Flame-retardant hydrophobic porous adsorbent, preparation method and application thereof

Abstract

The application relates to a flame-retardant hydrophobic honeycomb adsorbent, a preparation method and application thereof. The preparation method of the flame-retardant hydrophobic honeycomb adsorbent is simple, the mechanical strength is high, the water and heat resistance is strong, the volatile organic compound adsorption performance is good in the treatment of VOCs containing moisture, and the service life is long and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of flame-retardant hydrophobic porous adsorbent.More specifically, the present application relates to a kind of flame-retardant hydrophobic porous adsorbent, and its preparation method, the present application also relates to the application of the flame-retardant hydrophobic porous adsorbent in the adsorption treatment volatile organic compounds. BACKGROUND

[0002] In recent years, with the increasing requirements of the state on environmental protection, adsorption method, catalytic oxidation method, high-temperature incineration method, absorption method, condensation method and membrane separation method are widely used in the recovery / treatment of various waste gas containing volatile organic compounds (VOCs). Among them, for the industrial waste gas with stable flow and concentration, there are quite mature treatment methods, such as using catalytic oxidation method to treat PTA oxidation tail gas. However, for the VOCs-containing waste gas with fluctuating concentration and flow, a single treatment method is difficult to achieve the desired effect. It is worth noting that for the waste gas with large air volume (>10000 Nm 3 / h) and low VOCs concentration (<500 mg / m 3 ), it is difficult to achieve the effect of treating the symptoms by using condensation method, membrane separation method, absorption method, etc. Although high-temperature incineration can meet the standard treatment, a large amount of flammable gas such as natural gas is needed to maintain the temperature of combustion, and the operation cost is high. Adsorption-catalytic oxidation method is a common method for this difficult-to-treat tail gas in recent years, and the adsorbent in the process is usually honeycomb activated carbon. However, the honeycomb activated carbon adsorbent has small pore size (usually microporous) and is not suitable for adsorbing VOCs molecules with large molecular diameter. Moreover, the honeycomb activated carbon adsorbent is not resistant to high temperature in the presence of air, has poor hydrothermal stability, and the adsorbed substances will undergo self-polymerization reaction during desorption, and local hot spots will be generated, thereby affecting the safety and reliability of the device operation. For example, Chinese invention patent CN106395817A discloses a preparation method of honeycomb activated carbon, which has the disadvantage that although the material usage is relatively large, the effective utilization rate is not high, and the adsorption capacity of gas is small.

[0003] ZL201510778243.2 discloses a preparation method of molecular sieve adsorption profile, which uses glass fiber to coat the molecular sieve in the process. However, the adhesion of the molecular sieve on the glass fiber is not high, and it may fall off during the process, affecting the long-term use. In addition, there is usually a small amount of water vapor in VOCs gas, which will adversely affect the adsorption performance of the adsorbent with good hydrophilicity. Therefore, Chinese invention patent CN111203175A discloses a honeycomb hydrophobic molecular sieve adsorbent, the raw materials of which include hydrophobic molecular sieve and adhesive. The adhesive includes organic adhesive and inorganic adhesive. However, the amount of hydrophobic modification compound used in the hydrophobic modification of this hydrophobic molecular sieve is large, and the available hydrophobic surface of the honeycomb adsorbent is limited after being prepared, which is expensive.

[0004] Therefore, there is an urgent need in the existing technology for an adsorbent that can be manufactured at low cost, has good adsorption properties for VOCs, excellent hydrothermal stability, and can be used for a long time. Summary of the Invention

[0005] In view of the technical problems in the prior art, the inventors, through diligent research based on the prior art, discovered that by using at least one of attapulgite and kaolin as the original matrix, further combining it with an appropriate inorganic porous solid, and treating it with a hydrophobic modifier, a flame-retardant hydrophobic porous adsorbent can be prepared. This adsorbent has good adsorption performance of volatile organic compounds (VOCs or VOCs) and stable performance, thus completing the present invention.

[0006] Specifically, the present invention provides a flame-retardant hydrophobic porous adsorbent, characterized in that it contains at least one original matrix selected from attapulgite and kaolin, at least one inorganic material selected from inorganic porous solids, and a calcined oxide of a hydrophobic modifying material. Based on the total mass of the adsorbent, the content of the original matrix is ​​10-99.5% by mass, preferably 20-99% by mass; the content of the calcined oxide of the hydrophobic modifying material is 0.05-1% by mass, preferably 0.05-0.5% by mass; the content of the inorganic material is 0.5-90% by mass, preferably 1-80% by mass, more preferably 5-80% by mass, further preferably 8-70% by mass, and even more preferably the balance; the contact angle between the adsorbent and water is 40-90°, preferably 45-70°.

[0007] This invention also provides a method for preparing a flame-retardant hydrophobic porous adsorbent, characterized by comprising the following steps:

[0008] (1) A plastic mixed contact body is prepared by mixing and contacting at least one original matrix selected from attapulgite and kaolin, and at least one inorganic material selected from inorganic porous solids, a binder, and water, wherein, relative to the total amount of the original matrix and the inorganic material, the content of the original matrix is ​​10 to 99.5% by mass, preferably 20 to 99% by mass, and the content of the inorganic material is 0.5 to 90% by mass, preferably 1 to 80% by mass, more preferably 5 to 80% by mass, further preferably 8 to 70% by mass, and even more preferably the balance, and preferably the inorganic porous solid is at least one selected from silica, alumina, magnesium oxide, silica-alumina, magnesium-alumina, titanium-silicon oxide, titanium dioxide, molecular sieves, and montmorillonite;

[0009] (2) Optionally, the plastic mixed contact body is molded to obtain a porous adsorbent blank;

[0010] (3) The mixed contact body in step (1) or the porous adsorbent preform in step (2) is calcined in an inert gas, and then further contacted with a solution containing a hydrophobic modifier to obtain a modified preform; and

[0011] (4) The modified embryo is further calcined to obtain a flame-retardant hydrophobic porous adsorbent.

[0012] or

[0013] (1') After contacting at least one original matrix selected from attapulgite and kaolin, and at least one inorganic material selected from inorganic porous solids with a solution containing a hydrophobic modifier, calcination is performed to obtain a modified original matrix and a modified inorganic material. Preferably, the inorganic porous solid is at least one selected from silicon dioxide, alumina, magnesium oxide, aluminum silicate, aluminum magnesium oxide, silicon titanium dioxide, titanium dioxide, molecular sieves and montmorillonite.

