Treatment method of organic solvent waste liquid containing aluminum alkyl

Abstract

The invention relates to a treatment method of an aluminum alkyl-containing organic solvent waste liquid, the organic solvent waste liquid contains a small amount of aluminum alkyl, and the treatment method comprises the following steps: step 1, adding an adsorbent adsorbed with water into the organic solvent waste liquid in an inert atmosphere, reacting aluminum alkyl in the waste liquid with moisture in the adsorbent; step 2, dropwise adding a certain amount of water into the obtained organic solvent waste liquid, then standing for layering, and then separating the organic solvent on the upper layer from a mixture of water and alkyl aluminum hydrolysate on the lower layer, the adsorbent being contained in the lower layer; step 2, separating the adsorbent from the mixture of the water and the alkyl aluminum hydrolysate; step 3, dehydrating and regenerating the adsorbent; step 4, adding a regenerated adsorbent into the organic solvent obtained through treatment in the step 2 to adsorb residual moisture in the organic solvent; and step 5, separating the dehydrated organic solvent from the adsorbent adsorbed with water.

Description

Technical Field

[0001] The present invention relates to a method for treating an organic solvent waste liquid containing alkyl aluminum, in particular toluene waste liquid. More specifically, the present invention relates to a method for treating an organic solvent waste liquid containing a small amount of alkyl aluminum, in particular toluene waste liquid, generated by treating methylaluminoxane cocatalyst in the preparation process of a metallocene catalyst. Background Art

[0002] Metallocene catalysts are increasingly being used in the industrial production of polyolefins. In the preparation process, methylaluminoxane (MAO) is usually used as a co-catalyst, and commercial methylaluminoxane is usually a 10% toluene solution. When preparing metallocene catalysts, the MAO solution must first be subjected to solvent removal treatment. The main component of the solvent waste liquid removed is toluene, and it contains a small amount of alkyl aluminum and alkyl aluminum hydrolyzate. Since alkyl aluminum has active chemical properties and will spontaneously ignite when exposed to air, it is not suitable to use conventional distillation or rectification operations to recover toluene in the waste liquid.

[0003] CN114470605A proposes a method and system for treating alkyl aluminum hazardous waste. The method uses an inert organic solvent to dilute the alkyl aluminum hazardous waste to obtain a diluent, then injects the diluent into water and stirs it for hydrolysis treatment to obtain a hydrolyzed solution, and finally adds an acidic medium to the hydrolyzed solution and stirs it for acid hydrolysis treatment. Since the method needs to add an acidic substance to the waste liquid, the components in the waste liquid increase, which is not conducive to subsequent treatment and environmental protection.

[0004] CN103182156A proposes a method for recycling hazardous waste in the production process of alkyl aluminum. The method uses nitrogen to replace the reactor, then adds a solvent containing alkyl aluminum and aluminum powder into the reactor, first passes carbon dioxide into the reactor for passivation, then adds 50 to 300 volume % of water based on the volume of the solvent, and controls the reaction temperature to 10 to 60°C and the pressure during the reaction to 0.01 to 0.1 MPa to complete the hydrolysis process. However, the method does not note that the reaction between water and alkyl aluminum is very fast and violent. When a large amount of water is introduced into the organic solvent containing alkyl aluminum, local overheating is likely to occur, and the possibility of rapid temperature rise of the solvent is relatively high.

[0005] Therefore, the existing methods for treating organic solvent waste liquid containing alkyl aluminum have problems such as complicated processes, difficult control methods, and poor process safety. In order to recycle a large amount of organic solvent in the waste liquid and avoid polluting the environment, and also to reduce the production cost of metallocene catalysts, for example, it is necessary to develop a method for safely treating organic solvent waste liquid. Summary of the invention

[0006] The main purpose of the present invention is to provide a safe method for treating organic solvent waste liquid containing alkyl aluminum and to realize the recycling of the organic solvent in the waste liquid.

