CN118527122B

CN118527122B - Solid amine honeycomb adsorbent and preparation method and application thereof

Info

Publication number: CN118527122B
Application number: CN202410993636.4A
Authority: CN
Inventors: 李子宜; 龙鹏; 王聪; 陈云播; 杨雄; 刘应书
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2024-07-24
Filing date: 2024-07-24
Publication date: 2024-10-18
Anticipated expiration: 2044-07-24
Also published as: CN118527122A

Abstract

The application relates to the technical field of adsorbent preparation, in particular to a solid amine honeycomb adsorbent, and a preparation method and application thereof. The preparation method is that the silica sol is modified and then is made into the solid amine honeycomb adsorbent with solid amine, base material and the like, and the modified silica sol is wrapped with the solid amine and the base material to be better combined. The solid amine honeycomb adsorbent prepared by the preparation method has excellent mechanical strength and load strength on the premise of not reducing the adsorption performance and keeping higher load capacity, and is not easy to fly or fall off when in use.

Description

Solid amine honeycomb adsorbent and preparation method and application thereof

Technical Field

The invention relates to the technical field of preparation of solid amine honeycomb adsorbents, in particular to a solid amine honeycomb adsorbent, and a preparation method and application thereof.

Background

CO ₂ is a major greenhouse gas, and the problem of emission is increasing. Carbon capture technology is currently employed to control CO ₂ emissions.

The carbon capture technology mainly comprises amine solvent carbon capture and solid amine honeycomb adsorbent adsorption. The amine solvent carbon capture still has the problems of high external heat quantity, equipment corrosion and the like required by solvent regeneration; while the solid amine honeycomb adsorbent has the advantages of low regeneration energy consumption, environmental friendliness, small equipment corrosion and the like, most solid amine honeycomb adsorbents are applied to various CO ₂ adsorption and trapping scenes in the form of powder or particles at present, the powder or particle adsorbent can be basically adsorbed and trapped only in a fixed bed or fluidized bed process flow, the diffusion path of the adsorbent is long, the adsorption kinetics speed is low, a thicker adsorption bed layer is required to realize enough target gas removal rate, the adsorbent consumption is increased, meanwhile, the problem of high piezoresistance is brought, the energy consumption is increased due to high piezoresistance, the adsorption/desorption cycle time is prolonged due to low heat and mass transfer speed, and the adsorption rate is seriously influenced.

Disclosure of Invention

In order to solve the problems, the application provides a solid amine honeycomb adsorbent, and a preparation method and application thereof. The preparation method is that the silica sol is modified and then is made into the solid amine honeycomb adsorbent with solid amine, base materials and the like, and the modified silica sol is wrapped with the solid amine to be better combined with the base materials. The solid amine honeycomb adsorbent prepared by the preparation method has excellent mechanical strength and load strength on the premise of not reducing the adsorption performance and keeping higher load capacity, and is not easy to fly or fall off when in use.

The application is realized by the following technical scheme:

The application aims at providing a preparation method of a solid amine honeycomb adsorbent, which comprises the following steps:

Preparing modified silica sol by adopting raw materials comprising an aminosilane coupling agent, organic gel and silica sol;

preparing a coating slurry by adopting raw materials comprising the modified silica sol, solid amine slurry and an auxiliary agent;

And carrying out load treatment on the base material by the coating slurry to obtain the solid amine honeycomb adsorbent.

According to the preparation method of the solid amine honeycomb adsorbent, alkoxy in the aminosilane coupling agent reacts with surface hydroxyl of the silica sol, and amino groups of the aminosilane coupling agent react with carboxyl, aldehyde group, ester group or epoxy group of the organic sol, so that modified silica sol with an organic crosslinking function is obtained, and aminosilane in the modified silica sol serves as a 'molecular bridge' between silica particles in the silica sol and the organic sol, so that a rigid, interconnected, porous and three-dimensional network structure is formed among silica sol particles. In the coating slurry prepared from the modified silica sol with a network structure and the solid amine, the modified silica sol reduces the internal stress and the shrinkage rate in the slurry crosslinking and curing process and prevents the cracking of the adsorbent after drying; when the modified silica sol is prepared, the amino silane coupling agent is firstly hydrolyzed by water in the silica sol, alkoxy (such as ethoxy, -OCH ₂CH₃) of the amino silane coupling agent can be hydrolyzed to generate silanol groups (-SiOH) in the presence of water, the generated silanol groups can be further subjected to condensation reaction with hydroxyl groups (-OH) on the surfaces of silica particles in the silica sol to form siloxane (Si-O-Si) bonds, and after the organic gel is added, amino groups of the amino silane coupling agent react with carboxyl groups, aldehyde groups, ester groups or epoxy groups of the organic gel to form stable covalent bonds, so that the modified silica sol is finally obtained. And preparing the coating slurry, wherein the modified silica sol is wrapped with solid amine, so that the solid amine and the base material can be better combined when the coating slurry is loaded, and the prepared solid amine honeycomb adsorbent has high loading strength and mechanical strength while keeping the adsorption performance and high loading capacity of the solid amine, so that the solid amine is not easy to fall off from the base material (no powder falling phenomenon occurs). The preparation method disclosed by the application has the advantages of simple steps, easiness in obtaining raw materials, no pollution, lower cost, high stability and easiness in industrial large-scale production.

In some possible implementations, the step of preparing the modified silica sol includes:

Carrying out a first mixing reaction on an aminosilane coupling agent solution and silica sol to obtain hydroxyl modified silica sol;

and carrying out a second mixing reaction on the hydroxyl modified silica sol and the organic gel solution to obtain the modified silica sol.

In the step of preparing the modified silica sol, the aminosilane coupling agent solution and the silica sol firstly carry out a first mixing reaction, so that silanol formed after alkoxy hydrolysis of aminosilane reacts with surface hydroxyl of the silica sol to obtain hydroxyl modified silica sol; in the modified silica sol, the amino group of the aminosilane coupling agent reacts with the carboxyl group, aldehyde group, ester group or epoxy group of the organic gel, so that the modified silica sol is obtained.

