 -C 24 Fatty acid silver salt; organic silver salt is used to promote the decomposition of heavy components such as cumylphenol to produce α-methylstyrene, while reducing its polymerization activity, effectively reducing the amount of side reactions and improving the recovery rate.

[0067] In some embodiments, the organic silver salt catalyst may be one or more of silver palmitate, silver stearate, silver caprate, silver dilaurate, and the like.

[0068] In some embodiments, the amount of the long-chain fatty acid silver salt added is 0.05%-0.3% of the mass of the phenol tar, preferably 0.1%-0.2%. The above parameters can reduce the amount of catalyst used while ensuring a higher conversion rate and inhibition effect.

[0069] Preferably, the cumylphenol mixture obtained in step 2) is returned to step 1) to participate in the reaction, so that the evaporated cumylphenol mixture is cracked again to improve the cracking conversion rate.

[0070] Preferably, the phenol light component obtained in step 4) is returned to the AMS product tower in step 3) for distillation, so that the AMS in the light component can be further recovered in the AMS product tower, thereby reducing material loss.

[0071] Preferably, the acetophenone light component obtained in step 5) is returned to the phenol product tower in step 4) for distillation, so that the phenol in the acetophenone light component is further recovered in the phenol product tower, thereby reducing material loss.

[0072] refer to Figure 1 The second aspect of the present invention provides a system for cracking and recovering phenol tar, comprising:

[0073] Heater 1, used for preheating the mixture of phenol tar and organic silver salt catalyst to obtain high-temperature material;

[0074] Reactor 2, for receiving high temperature materials and subjecting the high temperature materials to cracking reactions to obtain light components and heavy components;

[0075] A crude fraction tower 3, for receiving the light component and performing distillation on the light component to separate the cumylphenol mixture at the bottom of the tower and the first component at the top of the tower;

[0076] AMS product tower 4, used for receiving the first component and distilling the first component to separate and obtain AMS product, phenol and acetophenone mixed solution and light component;

[0077] A phenol product tower 5 is used to receive the phenol and acetophenone mixed solution and distill the mixed solution to separate and obtain phenol light components, phenol products and crude acetophenone;

[0078] The acetophenone product tower 6 is used to receive the crude acetophenone and distill the crude acetophenone to separate and obtain the acetophenone light component, the acetophenone product and the acetophenone heavy component.

[0079] In some embodiments, the heater 1 is heated by an electric heating jacket, and the preheating temperature ranges from 350-400°C.

[0080] In some embodiments, the reactor 2 is a tank reactor or a tubular reactor, preferably a tank reactor;

[0081] Preferably, the reaction temperature is 300-450°C, more preferably 320-350°C; the above parameters can save energy while maintaining a high conversion rate;

[0082] Preferably, the reactor 2 is made of one or two composite materials selected from carbon steel, 316L, nickel, 59 alloy, and Ha C, and more preferably nickel;

[0083] Preferably, the pressure of the reactor 2 is 2-10 bar, more preferably 3-4 bar; the above parameters can ensure that light components such as phenol and AMS are evaporated in time, avoid AMS polymerization again, and improve the cracking yield;

[0084] Preferably, the residence time of the reactor 2 is 0.5-3 h, more preferably 0.8-1.2 h; the above parameters can improve the reaction capacity while ensuring the cracking yield.

[0085] In some embodiments, the crude fraction tower 3 may be a packed tower or a plate tower, preferably a plate tower;

[0086] Preferably, the pressure of the crude fraction tower 3 is 10-50 kPa, more preferably 20-30 kPa; adopting the above parameters and maintaining a suitable pressure can reduce equipment investment and reduce the grade of distillation steam;

[0087] Preferably, the number of theoretical plates of the crude fraction tower 3 is 20-40, more preferably 28-34; adopting the above parameters and maintaining a suitable number of theoretical plates can reduce equipment investment and reduce distillation energy consumption;

[0088] Preferably, the reflux ratio of the coarse fraction tower 3 is 0.2-5, more preferably 0.8-1.2; adopting the above parameters and maintaining a suitable reflux ratio can reduce the energy consumption of distillation.