[0014] (2') The modified original matrix, the modified inorganic material, the adhesive solvent, and water are mixed and brought into contact to form a plastic mixed modified contact body; wherein, relative to the total amount of the modified original matrix and the modified inorganic material, the content of the modified original matrix is ​​10~99.5% by mass, preferably 20~99% by mass, and the content of the modified inorganic material is 0.5~90% by mass, preferably 1~80% by mass, more preferably 5~80% by mass, even more preferably 8~70% by mass, and even more preferably the balance;

[0015] (3') Optionally, the plastic mixed modified contact body is molded to obtain a porous adsorbent modified preform; and

[0016] (4') The mixed modified contact body in step (2') or the modified preform in step (3') is further calcined to obtain a flame-retardant hydrophobic porous adsorbent.

[0017] The present invention also provides a porous matrix comprising the flame-retardant and hydrophobic porous adsorbent described above.

[0018] The present invention also provides the use of the flame-retardant and hydrophobic porous adsorbent described above in a porous matrix (preferably a porous carrier).

[0019] The present invention also provides the use of the flame-retardant and hydrophobic porous adsorbent described above for the adsorption and treatment of volatile organic compounds.

[0020] Technical effect

[0021] The preparation method of the flame-retardant hydrophobic porous adsorbent of the present invention is simple, does not require vacuum and microwave treatment, and is inexpensive. It allows for the design of the adsorbent based on the molecular size of the adsorbate, effectively adsorbing and removing VOCs. Compared with existing technologies, the flame-retardant hydrophobic porous adsorbent of the present invention uses a hydrophobic modifier to treat the adsorbent, constructing a thin hydrophobic surface inside the pores, thus imparting a certain degree of hydrophobicity to the adsorbent. Furthermore, the amount of hydrophobic modifier added during the preparation process is small, resulting in even lower costs.

[0022] The flame-retardant and hydrophobic porous adsorbent of the present invention has good hydrothermal properties, can perform well in the treatment of humid VOCs, and has excellent long-term stability. Detailed Implementation

[0023] The embodiments of the present invention will be described in more detail below with reference to specific examples. However, those skilled in the art will understand that the specific embodiments described below are for illustrative purposes only and should not be considered as limiting the scope of protection of the present invention. Rather, the present invention is intended to cover all alternatives, modifications, and equivalents that may be included within the scope of the present invention as defined by the claims.

[0024] Unless otherwise specified, the various embodiments of the present invention can be combined in any way, and the resulting transformations, modifications, and alterations of the technical solutions are also included within the scope of the present invention and do not exceed the scope of the present invention.

[0025] Attapulgite, also known as palygorskite, is a natural hydrated clay material rich in magnesium aluminum silicate with a layered chain structure. Its basic structural unit is a sandwich structure consisting of two layers of silicon-oxygen tetrahedra and one layer of magnesium (aluminum)-oxygen octahedra. The ideal unit cell formula is (Mg)₅Si₈O. 20 (OH)2(OH2)4·4H2O. Attapulgite clay exhibits a high specific surface area, open mesoporous-microporous composite channels, and good thermal stability, making it suitable as an adsorbent for VOCs. Furthermore, it is similar to inorganic materials such as molecular sieves, SiO2, Al2O3, and TiO2, all of which belong to inorganic mineral materials. It has good kneading properties after mixing, and the adsorbent can be designed according to the molecular size of the adsorbate.

[0026] This invention provides a flame-retardant, hydrophobic porous adsorbent, characterized in that it contains at least one primary matrix selected from attapulgite and kaolin, at least one inorganic material selected from inorganic porous solids, and a calcined oxide of a hydrophobic modifying material. Based on the total mass of the adsorbent, the content of the primary matrix is ​​10-99.5% by mass, preferably 20-99% by mass; the content of the calcined oxide of the hydrophobic modifying material is 0.05-1% by mass, preferably 0.05-0.5% by mass; the content of the inorganic material is 0.5-90% by mass, preferably 1-80% by mass, more preferably 5-80% by mass, further preferably 8-70% by mass, and even more preferably the balance; the contact angle between the adsorbent and water is 40-90°, preferably 45-70°.

[0027] In one embodiment of the invention, the adsorbent is substantially composed of the calcined oxide of the original matrix, the inorganic material, and the hydrophobic modified material. In another embodiment of the invention, the adsorbent is composed only of the calcined oxide of the original matrix, the inorganic material, and the hydrophobic modified material.

[0028] In one embodiment of the present invention, the content of the original matrix is ​​10 to 99.5% by mass, preferably 20 to 99% by mass, based on the total mass of the adsorbent.

[0029] In one embodiment of the present invention, based on the total mass of the adsorbent, the content of the calcined oxide of the hydrophobic modified material is 0.05~1% by mass, preferably 0.05~0.5% by mass.

[0030] In one embodiment of the present invention, based on the total mass of the adsorbent, the content of the inorganic material is 0.5-90% by mass, preferably 1-80% by mass, more preferably 5-80% by mass, even more preferably 8-70% by mass, and even more preferably the balance.

[0031] In this invention, the attapulgite clay can be any type of attapulgite clay known in the art, and it can be a commercially available product. The kaolin clay can also be any type of kaolin clay known in the art, and it can be a commercially available product.

[0032] In this invention, the inorganic porous solids can include refractory oxides of metals from Groups IIA, IIIA, IVA, or IVB of the periodic table (such as silicon dioxide, aluminum oxide, magnesium oxide, titanium oxide, zirconium oxide, or thorium oxide), or any refractory composite oxide of these metals (such as aluminum silicate, aluminum magnesium oxide, silicon titanium oxide, magnesium titanium oxide, and aluminum titanium oxide), as well as clay, molecular sieves, mica, montmorillonite, bentonite, and diatomaceous earth.

[0033] In one embodiment of the present invention, the inorganic porous solid is preferably selected from at least one of silicon dioxide, aluminum oxide, magnesium oxide, aluminum silicate, aluminum magnesium oxide, silicon dioxide, titanium dioxide, molecular sieve and montmorillonite.

[0034] In this invention, the molecular sieve can be any molecular sieve known in the art. For example, the molecular sieve can be selected from one or more combinations of type A molecular sieve, type X molecular sieve, type Y molecular sieve, ZSM series, SAPO, AIPO, mordenite molecular sieve, SBA, and MCM.

[0035] In this invention, silicon dioxide, aluminum oxide, magnesium oxide, aluminum silicate, aluminum magnesium oxide, silicon titanium dioxide, titanium dioxide, molecular sieves, and montmorillonite can be any inorganic material known in the art, can be manufactured by known methods, or can be any commercially available product.

[0036] In this invention, various hydrophobic modifying materials known in the art can be used as the hydrophobic modifying materials. Preferably, the hydrophobic modifying materials are silicon-based or metal compound-based. Specifically, the silicon-based modifying material can be selected from one or a combination of several of methyl silicate, ethyl silicate, propyl silicate, butyl silicate, (tetra)silicon chloride, and sodium silicate.