In some possible implementations, a pH adjuster is used to adjust the pH of the coating slurry to a pH of 8-14. In this case, the pH adjuster can increase the adsorption capacity of the amino group, and can ensure that the solid amine slurry is in a strongly alkaline environment, thereby ensuring the stability of the slurry, and further enabling the coating slurry after the impregnation treatment to be uniformly supported on the substrate.

In some possible implementations, the loading treatment step includes repeatedly performing a post-dip drying treatment on the substrate in the coating slurry. In some possible implementations, the number of post-dip drying treatments is 2-10. In this case, the first impregnation time may be longer (1 min-15 min), and the subsequent impregnation time is less than or equal to the first impregnation time, controlled to 1 min-10 min, because the impregnated substrate is still in a wet state although being air-dried, and the subsequent impregnation time is too long, which is easy to cause damage to the substrate or too low in substrate strength, and is more easy to cause the solid amine applied in the front to be redissolved in the coating slurry; the times of drying treatment after dipping are 2-10 times, so that the solid amine raw powder on the base material has good load, and the solid amine in the base material can also participate in adsorbing CO ₂, so that the base material has higher CO ₂ adsorption capacity.

Further, the aminosilane coupling agent solution is 6-15 parts by weight. Further, the weight portion of the silica sol is 10-20. Under the weight part range, alkoxy in the aminosilane coupling agent can be fully hydrolyzed by means of water in the silica sol, and the silanol generated by hydrolysis and hydroxyl on the surface of the silica sol are guaranteed to fully react, so that slurry settlement caused by excessive aminosilane coupling agent is avoided, and meanwhile, incomplete modification of the silica sol and influence on the final adhesive property of the silica sol caused by insufficient aminosilane coupling agent are avoided.

Further, the silica sol is a neutral silica sol. This neutral silica sol can avoid side reactions because: the active group of the selected aminosilane coupling agent is amino, so that any acidic substance is avoided to be added to cause the reaction, and the silica sol cannot be acidic; secondly, under alkaline environment, OH ^- ions can be used as a nuclear catalyst to attack silicon atoms in silane groups, promote the breakage of Si-OR bonds and accelerate the hydrolysis reaction, and the alkaline environment can increase the contact frequency of reactants (such as water molecules and hydroxide ions) and the silane groups, so that the rate of the hydrolysis reaction is increased, sedimentation caused by too fast hydrolysis is unacceptable in the modification process, and therefore, the silica sol must be neutral.

In some possible implementations, the mass ratio of the aminosilane coupling agent, the organic gum and the silica sol in the modified silica sol is (1-5): (1-10): (10-20). In the mass ratio range, silanol generated by hydrolysis of the aminosilane coupling agent can fully react with most of hydroxyl groups on the surface of the silica sol and carboxyl groups, aldehyde groups, ester groups or epoxy groups of the organic gel at the same time, so that the modified silica sol with reliable performance is obtained.

In some possible implementations, the components and parts by weight in the solid amine slurry include: 1-2 parts of anti-settling agent, 90-120 parts of water and 40-60 parts of solid amine raw powder. In the weight part range, the solid amine slurry can be effectively prevented from generating precipitation, and the problems of hole blocking or uneven coating (dipping) during subsequent coating (dipping) caused by excessive viscosity of the solid amine slurry can be avoided.

In some possible implementations, the parts by weight of each component in the coating slurry include 10-20 parts of modified silica sol, 100-180 parts of the solid amine slurry, and 0.2-2 parts of the auxiliary agent. In these parts by weight ranges, the dispersibility, stability, rheology and coating properties of the coating slurry can be made high.

In some possible implementations, the solids to liquid ratio of the substrate and the coating slurry is (10 g-20 g): (300-600 ml). At this solid-to-liquid ratio range, the substrate can be completely immersed in the slurry and coated uniformly.

In some possible implementations, the organic glue includes at least one of polyvinyl alcohol, polyurethane, polyacrylate, cyanoacrylate, silicone, phenolic resin, polyvinyl acetate, polyamide, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polystyrene, polyethylene terephthalate, polylactic acid, polyetheretherketone. The carboxyl, aldehyde, ester or epoxy groups on these organosols can react with the aminosilane coupling agent to form stable covalent bonds, i.e. participate in the modification process of the silica sol.

The second purpose of the application is to provide the solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent, wherein the load of the solid amine raw powder in the solid amine honeycomb adsorbent is 70kg/m to 240 kg/m.

In some possible implementations, the solid amine honeycomb adsorbent comprises the following components in parts by weight:

10-20 parts of modified silica sol, 131-182 parts of solid amine slurry and 0.2-2 parts of auxiliary agent. Under the weight part range of each component in the solid amine honeycomb adsorbent, the solid amine loading capacity of the solid amine honeycomb adsorbent is 70kg/m to 240kg/m, and the adsorption capacity of the solid amine honeycomb adsorbent to CO ₂ is 70mg/g to 120mg/g.

The application further aims to provide the solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent or application of the solid amine honeycomb adsorbent in the field of gas adsorption, separation, purification and/or trapping containing CO ₂.

The application of the solid amine honeycomb adsorbent in the field of CO ₂ trapping is that the solid amine honeycomb adsorbent has the advantages of small airflow pressure drop, good heat and mass transfer performance and good heat conduction performance, and not only can reduce the current energy consumption of carbon trapping, but also is very suitable for industrialization.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing a solid amine honeycomb adsorbent according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a solid amine honeycomb adsorbent according to an embodiment of the present application;

FIG. 3 is a CO ₂ adsorption isotherm of a solid amine honeycomb adsorbent of an example of the application and a comparative adsorbent;

Fig. 4 is a graph of CO ₂ breakthrough for the solid amine honeycomb adsorbent of example 1 of the present application under direct air capture.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be described in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

On the contrary, the application is intended to cover any alternatives, modifications, and equivalents, which may be included within the spirit and scope of the application as defined by the appended claims. Further, in the following detailed description of the present application, certain specific details are set forth in order to provide a better understanding of the present application. The present application will be fully understood by those skilled in the art without the details described herein.