[0007] In order to achieve the above object, the present invention relates to a method for treating an organic solvent waste liquid containing alkyl aluminum, wherein an adsorbent having absorbed water is added to the organic solvent waste liquid so that a small amount of alkyl aluminum in the waste liquid reacts with water in a safe state. The method comprises the following steps:

[0008] Step 1, adding an adsorbent having absorbed water into an organic solvent waste liquid under an inert atmosphere, so that the alkyl aluminum in the waste liquid reacts with the water in the adsorbent for a period of time;

[0009] Step 2, adding a certain amount of water dropwise to the obtained organic solvent waste liquid containing the adsorbent, and then standing to separate the layers, and then separating the organic solvent in the upper layer and the mixture of water and alkyl aluminum hydrolyzate in the lower layer, wherein the adsorbent is contained in the lower layer;

[0010] Step 3, separating the adsorbent from the mixture of water and alkyl aluminum hydrolyzate;

[0011] Step 4, dehydrating and regenerating the adsorbent;

[0012] Step 5, adding the regenerated adsorbent to the organic solvent obtained by the treatment in step 2 to adsorb the residual water in the organic solvent;

[0013] Step 6, separating the dehydrated organic solvent and the adsorbent adsorbed with water.

[0014] In a preferred embodiment, the adsorbent having absorbed water used in step 1 is an adsorbent having absorbed water obtained by treating a previous batch of organic solvent waste liquid using the method of the present invention.

[0015] The present invention uses the water absorbed in the adsorbent particles to react with a small amount of chemically active alkyl aluminum in the organic solvent waste liquid in an inert atmosphere with controllable speed and intensity, and after the reaction, a certain amount of water is slowly added to obtain an upper layer of organic solvent and a mixture of water and aluminum oxide hydrolyzate in the lower layer that can be layered, thereby recovering toluene. Through the method of the present invention, more than 95 wt.% of the organic solvent contained in the original organic solvent waste liquid is recovered and can be reused, wherein the content of alkyl aluminum is reduced to 0.001 wt.% or less of the organic solvent, and the obtained adsorbent adsorbed with water can be used for the treatment of the next batch of organic solvent waste liquid containing alkyl aluminum, thereby greatly reducing the amount of adsorbent used. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1The present invention is a flow chart of one embodiment of the method for treating an organic solvent waste liquid containing alkyl aluminum. DETAILED DESCRIPTION

[0017] The present application will be further described in detail below through specific implementation methods. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, but do not limit the present invention in any way.

[0018] Any specific numerical value disclosed herein (including the endpoint of the numerical range) is not limited to the exact value of the numerical value, but should be understood to also cover values ​​close to the exact value, such as all possible numerical values ​​within the range of ±5% of the exact value. In addition, for the disclosed numerical range, the endpoint values ​​of the range, the endpoint values ​​and the specific point values ​​in the range, and the specific point values ​​can be arbitrarily combined to obtain one or more new numerical ranges, and these new numerical ranges should also be regarded as specifically disclosed herein.

[0019] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0020] The expressions "comprising" or "including" herein should be interpreted as including all the specifically mentioned features as well as optional, additional, unspecified features. As used herein, the use of the term "comprising" also discloses solutions in which there are no further features than the specifically mentioned features, such as the expressions "consisting essentially of" and "consisting of".

[0021] According to the present invention, the organic solvent waste liquid contains less than or equal to about 1.0 wt.%, such as less than or equal to about 0.5 wt.%, or less than or equal to about 0.1 wt.% of alkyl aluminum. In one embodiment, the organic solvent waste liquid contains about 0.05 wt.% to about 1.0 wt.% of alkyl aluminum.

[0022] According to the present invention, the organic solvent has a density less than that of water, is non-reactive with water and alkylaluminum, and is insoluble in water. In one embodiment, the organic solvent is an aprotic solvent. Preferably, the organic solvent is selected from linear aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and aromatic hydrocarbons. More preferably, the organic solvent is selected from benzene, toluene, and xylene. In a particularly preferred embodiment, the organic solvent is toluene.