[0037] As a metal compound modifier, it can be selected from titanium-based modifiers and / or aluminum-based modifiers. The titanium-based modifier can be a titanate ester or titanium halide, selected from one or more combinations of methyl titanate, ethyl titanate, propyl titanate, butyl titanate, and titanium chloride. The aluminum-based modifier can be an aluminate ester or aluminum halide, selected from one or more combinations of methyl aluminate, ethyl aluminate, propyl aluminate, butyl aluminate, and aluminum chloride.

[0038] In one embodiment of the present invention, the flame-retardant hydrophobic porous adsorbent BET has a specific surface area of ​​100~800 m². 2 ·g -1 Preferred depth: 110~800m 2 ·g -1 The most probable pore size is 2~16nm, preferably 4~12nm, and the pore volume is 0.15~1.2ml·g. -1 Preferably, the concentration is 0.3~1.2 ml·g. -1 .

[0039] In one embodiment of the present invention, the flame-retardant hydrophobic porous adsorbent can be molded into a macroscopic adsorbent molded body with an appearance of spheres, cubes, cuboids, cylinders, Raschig rings, etc.

[0040] In one embodiment of the present invention, when the adsorbent is molded into an adsorbent body, the adsorbent body may have macroscopic channels, which can be one or more of the following channel structures: circular, square, triangular, hexagonal, or rhombic. The arrangement of these macroscopic channels on the adsorbent body can be ordered or disordered, preferably uniformly ordered honeycomb channels. Generally, to reduce adsorption resistance, the macroscopic channels on the adsorbent body are permeable.

[0041] In one embodiment of the present invention, the cross-sectional area of ​​a single pore in the macroscopic pores of the macroscopic adsorbent molded body is 1 mm. 2 ~80mm 2 Preferably 1mm 2 ~40mm 2 The hole wall thickness is 1~4mm, preferably 1~2.5mm.

[0042] In one embodiment of the present invention, the flame-retardant porous adsorbent has a positive pressure strength of 2 to 8 MPa, preferably 3 to 6 MPa, as determined by the standard method of GB / T 5072-2008, and a lateral pressure strength of 0.1 to 2 MPa, preferably 0.25 to 1.5 MPa.

[0043] Without impairing the effects of the present invention, the porous adsorbent may optionally contain other auxiliary agents. Examples of such auxiliary agents include various metal oxides and various inert organic porous solids, in addition to the inorganic materials described above. The amount of such auxiliary agent used is 5% to 30% relative to the total mass of the porous adsorbent. In one embodiment of the present invention, the porous adsorbent does not contain carbonaceous materials (including but not limited to activated carbon, carbon fibers, etc.).

[0044] In this invention, without any theoretical limitations, the inventors believe that after all the raw material components of the adsorbent are made into a preform, a hydrophobic modification treatment is performed on it before calcination to make the final adsorbent; or after all the raw material components of the adsorbent are hydrophobically modified with a hydrophobic modification material, a modified preform is made, and then calcination is performed, so that a calcined oxide (hydrophobic layer) of the hydrophobic modification material is formed on the surface of the final adsorbent, which imparts a certain degree of hydrophobicity to the adsorbent.

[0045] In addition, in this invention, since the hydrophobic layer is a very thin layer, the weight of the hydrophobic layer is very low relative to the adsorbent itself. Typically, based on the total mass of the adsorbent, the content of the calcined oxide of the hydrophobic modified material is 0.05 to 1% by mass, preferably 0.05 to 0.5% by mass.

[0046] In this invention, the flame-retardant hydrophobic porous adsorbent is hydrophobically modified to produce a calcined oxide content of 0.05-1% by mass, preferably 0.05-0.5% by mass, thereby imparting a certain degree of hydrophobicity to the adsorbent. The contact angle of water on the surface of the porous adsorbent is used as an indicator of hydrophobicity. When measured according to the method of GB / T36086-2018, the contact angle between the adsorbent and water is 40-90°, preferably 45-70°.

[0047] This invention also provides a method for preparing a flame-retardant hydrophobic porous adsorbent, characterized by comprising the following steps:

[0048] (1) A plastic mixed contact body is prepared by mixing and contacting at least one original matrix selected from attapulgite and kaolin, and at least one inorganic material selected from inorganic porous solids, a binder, and water, wherein, relative to the total amount of the original matrix and the inorganic material, the content of the original matrix is ​​10 to 99.5% by mass, preferably 20 to 99% by mass, and the content of the inorganic material is 0.5 to 90% by mass, preferably 1 to 80% by mass, more preferably 5 to 80% by mass, further preferably 8 to 70% by mass, and even more preferably the balance;

[0049] (2) Optionally, the plastic mixed contact body is molded to obtain a porous adsorbent blank;

[0050] (3) The mixed contact body in step (1) or the porous adsorbent preform in step (2) is calcined in an inert gas, and then further contacted with a solution containing a hydrophobic modifier to obtain a modified preform; and

[0051] (4) The modified embryo is further calcined to obtain a flame-retardant hydrophobic porous adsorbent.

[0052] or

[0053] (1') After contacting at least one original matrix selected from attapulgite and kaolin, and at least one inorganic material selected from inorganic porous solids with a solution containing a hydrophobic modifier, they are calcined to obtain a modified original matrix and a modified inorganic material.

[0054] (2') The modified original matrix, the modified inorganic material, the adhesive solvent, and water are mixed and brought into contact to form a plastic mixed modified contact body; wherein, relative to the total amount of the modified original matrix and the modified inorganic material, the content of the modified original matrix is ​​10~99.5% by mass, preferably 20~99% by mass, and the content of the inorganic material is 0.5~90% by mass, preferably 1~80% by mass, more preferably 5~80% by mass, even more preferably 8~70% by mass, and even more preferably the balance;

[0055] (3') Optionally, the plastic mixed modified contact body is molded to obtain a porous adsorbent modified preform; and

[0056] (4') The mixed modified contact body in step (2') or the modified preform in step (3') is further calcined to obtain a flame-retardant hydrophobic porous adsorbent.

[0057] In one embodiment of the present invention, in steps (1) and (1') of the above preparation method, no pretreatment is performed on at least one original matrix selected from attapulgite and kaolin.

[0058] In the preparation method of this invention, the attapulgite can be any attapulgite known in the art, and it can be a commercially available product. The kaolin can be any kaolin known in the art, and it can be a commercially available product.

[0059] In the preparation method of the present invention, in the above steps (1) and (1'), the inorganic porous solid can be refractory oxides of metals of Group IIA, IIIA, IVA or IVB of the periodic table (such as silicon dioxide (also known as silicon oxide or silica gel), aluminum oxide, magnesium oxide, titanium oxide, zirconium oxide or thorium oxide, etc.), or any refractory composite oxide of these metals (such as aluminum silicate, aluminum magnesium oxide, silicon titanium oxide, magnesium titanium oxide and aluminum titanium oxide, etc.), as well as clay, molecular sieve, mica, montmorillonite, bentonite and diatomaceous earth, etc.

