Process and apparatus for separating and recovering anthracene alkylated catalyst

Abstract

The present application relates to the technical field of alkylanthracene production, and particularly relates to a method for separating and recovering an anthracene alkylation catalyst and a device for separating and recovering an anthracene alkylation catalyst. The method comprises the following steps: (1) performing extraction on an acid oil mixture containing an anthracene alkylation catalyst to obtain an aqueous solution containing the anthracene alkylation catalyst; (2) performing membrane distillation on the aqueous solution containing the anthracene alkylation catalyst to obtain a concentrated aqueous solution of the anthracene alkylation catalyst with a concentration of greater than or equal to 22 wt%; and (3) sequentially performing first vacuum distillation and second vacuum distillation on the concentrated aqueous solution of the anthracene alkylation catalyst to obtain a recovered anthracene alkylation catalyst with a purity of greater than or equal to 98 wt%. The recovered anthracene alkylation catalyst prepared by the method has high purity and high yield.

Description

Technical Field

[0001] This invention relates to the field of alkyl anthracene production technology, specifically to a method and apparatus for separating and recovering anthracene alkylation catalysts. Background Technology

[0002] Hydrogen peroxide is an important green basic chemical with a wide range of industrial applications. The main process technology for producing hydrogen peroxide both domestically and internationally is the anthraquinone process. In this process, 2-alkylanthraquinone acts as a "carrier," directly affecting the quality and yield of hydrogen peroxide.

[0003] The process route for preparing 2-alkylanthraquinone via the oxidation of 2-alkylanthracene is considered a green production technology with broad application prospects due to its advantages such as simple process flow, wide availability of raw materials, and low environmental pollution. Anthracene can undergo an alkylation reaction with alkylating agents under acid catalysis. After separation, the product system yields the target product, 2-alkylanthracene. Then, using specific oxidation techniques, the efficient preparation of 2-alkylanthraquinone from 2-alkylanthracene can be achieved.

[0004] The key raw material for the above process, 2-alkylanthracene, can be prepared by heterogeneous liquid acid alkylation technology. This technology has the advantages of simple process flow and the required acid catalyst is inexpensive, readily available, and has excellent catalytic performance.

[0005] US4255343A, CN111825512B, CN109574779B, and CN111825510B disclose methods for heterogeneous liquid acid-catalyzed anthracene alkylation, but none of them involve the reuse of the catalyst. Because strong acid-catalyzed alkylation processes produce acid-soluble oil as a byproduct, the continuous accumulation of this oil during the reaction leads to a decrease in acidity and an increase in viscosity, thereby reducing the catalytic activity of the catalyst.

[0006] Currently, high-temperature cracking is commonly used in industry to process alkylation catalysts. Taking sulfuric acid as an example, it first undergoes heating, sedimentation, and degassing to remove acid-soluble oils, followed by incineration cracking, sulfur dioxide conversion, cooling, and sulfuric acid condensation to produce fresh sulfuric acid. The obvious drawbacks of this method are high energy consumption, complex processes, and high costs. Therefore, to achieve catalyst reuse, efficient separation technologies must be developed. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of complex processes, high energy consumption, and environmental pollution in the separation and recovery of existing anthracene alkylation catalysts, as well as the low purity and low yield of the recovered anthracene alkylation catalysts. This invention provides a new method and a new apparatus for separating and recovering anthracene alkylation catalysts. The recovered anthracene alkylation catalyst obtained by this method has high purity and high yield.

[0008] To achieve the above objectives, a first aspect of the present invention provides a method for separating and recovering anthracene alkylation catalysts, the method comprising the following steps:

[0009] (1) Extract the acid oil mixture containing anthracene alkylation catalyst to obtain an aqueous solution containing anthracene alkylation catalyst;

[0010] (2) The aqueous solution containing anthracene alkylation catalyst was subjected to membrane distillation to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%;

[0011] (3) The concentrated anthracene alkylation catalyst aqueous solution was subjected to a first vacuum distillation and a second vacuum distillation in sequence to obtain a recovered anthracene alkylation catalyst with a purity of ≥98wt%.

[0012] A second aspect of the present invention provides an apparatus for separating and recovering anthracene alkylation catalyst, the apparatus comprising: an extraction unit, a membrane distillation unit, and a vacuum distillation unit connected in sequence;

[0013] The extraction unit is used to mix and extract an acid oil mixture containing anthracene alkylation catalyst with water to obtain an aqueous solution containing anthracene alkylation catalyst.

[0014] The membrane distillation unit is used to perform membrane distillation on the aqueous solution containing anthracene alkylation catalyst to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%.

[0015] The vacuum distillation unit includes a first vacuum distillation column and a second vacuum distillation column connected in sequence, used to sequentially perform first vacuum distillation and second vacuum distillation on the concentrated anthracene alkylation catalyst aqueous solution to obtain a recovered anthracene alkylation catalyst with a purity ≥98wt%.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The method provided by the present invention uses an acid oil mixture containing anthracene alkylation catalyst as raw material and sequentially employs extraction, membrane distillation, first vacuum distillation and second vacuum distillation techniques to recover anthracene alkylation catalyst with high purity and high yield, that is, the purity of the recovered anthracene alkylation catalyst is ≥98wt% and the yield is ≥90%.