[0023] According to the present invention, the alkyl aluminum contained in the organic solvent waste liquid has the structural formula R n AlX 3-n, wherein each R is independently an alkyl group having 1 to 5 carbon atoms, each X is independently a halogen selected from fluorine, chlorine and bromine, and n=1, 2 or 3.

[0024] In one embodiment, n=3, i.e., the structure of the alkyl aluminum does not contain halogen. In a preferred embodiment, the alkyl groups contained in the structure of the alkyl aluminum are the same. In a more preferred embodiment, the alkyl aluminum is selected from trimethyl aluminum, triethyl aluminum or a combination thereof.

[0025] According to the present invention, the organic solvent waste liquid comes from a solution of supported methylaluminoxane (MAO) used in the preparation process of the metallocene catalyst, preferably a toluene solution, and the solution usually contains a certain amount of alkylaluminum.

[0026] According to the present invention, the adsorbent is selected from activated carbon, activated alumina, activated clay, silica gel dehydration and molecular sieves. In one embodiment, the adsorbent is selected from activated alumina and molecular sieves, in particular zeolite molecular sieves. In a preferred embodiment, the adsorbent is in the form of particles, in particular spherical particles. In a particularly preferred embodiment, the adsorbent is selected from zeolite molecular sieve spherical particles and activated alumina spherical particles.

[0027] According to the present invention, the bulk density of the adsorbent is about 0.3 g / cm 3 Up to about 1.2g / cm 3 , preferably about 0.45 g / cm 3 To about 0.80g / cm 3 , or about 0.65 g / cm 3 Up to about 0.75g / cm 3 For example, when the adsorbent is selected from molecular sieves, its bulk density is preferably about 0.65 g / cm 3 Up to about 0.75g / cm 3 .

[0028] According to the present invention, the inert atmosphere is a nitrogen atmosphere or an inert gas atmosphere, such as an argon atmosphere. In a preferred embodiment, the inert atmosphere is a nitrogen atmosphere.

[0029] Step 1) Alkyl aluminum reacts with water contained in the adsorbent

[0030] According to the present invention, an adsorbent having absorbed water is added to an organic solvent waste liquid under an inert atmosphere, so that the alkyl aluminum in the waste liquid reacts with the water in the adsorbent for a period of time.

[0031] When treating the first batch of organic solvent waste liquid, the adsorbent that has absorbed water is an adsorbent that has been pre-impregnated with water. The impregnation can be a commonly used impregnation method for treating adsorbents, especially molecular sieves in the art, such as immersing the adsorbent in distilled water or deionized water for a period of time.

[0032] When treating the next batch of organic solvent waste liquid except the first batch, the adsorbent that has absorbed water is an adsorbent that has been pre-impregnated with water, or an adsorbent that has absorbed water obtained by treating the previous batch of organic solvent waste liquid using the method of the present invention. In the case of using an adsorbent that has been pre-impregnated with water, the same method as that used to treat the first batch of organic solvent waste liquid can be used. Preferably, when treating the next batch of organic solvent waste liquid except the first batch, the adsorbent that has absorbed water is an adsorbent that has absorbed water obtained by treating the previous batch of organic solvent waste liquid using the method of the present invention.

[0033] According to the present invention, the amount of adsorbent added may be about 1% to about 50%, preferably about 5% to about 30%, of the volume of the organic solvent waste liquid, wherein the bulk density of the adsorbent is about 0.3 g / cm 3 Up to about 1.2g / cm 3 , preferably about 0.45 g / cm 3 To about 0.80g / cm 3 , or about 0.65 g / cm 3 Up to about 0.75g / cm 3 .

[0034] According to the present invention, the reaction time of the alkylaluminum and the moisture contained in the adsorbent may be about 0.5 hour to about 10 hours, preferably about 0.8 hour to about 5 hours, and more preferably about 1 hour to about 3 hours.