[0060] In one embodiment of the present invention, the inorganic porous solid is preferably selected from at least one of silicon dioxide, aluminum oxide, magnesium oxide, aluminum silicate, aluminum magnesium oxide, silicon dioxide, titanium dioxide, molecular sieve and montmorillonite.

[0061] Molecular sieves may be those known in the art, such as those selected from type A molecular sieves, type X molecular sieves, type Y molecular sieves, ZSM series, SAPO, AIPO, mordenite molecular sieves, SBA, and MCM, or a combination of two or more of these. Silica, alumina, magnesium oxide, silica-alumina, magnesium-alumina, titanium dioxide-silicon, titanium dioxide, molecular sieves, and montmorillonite may be any materials known in the art, manufactured by known methods, or any commercially available product.

[0062] In step (1') above, the original matrix and inorganic material after contact with the hydrophobic modifier are calcined at a temperature of 200-550°C, preferably 200-500°C, and more preferably 250-500°C. Calcination can be carried out in air. Preferably, calcination is carried out in an inert gas atmosphere. Examples of inert gases include nitrogen or rare gases, with nitrogen being preferred. The calcination time is not particularly limited and can be 2-20 hours, preferably 4-16 hours.

[0063] In the preparation method of this invention, in steps (1) and (2') above, the adhesive solvent only needs to be able to disperse the original matrix (or modified original matrix) and the inorganic material (or modified inorganic material). It can be an organic or inorganic substance, such as inorganic acids, inorganic bases, polycarboxylic acids, monohydric alcohols, polyhydric alcohols, polyamines, cellulose derivatives, carboxylates, etc. These adhesive solvents can be used alone or in combination as needed. The amount of adhesive solvent is not particularly limited and can be adjusted according to the total amount of the original matrix (or modified original matrix) and inorganic material (or modified inorganic material). Preferably, the amount of adhesive solvent is 1 to 20 parts by mass relative to 100 parts by mass of the total amount of the original matrix (or modified original matrix) and inorganic material (or modified inorganic material), preferably 1.2 to 10 parts by mass, and more preferably 1.5 to 5 parts by mass.

[0064] As the inorganic acid, various inorganic acids known in the art can be used, such as one or more combinations of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and perchloric acid.

[0065] The inorganic base can be an alkali metal hydroxide or an alkaline earth metal hydroxide, for example, one or more combinations of sodium hydroxide, calcium hydroxide, potassium hydroxide, magnesium hydroxide, and lithium hydroxide.

[0066] As the polycarboxylic acid, various polycarboxylic acids known in the art can be used, for example, those with 2 to 10 (preferably 3 to 6) carboxyl groups. 2-20 Alkanes, for example, include oxalic acid, succinic acid, and adipic acid. As polycarboxylic acids, examples include those with one or more hydroxyl groups (e.g., 1 to 6) and 2 to 10 (preferably 3 to 6) carboxyl groups. 2-20 Alkanes, such as malic acid, tartaric acid, citric acid, and stearic acid, can also be used as polycarboxylic acids, specifically those in the C2O2 group. 2-20 Polycarboxylated alkyl (poly)amines are obtained by inserting one or more nitrogen atoms into an alkane chain, such as hypozinotriacetic acid and ethylenediaminetetraacetic acid.

[0067] As the monohydric alcohol, various monohydric alcohols known in the art can be used, such as C16 alcohols with one hydroxyl group. 1-20 Alkanes, for example, include methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol.

[0068] As the polyol, various polyols known in the art can be used, such as those with 2 to 10 (preferably 3 to 6) hydroxyl groups. 2-20Alkanes, such as ethylene glycol, diethylene glycol, propylene glycol, glycerol, pentaerythritol, or polymers of such polyols, such as polyethylene glycol, polyvinyl alcohol, etc., or may be those contained in the C... 2-20 Polyhydroxyalkyl (poly)amines are obtained by inserting one or more nitrogen atoms into an alkane chain, such as monoethanolamine and triethanolamine.

[0069] As the polyamine, various polyamines known in the art can be used, such as ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, etc.

[0070] As the cellulose derivatives mentioned above, those known in the art can be used, such as methylcellulose, hydroxymethylcellulose, hydroxymethylpropylcellulose, carboxymethylcellulose, etc.

[0071] As the carboxylate, those carboxylate salts known in the art can be used, such as magnesium stearate, sodium stearate, etc.

[0072] In steps (1) and (2'), the amount of water added is not particularly limited, as long as it is sufficient to disperse the original matrix (or modified original matrix) and the inorganic material (or modified inorganic material). Preferably, the amount of water is 20 to 120 parts by mass relative to 100 parts by mass of the total amount of the original matrix (or modified original matrix) and the inorganic material (or modified inorganic material). In steps (1) and (2'), a kneader can be used for stirring to prepare the contact body.

[0073] In steps (2) and (3'), the plastic mixed contact body (plastic mixed modified contact body) is molded to obtain a porous adsorbent preform (porous adsorbent modified preform). The equipment and conditions for molding are not particularly limited and can be those known in the art.

[0074] In steps (2) and (3'), during molding, an extruder can be used for molding, at which time the pressure inside the barrel reaches 2 to 8 MPa and the extrusion temperature of the barrel is 20 to 80°C.

[0075] It can be molded into various shapes as needed, such as spheres, cubes, cuboids, cylinders, and Raschig rings. These preforms can have macroscopic channels such as circles, squares, triangles, hexagons, or rhombuses. These macroscopic channels are preferably uniformly ordered, transparent honeycomb channels.

[0076] In step (3), the porous adsorbent preform is calcined in an inert gas. The calcination temperature is 200~580℃, preferably 300~500℃. Examples of inert gases include nitrogen or rare gases, with nitrogen being preferred. The calcination time is not particularly limited and can be 2~20 hours, preferably 4~16 hours.

[0077] In step (3), the solution containing hydrophobic modifier is brought into contact with the calcined mixed contact body or porous adsorbent blank at a ratio of 1 / 5 to 1 / 30 relative to the mass of the calcined mixed contact body or porous adsorbent blank.

[0078] In step (1'), the solution containing the hydrophobic modifier is contacted with the original matrix at a ratio of 1 / 5 to 1 / 30 of the mass of at least one inorganic material selected from inorganic porous solids.