The following examples serve to illustrate the application. In the examples, parts are by weight, percentages are by weight and temperatures are in degrees celsius unless otherwise indicated. The relationship between the fractions by weight and the fractions by volume is the same as the relationship between grams and cubic centimeters.

In the present application, the term "and/or" describes an association relationship of an association object, which means that three relationships may exist, for example, a and/or B may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

It should be understood that, in various embodiments of the present application, the sequence number of each process described above does not mean that the execution sequence of some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weights of the relevant components mentioned in the description of the embodiments of the present application may refer not only to the specific contents of the components, but also to the proportional relationship between the weights of the components, so long as the contents of the relevant components in the description of the embodiments of the present application are scaled up or down within the scope of the disclosure of the embodiments of the present application. Specifically, the mass described in the description of the embodiment of the application may be a mass unit known in the chemical industry field such as [ mu ] g, mg, g, kg.

The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated for distinguishing between objects such as substances from each other. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

The powder or granular solid amine can only be used for adsorption trapping in a fixed bed or fluidized bed process flow, which results in longer diffusion paths of the adsorbents, slow adsorption kinetics, and a thicker adsorption bed layer is needed to achieve enough target gas removal rate, so that the use amount of the adsorbent is increased, and meanwhile, the problem of high piezoresistance is brought, the high piezoresistance means the increase of energy consumption, the slow heat and mass transfer speed means the lengthening of adsorption/desorption cycle time, and the adsorption rate is seriously influenced. Thus, there is a need to make solid amines into honeycomb adsorbents.

Currently, for honeycomb adsorbents, an impregnation method is adopted to coat raw powder of the other adsorbent on a substrate; the honeycomb adsorbent is fully distributed in the honeycomb ordered holes, so that the air flow resistance is greatly reduced; the honeycomb adsorbent is generally a high-heat-conductivity substrate, so that the thermal desorption efficiency is greatly improved; this fills the advantages of honeycomb adsorbents in large scale applications.

However, solid amines contain amino groups, typically linear or cyclic chain molecules, which are relatively complex in structure, and different types of solid amines have different chemical structures. However, if the solid amine is directly coated on the substrate, the loading, loading strength, mechanical strength and adsorption performance of the prepared honeycomb adsorbent cannot achieve ideal effects, because the solid amine is a powdery solid obtained by loading the organic amine in mesoporous channels of the porous material and then drying and crushing, the solid material has extremely high surface energy due to the characteristics of the organic amine, and is prepared into slurry, and the surface tension is extremely high, and the solid material is almost impossible to penetrate into the inside of the substrate as the adsorbent such as zeolite and the like, and only forms a film on the surface of the substrate, so that even if a uniform coating is hardly formed on the substrate according to the traditional slurry preparation method, even if the coating is formed, the mechanical strength and loading strength of the substrate cannot be increased, and the loading amount of the solid amine is extremely low due to the fact that the formed coating is too thin, so that the adsorption capacity of the adsorbent is extremely low.

In order to effectively prepare the solid amine into the honeycomb adsorbent so as to solve the problems of low adsorption dynamics speed, high pressure resistance, high energy consumption and the like of powder or granular solid amine. The embodiment of the application provides a preparation method of a solid amine honeycomb adsorbent, which comprises the steps of firstly modifying silica sol by using a silane coupling agent and organic glue to form a rigid interconnected porous three-dimensional network structure among silica sol particles of the modified silica sol, so that the combination capability of the modified silica sol and solid amine is effectively improved; after the modified silica sol and the solid amine are used for preparing the slurry, the modified silica sol is wrapped with the solid amine, so that the solid amine and the base material are better combined, and the prepared solid amine honeycomb adsorbent has high load strength and mechanical strength while keeping the adsorption performance of the solid amine.

The following examples illustrate the preparation of solid amine honeycomb adsorbents, and applications for convenience of illustration.

[ Method for preparing solid amine honeycomb adsorbent ]

One of the purposes of the embodiments of the present application is to provide a method for preparing a solid amine honeycomb adsorbent, as shown in fig. 1, comprising the following steps:

S1, preparing modified silica sol by adopting raw materials comprising an aminosilane coupling agent, organic gel and silica sol.

S2, preparing coating slurry by adopting raw materials comprising modified silica sol, solid amine slurry and an auxiliary agent.

S3, carrying out load treatment on the base material by using the coating slurry to obtain the solid amine honeycomb adsorbent.

According to the preparation method of the solid amine honeycomb adsorbent provided by the embodiment of the application, alkoxy in the aminosilane coupling agent reacts with surface hydroxyl of the silica sol, and amino groups of the aminosilane coupling agent react with carboxyl, aldehyde group, ester group or epoxy group of the organic sol, so that the modified silica sol with an organic crosslinking function is obtained, and aminosilane in the modified silica sol is used as a 'molecular bridge' between silica particles in the silica sol and the organic sol, so that a rigid, porous and three-dimensional network structure is formed among silica sol particles. In the coating slurry prepared from the modified silica sol with a network structure and the solid amine, the modified silica sol reduces the internal stress and the shrinkage rate in the slurry crosslinking and curing process, and prevents the cracking of the adsorbent after drying; when the modified silica sol is prepared, the amino silane coupling agent is firstly hydrolyzed by water in the silica sol, alkoxy (such as ethoxy, -OCH ₂CH₃) of the amino silane coupling agent can be hydrolyzed to generate silanol groups (-SiOH) in the presence of water, the generated silanol groups can further undergo condensation reaction with hydroxyl groups (-OH) on the surfaces of silica particles in the silica sol to form siloxane (Si-O-Si) bonds, and after the organic glue is added, amino groups of the amino silane coupling agent react with carboxyl groups, aldehyde groups, ester groups or epoxy groups of the organic glue to form stable covalent bonds, so that the modified silica sol is finally obtained. And preparing the coating slurry, wherein the modified silica sol is wrapped with solid amine, so that the solid amine and the base material can be better combined when the coating slurry is loaded, and the prepared solid amine honeycomb adsorbent has high loading strength and mechanical strength while keeping the adsorption performance and high loading capacity of the solid amine, and the solid amine is not easy to fall off from the base material (no powder falling phenomenon occurs). The preparation method provided by the embodiment of the application has the advantages of simple steps, readily available raw materials, no pollution, low cost, high stability and easiness in industrial mass production.

