Method for recovering anhydrous aluminum trichloride from waste liquid containing aluminum trichloride

Abstract

The invention provides a method for recovering anhydrous aluminum trichloride from waste liquid containing aluminum trichloride. The method comprises the following steps: (1) removing a solvent from the waste liquid containing aluminum trichloride to obtain a product A; (2) roasting the product A at a high temperature in a certain atmosphere to obtain a product B; and (3) mixing the product B with a reducing agent, and introducing chlorine at high temperature for chlorination to obtain anhydrous aluminum trichloride.

Description

Technical Field

[0001] This invention relates to the field of chemical catalyst regeneration technology, specifically to a method for recovering anhydrous aluminum trichloride from aluminum trichloride-containing waste liquid after a catalytic reaction. Background Technology

[0002] Aluminum trichloride, as a highly efficient Lewis acid catalyst, is widely used in the chemical industry for esterification, acylation, alkylation, isomerization, and other chemical reactions. Currently, in most applications of anhydrous aluminum trichloride catalysts, except for alkylbenzene synthesis and the synthesis of some fine organic chemicals, such as the synthesis of pharmaceutical intermediates, the aluminum trichloride wastewater generated after reaction quenching is largely not recycled. This acidic aluminum trichloride wastewater, with high organic content, is highly chromatic, corrosive, and difficult to treat, causing significant environmental damage, resource waste, and environmental pressure.

[0003] Therefore, anhydrous aluminum trichloride can be prepared from aluminum trichloride wastewater containing organic matter generated in industrial production, thus realizing the recycling and reuse of aluminum trichloride. Summary of the Invention

[0004] The purpose of this application is to solve the problem of recovering anhydrous aluminum trichloride from aluminum trichloride-containing waste liquid in the prior art, and to provide an environmentally friendly and high-purity method for recovering anhydrous AlCl3 from waste AlCl3 catalyst, which can achieve low-cost, low-energy consumption, green and recyclable recovery of high-purity anhydrous aluminum trichloride.

[0005] This application provides a method for recovering anhydrous aluminum trichloride from waste liquid containing aluminum trichloride, the method comprising the following steps:

[0006] (1) The waste liquid containing aluminum trichloride was desolventized to obtain product A;

[0007] (2) Under a certain atmosphere, product A is calcined at high temperature to obtain product B;

[0008] (3) The product B and the reducing agent are mixed and chlorine gas is introduced at high temperature to chlorinate the product to obtain anhydrous aluminum trichloride.

[0009] The advantages of this invention are:

[0010] (1) This recycling method can recover low-value aluminum trichloride waste liquid to obtain anhydrous aluminum trichloride, realize the recycling of Al resources, and meet the requirements of green circular economy development.

[0011] (2) Compared with the traditional aluminum ingot method, the process route of the present invention does not require the electrolysis of alumina to produce aluminum elemental, and then the preparation of aluminum trichloride by chlorination, thereby reducing the recycling process steps and reducing production power consumption. Detailed Implementation

[0012] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0013] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0014] The "range" disclosed herein is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0015] Unless otherwise specified in this application, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0016] Unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0017] In this application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0018] In this application, unless otherwise specified, the terms "comprising" and "including" as used herein are open-ended or closed-ended. For example, "comprising" and "including" may mean that other components not listed may also be included, or that only the listed components may be included.

[0019] In the description of this article, it should be noted that, unless otherwise stated, "above" and "below" include the number itself, and "several" in "one or more" means two or more.

[0020] In this description, unless otherwise stated, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0021] Unless otherwise specified, percentages (%) or parts refer to weight percentages or parts by weight of the composition.

[0022] Unless otherwise stated herein, the sum of the contents of the components in the composition is 100%.

[0023] Unless otherwise stated herein, the sum of the parts of each component in the composition may be 100 parts by weight.

[0024] In this document, unless otherwise stated, “combination of” means a multi-component mixture of the elements, such as two, three, four, and up to the maximum possible multi-component mixture.

[0025] Unless otherwise specified, the term "a" as used in this specification means "at least one".

[0026] This application provides a method for recovering anhydrous aluminum trichloride from waste liquid containing aluminum trichloride, the method comprising the following steps:

[0027] (1) The waste liquid containing aluminum trichloride was desolventized to obtain product A;

[0028] (2) Under a certain atmosphere, product A is calcined at high temperature to obtain product B; and

[0029] (3) The product B and the reducing agent are mixed and chlorine gas is introduced at high temperature to chlorinate the product to obtain anhydrous aluminum trichloride.