[0079] In steps (3) and (1'), the hydrophobic modifier can be any of the various hydrophobic modifiers known in the art. In this invention, the hydrophobic modifier is preferably a silicon-based modifier or a metal compound modifier. The silicon-based modifier can be selected from one or a combination of several of methyl silicate, ethyl silicate, propyl silicate, butyl silicate, (tetra)silicon chloride, and sodium silicate.

[0080] As a metal compound modifier, it can be selected from titanium-based modifiers and / or aluminum-based modifiers. The titanium-based modifier can be a titanate ester or titanium halide, and can be selected from one or more combinations of methyl titanate, ethyl titanate, propyl titanate, butyl titanate, and titanium chloride. The aluminum-based modifier can be an aluminate ester or aluminum halide, and can be selected from one or more combinations of methyl aluminate, ethyl aluminate, propyl aluminate, butyl aluminate, and aluminum chloride.

[0081] As a solvent for preparing solutions containing hydrophobic modifiers, various organic non-aqueous solvents commonly used in the art can be used. For example, the solvent can be selected from one or a combination of methanol, ethanol, propanol, butanol, benzene, toluene, xylene, long-chain alcohols having 8-12 carbons, and N,N-dimethylformamide. Preferably, it is an organic solvent that is completely miscible with silicon-based modifiers, titanium-based modifiers, and aluminum-based modifiers.

[0082] In the solution containing the hydrophobic modifier, the concentration of the hydrophobic modifier can be adjusted as needed, and its mass concentration can be 0.5~40%, preferably 0.8~30%. As long as a hydrophobic layer is formed on the surface of the final adsorbent, such that the contact angle of water on the surface of the porous adsorbent is 40~90°, preferably 45~70°, it is acceptable.

[0083] In steps (4) and (4'), the modified embryo is calcined to obtain a flame-retardant hydrophobic porous adsorbent.

[0084] The roasting temperature in steps (4) and (4') is not particularly limited, and can be 200~580℃, preferably 200~550℃, and more preferably 300~550℃. The roasting time can be 1~20 hours, preferably 2~20 hours, and more preferably 4~16 hours.

[0085] In the preparation method of the present invention, step (2) is an optional step. In the absence of step (2), in step (3), the plastic mixed contact body in step (1) is calcined. The calcination conditions are the same as those described above.

[0086] In the preparation method of the present invention, step (3') is optional. In the absence of step (3'), the mixed modified contact body in step (2') is calcined in step (4'). The calcination conditions are the same as those described above.

[0087] According to the present invention, in the contact steps of steps (1) and (2'), there is no particular limitation on the contact order of the raw material components (i.e., at least one original matrix selected from attapulgite and kaolin, at least one inorganic material selected from inorganic porous solids and a binder, water; or modified original matrix, modified inorganic material and binder, and water).

[0088] According to the present invention, there are no particular limitations on the manner in which the contacting step is performed in steps (1) and (2'), as long as sufficient mixing and contact of the raw material components can be achieved to form a uniform contact product. For example, the raw material components can be mixed (with auxiliary stirring if necessary) in any manner known in the art until uniform. In steps (1) and (2'), the contacting step can be performed at any temperature from 0°C to 150°C, for example at room temperature.

[0089] According to the present invention, there are no particular restrictions on the manner in which the contact is performed in steps (3) and (1'), as long as the solution containing the hydrophobic modifier is in contact with the calcined porous adsorbent preform; or the solution containing the hydrophobic modifier is in contact with the original matrix or inorganic material. For example, contact can be performed by impregnation. In steps (3) and (1'), the contact step can be performed at any temperature between 0°C and the boiling point of the solvent used in the solution containing the hydrophobic modifier, for example, at room temperature. There are no particular restrictions on the contact time, as long as a hydrophobic layer is formed on the surface of the finally obtained porous matrix, such that the contact angle of water on the surface of the porous matrix is ​​40~90°, preferably 45~70°.

[0090] In the above method of the present invention, heat treatment can be performed before roasting (e.g., roasting in step (3), roasting in step (4), roasting in step (1'), and roasting in step (4')). The material to be roasted is subjected to heat treatment steps such as drying, air drying, and air drying to remove moisture. The heat treatment is performed at 20~150°C, preferably at 30~120°C, and more preferably at 50~100°C.

[0091] The present invention also provides a porous matrix comprising the flame-retardant hydrophobic porous adsorbent described above or the flame-retardant hydrophobic porous adsorbent prepared according to the preparation method described above. The content of the porous adsorbent relative to the mass of the porous matrix is ​​60-100% by mass, preferably 80-100% by mass, and more preferably 90-100% by mass.

[0092] The porous matrix of the present invention may also contain other porous materials, which may be inorganic or organic porous materials. Examples of inorganic porous materials include the inorganic porous solids described above. Examples of organic porous materials include olefin homopolymers or copolymers, polyvinyl alcohol or copolymers thereof, cyclodextrin, (co)polyesters, (co)polyamides, vinyl chloride homopolymers or copolymers, acrylate homopolymers or copolymers, methacrylate homopolymers or copolymers, and styrene homopolymers or copolymers, as well as partially crosslinked forms of these homopolymers or copolymers.

[0093] In one embodiment of the present invention, the surface of the organic porous solid has one or more active functional groups selected from hydroxyl, primary amino, secondary amino, sulfonic acid group, carboxyl group, amide group, N-monosubstituted amide group, sulfonamide group, N-monosubstituted sulfonamide group, mercapto, imino and hydrazide group, wherein at least one of carboxyl and hydroxyl groups is preferred.

[0094] The present invention also provides a use of a flame-retardant hydrophobic porous adsorbent for use in a porous matrix (preferably a porous carrier).

[0095] The present invention also provides a use of a flame-retardant hydrophobic porous adsorbent for the adsorption and treatment of volatile organic compounds.

[0096] In the application of this invention for the adsorption treatment of volatile organic compounds, a flame-retardant, hydrophobic porous adsorbent is packed into a reactor, and a gas containing VOCs is introduced, with a gas hourly space velocity of 500-20000 h⁻¹. -1 The adsorption temperature is 10~100℃, and the desorption temperature is 120~400℃.

[0097] As a desorption method, the adsorbed VOCs can be introduced into a catalytic oxidation reactor or a direct oxidation reaction for combustion. Example

[0098] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0099] In this invention, the surface area is determined by the BET specific surface area measurement method.

[0100] The pore volume was determined using the BJH (Barrett-Joyner-Halenda) method.

[0101] The most probable pore size was determined by BJH.

[0102] The cross-sectional area of ​​a single macroscopic cell (also referred to as a cell) is calculated based on its specific shape.