[0035] As will be appreciated by those skilled in the art, the hydrolyzate obtained by the reaction of the alkylaluminum with water mainly comprises aluminum hydroxide, ie, consists essentially of aluminum hydroxide.

[0036] By adopting step 1) of the method of the present invention, a small amount of alkyl aluminum with active chemical properties in the organic solvent waste liquid reacts with the water contained in the adsorbent under an inert atmosphere, and the reaction process is safe and controllable.

[0037] Step 2) Slowly introduce water into the organic solvent waste liquid

[0038] After the alkylaluminum reacts with the moisture contained in the adsorbent, a certain amount of water is added dropwise to the resulting organic solvent waste liquid containing the adsorbent, and then allowed to stand for stratification, and then the organic solvent in the upper layer and the mixture of water and alkylaluminum hydrolyzate in the lower layer are separated, wherein the adsorbent is contained in the lower layer.

[0039] According to the present invention, the water added dropwise may be distilled water or deionized water.

[0040] According to the present invention, since there may still be a trace amount of alkyl aluminum in the waste liquid after step 1) and the alkyl aluminum reacts violently with water, the speed of adding water dropwise is relatively slow. Specifically, the speed of adding water dropwise may not exceed about 5 mL / s, preferably not exceed about 3 mL / s, and more preferably not exceed about 1 mL / s. In one embodiment, the speed of adding water dropwise is about 0.1 mL / s to about 5 mL / s, preferably about 0.5 mL / s to about 1 mL / s.

[0041] According to the present invention, the volume of the amount of water added can be no more than about 30% of the volume of the organic solvent waste liquid. In one embodiment, the volume of the amount of water added is no less than about 5% of the volume of the organic solvent waste liquid. In one embodiment, the volume of the amount of water added is about 5% to about 30% of the volume of the organic solvent waste liquid. In a preferred embodiment, the volume of the amount of water added is about 10% to about 20% of the volume of the organic solvent waste liquid.

[0042] According to the present invention, after the addition of water is completed, the standing time is not less than about 1 hour, more preferably not less than 2 hours. In one embodiment, the standing time is from about 1 hour to about 10 hours, preferably from about 2 hours to about 6 hours.

[0043] According to the present invention, the separation of the organic solvent in the upper layer and the mixture of water and alkylaluminum hydrolyzate in the lower layer can be carried out by conventional methods in the art, such as using an extraction device, including an extractor and an extraction tower, and a settler, including a gravity settler, etc. After separation, the adsorbent is contained in the mixture of water and alkylaluminum hydrolyzate.

[0044] By adding a certain amount of water to the waste liquid after the reaction, it is possible to achieve a better separation of water and the alkyl aluminum reactant from the organic solvent, and by adding water dropwise, the trace amount of alkyl aluminum that may still exist in the organic solvent waste liquid treated in step 1) can be substantially completely hydrolyzed, and the reaction process is relatively mild.

[0045] Step 3) Separating the adsorbent

[0046] After the organic solvent in the upper layer and the mixture of water and alkylaluminum hydrolyzate in the lower layer are separated, the adsorbent is separated from the mixture of water and alkylaluminum hydrolyzate.

[0047] The separation can be carried out in a manner well known in the art, such as filtration. In one embodiment, the filtration refers to atmospheric gravity filtration or suction filtration. In one embodiment, the separation process is to separate the adsorbent from the mixture of water and alkylaluminum hydrolyzate (also referred to as wastewater in this application) by using a filtration device well known in the art.

[0048] According to the present invention, after the adsorbent is separated, the organic solvent content contained in the lower layer wastewater is equal to or less than about 5% by weight.

[0049] Step 4) Adsorbent regeneration

[0050] After the adsorbent is separated, the adsorbent adsorbed with water is dehydrated and regenerated.