[0030] In step (1), the aluminum trichloride waste liquid is derived from a reaction using anhydrous aluminum trichloride as a catalyst. The reaction includes, but is not limited to: Friedel-Crafts alkylation, Friedel-Crafts acylation, isomerization or disproportionation, esterification and polymerization.

[0031] In step (1), the aluminum trichloride waste liquid contains 2-95% by weight of aluminum trichloride, 0-50% by weight of organic matter, 5-95% by weight of water, and no more than 6000 ppm of metallic impurities, based on the total weight of the aluminum trichloride waste liquid; preferably, the aluminum trichloride waste liquid contains 3-90% by weight of aluminum trichloride, 1-40% by weight of organic matter, 8-90% by weight of water, and no more than 5000 ppm of metallic impurities, based on the total weight of the aluminum trichloride waste liquid; preferably, the aluminum trichloride waste liquid contains 5-85% by weight of aluminum trichloride, 2-10% by weight of organic matter, 10-85% by weight of water, and no more than 4000 ppm of metallic impurities, based on the total weight of the aluminum trichloride waste liquid.

[0032] In step (1), the aluminum trichloride waste liquid also contains acid. The acid is selected from HCl, sulfuric acid, etc.; preferably, the acid content is 0-10% by weight, based on the total weight of the aluminum trichloride waste liquid; more preferably, the acid content is 0.1-5% by weight or 0.1-1% by weight, based on the total weight of the aluminum trichloride waste liquid.

[0033] The organic compounds mainly originate from incompletely reacted raw materials, target products, by-products, and reaction intermediates, including but not limited to aromatics, alkanes, alkenes, alcohols, acyl chlorides, alkyl aromatics, chloroaromatics, carboxylic acids, esters, ketones, tar-like resins, and polymers of different molecular weights. Preferably, the organic compounds are selected from one or more of aromatics, alkanes, alkenes, alcohols, acyl chlorides, alkyl aromatics, chloroaromatics, carboxylic acids, esters, ketones, tar-like resins, and polymers of different molecular weights; more preferably, the organic compounds are selected from benzene, xylene, diethylbenzene, ethanol, and triethylbenzene.

[0034] The metallic impurities are selected from Fe, Ni, Na, V, Cr, Mo, Mn, Zn, Ca, Mg, or combinations thereof. More preferably, the metallic impurities are selected from iron, nickel, zinc, calcium, and magnesium. For example, the metallic impurities may be iron (Fe), nickel (Ni), Na, and V introduced by industrial raw materials; and iron (Fe), Cr, Mo, and Mn dissolved by corrosion from reactors, pipes, and valves.

[0035] In step (1), the solvent removal method is selected from spray drying, freeze drying, oven drying, negative pressure dehydration drying, microwave drying, or a combination thereof;

[0036] Preferably, the temperature of the spray drying method is 50-200℃, or 60-150℃, or 80-120℃; the pressure is 10-101kPa, or 12-80kPa, or 15-50kPa, or 15-25kPa.

[0037] Preferably, the freeze-drying temperature is -40°C to -80°C, or -45°C to -75°C, or -50°C to -70°C; the pressure is 1-10 kPa, or 2-8 kPa, or 3-7 kPa, or 4-6 kPa.

[0038] Preferably, the temperature of the negative pressure dehydration drying is 50-200℃, or 70-190℃, or 100-180℃, or 120-160℃, and the pressure is 20-90KPa.

[0039] Preferably, the drying temperature is 50-200℃, or 70-190℃, or 100-180℃, or 120-160℃, and the pressure is atmospheric pressure.

[0040] Preferably, the microwave drying temperature is 60-180℃, or 70-150℃, or 75-90℃, and the pressure is atmospheric pressure.

[0041] In step (2), the high-temperature roasting temperature is 200-1000℃, or 250-800℃, or 300-700℃;

[0042] In step (2), the heating rate of the high-temperature calcination is 1-20℃ / minute, or 1.5-15℃ / minute; or 2-10℃ / minute;

[0043] In step (2), the high-temperature roasting time is 1-10 hours, or 2-8 hours, or 3-6 hours.

[0044] In step (2), the atmosphere for high-temperature roasting is air, nitrogen, oxygen, an inert gas, or a mixture thereof. Preferably, the inert gas is argon. Preferably, the atmosphere for high-temperature roasting is air; air mixed with 10%-50% (preferably 15%-45% (more preferably 20%-40% (based on the total weight of air mixed with nitrogen or inert gas)) of nitrogen or inert gas; or air mixed with 10%-90% (preferably 15%-80% (more preferably 50%-75% (based on the total weight of oxygen mixed with nitrogen or inert gas)) of nitrogen or inert gas; preferably, the inert gas is argon.