[0018] (2) The method provided by the present invention couples extraction, membrane distillation, first vacuum distillation and second vacuum distillation to obtain a recovered anthracene alkylation catalyst with both high purity and high yield. That is, the acid oil mixture is first extracted to avoid side reactions of acid-soluble oil in the acid oil mixture; then membrane distillation is performed to save energy and reduce consumption; finally, two-step vacuum distillation is performed to dehydrate and remove impurities respectively. At the same time, the method also has the characteristics of simple process, low energy consumption, environmental friendliness and low cost, which is convenient for industrial production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an apparatus for separating and recovering anthracene alkylation catalysts provided by the present invention.

[0020] Explanation of reference numerals in the attached figures

[0021] I. Extraction Unit II. Membrane Distillation Unit III. Vacuum Distillation Unit

[0022] III-1, First vacuum distillation column; III-2, Second vacuum distillation column

[0023] 1. Acid-oil mixture; 2. Water; 3. Aqueous solution containing anthracene alkylation catalyst.

[0024] 4. Acid-containing oil phase; 5. Concentrated anthracene alkylation catalyst aqueous solution; 6. Crude anthracene alkylation catalyst.

[0025] 7. Moisture 8. Recovery of anthracene alkylation catalyst 9. Impurities Detailed Implementation

[0026] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] In this invention, unless otherwise specified, "first" and "second" do not indicate a sequence or limit the specific materials or steps; they are merely used to distinguish between different materials or steps. For example, "first" and "second" in "first vacuum distillation" and "second vacuum distillation" are used only to indicate that they are not the same vacuum distillation process; "first" and "second" in "first vacuum distillation column" and "second vacuum distillation column" are used only to indicate that they are not the same vacuum distillation column.

[0028] The first aspect of this invention provides a method for separating and recovering anthracene alkylation catalysts, the method comprising the following steps:

[0029] (1) Extract the acid oil mixture containing anthracene alkylation catalyst to obtain an aqueous solution containing anthracene alkylation catalyst;

[0030] (2) The aqueous solution containing anthracene alkylation catalyst was subjected to membrane distillation to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%;

[0031] (3) The concentrated anthracene alkylation catalyst aqueous solution was subjected to a first vacuum distillation and a second vacuum distillation in sequence to obtain a recovered anthracene alkylation catalyst with a purity of ≥98wt%.

[0032] The inventors of this invention discovered that, theoretically, liquid acid and acid-soluble oil can be separated by vacuum distillation based on the difference in boiling points. However, they found that vacuum distillation cannot separate the liquid acid and acid-soluble oil. For example, with methanesulfonic acid, under a certain vacuum pressure, when the liquid phase temperature reaches the boiling point of methanesulfonic acid (but not its decomposition temperature), methanesulfonic acid cannot be collected at the top of the column. This is likely because side reactions occur between the organic liquid acid and the acid-soluble oil. Therefore, the acid catalyst cannot be separated and recovered using a single vacuum distillation method. Consequently, the inventors combined extraction, membrane distillation, and first and second vacuum distillation techniques for the separation and recovery of anthracene alkylation catalysts, resulting in high-purity and high-yield recovered anthracene alkylation catalysts.

[0033] In this invention, unless otherwise specified, the acid oil mixture containing anthracene alkylation catalyst is simply referred to as the acid oil mixture.

[0034] In some embodiments of the present invention, preferably, in step (1), the concentration of the anthracene alkylation catalyst in the acid oil mixture is 80-95 wt%, for example, 80 wt%, 85 wt%, 88 wt%, 90 wt%, 95 wt%, and any value within the range of any two values, preferably 85-90 wt%.

[0035] In this invention, unless otherwise specified, the acid-oil mixture contains acid-soluble oil and impurities in addition to the anthracene alkylation catalyst.

[0036] In this invention, the source of the acid-oil mixture is subject to a wide range of selection, as long as the anthracene alkylation catalyst in the acid-oil mixture meets the above-mentioned limitations. Preferably, the acid-oil mixture is selected from the lower layer solution of the anthracene alkylation reaction solution, wherein the anthracene alkylation reaction process conditions include: a temperature of 80-150°C, a mechanical stirring rate of 200-500 r / min, and an alkylating agent olefin feeding time of 6-15 h.

[0037] In some embodiments of the present invention, preferably, the anthracene alkylation catalyst is selected from liquid acid catalysts; more preferably, the anthracene alkylation catalyst is selected from C1-C5 alkyl sulfonic acids and / or C1-C5 perfluorinated substituted alkyl sulfonic acids.

[0038] In one specific embodiment of the present invention, preferably, the anthraquinone alkylation catalyst is selected from at least one of methane sulfonic acid, ethane sulfonic acid, propane sulfonic acid, butane sulfonic acid, perfluoromethane sulfonic acid, perfluoroethane sulfonic acid, perfluoropropane sulfonic acid, and perfluorobutane sulfonic acid.

[0039] In this invention, the extraction aims to avoid the influence of the acid-soluble oil in the acid-oil mixture on subsequent vacuum distillation, that is, to prevent side reactions between the acid-soluble oil and the anthracene alkylation catalyst. Preferably, in step (1), the extraction process includes: mixing the acid-oil mixture containing the anthracene alkylation catalyst with water and performing the extraction.

[0040] In some embodiments of the present invention, preferably, in step (1), the weight ratio of the acid oil mixture to water, based on the anthracene alkylation catalyst, is 1:2-20, for example, 1:2, 1:3, 1:5, 1:6, 1:8, 1:10, 1:15, 1:20, and any value within the range of any two values, preferably 1:5-10. Using this preferred weight ratio is more conducive to removing acid-soluble oil from the acid oil mixture, thereby improving the purity of the recovered anthracene alkylation catalyst.