[0051] According to the present invention, the dehydration regeneration of the adsorbent can be carried out by a method commonly used in the art. In one embodiment, the dehydration regeneration operation is carried out by hot nitrogen purging. In one embodiment, the dehydration regeneration operation is carried out by muffle furnace drying.

[0052] Since the regenerated adsorbent is used in the next step, the use of additional adsorbent can be avoided, thereby saving costs.

[0053] Step 5) Removing residual water from the organic solvent using a regenerated adsorbent

[0054] After the adsorbent is dehydrated and regenerated, the regenerated adsorbent is added to the organic solvent obtained by the treatment in step 2) to adsorb the residual water in the organic solvent.

[0055] According to the present invention, the adsorption time in step 5) can be about 3 hours to about 30 hours. In one embodiment, the adsorption time is about 6 hours to about 24 hours.

[0056] Step 6) Separating the dehydrated organic solvent and the adsorbent adsorbing water

[0057] After the water remaining in the organic solvent is adsorbed by the regenerated adsorbent, the dehydrated organic solvent and the adsorbent having adsorbed water are separated.

[0058] According to the present invention, the separation in step 6) can be carried out in a manner well known in the art, such as filtration. In one embodiment, the filtration refers to atmospheric gravity filtration or suction filtration. In one embodiment, the separation process is to separate the dehydrated organic solvent and the adsorbent adsorbed with water by using a filtration device well known in the art.

[0059] According to the present invention, after separating the dehydrated organic solvent and the adsorbent adsorbing water, the water content in the recovered organic solvent is less than or equal to about 0.01 wt.%.

[0060] After the regenerated adsorbent absorbs the moisture in the organic solvent, the separated organic solvent can be recycled and the adsorbent adsorbed with moisture can be used in the treatment of the next batch of organic solvent waste liquid containing alkyl aluminum, so that the adsorbent can be recycled in the method of the present invention, thereby greatly reducing the amount of adsorbent used.

[0061] In a preferred embodiment, the present invention relates to a method for treating an organic solvent waste liquid containing alkyl aluminum, preferably toluene waste liquid, wherein the organic solvent waste liquid contains less than or equal to 1.0 wt.%, such as 0.05 wt.% to 1.0 wt.% of alkyl aluminum, and the treatment method comprises the following steps:

[0062] Step 1, adding the adsorbent having absorbed water into the organic solvent waste liquid under an inert atmosphere, so that the alkyl aluminum in the waste liquid reacts with the water in the adsorbent for 0.5 to 10 hours, preferably 1 to 3 hours;

[0063] Step 2, adding water dropwise to the obtained waste liquid containing the adsorbent to 5% to 30%, preferably 10% to 20% of the volume of the waste liquid, and then standing to allow the mixture of water and alkylaluminum hydrolyzate and the organic solvent to separate into layers, and then separating the organic solvent in the upper layer and the mixture of water and alkylaluminum hydrolyzate in the lower layer, wherein the adsorbent is contained in the water layer;

[0064] Step 3, separating the adsorbent from the mixture of water and alkyl aluminum hydrolyzate to obtain the adsorbent adsorbed with water and wastewater;

[0065] Step 4, dehydrating and regenerating the adsorbent adsorbed with water;

[0066] Step 5, adding the regenerated adsorbent to the organic solvent obtained by the treatment in step 2 to adsorb the residual water in the organic solvent; and

[0067] Step 6, separating the dehydrated organic solvent and the adsorbent adsorbing water,

[0068] The adsorbent having absorbed water in step 1 is an adsorbent having absorbed water obtained by treating a previous batch of organic solvent waste liquid using the method including steps 1 to 6, and the speed of adding water in step 2 is about 0.1 mL / s to about 5 mL / s, preferably about 0.5 mL / s to about 1 mL / s.

[0069] Example

[0070] The present invention is further described in detail below using examples, but the present invention is not limited to these examples.