[ Step S1 ]

In some embodiments, in step S1 above, the aminosilane coupling agent comprises 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl triethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyldiethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyldichlorosilane, 3-aminopropyl methyldiethoxysilane, 3-aminopropyl methyldimethoxysilane, 3-aminopropyl methyldichlorosilane, N- (2-aminoethyl) -3-aminopropyl dimethoxysilane, N- (2-aminoethyl) -3-aminopropyl diethoxysilane, N- (2-aminoethyl) -3-aminopropyl dichlorosilane, 3-aminopropyl tris (methoxyethoxy) silane, 3-aminopropyl tris (ethoxyethoxy) vinylsilane, N- (2-aminoethyl) -3-aminopropyl diethoxy silane, N- (2-aminopropyl) diethoxy silane, at least one of N- (2-aminoethyl) -3-aminopropyl dichlorosilane, 3-aminopropyl methyl diisopropyloxysilane, N- (3-triaminopropyl) triaminopropyl triethoxysilane and di (triaminopropyl) tetraamine silane. The aminosilane coupling agents comprise amino groups and alkoxy groups, silanol groups formed after the alkoxy groups are hydrolyzed react with surface hydroxyl groups of the silica sol, and amino groups of the aminosilane coupling agents react with carboxyl groups, aldehyde groups, ester groups or epoxy groups of the organic gel, so that modified silica sol is obtained, and aminosilane in the modified silica sol is used as a molecular bridge between silica nano particles in the silica sol and the organic gel, so that a rigid, porous and three-dimensional network structure is formed among silica sol particles.

In some embodiments, in step S1 above, the organic glue comprises at least one of polyvinyl alcohol, polyurethane, polyacrylate, cyanoacrylate, silicone, phenolic resin, polyvinyl acetate, polyamide, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polystyrene, polyethylene terephthalate, polylactic acid, polyetheretherketone. The carboxyl, aldehyde, ester or epoxy groups on these organosols can react with the aminosilane coupling agent to form stable covalent bonds, i.e. participate in the modification process of the silica sol.

In some embodiments, in the step S1, the relative molecular weight of the organic gel is 10 ⁴~10⁵, and in an exemplary embodiment, the relative molecular weight may be, but not limited to, 10 ⁴、10⁵ or the like, or a range between any two relative molecular weights. Under the relative molecular weight range, the organic adhesive shows lower viscosity, more organic matters are added in the whole slurry formula, one of key factors of successful coating is viscosity, and the slurry can smoothly flow in the pore channels of the honeycomb substrate only by ensuring lower viscosity, so that the blocking of pores is avoided.

In some embodiments, in the step S1, the particle size of the silica sol is10 nm to 300nm, and in an exemplary embodiment, the particle size may be a typical but non-limiting particle size or a range between any two particle sizes, such as 10nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, etc. At this particle size range, silica sols have a relatively large specific surface area and surface hydroxyl number, and generally better form stable colloidal dispersions.

In some embodiments, in the step S1, the mass concentration of the silica in the silica sol is 30% -60%, and in an example, the mass concentration may be typically but not limited to 30%, 40%, 50%, 60%, or the like, or a range between any two mass concentrations. At this mass concentration range, =1\gb 3 ① silica sol has lower viscosity, better flowability, easier processing and handling, =2\gb 3 ② has higher dispersion stability, because lower solids content reduces the possibility of interactions and agglomeration between particles, =3\gb 3 ③ can increase the mechanical strength and thermal stability of the final adsorbent.

In some embodiments, in the step S1, the specific surface area of the silica sol is 100m ²/g~300m²/g, and in an example, the specific surface area may be a typical but non-limiting specific surface area such as 100m ²/g、150m²/g、200m²/g、250m²/g、300m²/g or a range between any two specific surface areas. In this specific surface area range, the rheological properties of the silica sol are good and have good stability.

In some embodiments, in the step S1, the pore size of the silica sol is 2nm to 50nm, and in an exemplary embodiment, the pore size may be a typical but non-limiting pore size or a range between any two pore sizes, such as 2nm, 3nm, 4nm, 5nm, etc. In this pore size range, a large amount of physical adsorption of porous silica formed after drying of silica sol can be avoided, resulting in a decrease in the separation performance of the entire adsorbent.

In some embodiments, in the step S1, the pore volume of the silica sol is 0.5mL/g to 1mL/g, and in an exemplary embodiment, the pore volume may be, but is not limited to, 0.5mL/g, 0.6mL/g, 0.7mL/g, 0.8mL/g, 0.9mL/g, 1mL/g, or the like, or a range between any two pore volumes. Under the pore volume range, the silica sol has better dispersibility and stability. Wherein the unit mL/g represents the total volume of pores contained per g of silica sol.

In some embodiments, in the step S1, the step of preparing the modified silica sol includes:

S1-1, carrying out a first mixing reaction on an aminosilane coupling agent solution and silica sol to obtain hydroxyl modified silica sol.

S1-2, carrying out a second mixing reaction on the hydroxyl modified silica sol and the organic gel solution to obtain the modified silica sol.

In the step of preparing the modified silica sol, the aminosilane coupling agent solution and the silica sol firstly carry out a first mixing reaction, so that silanol formed after alkoxy hydrolysis of the aminosilane reacts with surface hydroxyl of the silica sol to obtain hydroxyl modified silica sol; in the modified silica sol, the amino group of the aminosilane coupling agent reacts with the carboxyl group, aldehyde group, ester group or epoxy group of the organic glue, so that the modified silica sol is obtained.