[0041] In this invention, the mixing aims to homogenize the acid-oil mixture and water, thereby improving the extraction effect. Preferably, the mixing conditions include: a temperature of 20-100°C, more preferably 40-80°C; and a time of 0.1-1 h, more preferably 0.25-0.8 h.

[0042] In this invention, the extraction aims to separate the anthracene alkylation catalyst and the acid-soluble oil in the acid-oil mixture, i.e., to obtain an extract phase containing an aqueous solution of the anthracene alkylation catalyst and a raffinate phase containing the acid-soluble oil. Preferably, the extraction conditions include: a temperature of 20-100°C, more preferably 40-80°C; and a time of 0.1-3 h, more preferably 0.5-2 h. Using these preferred conditions is more advantageous for achieving stratification of the extract phase and the raffinate phase, i.e., obtaining an extract phase in the lower layer and a raffinate phase in the upper layer.

[0043] In this invention, compared with directly subjecting the extracted phase to vacuum distillation, membrane distillation technology can greatly reduce the energy consumption of subsequent vacuum distillation dehydration. In particular, for aqueous solutions containing anthracene alkylation catalysts with very low concentrations, the energy-saving and consumption-reducing advantages of membrane distillation technology are even more obvious.

[0044] In this invention, the membrane distillation concentrates the aqueous solution containing anthracene alkylation catalyst by dehydration to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration of ≥22wt%.

[0045] In some embodiments of the present invention, preferably, in step (2), the conditions for membrane distillation include: feed temperature of 30-80°C, feed flow rate of 0.1-2 L / min, membrane inlet side pressure of 0-0.2 MPa, membrane permeate side pressure of -0.1 to -0.06 MPa, membrane permeate side cooling liquid temperature of 0-10°C, and average membrane permeate flux of 0.5-2 L·m -2 ·h -1 The separation time is 3-20 hours.

[0046] In some embodiments of the present invention, more preferably, in step (2), the membrane distillation conditions include: a feed temperature of 40-70°C, a feed flow rate of 0.5-1.5 L / min, a membrane inlet side pressure of 0.05-0.1 MPa, a membrane permeation side pressure of -0.1 to -0.08 MPa, a membrane permeation side cooling liquid temperature of 2-8°C, and an average membrane permeation flux of 0.7-1.5 L·m -2 ·h -1 The separation time is 7-15 hours.

[0047] In some embodiments of the present invention, preferably, the membrane permeate side cooling liquid is selected from circulating condensate and / or liquid nitrogen.

[0048] In some embodiments of the present invention, more preferably, the concentration of the concentrated anthracene alkylation catalyst aqueous solution is 22-32 wt%. Membrane distillation within this concentration range results in the lowest energy consumption for the entire separation process; when the concentration of the concentrated anthracene alkylation catalyst aqueous solution is below 22 wt%, more water needs to be distilled under reduced pressure; when the concentration of the concentrated anthracene alkylation catalyst aqueous solution is above 32 wt%, membrane distillation requires more energy.

[0049] In this invention, there is a wide range of options for the membrane distillation method. Preferably, in step (2), the membrane distillation is selected from direct contact membrane distillation or air gap membrane distillation.

[0050] In one specific embodiment of the present invention, when the membrane distillation is a direct contact membrane distillation, both the membrane feed liquid (hot side) and the membrane permeate (condenser side) are in direct contact with the membrane; when the membrane distillation is a gas-gap membrane distillation, the membrane feed liquid (hot side) is in contact with the membrane, and there is a gas gap between the membrane permeate (condenser side) and the membrane. In the present invention, when direct contact membrane distillation is used, it has high membrane flux, but relatively low rejection rate, and the membrane is more prone to wetting, leading to membrane distillation failure; when gas-gap membrane distillation is used, it has higher rejection rate and longer membrane life, but lower membrane flux and higher energy consumption.

[0051] In some embodiments of the present invention, preferably, the membrane material of the membrane distillation is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride and polypropylene.

[0052] In some embodiments of the present invention, preferably, the membrane pore size of the membrane distillation is ≤1 μm, more preferably 0.1-1 μm. Using these preferred conditions, a high membrane flux can be guaranteed while ensuring a high rejection rate.

[0053] In some embodiments of the present invention, preferably, the membrane for membrane distillation is selected from flat sheet type or hollow fiber type.

[0054] In this invention, unless otherwise specified, the first vacuum distillation is carried out in a first vacuum distillation column, at the bottom of the column a crude anthracene alkylation catalyst containing almost no water but containing impurities is obtained, and at the top of the column a water containing almost no catalyst is obtained.

[0055] In some embodiments of the present invention, preferably, in step (3), the first vacuum distillation process includes: performing the first vacuum distillation on the concentrated anthracene alkylation catalyst aqueous solution to obtain crude anthracene alkylation catalyst with a water content ≤1wt% and water with a catalyst content ≤0.1wt%.

[0056] In some embodiments of the present invention, preferably, in step (3), the conditions for the first vacuum distillation include: a liquid phase temperature of 50-100°C; a gas phase temperature of 25-75°C; a pressure of 0-5 kPa; a theoretical plate number of 10-30; and a reflux ratio of 0.2-5. In the present invention, the liquid phase temperature refers to the temperature of the aqueous solution of the crude anthracene alkylation catalyst in the bottom of the column under a specific pressure; the gas phase temperature refers to the vaporization temperature of water under the same specific pressure.