[0045] In step (3), the reducing agent is CO, other carbon sources, or a mixture of the two. The other carbon sources have the following characteristics: carbon content ≥ 80% by weight, ash content ≤ 1.5% by weight, volatile matter content ≤ 8% by weight, hydrogen content ≤ 8% by weight, and sulfur content ≤ 2% by weight, based on the total weight of the other carbon sources. Preferably, the reducing agent is CO, other carbon sources, or a mixture of the two. The other carbon sources have the following characteristics: carbon content ≥ 85% by weight, ash content ≤ 1.0% by weight, volatile matter content ≤ 6% by weight, hydrogen content ≤ 6% by weight, and sulfur content ≤ 1.5% by weight, based on the total weight of the other carbon sources.

[0046] Preferably, in step (3), the reducing agent is CO, activated carbon, petroleum coke, biochar, charcoal, calcined coke or a mixture thereof;

[0047] In step (3), the weight ratio of product B to reducing agent is (1-10):1, or (2-6):1, or (3-5.5):1;

[0048] In step (3), the weight ratio of product B to chlorine is 1:(2-6), or 1:(2.2-5), or 1:(2.5-4);

[0049] In step (3), the high temperature is 400-1000℃, or 450-950℃, or 500-900℃, or 700-900℃;

[0050] In step (3), the heat preservation temperature under chlorine atmosphere is 400-1000℃, or 450-950℃, or 500-900℃ or 700-900℃;

[0051] In step (3), the heat preservation time under chlorine atmosphere is 1-10 hours, or 1.5-9 hours, or 2-6 hours.

[0052] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0053] Example

[0054] A. Source of raw materials:

[0055] Activated carbon (model ZX-777, purchased from Jiangsu Zhuxi Activated Carbon Co., Ltd.)

[0056] Petroleum coke (0.3-0.8 mm specification, purchased from Jiangsu Taizhi New Material Technology Co., Ltd.)

[0057] Biochar (purchased from Henan Housen Environmental Protection Technology Co., Ltd.)

[0058] Charcoal (purchased from Shaanxi Coal Industry New Energy Technology Co., Ltd.)

[0059] Calcined coke (purchased from Shaanxi Coal Industry New Energy Technology Co., Ltd.)

[0060] B. Equipment:

[0061] Muffle furnace (model BFC, purchased from Anhui Kemi Instrument Co., Ltd.)

[0062] Tube furnace (model TFH-1200-100-Ⅱ-440, purchased from Anhui Kemi Instrument Co., Ltd.)

[0063] C. Testing or analysis methods:

[0064] Test method for anhydrous aluminum trichloride content: The content of aluminum trichloride is determined by ICP and chloride ion titration.

[0065] Example 1

[0066] Waste liquid containing 80% by weight of aluminum trichloride (80% by weight of aluminum trichloride, 15.4% by weight of water, 4.4% by weight of xylene, and 2000 ppm of iron) was spray-dried at 100°C and 20 kPa to obtain product A. Product A was then calcined in a muffle furnace for 4 hours in air at 600°C with a heating rate of 5°C / min to obtain product B. Product B and activated carbon were mixed at a weight ratio of 5.5:1 and placed in a tube furnace. The temperature was increased to 700°C at a rate of 2°C / min, and chlorine gas was introduced while maintaining a weight ratio of 1:2.5 between product B and chlorine gas. The mixture was held at this temperature for 4 hours and then condensed to obtain anhydrous aluminum trichloride. The product yield reached 99.2%, the anhydrous aluminum trichloride content was 99.6%, and the metal impurity content was less than 50 ppm.

[0067] Example 2

[0068] Waste liquid containing 5.3% by weight of aluminum trichloride (5.3% by weight of aluminum trichloride, 83.9% by weight of water, 2.5% by weight of HCl, 7.9% by weight of benzene, 1000 ppm of iron, 1000 ppm of calcium, and 2000 ppm of magnesium) was dried at atmospheric pressure and 120°C to obtain product A. Product A was then calcined in a muffle furnace for 3 hours in air at 300°C with a heating rate of 2°C / min to obtain product B. Product B and petroleum coke were mixed at a weight ratio of 4:1 and placed in a tube furnace. The temperature was increased to 500°C at a rate of 5°C / min, and chlorine gas was introduced while maintaining a weight ratio of 1:3 for product B. The mixture was held at this temperature for 2 hours and then condensed to obtain anhydrous aluminum trichloride. The product yield reached 89.6%, the anhydrous aluminum trichloride content was 96.8%, and the metal impurity content was less than 350 ppm.