[0089] In some embodiments, the AMS product tower 4 may be a plate tower or a packed tower, preferably a packed tower;

[0090] Preferably, the pressure of the AMS product tower 4 is 10-50 kPa, more preferably 20-30 kPa; adopting the above parameters and maintaining a suitable pressure can reduce equipment investment and reduce the grade of distillation steam;

[0091] Preferably, the reflux ratio of the AMS product tower 4 is 0.2-5, more preferably 0.8-1.2; adopting the above parameters and maintaining a suitable reflux ratio can reduce the distillation energy consumption;

[0092] Preferably, the packing height of the AMS product tower 4 is 0.5-3 m, more preferably 1-2 m;

[0093] Preferably, the purity of the AMS product is > 99.8%

[0094] In some embodiments, the phenol product tower 5 may be a plate tower or a packed tower, preferably a packed tower;

[0095] Preferably, the pressure of the phenol product tower 5 is 10-50 kPa, more preferably 20-30 kPa;

[0096] Preferably, the reflux ratio of the phenol product tower 5 is 0.2-5, more preferably 0.8-1.2;

[0097] Preferably, the packing height of the phenol product tower 5 is 0.5-3m, more preferably 1-2m;

[0098] Preferably, the purity of the phenol product is >99.9%.

[0099] In some embodiments, the acetophenone product tower 6 may be a plate tower or a packed tower, preferably a packed tower;

[0100] Preferably, the pressure of the acetophenone product column 6 is 10-50 kPa, more preferably 20-30 kPa;

[0101] Preferably, the reflux ratio of the acetophenone product tower 6 is 0.2-5, more preferably 0.8-1.2;

[0102] Preferably, the packing height of the acetophenone product tower 6 is 0.5-3 m, more preferably 1-2 m;

[0103] Preferably, the purity of the acetophenone product is >99.5%.

[0104] The present invention is further described below in conjunction with embodiments:

[0105] Example 1

[0106] The phenol tar from the previous process (a device for producing phenol and acetone by isopropylbenzene peroxidation method) contains 5% phenol, 15% acetophenone, 8% dimethylbenzyl alcohol, 6% AMS dimer and 27% cumylphenol. Silver stearate accounting for 0.2% of the mass of phenol tar is added as a catalyst. The tar enters the electric heater at a feed rate of 5kg / h, is preheated to 350℃ and then enters the reactor. The temperature in the reactor is maintained at 320℃ and the pressure is 3bar. The reaction is continued for 1h. The light components in the reactor enter the coarse fractionation tower. The coarse fractionation tower has 30 theoretical plates, a pressure of 25kPa and a reflux ratio of 1:1.

[0107] The first component at the top of the tower enters the AMS product tower, which has 2m packing, a pressure of 25kPa, and a reflux ratio of 1: 1. The purity of the side-line AMS product is 99.85% and the output is 1.55kg / h.

[0108] The phenol and acetophenone mixture enters the phenol tower, which has 2m packing, a pressure of 20kPa, and a reflux ratio of 1:1. The purity of the side-line phenol product is 99.92% and the output is 1.56kg / h.

[0109] The phenol recombinant component enters the acetophenone tower, which has 2m filler, a pressure of 20kPa, and a reflux ratio of 1.2:1. The purity of the side-line acetophenone product is 99.6%, and the output is 0.75kg / h.

[0110] Example 2

[0111] The phenol tar from the previous process (a device for producing phenol and acetone by isopropylbenzene peroxidation method) contains 1% phenol, 20% acetophenone, 3% dimethylbenzyl alcohol, 10% AMS dimer and 30% cumylphenol. 0.1% silver palmitate is added as a catalyst and fed into an electric heater at a feed rate of 5kg / h. After being preheated to 400°C, the tar enters the reactor and the temperature in the reactor is maintained at 350°C and the pressure is 4bar. The reaction is continued for 0.8h. The light components in the reactor enter the coarse fractionation tower. The coarse fractionation tower has 28 theoretical plates, a pressure of 20kPa and a reflux ratio of 0.8:1.

[0112] The first component at the top of the tower enters the AMS product tower, which has 1m filler, a pressure of 20kPa, and a reflux ratio of 0.8: 1. The purity of the side-line AMS product is 99.85% and the output is 1.50kg / h.

[0113] The phenol and acetophenone mixture enters the phenol tower, which has 1m packing, a pressure of 20kPa, and a reflux ratio of 0.8: 1. The purity of the side-line phenol product is 99.92% and the output is 1.42kg / h.

[0114] The phenol recombinant component enters the acetophenone tower, which has 1m filler, a pressure of 20kPa, and a reflux ratio of 0.8:1. The purity of the side-line acetophenone product is 99.6%, and the output is 1kg / h.