In some embodiments, in the step S1-1 described above, the preparation step of the aminosilane coupling agent solution includes: mixing an aminosilane coupling agent and a first solvent, and stirring at normal temperature at a rotating speed of 200-280 r/min for 10-30 min to obtain a fully dispersed aminosilane solution; in an exemplary embodiment, the rotation speed may be a typical but non-limiting rotation speed or a range between any two rotation speeds, such as 200r/min, 230r/min, 250r/min, 260r/min, 280r/min, etc., and the stirring time may be a typical but non-limiting stirring time or a range between any two stirring times, such as 10min, 15min, 20min, 25min, 30min, etc. At the rotating speed, the solution can be uniformly mixed, and the alcohol solution can be prevented from volatilizing due to the too high stirring speed; under the condition, the aminosilane coupling agent and the first solvent are prepared into an aminosilane coupling agent solution, and the first solvent not only can dissolve the aminosilane coupling agent into the solution, but also can inhibit the hydrolysis reaction of the aminosilane coupling agent, so that the problem of solution sedimentation of the aminosilane coupling agent caused by a large amount of hydrolysis is avoided.

In some embodiments, the aminosilane coupling agent solution comprises the following components in parts by weight: 1-5 parts of an aminosilane coupling agent, 5-10 parts of a first solvent; in an exemplary embodiment, the aminosilane coupling agent may be present in an amount of typically, but not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc., or in a range between any two parts by weight, and the first solvent may be present in an amount of typically, but not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., or in a range between any two parts by weight. Under the condition, the aminosilane coupling agent can be completely dissolved into a solution state, the hydrolysis speed of the alcohol solution in the part can be well controlled, the evaporation speed of the pure solvent can be controlled by controlling the stirring rotating speed after the silica sol is added, and finally the aim of controlling the hydrolysis reaction speed of the aminosilane coupling agent is fulfilled.

In some embodiments, the first solvent comprises at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, methylene chloride, chloroform, toluene. The first solvents are common micromolecular alcohol solvents, so that the aminosilane coupling agent can be dissolved into a solution, the hydrolysis reaction of the aminosilane coupling agent can be inhibited, and the solution sedimentation problem of the aminosilane coupling agent caused by a large amount of hydrolysis is avoided.

In some embodiments, in the step S1-1, the weight portion of the aminosilane coupling agent solution is 6-15; 10-20 parts of silica sol; in an exemplary embodiment, the aminosilane coupling agent solution may be present in an exemplary but non-limiting range of 6 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, or the like, or between any two parts by weight, and the silica sol may be present in an exemplary but non-limiting range of 10 parts by weight, 15 parts by weight, 20 parts by weight, or the like, or between any two parts by weight. Under the weight part range, alkoxy in the aminosilane coupling agent can be fully hydrolyzed by means of water in the silica sol, and the silanol generated by hydrolysis and hydroxyl on the surface of the silica sol are guaranteed to fully react, so that slurry settlement caused by excessive aminosilane coupling agent is avoided, and meanwhile, incomplete modification of the silica sol and influence on the final adhesive property of the silica sol caused by insufficient aminosilane coupling agent are avoided.

In some embodiments, in step S1-1 described above, the silica sol is a neutral silica sol. This neutral silica sol can avoid side reactions because: the active group of the selected aminosilane coupling agent is amino, so that any acidic substance is avoided to be added to cause the reaction, and the silica sol cannot be acidic; secondly, under alkaline environment, OH ⁻ ions can be used as a nuclear catalyst to attack silicon atoms in silane groups, promote the breakage of Si-OR bonds and accelerate the hydrolysis reaction, and the alkaline environment can increase the contact frequency of reactants (such as water molecules and hydroxide ions) and the silane groups, so that the rate of the hydrolysis reaction is increased, sedimentation caused by too fast hydrolysis is unacceptable in the modification process, and therefore, the silica sol must be neutral.

In some embodiments, in step S1-1 above, the first mixing reaction step comprises: adding an aminosilane coupling agent solution into silica sol under the stirring condition with the speed of 600 r/min-800 r/min to obtain a mixed solution;

stirring the mixed solution at the temperature of 40-60 ℃ and the rotating speed of 300-400 r/min for 6-8 hours, and cooling at normal temperature to obtain the hydroxyl modified silica sol.

In the first mixing reaction step, firstly preparing a mixed solution, and fully contacting and mixing an aminosilane coupling agent solution and silica sol to obtain a uniformly mixed solution; and then the mixed solution is heated and stirred for reaction, so that the solvent in the mixed solution is completely volatilized, and silanol generated after alkoxy hydrolysis of the aminosilane coupling agent can be fully reacted with surface hydroxyl of the silica sol to obtain the hydroxyl modified silica sol.

In some embodiments, in the above step S1-2, the preparation of the organic gum solution includes the steps of: and mixing the organic adhesive and the second solvent for 10-30 min under the stirring condition of normal temperature and the rotating speed of 200-280 r/min to obtain an organic adhesive solution. The organic glue and the second solvent are stirred for 10 min-30 min under the stirring condition of 200 r/min-280 r/min, so that the organic glue can be fully dispersed in the second solvent to form a homogeneous organic glue solution.

In some embodiments, the organic gum solution comprises the following components in parts by weight: 1-10 parts of organic glue and 5-15 parts of second solvent; in an exemplary embodiment, the aminosilane coupling agent solution may be in a typical but non-limiting range of 1 part by weight, 3 parts by weight, 5 parts by weight, 7 parts by weight, 10 parts by weight, etc., and the second solvent may be in a typical but non-limiting range of 5 parts by weight, 7 parts by weight, 10 parts by weight, 13 parts by weight, 15 parts by weight, etc., or between any two parts by weight. In this case, the organic gel can be completely dissolved into a homogeneous solution state, reducing the reaction time of the organic gel and the hydroxy-modified silica sol.

In some embodiments, the second solvent comprises at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, methylene chloride, chloroform, toluene. The second solvents can fully dissolve the organic gel, so that the organic gel can fully react with the hydroxyl modified silica sol, and the reaction time is shortened.