[0069] Example 3

[0070] Waste liquid containing 85% by weight of aluminum trichloride (85% by weight of aluminum trichloride, 6.3% by weight of water, 5.1% by weight of ethanol, 3.2% by weight of diethylbenzene, 1200 ppm of iron, 700 ppm of nickel, 200 ppm of zinc, 1100 ppm of calcium, and 800 ppm of magnesium) was freeze-dried at -60°C and 5 kPa to obtain product A. Product A was then calcined in a muffle furnace for 6 hours using a mixture of oxygen and argon (based on the total weight of the mixture). The product was calcined at 700℃ (oxygen content 30% by weight) at a rate of 10℃ / min to obtain product B. Product B and biochar were mixed at a weight ratio of 3:1 and placed in a tube furnace. The temperature was increased to 900℃ at a rate of 10℃ / min, and chlorine gas was introduced. The weight ratio of product B to chlorine gas was controlled at 1:4. The mixture was kept at this temperature for 6 hours and then condensed to obtain anhydrous aluminum trichloride. The product yield reached 95.7%, the anhydrous aluminum trichloride content was 99.1%, and the metal impurity content was less than 160ppm.

[0071] Example 4

[0072] Waste liquid containing 70% by weight of aluminum trichloride (70% by weight of aluminum trichloride, 27.5% by weight of water, 2.4% by weight of triethylbenzene, and 1000 ppm of iron) was microwave-dried at 80°C to obtain product A. Product A was then calcined in a muffle furnace for 5 hours with a mixture of oxygen and nitrogen (oxygen content of 25% by weight of the mixture) at 500°C and a heating rate of 8°C / min to obtain product B. Product B was then mixed with charcoal at a weight ratio of 3.5:1 and placed in a tube furnace. The temperature was increased to 700°C at 7°C / min, and chlorine gas was introduced while maintaining a weight ratio of product B to chlorine of 1:3.5. The mixture was held at this temperature for 5 hours and then condensed to obtain anhydrous aluminum trichloride. The product yield reached 96.9%, the anhydrous aluminum trichloride content was 99.3%, and the metal impurity content was less than 120 ppm.

[0073] Example 5

[0074] Waste liquid containing 50% by weight of aluminum trichloride (50% by weight of aluminum trichloride, 43.6% by weight of water, 6.1% by weight of benzene, 2000 ppm of iron, and 1000 ppm of nickel) was dried at atmospheric pressure and 160°C to obtain product A. Product A was then calcined in a muffle furnace for 4.5 hours in air atmosphere at 550°C and a heating rate of 4°C / min to obtain product B. Product B and calcined coke were mixed at a weight ratio of 4.5:1 and placed in a tube furnace. The temperature was increased to 650°C at a rate of 5°C / min, and chlorine gas was introduced. The weight ratio of product B to chlorine gas was controlled at 1:3. The mixture was held at this temperature for 4.5 hours and then condensed to obtain anhydrous aluminum trichloride. The product yield reached 97.4%, the anhydrous aluminum trichloride content was 98.9%, and the metal impurity content was less than 190 ppm.

[0075] Example 6

[0076] The high-temperature chlorination temperature was changed from "700℃" to "500℃", and other conditions were the same as in Example 1. The product yield reached 89.4%, the anhydrous aluminum trichloride content was 97.0%, and the metal impurity content was less than 400ppm.

[0077] Example 7

[0078] The high-temperature chlorination temperature was changed from "700℃" to "900℃", and other conditions were the same as in Example 1. The product yield reached 99.1%, the anhydrous aluminum trichloride content was 99.7%, and the metal impurity content was less than 40 ppm.

[0079] Example 8

[0080] The high-temperature chlorination temperature was changed from "700℃" to "300℃", and other conditions remained the same as in Example 1, resulting in a product yield of 0%.

[0081] Example 9

[0082] The reducing agent was changed from "activated carbon" to "petroleum coke". Other conditions were the same as in Example 1. The product yield reached 97.4%, the anhydrous aluminum trichloride content was 98.2%, and the metal impurity content was less than 170 ppm.