[0057] In this invention, unless otherwise specified, all pressure parameters refer to gauge pressure.

[0058] In some embodiments of the present invention, more preferably, in step (3), the conditions for the first vacuum distillation include: liquid phase temperature of 55-80°C; gas phase temperature of 40-60°C; pressure of 1-3 kPa; number of theoretical plates of 15-25; and reflux ratio of 0.4-3.

[0059] In this invention, unless otherwise specified, the second vacuum distillation is carried out in a second vacuum distillation column, at the bottom of the column to obtain impurities that are almost free of catalyst, such as black solid residue; and at the top of the column to obtain high-purity recovered anthracene alkylation catalyst.

[0060] In some embodiments of the present invention, preferably, in step (3), the second vacuum distillation process includes: subjecting the crude anthracene alkylation catalyst to the second vacuum distillation to obtain the recovered anthracene alkylation catalyst and impurities with a catalyst content ≤5wt%.

[0061] In some embodiments of the present invention, preferably, in step (3), the conditions for the second vacuum distillation include: a liquid phase temperature of 150-300°C; a gas phase temperature of 100-200°C; a pressure of 0.1-4 kPa; a theoretical plate number of 30-50; and a reflux ratio of 0.1-4. In the present invention, the liquid phase temperature is the temperature of the crude anthracene alkylation catalyst in the bottom of the column under a specific pressure; the gas phase temperature is the vaporization temperature of the anthracene alkylation catalyst under the same specific pressure.

[0062] In some embodiments of the present invention, more preferably, in step (3), the conditions for the second vacuum distillation include: liquid phase temperature of 180-280℃; gas phase temperature of 130-180℃; pressure of 0.5-2kPa; number of theoretical plates of 35-45; and reflux ratio of 0.2-2.

[0063] A second aspect of the present invention provides an apparatus for separating and recovering anthracene alkylation catalyst, the apparatus comprising: an extraction unit, a membrane distillation unit, and a vacuum distillation unit connected in sequence;

[0064] The extraction unit is used to mix and extract an acid oil mixture containing anthracene alkylation catalyst with water to obtain an aqueous solution containing anthracene alkylation catalyst.

[0065] The membrane distillation unit is used to perform membrane distillation on the aqueous solution containing anthracene alkylation catalyst to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%.

[0066] The vacuum distillation unit includes a first vacuum distillation column and a second vacuum distillation column connected in sequence, used to sequentially perform first vacuum distillation and second vacuum distillation on the concentrated anthracene alkylation catalyst aqueous solution to obtain a recovered anthracene alkylation catalyst with a purity ≥98wt%.

[0067] In this invention, there is a wide range of choices for the types of extraction units, which include, but are not limited to, mixing tanks and extraction towers.

[0068] In this invention, the membrane distillation unit has a wide range of selection, and the membrane distillation unit is a membrane distillation device.

[0069] In some embodiments of the present invention, preferably, the first vacuum distillation column is used to perform a first vacuum distillation on the concentrated alkylation catalyst aqueous solution to obtain a crude anthracene alkylation catalyst with a water content ≤1 wt% and a catalyst content ≤0.1 wt% of water; the second vacuum distillation column is used to perform a second vacuum distillation on the crude anthracene alkylation catalyst to obtain a recovered anthracene alkylation catalyst with a purity ≥98 wt% and a catalyst content ≤5 wt% of impurities.

[0070] The present invention provides a schematic diagram of an apparatus for separating and recovering anthracene alkylation catalysts, as shown below. Figure 1 As shown, the device includes: an extraction unit I, a membrane distillation unit II, a first vacuum distillation column III-1, and a second vacuum distillation column III-2 connected in sequence.

[0071] Among them, extraction unit I is used to mix and extract an acid oil mixture 1 containing anthracene alkylation catalyst and water 2, and the resulting aqueous solution 3 containing anthracene alkylation catalyst is used as the extraction phase and the acid-soluble oil phase 4 is used as the raffinate phase.

[0072] Among them, membrane distillation unit II is used to perform membrane distillation on the aqueous solution 3 containing anthracene alkylation catalyst to obtain a concentrated aqueous solution 5 of anthracene alkylation catalyst with a concentration ≥22wt%;

[0073] The first vacuum distillation column III-1 is used to perform a first vacuum distillation on the concentrated alkylation catalyst aqueous solution 5 to obtain crude anthracene alkylation catalyst 6 with a water content ≤1wt% and water 7 with a catalyst content ≤0.1wt%.

[0074] The second vacuum distillation column III-2 is used to perform a second vacuum distillation on the crude anthracene alkylation catalyst 6 to obtain a recovered anthracene alkylation catalyst 8 with a purity ≥98wt% and impurities 9 with a catalyst content ≤5wt%.

[0075] According to a particularly preferred embodiment of the present invention, a method for separating and recovering anthracene alkylation catalysts, the method comprising:

[0076] (1) Extract the acid oil mixture containing anthracene alkylation catalyst with water to obtain an aqueous solution containing anthracene alkylation catalyst;

[0077] (2) The aqueous solution containing anthracene alkylation catalyst was subjected to membrane distillation to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%;

[0078] (3) The concentrated anthracene alkylation catalyst aqueous solution is subjected to a first vacuum distillation to obtain a crude anthracene alkylation catalyst with a water content of ≤1wt% and a catalyst content of ≤0.1wt% water; the crude anthracene alkylation catalyst is subjected to a second vacuum distillation to obtain a recovered anthracene alkylation catalyst with a purity of ≥98wt% and a catalyst content of ≤5wt% impurities;

[0079] The weight ratio of the acid oil mixture to water, calculated based on the anthracene alkylation catalyst, is 1:5-10.