[0103] Specifically, when the macroscopic holes in the honeycomb are circular, square, triangular, hexagonal, or rhomboid, the cross-sectional area can be calculated using conventional area calculation methods. When the macroscopic holes in the honeycomb are irregularly shaped, the longest diameter (or longest diagonal length) and the shortest diameter (or shortest diagonal length) of that shape are measured, and the cross-sectional area is calculated as: [(longest diameter (or longest diagonal length) + shortest diameter (or shortest diagonal length)) / 4] 2 ·π. Calculate the cross-sectional area of ​​10 honeycomb cells, and use their average value as the cross-sectional area of ​​a single honeycomb cell.

[0104] The contact angle was determined according to the method in GB / T36086-2018.

[0105] The methods for determining the positive pressure strength and lateral pressure strength are in accordance with the national standard method GB / T 5072-2008.

[0106] Example 1

[0107] Attapulgite clay, 13X molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25℃ and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% ethyl silicate ethanol solution at a mass ratio of 20:1 and immersed for 1 hour. It was then calcined at 400℃ for 4 hours to obtain flame-retardant hydrophobic honeycomb adsorbent preform A with a surface area of ​​158m². 2 ·g -1 The most probable pore size is 5.3 nm, and the pore volume is 0.42 ml·g.-1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 53°.

[0108] Comparative Example 1

[0109] Attapulgite clay, 13X molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300°C under N2 conditions for 2 hours, and then at 400°C for 4 hours to obtain flame-retardant honeycomb adsorbent molded body A1, with a surface area of ​​172m². 2 ·g -1 The most probable pore size is 5.6 nm, and the pore volume is 0.45 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 14°.

[0110] Comparative Example 2

[0111] Activated carbon powder, 13X molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 6 MPa to form a square honeycomb preform. The four base sides and height of the preform were 80 cm and 100 cm, respectively. The honeycomb preform was calcined at 450°C in a nitrogen atmosphere for 5 hours to obtain a flame-retardant hydrophobic honeycomb adsorbent molded body A2 with a surface area of ​​300 m². 2 ·g -1 The most probable pore size is 1.7 nm, and the pore volume is 0.5 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 10°.

[0112] Example 2

[0113] Attapulgite, kaolin, Y molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 8:2:2:0.02:0.2:0.03. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 30℃ and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% toluene solution of silicon tetrachloride at a mass ratio of 30:1 and immersed for 20 minutes. It was then calcined at 400℃ for 4 hours to obtain flame-retardant hydrophobic honeycomb adsorbent preform B with a surface area of ​​201m². 2 ·g -1 The most probable pore size is 4.9 nm, and the pore volume is 0.68 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 58°.

[0114] Example 3

[0115] Attapulgite, kaolin, SBA-15 molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 7:3:4:0.02:0.2:0.03. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 30℃ and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% butanol solution containing ethyl titanate at a mass ratio of 30:1 and immersed for 1 hour. It was then calcined at 400℃ for 4 hours to obtain flame-retardant hydrophobic honeycomb adsorbent preform C with a surface area of ​​409m². 2 ·g -1 The most probable pore size is 5.7 nm, and the pore volume is 0.65 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 61°.

[0116] Example 4

[0117] Attapulgite, kaolin, 5A molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 7:3:1.4:0.02:0.2:0.03. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 30℃ and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% aluminum chloride ethanol solution at a mass ratio of 10:1 and immersed for 1 hour. It was then calcined at 350℃ for 4 hours to obtain the flame-retardant hydrophobic honeycomb adsorbent molded body D, with a surface area of ​​228m². 2 ·g -1 The most probable pore size is 7.4 nm, and the pore volume is 0.51 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 30 mm². 2 The contact angle between the adsorbent and water was measured to be 57°.

[0118] Example 5

[0119] Attapulgite, kaolin, SAPO molecular sieve, 65% nitric acid, methylcellulose, hexamethylenediamine, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 7:3:1.4:0.02:0.2:0.01:0.03. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 30℃ and 7MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The preform was calcined at 200℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 2% ethyl silicate ethanol solution at a mass ratio of 18:1 and immersed for 1 hour. It was then calcined at 300℃ for 3 hours to obtain flame-retardant hydrophobic honeycomb adsorbent molded body E, with a surface area of ​​204m². 2 ·g -1 The most probable pore size is 5.9 nm, and the pore volume is 0.38 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 28 mm². 2 The contact angle between the adsorbent and water was measured to be 49°.

[0120] Example 6

[0121] Kaolin, 13X molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 10:4:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25℃ and 5MPa to form a square honeycomb preform. The four base sides and height of the preform were 80cm and 100cm, respectively. The honeycomb preform was calcined at 300℃ under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% ethyl silicate ethanol solution at a mass ratio of 8:1 and immersed for 1 hour. It was then calcined at 450℃ for 4 hours to obtain the flame-retardant hydrophobic honeycomb adsorbent molded body F, with a surface area of ​​141m². 2 ·g -1 The most probable pore size is 6.4 nm, and the pore volume is 0.37 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 51°.

[0122] Example 7

[0123] Attapulgite clay, silica, 65% nitric acid, hydroxymethyl propyl cellulose, and glycerol were mixed evenly in a kneader at a mass ratio of 10:4:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 5 MPa to form a square honeycomb preform. The four base sides and height of the preform were 80 cm and 100 cm, respectively. The honeycomb preform was calcined at 300°C under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% ethyl silicate ethanol solution at a mass ratio of 9:1 and immersed for 1 hour. It was then calcined at 450°C for 4 hours to obtain a flame-retardant hydrophobic honeycomb adsorbent molded body G with a surface area of ​​251 m². 2 ·g -1 The most probable pore size is 6.4 nm, and the pore volume is 0.62 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 61°.

[0124] Example 8

[0125] Attapulgite clay, alumina, 65% nitric acid, hydroxymethylpropyl cellulose, and glycerol were mixed evenly in a kneader at a mass ratio of 10:4:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 5 MPa to form a preform with square honeycomb cells. The four base sides of the preform were 80 cm long and the height was 100 cm high. The honeycomb preform was calcined at 300°C under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% ethyl silicate ethanol solution at a mass ratio of 12:1 and immersed for 1 hour. It was then calcined at 500°C for 4 hours to obtain the flame-retardant hydrophobic honeycomb adsorbent molded body H, with a surface area of ​​213 m². 2 ·g -1 The most probable pore size is 6.1 nm, and the pore volume is 0.54 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 58°.

[0126] Example 9

[0127] Attapulgite clay, titanium dioxide, 65% nitric acid, hydroxymethyl propyl cellulose, and glycerol were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 5 MPa to form a square honeycomb preform. The four base sides and height of the preform were 80 cm and 100 cm, respectively. The honeycomb preform was calcined at 300°C under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% ethyl silicate ethanol solution at a mass ratio of 14:1 and immersed for 1 hour. It was then calcined at 480°C for 4 hours to obtain flame-retardant hydrophobic honeycomb adsorbent molded body I, with a surface area of ​​161 m². 2 ·g -1 The most probable pore size is 8.1 nm, and the pore volume is 0.32 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 54°.