[0071] Instruments and Materials

[0072] 1) The molecular sieve particles are 4A molecular sieve;

[0073] 2) The content of alkyl aluminum in the organic solvent was measured using a Flame spectrometer from Ocean Optics, USA;

[0074] 3) The water content in the organic solvent was measured using a MKC-710 water analyzer from Kyoto Electronics (KEM), Japan.

[0075] Example 1

[0076] 5000mL of toluene waste liquid was added to a 10L pressure container, wherein the alkyl aluminum content was 1.0wt.%, and the container was filled with nitrogen atmosphere at a pressure of 0.01-0.1MPa. 250mL of water-containing molecular sieve particles was added. After reacting for 1h, 500mL of deionized water was added dropwise at a rate of 0.5mL / s. After standing for 2h, the toluene on the upper layer was taken out, the waste water and molecular sieve on the lower layer were filtered, and the filtered molecular sieve was activated and regenerated with hot nitrogen. The regenerated molecular sieve was added to the toluene taken out above. After 6h, it was filtered to obtain 4800mL of toluene, and the toluene recovery rate was 96wt.%. The water content in toluene was 0.009wt.%, and the alkyl aluminum content was 0.001wt.%.

[0077] Example 2

[0078] 5000mL of toluene waste liquid was added to a 10L pressure container, wherein the alkyl aluminum content was 1.0wt.%, and the container was filled with nitrogen atmosphere at a pressure of 0.01-0.1MPa. 500mL of water-containing molecular sieve particles was added. After reacting for 2h, 1000mL of deionized water was added dropwise at a rate of 1mL / s. After standing for 3h, the toluene on the upper layer was taken out, and the waste water and molecular sieve on the lower layer were filtered. The filtered molecular sieve was dried, activated and regenerated in a muffle furnace, and the regenerated molecular sieve was added to the toluene taken out above. After 12h, it was filtered to obtain 4850mL of toluene, and the toluene recovery rate was 97wt.%, the water content in toluene was 0.008wt.%, and the alkyl aluminum content was 0.001wt.%.

[0079] Example 3

[0080] 5000mL of toluene waste liquid, wherein the alkyl aluminum content is 1.0wt.%, is added to a 10L pressure container. The container is filled with nitrogen atmosphere and the pressure is 0.01-0.1MPa. 1500mL of hydrous activated alumina spherical adsorbent particles are added. After reacting for 3h, 1000mL of deionized water is added dropwise at a rate of 1mL / s. After standing for 6h, the toluene on the upper layer is taken out, the waste water and adsorbent particles on the lower layer are filtered, and the filtered adsorbent is dried and activated and regenerated in a muffle furnace. The regenerated adsorbent is added to the toluene taken out above. After 24h, it is filtered to obtain 4750mL of toluene, and the toluene recovery rate is 95wt.%. The water content in toluene is 0.01wt.%, and the alkyl aluminum content is 0.001wt.%.

[0081] Example 4

[0082] 5000mL of toluene waste liquid was added to a 10L pressure container, wherein the alkyl aluminum content was 1.0wt.%, the container was filled with nitrogen atmosphere, the pressure was 0.01-0.1MPa, and 250mL of water-containing molecular sieve particles were added. After reacting for 1h, 500mL of deionized water was added dropwise at a rate of 1mL / s. After standing for 1h, the toluene on the upper layer was taken out, the waste water and molecular sieve on the lower layer were filtered, and the filtered molecular sieve was activated and regenerated with hot nitrogen. The regenerated molecular sieve was added to the toluene taken out above. After 6h, it was filtered to obtain 4750mL of toluene, and the toluene recovery rate was 95wt.%, the water content in toluene was 0.01wt.%, and the alkyl aluminum content was 0.001wt.%.

[0083] Example 5

[0084] The process of Example 4 was repeated, except that the amount of water-containing molecular sieve particles added was 200 mL, and other conditions remained unchanged.

[0085] After treatment, 4730 mL of toluene was obtained, and the toluene recovery rate was 94.6 wt.%. The water content in the toluene was 0.013 wt.%, and the alkyl aluminum content was 0.001 wt.%.