[0080] The present invention will be described in detail below through embodiments.

[0081] The concentration of anthracene alkylation catalyst (methanesulfonic acid) in the acid oil mixture containing anthracene alkylation catalyst (hereinafter referred to as acid oil mixture A1) is 88.6 wt%.

[0082] The concentration of anthracene alkylation catalyst (perfluoroethane sulfonic acid) in the acid oil mixture containing anthracene alkylation catalyst (hereinafter referred to as acid oil mixture A2) is 92.4 wt%.

[0083] Example 1

[0084] (1) A mixture of acid oil A1 based on anthracene alkylation catalyst and water were mixed at a weight ratio of 1:10 (temperature 30℃, time 0.3h) and extracted (temperature 30℃, time 0.5h) to obtain an aqueous solution containing anthracene alkylation catalyst with a mass of 1kg and a concentration of 9.09wt%.

[0085] (2) The above-mentioned aqueous solution containing anthracene alkylation catalyst was subjected to direct contact membrane distillation using a flat-plate PTFE membrane with a pore size of 0.22 μm. The feed temperature was 60 °C, the feed flow rate was 0.2 L / min, the membrane inlet pressure was 0 MPa, the membrane permeate pressure was -0.1 MPa, and the permeate liquid was condensed with liquid nitrogen at 6 °C. The average permeate flux was 0.8 L·m -2 ·h -1 The separation time was 5 h, and a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 22.5 wt% was obtained.

[0086] (3) The above concentrated alkylation catalyst aqueous solution was subjected to a first vacuum distillation (liquid phase temperature of 78°C, gas phase temperature of 58°C, distillation pressure of 3 kPa, theoretical number of plates of 18, and top reflux ratio of 2) to obtain crude anthracene alkylation catalyst with a water content of 0.8 wt% and catalyst with a water content of 0.01 wt%.

[0087] The above crude anthracene alkylation catalyst was subjected to a second vacuum distillation (liquid phase temperature 217℃, gas phase temperature 178℃, distillation pressure 2kPa, theoretical plate number 35, and top reflux ratio 1) to obtain the recovered anthracene alkylation catalyst S1.

[0088] The purity of the recovered anthracene alkylation catalyst S1 was 99.6 wt%, and the yield was 90.3%.

[0089] Comparative Example 1

[0090] According to Example 1, the difference is that in step (2), the above-mentioned anthracene alkylation catalyst aqueous solution is subjected to vacuum distillation (liquid phase temperature is 78°C, gas phase temperature is 58°C, distillation pressure is 3 kPa, theoretical plate number is 18, and top reflux ratio is 2) to obtain a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 22.5 wt%.

[0091] Compared to Comparative Example 1, which consumed 4357 kJ of energy through vacuum distillation, Example 1, which consumed 1452 kJ of energy to obtain the same concentration of concentrated anthracene alkylation catalyst aqueous solution through membrane distillation, consumed only 33.3% of the energy consumption of Comparative Example 1. Therefore, the method provided by this invention can more effectively reduce energy consumption while ensuring high purity and high yield of the recovered anthracene alkylation catalyst.

[0092] Example 2

[0093] (1) A mixture of acid oil A1 based on anthracene alkylation catalyst and water were mixed at a weight ratio of 1:9 (temperature 40℃, time 0.4h) and extracted (temperature 40℃, time 0.6h) to obtain an aqueous solution containing anthracene alkylation catalyst with a mass of 1kg and a concentration of 10wt%.

[0094] (2) The above-mentioned aqueous solution containing anthracene alkylation catalyst was subjected to direct contact membrane distillation using a flat-plate PTFE membrane with a pore size of 0.45 μm. The feed temperature was 60 °C, the feed flow rate was 0.2 L / min, the membrane inlet pressure was 0 MPa, the membrane permeate pressure was -0.1 MPa, and the permeate liquid was condensed with liquid nitrogen at 5 °C. The average permeate flux was 1.2 L·m -2 ·h -1 The separation time was 5 h, and a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 28.6 wt% was obtained.

[0095] (3) The above concentrated alkylation catalyst aqueous solution was subjected to a first vacuum distillation (liquid phase temperature of 71℃, gas phase temperature of 53℃, distillation pressure of 2.5kPa, theoretical plate number of 18, and top reflux ratio of 2) to obtain crude anthracene alkylation catalyst with a water content of 0.6wt% and catalyst with a water content of 0.02wt%.

[0096] The above crude anthracene alkylation catalyst was subjected to a second vacuum distillation (liquid phase temperature 202℃, gas phase temperature 169℃, distillation pressure 1.8kPa, theoretical plate number 35, and top reflux ratio 1) to obtain the recovered anthracene alkylation catalyst S2.

[0097] The purity of the recovered anthracene alkylation catalyst S2 was 99.5 wt%, and the yield was 91.5%.

[0098] Comparative Example 2

[0099] According to Example 2, the difference is that in step (2), the above-mentioned anthracene alkylation catalyst aqueous solution is subjected to vacuum distillation (liquid phase temperature is 71°C, gas phase temperature is 53°C, distillation pressure is 2.5 kPa, theoretical plate number is 18, and top reflux ratio is 1.8) to obtain a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 28.6 wt%.