[0128] Example 10

[0129] Attapulgite clay, titanium dioxide, 65% nitric acid, hydroxymethylpropyl cellulose, and glycerol were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic composite. This composite was then loaded into an extruder and extruded at 25°C and 5 MPa to form a square honeycomb preform. The four base sides and height of the preform were 80 cm and 100 cm, respectively. The preform was calcined at 300°C under N2 conditions for 2 hours. After cooling to room temperature, the preform was transferred to a 1% titanium dioxide ethanol solution at a mass ratio of 14:1 and immersed for 1 hour. It was then calcined at 480°C for 4 hours to obtain a flame-retardant hydrophobic honeycomb adsorbent molded body J with a surface area of ​​156 m². 2 ·g -1 The most probable pore size is 8.3 nm, and the pore volume is 0.31 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the water-adsorbent and water was measured to be 47°.

[0130] Example 11

[0131] Silicon-based modification treatment was carried out on attapulgite powder and 13X molecular sieve powder. Specifically, the attapulgite powder and 13X molecular sieve powder were immersed in an ethanol solution with a mass ratio of 14:1 of powder to modification solution for 1 hour. After being removed, they were calcined at 300°C under N2 conditions for 2 hours to obtain modified attapulgite powder and 13X molecular sieve powder.

[0132] Modified attapulgite, modified 13X molecular sieve, 65% nitric acid, methylcellulose, and magnesium stearate were mixed evenly in a kneader at a mass ratio of 10:3:0.02:0.2:0.001. A suitable amount of water was added, and the mixture was kneaded to form a plastic, modified contact body. This contact body was then loaded into an extruder and extruded at 25°C and 5MPa to produce a modified preform with square honeycomb cells. The four base sides and height of the modified preform were 80cm and 100cm, respectively. The honeycomb modified preform was calcined at 400°C for 4 hours under N2 conditions to obtain the flame-retardant honeycomb adsorbent molded body K, with a surface area of ​​143m². 2 ·g -1 The most probable pore size is 5.9 nm, and the pore volume is 0.38 ml·g. -1 The cross-sectional area of ​​a single honeycomb cell is 10 mm². 2 The contact angle between the adsorbent and water was measured to be 55°.

[0133] Example 12

[0134] The flame-retardant and hydrophobic honeycomb adsorbents from Examples 1-11 were loaded into an adsorption tower, and a mixed VOCs gas containing benzene-toluene-xylene with a volume fraction of 0.5% water vapor was introduced at a temperature of 40°C. The adsorbed honeycomb adsorbents were then desorbed and regenerated using hot air at 250°C. The honeycomb adsorbents from Comparative Examples 1-2 were loaded into an adsorption tower, and a gas containing VOCs was introduced at a temperature of 40°C. The adsorbed honeycomb adsorbents were then desorbed and regenerated using vacuum. The results are shown in Table 1. As can be seen from Table 1, the flame-retardant and hydrophobic honeycomb adsorbent of the present invention exhibits good recyclability, significantly superior to the adsorption performance of the comparative examples' honeycomb adsorbents.

[0135] This indicates that, in this invention, an adsorbent with excellent long-term stability can be obtained by hydrophobic treatment of the adsorbent.

[0136] Table 1 Adsorption-regeneration results of flame-retardant hydrophobic honeycomb adsorbent

[0137] Adsorbent airspeed (h -1 )]]> Adsorbed VOCs inlet concentration (mg / m 3 ) Single adsorption VOCs outlet concentration (mg / m 3 )]]> Adsorbed VOCs inlet concentration (mg / m 3 )]]> Secondary adsorption VOCs outlet concentration (mg / m 3 )]]> Adsorbed VOCs inlet concentration (mg / m 3 )]]> Ten adsorption VOCs outlet concentration (mg / m 3 )]]> A 10000 350 Not detected 350 Not detected 350 Not detected A1 10000 350 14.5 350 23.1 350 40.7 A2 10000 350 6.7 350 9.4 350 15.3 B 10000 350 Not detected 350 Not detected 350 Not detected C 10000 350 0.3 350 0.4 350 0.6 D 10000 350 Not detected 350 Not detected 350 0.4 E 10000 350 Not detected 350 0.1 350 0.4 F 10000 350 Not detected 350 0.4 350 0.6 G 10000 350 Not detected 350 Not detected 350 0.5 H 10000 350 Not detected 350 Not detected 350 Not detected I 10000 350 Not detected 350 Not detected 350 Not detected J 10000 350 Not detected 350 Not detected 350 Not detected K 10000 350 Not detected 350 Not detected 350 2.4

[0138] Example 13

[0139] For the flame-retardant hydrophobic honeycomb adsorbents in Examples 1-5 and the adsorbent in Comparative Example 1, water vapor at 130°C was introduced. After 10 hours, hot air was used for purging until the weight of the adsorbent no longer changed. The results of the strength change of the adsorbent before and after were shown in Table 2. As can be seen from Table 2, the hydrophobic honeycomb adsorbent of the present invention has excellent hydrothermal stability.

[0140] Table 2. Hydrothermal stability results of flame-retardant hydrophobic honeycomb adsorbent

[0141] Adsorbent Fresh positive strength (MPa) Fresh side strength (MPa) After water resistance positive strength (MPa) After water resistance side strength (MPa) A 6.3 1.6 6.2 1.6 A1 6.2 1.6 6.0 1.5 B 5.5 1.2 5.3 1.1 C 5.2 1.2 5.1 1.1 D 4.9 1.2 4.8 1.1 E 4.7 1.2 4.5 1.2

[0142] Although the invention has been described in detail herein with reference to exemplary embodiments, it should be understood that the invention is not limited to the described embodiments. Other variations, modifications, and embodiments within the scope of the invention will be recognized by those skilled in the art and who have access to the teachings herein. Therefore, the invention should be broadly interpreted in accordance with the claims set forth below.

Claims

1. A flame-retardant hydrophobic porous adsorbent for adsorbing volatile organic compounds (VOCs), wherein the VOCs are a benzene-toluene-xylene mixture, and the flame-retardant hydrophobic porous adsorbent contains an attapulgite and kaolinite matrix, molecular sieves as inorganic materials, and calcined oxides as hydrophobic modifying materials. Based on the total mass of the adsorbent, the content of the original matrix is ​​10-99.5% by mass, the content of the calcined oxides of the hydrophobic modifying materials is 0.05-1% by mass, and the content of the inorganic materials is 0.5-90% by mass. The contact angle between the adsorbent and water is 40-90°. The hydrophobic modifying material is selected from at least one of methyl silicate, ethyl silicate, propyl silicate, butyl silicate, silicon tetrachloride, sodium silicate, methyl titanate, ethyl titanate, propyl titanate, butyl titanate, titanium chloride, methyl aluminate, ethyl aluminate, propyl aluminate, butyl aluminate, and aluminum chloride. The molecular sieve is selected from one or more combinations of type A molecular sieve, type X molecular sieve, type Y molecular sieve, ZSM molecular sieve, SAPO, AIPO, mordenite molecular sieve, SBA, and MCM.