In some embodiments, in step S1-2 above, the second mixing reaction step comprises: and mixing the organic gel solution and the hydroxyl modified silica sol to react for 4-6 hours under the stirring condition of 40-60 ℃ to obtain the modified silica sol. Under the condition, the organic glue solution and the hydroxyl modified silica sol are mixed and stirred at the temperature of 40-60 ℃ so that the second solvent is completely volatilized, and amino in the hydroxyl modified silica sol can fully react with carboxyl, aldehyde group, ester group or epoxy group of the organic glue to obtain the modified silica sol.

In some embodiments, in the steps S1-1 and S1-2, the weight portion of the aminosilane coupling agent solution is 6-15, the weight portion of the organic gum solution is 6-20, and the weight portion of the silica sol is 10-20.

In some embodiments, in the step S1, the mass ratio of the aminosilane coupling agent, the organic gum and the silica sol in the modified silica sol is (1-5): (1-10): (10-20), exemplary examples may be a typical but non-limiting mass ratio or a range between any two mass ratios of 2:6:12, 1:1:10, 5:10:20, etc. In the mass ratio range, silanol generated by hydrolysis of the aminosilane coupling agent can fully react with most of hydroxyl groups on the surface of the silica sol and carboxyl groups, aldehyde groups, ester groups or epoxy groups of the organic gel at the same time, so that the modified silica sol with reliable performance is obtained.

[ Step S2 ]

In some embodiments, in the step S2, the components and parts by weight of the solid amine slurry include: 1-2 parts of anti-settling agent, 90-120 parts of water and 40-60 parts of solid amine raw powder; in an exemplary embodiment, the anti-settling agent may be in a range of typically but not limited to 1 part, 1.5 parts, 2 parts, etc., the water may be in a range of typically but not limited to 90 parts, 100 parts, 110 parts, 120 parts, etc., and the solid amine raw powder may be in a range of typically but not limited to 40 parts, 50 parts, 60 parts, etc., or any range between two parts. In the weight part range, the solid amine slurry can be effectively prevented from generating precipitation, and the problems of hole blocking or uneven coating (dipping) during subsequent coating (dipping) caused by excessive viscosity of the solid amine slurry can be avoided.

In some embodiments, in step S2 above, the step of preparing the solid amine slurry comprises:

s2-1, preparing an anti-precipitation solution by adopting an anti-precipitation agent.

S2-2, preparing solid amine slurry by adopting an anti-precipitation solution and solid amine raw powder.

In the step of preparing the solid amine slurry, the anti-sedimentation solution is firstly prepared, and then the solid amine raw powder and the anti-sedimentation solution are adopted to prepare the solid amine slurry, so that the solid amine raw powder added subsequently can not be quickly aggregated into a group, and the solid sedimentation phenomenon can not occur in the subsequent slurry preparation process.

In some embodiments, in the above step S2-1, the step of preparing the anti-precipitation solution includes: mixing and stirring the anti-settling agent and water for 10-30 min under the stirring conditions of normal temperature and the rotating speed of 600-800 r/min. In this case, since the anti-settling agent is a polymer and is not easily dissolved in water, stirring is required to sufficiently dissolve the anti-settling agent, and the anti-settling agent in the prepared anti-settling solution is sufficiently dispersed, and the obtained solution is a clear and transparent solution.

In some embodiments, the anti-settling agent comprises at least one of sodium polyacrylate, hydroxymethyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidone, polysulfonate. The anti-settling principle of the anti-settling agents is that the settling speed of solid particles is slowed down by increasing the viscosity of the suspension; or by electrostatic repulsion to prevent particle aggregation and sedimentation.

In some embodiments, the water comprises at least one of deionized water, distilled water, ultrapure water. The water does not contain metal plasma impurities, and other side reactions can not be caused when the water is mixed into a solution.

In some embodiments, in the step S2-2, the anti-precipitation solution includes, in parts by weight: 1-2 parts of anti-settling agent and 90-120 parts of water. In some embodiments, in step S2-2 above, the solid amine slurry comprises the following components in parts by weight: 91-122 parts of anti-precipitation solution, 40-60 parts of solid amine raw powder; in an exemplary embodiment, the anti-settling solution may be in a range of typically, but not limited to, 91 parts, 100 parts, 110 parts, 120 parts, etc., or any range between two parts by weight, and the solid amine raw powder may be in a range of typically, but not limited to, 40 parts, 50 parts, 60 parts, etc., or any range between two parts by weight. Under the weight part range, the slurry can be effectively prevented from generating precipitation, the viscosity of the slurry is not excessively high, and the problems of hole blocking or uneven coating and the like are caused in the subsequent coating.

In some embodiments, in step S2-2 above, the organic amine in the solid amine raw powder comprises at least one of monoethanolamine, diethanolamine, polyethylenimine (PEI), an amide, tetraethylenepentamine, diethylenetriamine. These solid amines typically contain multiple amino groups, can provide more active sites, and have higher adsorption capacity; the solid amine is stable at higher temperature, is not easy to degrade and can be used for a long time; after adsorbing CO ₂, the solid amine can be regenerated through temperature or vacuum, and the adsorption capacity is recovered, so that the solid amine is suitable for recycling.

In some embodiments, in step S2-2 above, the specific steps for preparing a solid amine slurry using a solution comprising an anti-settling solution and a solid amine raw powder include: mixing the anti-precipitation solution and solid amine raw powder for 30-60 min at the temperature of 40-60 ℃ and the rotating speed of 1000-1200 r/min to obtain solid amine slurry. In this case, in the prepared solid amine slurry, the solid amine raw powder is completely dissolved and uniformly dispersed in the anti-precipitation solution, and the solid amine slurry is a white suspension.

In some embodiments, in step S2 above, the adjuvant includes a dispersant and/or a defoamer. When the auxiliary agent is a dispersing agent and a defoaming agent, the weight part of the dispersing agent in the coating slurry is 0.1-1 part, and the weight part of the defoaming agent in the coating slurry is 0.1-1 part.