[0100] Compared to Comparative Example 2, which consumed 4654 kJ using vacuum distillation, Example 2, which consumed 1662 kJ to obtain the same concentration of concentrated anthracene alkylation catalyst aqueous solution using membrane distillation, consumed only 35.7% of the energy consumption of Comparative Example 2. Therefore, the method provided by this invention can more effectively reduce energy consumption while ensuring high purity and high yield of the recovered anthracene alkylation catalyst.

[0101] Example 3

[0102] (1) A mixture of acid oil A1 based on anthracene alkylation catalyst and water were mixed at a weight ratio of 1:8 (temperature 50℃, time 0.5h) and extracted (temperature 50℃, time 0.7h) to obtain an aqueous solution containing anthracene alkylation catalyst with a mass of 1kg and a concentration of 11.11wt%.

[0103] (2) The above-mentioned aqueous solution containing anthracene alkylation catalyst was subjected to direct contact membrane distillation using a flat-plate PTFE membrane with a pore size of 0.22 μm. The feed temperature was 70 °C, the feed flow rate was 0.2 L / min, the membrane inlet pressure was 0 MPa, the membrane permeate pressure was -0.1 MPa, and the permeate liquid was condensed with liquid nitrogen at 3 °C. The average permeate flux was 0.83 L·m -2 ·h -1 The separation time was 5 h, and a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 23.1 wt% was obtained.

[0104] (3) The above concentrated alkylation catalyst aqueous solution was subjected to a first vacuum distillation (liquid phase temperature of 64℃, gas phase temperature of 48℃, distillation pressure of 2kPa, theoretical number of plates of 18, and top reflux ratio of 2) to obtain crude anthracene alkylation catalyst with a water content of 0.5wt% and catalyst with a water content of 0.04wt%.

[0105] The above crude anthracene alkylation catalyst was subjected to a second vacuum distillation (liquid phase temperature 194℃, gas phase temperature 161℃, distillation pressure 1.5kPa, theoretical plate number 35, and top reflux ratio 1) to obtain the recovered anthracene alkylation catalyst S3.

[0106] The purity of the recovered anthracene alkylation catalyst S3 was 99.3 wt%, and the yield was 92.2%.

[0107] Comparative Example 3

[0108] According to Example 3, the difference is that in step (2), the above-mentioned aqueous solution containing anthracene alkylation catalyst is subjected to vacuum distillation (liquid phase temperature is 64°C, gas phase temperature is 48°C, distillation pressure is 2kPa, theoretical plate number is 18, and top reflux ratio is 1.5) to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration of 23.1wt%.

[0109] Compared to Comparative Example 3, which consumed 3695 kJ of energy through vacuum distillation, Example 3, which consumed 1478 kJ of energy to obtain the same concentration of concentrated anthracene alkylation catalyst aqueous solution through membrane distillation, consumed only 40% of the energy of Comparative Example 3. Therefore, the method provided by this invention can more effectively reduce energy consumption while ensuring high purity and high yield of the recovered anthracene alkylation catalyst.

[0110] Example 4

[0111] (1) A mixture of acid oil A1 based on anthracene alkylation catalyst and water were mixed at a weight ratio of 1:7 (temperature 60℃, time 0.6h) and extracted (temperature 60℃, time 0.8h) to obtain an aqueous solution containing anthracene alkylation catalyst with a mass of 1kg and a concentration of 12.5wt%.

[0112] (2) The above-mentioned aqueous solution containing anthracene alkylation catalyst was subjected to air-gap membrane distillation using a flat-plate PTFE membrane with a pore size of 0.22 μm. The feed temperature was 60 °C, the feed flow rate was 0.2 L / min, the membrane inlet pressure was 0 MPa, the membrane permeate pressure was -0.1 MPa, and the permeate liquid was condensed with liquid nitrogen at 8 °C. The average permeate flux was 0.65 L·m -2 ·h -1 The separation time was 5 h, and a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 30.2 wt% was obtained.

[0113] (3) The above concentrated alkylation catalyst aqueous solution was subjected to a first vacuum distillation (liquid phase temperature of 58℃, gas phase temperature of 45℃, distillation pressure of 1.5kPa, theoretical plate number of 18, and top reflux ratio of 2) to obtain crude anthracene alkylation catalyst with a water content of 0.2wt% and catalyst with a water content of 0.05wt%.

[0114] The above crude anthracene alkylation catalyst was subjected to a second vacuum distillation (liquid phase temperature 189℃, gas phase temperature 157℃, distillation pressure 1.2kPa, theoretical plate number 35, and top reflux ratio 1) to obtain the recovered anthracene alkylation catalyst S4.

[0115] The purity of the recovered anthracene alkylation catalyst S4 was 99.1 wt%, and the yield was 93.4%.

[0116] Comparative Example 4

[0117] According to Example 4, the difference is that in step (2), the above-mentioned anthracene alkylation catalyst aqueous solution is subjected to vacuum distillation (liquid phase temperature is 58°C, gas phase temperature is 45°C, distillation pressure is 1.5 kPa, theoretical plate number is 18, and top reflux ratio is 1.2) to obtain a concentrated anthracene alkylation catalyst aqueous solution with a concentration of 30.2 wt%.

[0118] Compared to Comparative Example 4, which consumed 3747 kJ using vacuum distillation, Example 4, which consumed 1703 kJ to obtain the same concentration of concentrated anthracene alkylation catalyst aqueous solution using membrane distillation, consumed only 45.4% of the energy consumption of Comparative Example 4. Therefore, the method provided by this invention effectively reduces energy consumption while ensuring high purity and high yield of the recovered anthracene alkylation catalyst.