[0115] Example 3

[0116] The phenol tar from the previous process (a device for producing phenol and acetone by isopropylbenzene peroxidation method) contains 10% phenol, 10% acetophenone, 10% dimethylbenzyl alcohol, 3% AMS dimer and 20% cumylphenol. 0.2% silver decanoate is added as a catalyst and fed into an electric heater at a feed rate of 5kg / h. After being preheated to 360°C, the tar enters the reactor and the temperature in the reactor is maintained at 330°C and the pressure is 3.5bar. The reaction is continued for 0.9h. The light components in the reactor enter the coarse fractionation tower. The coarse fractionation tower has 34 theoretical plates, a pressure of 30kPa and a reflux ratio of 1.2:1.

[0117] The first component at the top of the tower enters the AMS product tower, which has 1.5m filler, 30kPa pressure, and a reflux ratio of 1.2: 1. The purity of the side-line AMS product is 99.85% and the output is 1.50kg / h.

[0118] The phenol and acetophenone mixture enters the phenol tower, which has 1.5m packing, 30kPa pressure, and a reflux ratio of 1.2: 1. The purity of the side-line phenol product is 99.92% and the output is 1.66kg / h.

[0119] The phenol recombinant component enters the acetophenone tower, which has 1.5m filler, a pressure of 30kPa, a reflux ratio of 1.2:1, and a side-line acetophenone product with a purity of 99.6% and an output of 0.5kg / h.

[0120] Example 4

[0121] The phenol tar from the previous process (a device for producing phenol and acetone by isopropylbenzene peroxidation method) contains 10% phenol, 20% acetophenone, 10% dimethylbenzyl alcohol, 10% AMS dimer and 30% cumylphenol. 0.15% silver dilaurate is added as a catalyst and enters the electric heater at a feed rate of 5kg / h. After being preheated to 370℃, it enters the reactor and the temperature in the reactor is maintained at 350℃ and the pressure is 3.5bar. The reaction is continued for 0.9h. The light components in the reactor enter the coarse fractionation tower. The coarse fractionation tower has 30 theoretical plates, a pressure of 22kPa and a reflux ratio of 0.9:1.

[0122] The first component at the top of the tower enters the AMS product tower, which has 1m packing, a pressure of 22kPa, and a reflux ratio of 1.2: 1. The purity of the side-line AMS product is 99.85% and the output is 1.60kg / h.

[0123] The phenol and acetophenone mixture enters the phenol tower, which has 1m packing, a pressure of 22kPa, and a reflux ratio of 0.9: 1. The purity of the side-line phenol product is 99.92% and the output is 1.71kg / h.

[0124] The phenol recombinant component enters the acetophenone tower, which has 1m filler, a pressure of 22kPa, a reflux ratio of 0.9:1, and a side-line acetophenone product with a purity of 99.6% and an output of 1kg / h.

[0125] Example 5

[0126] The phenol tar from the previous process (a device for producing phenol and acetone by isopropylbenzene peroxidation method) contains 1% phenol, 10% acetophenone, 3% dimethylbenzyl alcohol, 3% AMS dimer and 20% cumylphenol. 0.15% silver stearate is added as a catalyst and fed into an electric heater at a feed rate of 5kg / h. After being preheated to 380°C, the tar enters the reactor and the temperature in the reactor is maintained at 350°C and the pressure is 3.7bar. The reaction is continued for 0.9h. The light components in the reactor enter the coarse fractionation tower, which has 33 theoretical plates, a pressure of 25kPa and a reflux ratio of 1:1.

[0127] The first component at the top of the tower enters the AMS product tower, which has 2m packing, a pressure of 25kPa, and a reflux ratio of 1: 1. The purity of the side-line AMS product is 99.85%, and the output is 1.37kg / h.

[0128] The phenol and acetophenone mixture enters the phenol tower, which has 2m packing, a pressure of 25kPa, and a reflux ratio of 1:1. The purity of the side-line phenol product is 99.92% and the output is 1.34kg / h.

[0129] The phenol recombinant component enters the acetophenone tower, which has 2m filler, a pressure of 25kPa, a reflux ratio of 1:1, and a side-line acetophenone product with a purity of 99.6% and an output of 0.5kg / h.

[0130] Comparative Example 1

[0131] The phenol tar from the previous process, with a phenol content of 1%, an acetophenone content of 10%, a dimethyl benzyl alcohol content of 3%, an AMS dimer content of 10%, and a cumylphenol content of 30%, enters the electric heater at a feed rate of 5kg / h, is preheated to 320°C and then enters the reactor. The temperature in the reactor is maintained at 300°C and the pressure is 5bar. The reaction is continued for 2h, and the light components in the reactor enter the coarse fractionation tower. The coarse fractionation tower has 20 theoretical plates, a pressure of 40kPa, and a reflux ratio of 2:1.