In some embodiments, the dispersant includes at least one of Disperbyk-111, disperbyk-190, disperbyk-2016, disperbyk-2150, disperbyk-2200, disperbyk-191 of Ash kinetic energy released in material. These a kinetic energy released in material dispersant molecules typically have long chain structures or branches that form an adsorption layer on the particle surface that forms a physical barrier on the particle surface, increasing the spatial distance between the particles and preventing the particles from aggregating due to van der waals forces or other attractive forces.

In some embodiments, the defoamer includes at least one of BYK-022, BYK-024, BYK-025, BYK-028, BYK-032, BYK-060, of Pick corporation. These pith's defoamers can intercalate into the bubble film through its hydrophobic component, destabilizing the bubble film and collapse, and this mechanism of bubble collapse typically involves localized thinning or collapse of the bubble film by contact of hydrophobic particles or droplets in the defoamer with the bubble film; the novel foam formation can be restrained by forming a layer of hydrophobic film in the liquid, so that the slurry is prevented from generating more foam in the stirring process, and the coating effect is prevented from being influenced.

In some embodiments, in step S2 above, the step of preparing a coating slurry using a slurry comprising a modified silica sol, a solid amine slurry, a dispersant, and an antifoaming agent comprises: mixing the modified silica sol, the solid amine slurry, the dispersing agent and the defoaming agent for 30-60 min at the temperature of 40-60 ℃ and the rotating speed of 1000-1200 r/min to obtain the coating slurry. The components in the coating slurry prepared at the temperature of 40-60 ℃ and the rotating speed of 1000-1200 r/min are uniformly and fully mixed, and the prepared coating slurry is milky slurry.

In some embodiments, in the step S2, the parts by weight of each component in the coating slurry include 10 to 20 parts of modified silica sol, 131 to 182 parts of solid amine slurry, 0.1 to 1 part of dispersant, and 0.1 to 1 part of defoamer; in an exemplary embodiment, the modified silica sol may be in a range of typically but not limited to 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, or the like, the solid amine slurry may be in a range of typically but not limited to 100 parts by weight, 120 parts by weight, 150 parts by weight, 180 parts by weight, or the like, or any of the two parts by weight, the dispersant may be in a range of typically but not limited to 0.1 part by weight, 0.5 part by weight, 0.8 part by weight, 1 part by weight, or the like, or any of the two parts by weight, and the defoamer may be in a range of 0.1 part by weight, 0.5 part by weight, 0.8 part by weight, 1 part by weight, or the like. In these parts by weight ranges, the dispersibility, stability, rheology and coating properties of the coating slurry can be made high.

In some embodiments, in the step S2, a pH regulator is used to adjust the pH value of the coating slurry, so that the pH value of the coating slurry is 8-14; exemplary, but not limiting, pH values or ranges between any two pH values may be 8, 10, 12, 14, etc. In this case, the pH adjuster can increase the adsorption capacity of the amino group, and can ensure that the solid amine slurry is in a strongly alkaline environment, thereby ensuring the stability of the slurry, and further enabling the coating slurry to be uniformly loaded on the substrate after the impregnation treatment.

In some embodiments, the step of adjusting the pH of the coating slurry with a pH adjuster comprises: and adding a pH regulator into the coating slurry under stirring conditions of normal temperature and rotating speed of 1000-1200 r/min, and stirring for 8-12 h to obtain the coating slurry with the pH value of 8-14. In this case, when the pH value of the coating slurry is 8-14 by the added pH regulator, the addition is stopped, but stirring is continued until each component in the coating slurry is uniformly dispersed, and the pH value is kept at 8-14.

In some embodiments, the pH adjuster comprises at least one of ammonia, triethylamine, dimethylformamide, dimethylsulfoxide, ethylenediamine, triethylamine hydrochloride, dimethyl malonate, tripropylamine, methyl carbamate, t-butylamine, pyridine derivatives. The pH regulator can create a strong alkaline environment for the slurry, ensure the stability of the slurry, bring more amino groups and increase the adsorption capacity of the adsorbent after being molded.

In some embodiments, in the step S2, the viscosity of the coating paste is 10mpa·s to 100 mPa ·s; examples thereof include typical but not limited to viscosity values such as 10mPa s,20 mPa s, 30 mPa s, 40 mPa s, 50 mPa s, 60 mPa s, 70 mPa s, 80 mPa s, 90 mPa s, and 100 mPa s, and ranges between any two viscosity values. Under the condition, the proper viscosity can ensure that the coating slurry forms a uniform coating on the substrate, so that the phenomenon of uneven coating is avoided, and the quality and consistency of the product are improved; the viscosity range can balance the fluidity and the adhesive force of the coating slurry, so that the coating slurry can be firmly adhered to the substrate after being coated, and the probability of falling off or foaming is reduced; the too high viscosity leads to poor fluidity of the coating slurry and uneven coating; too low a viscosity tends to cause sagging (dripping or sagging of the coating).

[ Step S3 ]

In some embodiments, in the step S3, the substrate is pretreated and then subjected to a loading treatment with the coating paste. In some embodiments, the step of pre-treating the substrate comprises: roasting the substrate for 5-10 hours under the condition that the temperature is 100-800 ℃ and inert gas shielding gas (nitrogen, argon, helium, neon and the like) is adopted. In this case, in the pretreatment of the substrate, the calcination at a low oxygen content prevents the organic components in the substrate from reacting with oxygen too quickly during the calcination, and the resultant reactants cause a large impact on the substrate, damaging the substrate structure. The baked substrate has sufficient coating pore channels, is beneficial to the entry of coating slurry and improves the loading capacity.

In some embodiments, in step S3 above, the substrate comprises at least one of cordierite, mullite, aluminum titanate, silicon carbide, zirconia, silicon nitride, ceramic fibers, glass fibers, cordierite-mullite composite matrix, and aluminum cordierite-titanate composite matrix. These substrates have a rich porous structure, can hold enough solid amine, and are chemically stable and do not participate in the reaction.