[0119] Example 5

[0120] The method of Example 1 is followed, except that in step (1), acid oil mixture A1 is replaced with acid oil mixture A2, and the other conditions are the same, to obtain the recovered anthracene alkylation catalyst S5;

[0121] The purity of the recovered anthracene alkylation catalyst S5 was 99.2 wt%, and the yield was 91.8%.

[0122] Example 6

[0123] The method of Example 1 is followed, except that in step (1), the weight ratio of acid oil mixture A1 and water based on anthracene alkylation catalyst is replaced with 1:4, and the other conditions are the same, to obtain the recovered anthracene alkylation catalyst S6.

[0124] The purity of the recovered anthracene alkylation catalyst S6 was 98.2 wt%, and the yield was 95.4%.

[0125] Example 7

[0126] The method is the same as in Example 1, except that in step (2), the membrane distillation conditions are replaced with: feed temperature of 35°C, feed flow rate of 0.1 L / min, membrane inlet side pressure of 0 MPa, membrane permeate side pressure of -0.1 MPa, permeate liquid condensed with 0°C liquid nitrogen, and average membrane permeate flux of 0.45 L·m -2 ·h -1 The separation time was 5 hours, and the other conditions were the same, to obtain the recovered anthracene alkylation catalyst S7.

[0127] The purity of the recovered anthracene alkylation catalyst S7 was 99.5 wt%, and the yield was 90.6%.

[0128] Comparative Example 1

[0129] When the acid-oil mixture A1 was directly subjected to vacuum distillation (liquid phase temperature 189℃, gas phase temperature 175℃, distillation pressure 1kPa, and reflux ratio at the top of the column 1), methanesulfonic acid could not be collected at the top of the column. Instead, a dark green liquid with a foul odor and insoluble in water was obtained, proving that the single vacuum distillation method cannot recover the methanesulfonic acid catalyst.

[0130] Comparative Example 2

[0131] The method is the same as in Example 1, except that step (3) is omitted, that is, the concentrated anthracene alkylation catalyst aqueous solution obtained in step (2) is used as the recovered anthracene alkylation catalyst DS2.

[0132] The purity of the recovered anthracene alkylation catalyst DS2 was 22.5 wt%, and the yield was 90.5%.

[0133] Comparative Example 3

[0134] The method is the same as in Example 1, except that there is no second vacuum distillation, that is, the crude anthracene alkylation catalyst is directly used as the recovered anthracene alkylation catalyst DS3;

[0135] The purity of the recovered anthracene alkylation catalyst DS3 was 95.8 wt%, and the yield was 95.3%.

[0136] Comparative Example 4

[0137] The method is the same as in Example 1, except that there is no first vacuum distillation. That is, the above-mentioned concentrated alkylation catalyst aqueous solution is directly subjected to vacuum distillation (liquid phase temperature is 217°C, gas phase temperature is 178°C, distillation pressure is 2 kPa, theoretical plate number is 35, and top reflux ratio is 1). The other conditions are the same, and the anthracene alkylation catalyst cannot be recovered. Since the above-mentioned concentrated alkylation catalyst aqueous solution is directly distilled, the water and catalyst are mixed together, which is equivalent to no distillation.

[0138] Compared to Comparative Examples 1-4, the recovered anthracene alkylation catalyst prepared by the method provided by this invention has higher purity and yield, wherein the purity of the recovered anthracene alkylation catalyst is ≥98wt% and the yield is ≥90%. Compared to Comparative Examples 3-4, Example 1 achieves high purity and high yield of the recovered anthracene alkylation catalyst by controlling the vacuum distillation scheme, including a first vacuum distillation and a second vacuum distillation.

[0139] Compared to Example 5, Example 1, by adjusting the concentration of the anthracene alkylation catalyst in the acid-oil mixture within the preferred protection range, is more conducive to improving the purity of the recovered anthracene alkylation catalyst. Examples 1 and 5 demonstrate that different concentrations of the anthracene alkylation catalyst in the acid-oil mixture have little impact on the purity and yield of the recovered anthracene alkylation catalyst.

[0140] Compared to Example 6, Example 1, by adjusting the weight ratio of the acid-oil mixture and water (based on the anthracene alkylation catalyst) within the preferred protection range, is more conducive to improving the purity of the recovered anthracene alkylation catalyst.

[0141] Compared to Example 7, Example 1, by adjusting the electrodialysis conditions within the preferred protection range, is more conducive to improving the purity of the recovered anthracene alkylation catalyst.

[0142] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for separating and recovering anthracene alkylation catalyst, characterized in that, The method includes the following steps: (1) Extract the acid oil mixture containing anthracene alkylation catalyst to obtain an aqueous solution containing anthracene alkylation catalyst; (2) The aqueous solution containing anthracene alkylation catalyst is subjected to membrane distillation to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%; (3) The concentrated anthracene alkylation catalyst aqueous solution was subjected to a first vacuum distillation and a second vacuum distillation in sequence to obtain a recovered anthracene alkylation catalyst with a purity of ≥98wt%.

2. The method according to claim 1, wherein, In step (1), the concentration of the anthracene alkylation catalyst in the acid-oil mixture is 80-95 wt%. The anthraquinone alkylation catalyst is selected from liquid acid catalysts.