[0132] The first component at the top of the tower enters the AMS product tower, which has 0.8m packing, a pressure of 30kPa, and a reflux ratio of 2: 1. The purity of the side-line AMS product is 98.75% and the output is 0.1kg / h.

[0133] The phenol and acetophenone mixture enters the phenol tower, which has 0.8m packing, a pressure of 40kPa, and a reflux ratio of 2: 1. The purity of the side-line phenol product is 98.85%, and the output is 0.25kg / h.

[0134] The phenol recombinant component enters the acetophenone tower, which has 0.8m filler, 40kPa pressure and 2:1 reflux ratio. The purity of the side-line acetophenone product is 98.2% and the output is 0.5kg / h.

[0135] Comparative Example 2

[0136] The phenol tar from the previous process, with a phenol content of 5%, an acetophenone content of 15%, a dimethyl benzyl alcohol content of 8%, an AMS dimer content of 6%, and a cumylphenol content of 27%, was added with 0.2% copper sulfate as a catalyst and fed into the electric heater at a feed rate of 5kg / h. After being preheated to 350°C, it entered the reactor and maintained at a temperature of 320°C and a pressure of 2bar. The reaction was continued for 1h, and the light components in the reactor entered the coarse fractionation tower, which had 30 theoretical plates, a pressure of 25kPa, and a reflux ratio of 1:1.

[0137] The useful components at the top of the tower enter the AMS product tower, which has 1m filler, a pressure of 25kPa, and a reflux ratio of 1: 1. The purity of the side-line AMS product is 99.15%, and the output is 0.2kg / h.

[0138] The phenol and acetophenone mixture enters the phenol tower, which has 1m packing, a pressure of 20kPa, and a reflux ratio of 1:1. The purity of the side-line phenol product is 99.02% and the output is 0.4kg / h.

[0139] The phenol recombinant component enters the acetophenone tower, which has 1m filler, a pressure of 20kPa, and a reflux ratio of 2:1. The purity of the side-line acetophenone product is 99.1%, and the output is 0.75kg / h.

[0140] Comparative Example 1 does not add a catalyst, and Comparative Example 2 uses copper sulfate as a catalyst. By comparing the embodiments of the present invention and the comparative examples, it can be concluded that whether a catalyst is added and whether the catalyst has both an inhibitory effect and forms a homogeneous phase with the reaction liquid have a greater impact on the yield of AMS, phenol, and acetophenone.

[0141] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are within the spirit scope of the present invention.

Claims

1. A method for cracking and recovering phenol tar, characterized in that: The steps include: 1) preheating phenol tar and an organic silver salt catalyst and performing a cracking reaction to obtain a light component and a heavy component; 2) inputting the light component into a coarse fraction tower for rectification to separate and obtain a cumylphenol mixture at the bottom of the tower and a first component at the top of the tower; 3) inputting the first component into an AMS product tower for distillation to separate and obtain an AMS product, a mixed solution of phenol and acetophenone, and a light component; 4) inputting the mixed solution of phenol and acetophenone into a phenol product tower for rectification to separate and obtain phenol light components, phenol product and crude acetophenone; 5) The crude acetophenone is input into an acetophenone product tower for rectification to separate and obtain an acetophenone light component, an acetophenone product and an acetophenone heavy component.

2. The method for cracking and recovery according to claim 1, characterized in that: In the step 1), the phenol tar comes from a phenol and acetone production device using a cumene peroxidation process, and the components thereof include, by mass content, 1%-10% phenol, 10%-20% acetophenone, 3%-10% dimethyl benzyl alcohol, 3%-10% α-methylstyrene dimer, and 20%-30% cumylphenol.

3. The method for cracking and recovering according to claim 1 or 2, characterized in that: In step 1), the organic silver salt catalyst is a long-chain fatty acid silver salt; the addition amount of the long-chain fatty acid silver salt accounts for 0.05%-0.3% of the mass of phenol tar.

4. The method for cracking and recovery according to claim 3, characterized in that: In step 1), the organic silver salt catalyst is a C14-C24 fatty acid silver salt.

5. The method for cracking and recovery according to claim 3, characterized in that: The long-chain fatty acid silver salt is selected from one or more of silver palmitate, silver stearate, silver caprate, and silver dilaurate.