[0083] Example 10

[0084] The reducing agent was changed from "activated carbon" to "charcoal", and other conditions were the same as in Example 1. The product yield reached 98.6%, the anhydrous aluminum trichloride content was 99.0%, and the metal impurity content was less than 140 ppm.

[0085] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of the substantive technical content of this disclosure. The substantive technical content of this disclosure is broadly defined within the scope of the claims of this application. Any technical entity or method completed by others that is completely identical to or an equivalent modification of the claims of this application shall be deemed to be covered within the scope of the claims.

[0086] All documents mentioned in this disclosure are incorporated herein by reference as if each document were individually incorporated herein by reference. Furthermore, it should be understood that after reading the foregoing contents of this disclosure, those skilled in the art can make various alterations or modifications to this disclosure, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for recovering anhydrous aluminum trichloride from waste liquid containing aluminum trichloride, the method comprising the following steps: (1) The waste liquid containing aluminum trichloride was desolventized to obtain product A; (2) Under a certain atmosphere, product A is calcined at high temperature to obtain product B; (3) The product B and the reducing agent are mixed and chlorine gas is introduced at high temperature to chlorinate the product to obtain anhydrous aluminum trichloride.

2. The method according to claim 1, wherein in step (1), the aluminum trichloride waste liquid originates from a reaction using anhydrous aluminum trichloride as a catalyst, the reaction being selected from Friedel-Crafts alkylation, Friedel-Crafts acylation, isomerization or disproportionation, esterification and polymerization.

3. The method according to claim 2, wherein in step (1), the aluminum trichloride waste liquid contains 2-95% by weight of aluminum trichloride, 0-50% by weight of organic matter, 5-95% by weight of water, and the content of metal impurities does not exceed 6000 ppm, based on the total weight of the aluminum trichloride waste liquid.

4. The method of claim 3, wherein in step (1), the organic compound is selected from one or more of aromatic hydrocarbons, alkanes, alkenes, alcohols, acyl chlorides, alkyl aromatic hydrocarbons, chlorinated aromatic hydrocarbons, carboxylic acids, esters, ketones, tar-like resins and polymers of different molecular weights; The metallic impurities are selected from Fe, Ni, Na, V, Cr, Mo, Mn, Zn, Ca, Mg, or combinations thereof.

5. The method of claim 1, wherein in step (1), the solvent removal method is selected from spray drying, freeze drying, oven drying, negative pressure dehydration drying, microwave drying, or a combination thereof.

6. The method as described in claim 5, wherein the temperature of the spray drying method is 50-200℃; and the pressure is 10-101 kPa; The freeze-drying temperature is -40℃ to -80℃, and the pressure is 1-10kPa; The negative pressure dehydration and drying temperature is 50-200℃, and the pressure is 20-90Kpa; The drying temperature is 50-200℃, and the pressure is atmospheric pressure. The microwave drying temperature is 60-180℃, and the pressure is normal pressure.

7. The method of claim 1, wherein in step (2), the high-temperature calcination temperature is 200-1000℃; and / or In step (2), the heating rate of the high-temperature calcination is 1-20°C / minute; and / or In step (2), the high-temperature calcination time is 1-10 hours; and / or In step (2), the atmosphere for high-temperature roasting is air, nitrogen, oxygen, inert gas or a mixture thereof; preferably air; air mixed with 10%-50% by weight of nitrogen or inert gas, based on the total weight of the air mixed with nitrogen or inert gas; or air mixed with 10%-90% by weight of nitrogen or inert gas, based on the total weight of the oxygen mixed with nitrogen or inert gas.

8. The method of claim 1, wherein in step (3), the reducing agent is CO, other carbon sources or a mixture of the two, wherein the other carbon sources have the following characteristics: carbon content ≥ 80% by weight, ash content ≤ 1.5% by weight, volatile matter content ≤ 8% by weight, hydrogen content ≤ 8% by weight, and sulfur content ≤ 2% by weight, based on the total weight of the other carbon sources.

9. The method of claim 1, wherein in step (3), the reducing agent is CO, activated carbon, petroleum coke, biochar, charcoal, calcined coke or a mixture thereof.

10. The method of claim 1, wherein in step (3), the weight ratio of product B to reducing agent is (1-10):1; and / or In step (3), the weight ratio of product B to chlorine is 1:(2-6); and / or In step (3), the high temperature is 400-1000℃; and / or In step (3), the heat preservation temperature under chlorine atmosphere is 400-1000℃; and / or In step (3), the heat preservation time under chlorine atmosphere is 1-10 hours.