3. The method according to claim 2, wherein, In step (1), the concentration of the anthracene alkylation catalyst in the acid oil mixture is 85-90 wt%. The anthraquinone alkylation catalyst is selected from C1-C5 alkyl sulfonic acids and / or C1-C5 perfluorinated substituted alkyl sulfonic acids.

4. The method according to claim 3, wherein, In step (1), The anthraquinone alkylation catalyst is selected from at least one of methane sulfonic acid, ethane sulfonic acid, propane sulfonic acid, butane sulfonic acid, perfluoromethane sulfonic acid, perfluoroethane sulfonic acid, perfluoropropane sulfonic acid, and perfluorobutane sulfonic acid.

5. The method according to claim 1, wherein, In step (1), the extraction process includes: mixing the acid oil mixture containing the anthraquinone alkylation catalyst with water and performing the extraction; The weight ratio of the acid oil mixture to water, calculated based on the anthracene alkylation catalyst, is 1:2-20. The mixing conditions include: a temperature of 20-100℃ and a time of 0.1-1h; The extraction conditions include: a temperature of 20-100℃ and a time of 0.1-3h.

6. The method according to claim 5, wherein, In step (1), the weight ratio of the acid oil mixture to water, based on the anthracene alkylation catalyst, is 1:5-10; The mixing conditions include: a temperature of 40-80℃ and a time of 0.25-0.8h. The extraction conditions include: a temperature of 40-80℃ and a time of 0.5-2h.

7. The method according to claim 1, wherein, In step (2), the membrane distillation conditions include: feed temperature of 30-80℃, feed flow rate of 0.1-2 L / min, membrane inlet side pressure of 0-0.2 MPa, membrane permeate side pressure of -0.1 to -0.06 MPa, membrane permeate side cooling liquid temperature of 0-10℃, and average membrane permeate flux of 0.5-2 L·m -2 ·h -1 The separation time is 3-20 hours.

8. The method according to claim 7, wherein, In step (2), the membrane distillation conditions include: feed temperature of 40-70℃, feed flow rate of 0.5-1.5 L / min, membrane inlet pressure of 0.05-0.1 MPa, membrane permeate pressure of -0.1 to -0.08 MPa, membrane permeate cooling liquid temperature of 2-8℃, and average membrane permeate flux of 0.7-1.5 L·m -2 ·h -1 The separation time is 7-15 hours; And / or, the cooling liquid on the membrane permeate side is selected from circulating condensate and / or liquid nitrogen.

9. The method according to claim 1, wherein, In step (2), the membrane distillation is selected from direct contact membrane distillation or air gap membrane distillation; The membrane material used in the membrane distillation is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, and polypropylene. Wherein, the membrane pore size of the membrane distillation is ≤1µm; The membrane used in the membrane distillation is selected from flat sheet type or hollow fiber type.

10. The method according to claim 9, wherein, In step (2), the membrane pore size of the membrane distillation is 0.1-1µm.

11. The method according to any one of claims 1-10, wherein, In step (3), the first vacuum distillation process includes: performing the first vacuum distillation on the concentrated anthracene alkylation catalyst aqueous solution to obtain crude anthracene alkylation catalyst with a water content ≤1wt% and water with a catalyst content ≤0.1wt%.

12. The method according to any one of claims 1-10, wherein, In step (3), the conditions for the first vacuum distillation include: liquid phase temperature of 50-100℃; gas phase temperature of 25-75℃; pressure of 0-5kPa; number of theoretical plates of 10-30; and reflux ratio of 0.2-5.

13. The method according to claim 12, wherein, In step (3), the conditions for the first vacuum distillation include: liquid phase temperature of 55-80℃; gas phase temperature of 40-60℃; pressure of 1-3kPa; theoretical number of plates of 15-25; and reflux ratio of 0.4-3.

14. The method according to claim 11, wherein, In step (3), the second vacuum distillation process includes: subjecting the crude anthracene alkylation catalyst to the second vacuum distillation to obtain the recovered anthracene alkylation catalyst and impurities with a catalyst content ≤5wt%.

15. The method according to any one of claims 1-10, wherein, In step (3), the conditions for the second vacuum distillation include: liquid phase temperature of 150-300℃; gas phase temperature of 100-200℃; pressure of 0.1-4kPa; number of theoretical plates of 30-50; and reflux ratio of 0.1-4.

16. The method according to claim 15, wherein, In step (3), the conditions for the second vacuum distillation include: liquid phase temperature of 180-280℃; gas phase temperature of 130-180℃; pressure of 0.5-2kPa; number of theoretical plates of 35-45; and reflux ratio of 0.2-2.

17. An apparatus for separating and recovering anthracene alkylation catalyst, characterized in that, The apparatus includes: an extraction unit, a membrane distillation unit, and a vacuum distillation unit connected in sequence; The extraction unit is used to mix and extract an acid oil mixture containing anthracene alkylation catalyst with water to obtain an aqueous solution containing anthracene alkylation catalyst. The membrane distillation unit is used to perform membrane distillation on the aqueous solution containing anthracene alkylation catalyst to obtain a concentrated aqueous solution of anthracene alkylation catalyst with a concentration ≥22wt%. The vacuum distillation unit includes a first vacuum distillation column and a second vacuum distillation column connected in sequence, used to sequentially perform first vacuum distillation and second vacuum distillation on the concentrated anthracene alkylation catalyst aqueous solution to obtain a recovered anthracene alkylation catalyst with a purity ≥98wt%.

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