6. The method for cracking and recovery according to claim 3, characterized in that: The added amount of the long-chain fatty acid silver salt accounts for 0.1%-0.2% of the mass of the phenol tar.

7. The method for cracking and recovery according to claim 1, characterized in that: The cumylphenol mixture obtained in step 2) is returned to step 1) to participate in the reaction; and / or, The phenol light component obtained in step 4) is returned to the AMS product tower in step 3) for rectification; and / or, The acetophenone light component obtained in step 5) is returned to the phenol product tower in step 4) for rectification.

8. A system for cracking and recovering phenol tar, characterized in that: include: A heater, used for preheating a mixture of phenol tar and an organic silver salt catalyst to obtain a high-temperature material; A reactor, used to receive high-temperature materials and perform cracking reactions on the high-temperature materials to obtain light components and heavy components; A crude fraction tower, for receiving the light component and performing distillation on the light component to separate the cumylphenol mixture at the bottom of the tower and the first component at the top of the tower; An AMS product tower is used to receive the first component and distill the first component to separate and obtain an AMS product, a mixed solution of phenol and acetophenone, and a light component; A phenol product tower is used to receive the phenol and acetophenone mixed solution and distill the mixed solution to separate and obtain phenol light components, phenol products and crude acetophenone; The acetophenone product tower is used to receive the crude acetophenone and distill the crude acetophenone to separate and obtain the acetophenone light component, the acetophenone product and the acetophenone heavy component.

9. The cracking and recovery system according to claim 8, characterized in that: The heater is heated by an electric heating jacket, and the preheating temperature range is 350-400°C; The reactor is a tank reactor or a tubular reactor; The reaction temperature is 300-450°C; The reactor is made of one or two composite materials selected from carbon steel, 316L, nickel, 59 alloy, and Ha C; The pressure of the reactor is 2-10 bar; The residence time of the reactor is 0.5-3h.

10. The cracking and recovery system according to claim 9, characterized in that: The reactor is a tank reactor; The reaction temperature is 320-350°C; The reactor is made of nickel; The pressure of the reactor is 3-4 bar; The residence time of the reactor is 0.8-1.2h.

11. The cracking and recovery system according to claim 8, characterized in that: The coarse fraction tower is a packed tower or a plate tower; The pressure of the coarse fraction tower is 10-50 kPa; The number of theoretical plates of the crude fraction tower is 20-40; The reflux ratio of the coarse fraction tower is 0.2-5.

12. The cracking and recovery system according to claim 11, characterized in that: The coarse fraction tower is a plate tower; The pressure of the coarse fraction tower is 20-30 kPa; The number of theoretical plates of the coarse fraction tower is 28 to 34; The reflux ratio of the coarse fraction tower is 0.8-1.

2.

13. The cracking and recovery system according to claim 8, characterized in that: The AMS product tower is a plate tower or a packed tower; The pressure of the AMS product column is 10-50 kPa; The reflux ratio of the AMS product tower is 0.2-5; The packing height of the AMS product tower is 0.5-3m; The purity of the AMS product is >99.8%.

14. The cracking and recovery system according to claim 13, characterized in that: The AMS product tower is a packed tower; The pressure of the AMS product column is 20-30 kPa; The reflux ratio of the AMS product tower is 0.8-1.2; The packing height of the AMS product tower is 1-2 m.

15. The cracking and recovery system according to claim 8, characterized in that: The phenol product tower is a plate tower or a packed tower; The pressure of the phenol product tower is 10-50 kPa; The reflux ratio of the phenol product tower is 0.2-5; The packing height of the phenol product tower is 0.5-3m; The purity of the phenol product is greater than 99.9%.

16. The cracking and recovery system according to claim 15, characterized in that: The phenol product tower is a packed tower; The pressure of the phenol product tower is 20-30 kPa; The reflux ratio of the phenol product tower is 0.8-1.2; The packing height of the phenol product tower is 1-2m.

17. The cracking and recovery system according to claim 8, characterized in that: The acetophenone product tower is a plate tower or a packed tower; The pressure of the acetophenone product tower is 10-50 kPa; The reflux ratio of the acetophenone product tower is 0.2-5; The packing height of the acetophenone product tower is 0.5-3m; The purity of the acetophenone product is greater than 99.5%.

18. The cracking and recovery system according to claim 17, characterized in that: The acetophenone product tower is a packed tower; The pressure of the acetophenone product tower is 20-30 kPa; The reflux ratio of the acetophenone product tower is 0.8-1.2; The packing height of the acetophenone product tower is 1-2m.

Images