[0086] Example 6

[0087] The process of Example 4 was repeated, except that the regenerated molecular sieve was added to toluene for adsorption for 5 h, and other conditions remained unchanged.

[0088] After treatment, 4740 mL of toluene was obtained, and the toluene recovery rate was 94.8 wt.%. The water content in the toluene was 0.012 wt.%, and the alkyl aluminum content was 0.001 wt.%.

Claims

1. A method for treating an organic solvent waste liquid containing an alkyl aluminum, characterized in that: The organic solvent waste liquid contains less than or equal to 1.0 wt.%, such as 0.05 wt.% to 1.0 wt.% of alkyl aluminum, and the treatment method comprises the following steps: Step 1, adding an adsorbent having absorbed water into an organic solvent waste liquid under an inert atmosphere, so that the alkyl aluminum in the waste liquid reacts with the water in the adsorbent for 0.5 to 10 hours; Step 2, adding water dropwise to the obtained organic solvent waste liquid containing the adsorbent to 5% to 30%, preferably 10% to 20% of the volume of the waste liquid, and then standing to separate the organic solvent in the upper layer and the mixture of water and alkyl aluminum hydrolyzate in the lower layer, wherein the adsorbent is contained in the lower layer; Step 3, separating the adsorbent from the mixture of water and alkyl aluminum hydrolyzate; Step 4, dehydrating and regenerating the adsorbent; Step 5, adding the regenerated adsorbent to the organic solvent obtained by the treatment in step 2 to adsorb the residual water in the organic solvent; and Step 6, separating the dehydrated organic solvent and the adsorbent adsorbed with water.

2. The method according to claim 1, characterized in that The adsorbent having absorbed water in step 1 is an adsorbent pre-impregnated with water, or an adsorbent having absorbed water obtained by treating a previous batch of organic solvent waste liquid by the method described in claim 1.

3. The method according to claim 1 or 2, characterized in that The alkyl aluminum has the structural formula R n AlX 3-n , wherein each R is independently an alkyl group having 1 to 5 carbon atoms, each X is independently a halogen selected from fluorine, chlorine and bromine, and n=1, 2 or 3; preferably, the alkylaluminum is selected from trimethylaluminum, triethylaluminum or a combination thereof.

4. The method according to claim 1 or 2, characterized in that: The adsorbent is selected from activated carbon, activated alumina, activated clay, silica gel dehydration and molecular sieve, preferably selected from zeolite molecular sieve spherical particles and activated alumina spherical particles.

5. The method according to claim 1 or 2, characterized in that: The amount of adsorbent added in step 1 is 1% to 50%, preferably 5% to 30%, of the volume of the organic solvent waste liquid, wherein the bulk density of the adsorbent is 0.3 g / cm 3 Up to 1.2g / cm 3 , preferably 0.45g / cm 3 Up to 0.80g / cm 3 , or 0.65g / cm 3 Up to 0.75g / cm 3 and / or the reaction time in step 1 is 0.8 to 5 hours, preferably 1 to 3 hours; and / or the adsorption time in step 5 is 3 to 30 hours, preferably 6 to 24 hours.

6. The method according to claim 1 or 2, characterized in that: The speed of dropwise addition of water does not exceed 5 mL / s, preferably does not exceed 3 mL / s, and more preferably does not exceed 1 mL / s, such as 0.1 mL / s to 5 mL / s, or 0.5 mL / s to 1 mL / s.

7. The method according to claim 1 or 2, characterized in that: The adsorbent is regenerated by hot nitrogen or muffle furnace drying.

8. The method according to claim 1 or 2, characterized in that: The organic solvent is an aprotic solvent, preferably selected from linear aliphatic hydrocarbons, cyclic aliphatic hydrocarbons and aromatic hydrocarbons, more preferably selected from benzene, toluene, and xylene, especially toluene.

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