2. The use according to claim 1, wherein, The adsorbent is composed of the original matrix, the inorganic material, and the calcined oxide of the hydrophobic modified material.

3. The use according to claim 1 or 2, wherein, The adsorbent BET has a specific surface area of ​​100~800 m². 2 ·g -1 The most probable pore size is 2~16 nm, and the pore volume is 0.15~1.2 ml·g. -1 .

4. According to claim 1 or 2, the flame-retardant hydrophobic porous adsorbent is molded into an adsorbent body with an appearance of spheres, cubes, cuboids, cylinders, or Raschig rings, wherein the molded body has one or more macroscopic channel structures selected from circles, squares, triangles, hexagons, or rhombuses, and the cross-sectional area of ​​a single macroscopic channel is 1 mm². 2 ~80mm 2 The hole wall thickness is 1~4mm.

5. The use according to claim 1 or 2, wherein, The adsorbent has a positive pressure strength of 2–8 MPa and a lateral pressure strength of 0.1–2 MPa.

6. The use according to claim 1 or 2, wherein it satisfies at least one of the following conditions: The content of the original matrix is ​​20-99% by mass, the content of the calcined oxide of the hydrophobic modified material is 0.05-0.5% by mass, the content of the inorganic material is 5-80% by mass, and the contact angle between the adsorbent and water is 45-70°. The adsorbent BET has a specific surface area of ​​110~800 m². 2 ·g -1 The most probable pore size is 4~12 nm, and the pore volume is 0.3~1.2 ml·g. -1 ; The adsorbent is shaped into a spherical, cubic, cuboid, cylindrical, or Raschig ring form. The form has one or more macroscopic pore structures selected from circular, square, triangular, hexagonal, or rhombic shapes, with a cross-sectional area of ​​1 mm² for each macroscopic pore. 2 ~40mm 2 The hole wall thickness is 1~2.5mm; The adsorbent has a positive pressure strength of 3-6 MPa and a lateral pressure strength of 0.2-1.5 MPa.

7. The use according to claim 1 or 2, wherein the flame-retardant hydrophobic porous adsorbent is prepared by a preparation method comprising the following steps: (1) A plastic mixed contact body is prepared by mixing and contacting an original matrix containing attapulgite and kaolin, a molecular sieve as an inorganic material, a colloidal solvent, and water, wherein, The content of the original matrix is ​​10-99.5% by mass, and the content of the inorganic material is 0.5-90% by mass, relative to the total amount of the original matrix and the inorganic material. (2) Optionally, the plastic mixed contact body is molded to obtain a porous adsorbent blank; (3) The mixed contact body in step (1) or the porous adsorbent preform in step (2) is calcined in an inert gas and then further contacted with a solution containing a hydrophobic modifier to obtain a modified preform. and (4) The modified embryo is further calcined to obtain a flame-retardant hydrophobic porous adsorbent. or (1') The original matrix containing attapulgite and kaolin, and the molecular sieve as an inorganic material are respectively brought into contact with a solution containing a hydrophobic modifier and then calcined to obtain a modified original matrix and a modified inorganic material. (2') The modified original matrix, the modified inorganic material, the adhesive solvent, and water are mixed and brought into contact to form a plastic mixed modified contact body; wherein, relative to the total amount of the modified original matrix and the modified inorganic material, the content of the modified original matrix is ​​10~99.5% by mass, and the content of the modified inorganic material is 0.5~90% by mass. (3') Optionally, the plastic mixed modified contact body is molded to obtain a porous adsorbent modified preform; and (4') Further calcining the mixed modified contact body in step (2') or the modified preform in step (3') yields a flame-retardant hydrophobic porous adsorbent. The hydrophobic modifier is selected from at least one of methyl silicate, ethyl silicate, propyl silicate, butyl silicate, silicon tetrachloride, sodium silicate, methyl titanate, ethyl titanate, propyl titanate, butyl titanate, titanium chloride, methyl aluminate, ethyl aluminate, propyl aluminate, butyl aluminate, and aluminum chloride. The molecular sieve is selected from one or more of the following: type A molecular sieve, type X molecular sieve, type Y molecular sieve, ZSM molecular sieve, SAPO, AIPO, mordenite molecular sieve, SBA, and MCM.

8. The use according to claim 7, wherein, The adhesive solvent is selected from at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, sodium hydroxide, calcium hydroxide, potassium hydroxide, magnesium hydroxide, lithium hydroxide, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, diethylene glycol, propylene glycol, glycerol, pentaerythritol, ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, methylcellulose, hydroxymethylcellulose, hydroxymethylpropylcellulose, carboxymethylcellulose, magnesium stearate, and sodium stearate.

9. The use according to claim 7, wherein, In step (1'), calcination is carried out in an inert gas at a temperature of 200~550℃; in step (3), calcination is carried out in an inert gas at a temperature of 200~580℃; in steps (4) and (4'), the calcination temperature is 200~580℃.

10. The use according to claim 7, further comprising, prior to at least one of the roasting in step (3), step (4), step (1'), and step (4'), a heat treatment step is performed on the material to be roasted, said heat treatment being performed at 20 to 150°C.

11. The use according to claim 7, wherein it satisfies at least one of the following conditions: In step (1), the content of the original matrix is ​​20-99% by mass and the content of the inorganic material is 8-70% by mass relative to the total amount of the original matrix and the inorganic material; or in step (2'), the content of the modified original matrix is ​​20-99% by mass and the content of the modified inorganic material is 8-70% by mass relative to the total amount of the modified original matrix and the modified inorganic material. In step (1'), calcination is carried out in an inert gas at a temperature of 250~500℃; in step (3), calcination is carried out in an inert gas at a temperature of 300~500℃; in steps (4) and (4'), the calcination temperature is 300~550℃. Before at least one of the roasting steps (3), (4), (1'), and (4') mentioned above, the material to be roasted is subjected to a heat treatment step, wherein the heat treatment is carried out at 50~100°C.

12. The use according to claim 1, wherein, The volume hourly space velocity (VHSV) of gases containing volatile organic compounds is 500–20000 h⁻¹. -1 The adsorption temperature is 10~100℃, and the desorption temperature is 120~400℃.