In some embodiments, in the step S3, the solid-to-liquid ratio of the substrate and the coating slurry is (10 g to 20 g): (300 ml to 600 ml), for example, may be a typical but non-limiting solid-to-liquid ratio such as 10g：300ml、10g：400ml、10g：500ml、10g：600ml、15g：300ml、15g：400ml、15g：500ml、15g：600ml、20g：300ml、20g：400ml、20g：500ml、20g：600ml or a range between any two solid-to-liquid ratios. At this solid-to-liquid ratio range, the substrate can be completely immersed in the slurry and coated uniformly.

In some embodiments, in the step S3, the load processing step includes:

S3-1, immersing the substrate in the coating slurry, taking out, airing, putting into the coating slurry, repeating the steps of immersing, drying and processing to obtain the immersed wet material.

S3-2, purging the wet material after dripping, and then drying to obtain the solid amine honeycomb adsorbent.

In the impregnation treatment step, the substrate is repeatedly impregnated in the coating slurry, and the loading amount of the solid amine is increased; the wet material is purged from the top, so that all holes at the bottom of the wet material are all transparent, and a liquid film formed by surface tension is blown off by airflow, so that the holes at the bottom of the base material are not blocked.

In some embodiments, in the step S3-1, the substrate is immersed in the coating slurry for a single immersion time of 1min to 15min, a single drying time of 4h to 8h, and the immersion times of 2 times to 10 times; in an exemplary embodiment, the single dipping time may be a typical but non-limiting time or a range between any two times, such as 1min, 5min, 10min, 15min, etc., the single drying time may be a typical but non-limiting time or a range between any two times, such as 4h, 5h, 6h, 7h, 8h, etc., and the dipping times may be a typical but non-limiting time or a range between any two times, such as 2 times, 4 times, 6 times, 8 times, 10 times, etc. In this case, the first impregnation time may be longer (1 min-15 min), and the subsequent impregnation time is less than or equal to the first impregnation time, controlled to 1 min-10 min, because the impregnated substrate is still in a wet state although being dried, and the subsequent impregnation time is too long, which is easy to cause damage to the substrate or too low in substrate strength, and is more easy to cause the solid amine applied in the front to be redissolved in the coating slurry; the times of drying treatment after dipping are 2-10 times, so that the solid amine raw powder on the base material has good load, and the solid amine in the base material can also participate in adsorbing CO ₂, so that the base material has higher CO ₂ adsorption capacity.

In some embodiments, in the step S3-1, the drying process is performed after the dipping in such a manner that the drying process is performed by natural drying, gentle air drying or drying at a temperature lower than 70 ℃. Under the condition, the natural airing not only can save energy, but also can lead the base material to be evenly aired. Drying in the breeze and drying at the temperature lower than 70 ℃ can accelerate the drying speed.

In some embodiments, in the step S3-2, the dripping time is 10min to 30min, and the dripping condition is natural, and in an example, the dripping time may be a typical but non-limiting time or a range between any two times, such as 10min, 15min, 20min, 25min, 30min, etc. In this case, no significant coating paste drips out from the bottom of the substrate after the drip, so that it is ensured that the channels of the substrate are not blocked by the excess coating paste.

In some embodiments, in the step S3-2, the wet material is purged with compressed air for 5S to 20S, and in the exemplary embodiment, the purging time may be a typical but non-limiting time or a range between any two times, such as 5S, 10S, 15S, 20S, etc. In some embodiments, the pressure of the compressed air is 0.2MPa to 0.8MPa, and in an exemplary embodiment, the pressure may be typically but not limited to 0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa, or the like, or a range between any two times. Under the condition, compressed air is adopted to purge wet materials, so that redundant slurry in the pore channels can be blown out, and the pore channels of the base material are prevented from being blocked; all holes are completely penetrated when the wet material is blown to the bottom, so that the slurry cannot form a liquid film at the bottom due to surface tension, thereby blocking the pore channels.

In some embodiments, in the step S3-2 described above, the drying process step includes: and naturally airing the purged wet material for 4-8 hours, and drying the wet material for 6-15 hours under a vacuum condition of 70-100 ℃ to obtain the solid amine honeycomb adsorbent. Under the condition, naturally airing the wet material for 4-8 hours until the surface of the wet material is free of redundant slurry and is not in an obvious wet state, so that the solid amine is tightly adhered to the base material; drying the wet material at 70-100 ℃ under vacuum, wherein the vacuum drying prevents the solid amine from being greatly oxidized at more than 100 ℃.

[ Solid amine honeycomb adsorbent ]

The second purpose of the embodiment of the application is to provide the solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent provided by the embodiment of the application, as shown in fig. 2, the loading amount of the solid amine raw powder in the solid amine honeycomb adsorbent is 70 kg/m-240 kg/m.

The solid amine honeycomb adsorbent provided by the embodiment of the application has the advantages of low pressure resistance, low energy consumption, low replacement rate and the like, and has high load strength and mechanical strength while maintaining the adsorption performance of the solid amine. In addition, the solid amine honeycomb adsorbent is not easy to fall off from the substrate during the use process, so that the adsorption performance is reduced.

In embodiments, the loading of the solid amine raw powder in the solid amine honeycomb sorbent may be, for example, a typical but non-limiting loading of 70kg/m³、100kg/m³、130kg/m³、160kg/m³、190kg/m³、210kg/m³、220kg/m³、230kg/m³、240kg/m³ or a range between any two loadings.

In some embodiments, the solid amine honeycomb adsorbent is shaped to fit different adsorbent device configurations, including cylindrical or facade bodies, and the dimensions vary with the size of the adsorbent device. In this case, the gas flow through the honeycomb adsorbent does not create significant pressure drag and is easy to handle in industrial production without stress cracking due to the large adsorbent.

In some embodiments, the solid amine honeycomb adsorbent comprises the following components in parts by weight:

10-20 parts of modified silica sol, 100-180 parts of solid amine slurry and 0.2-2 parts of auxiliary agent; in an exemplary embodiment, the modified silica sol may be typically but not limited to 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, etc., the solid amine slurry may be typically but not limited to 100 parts, 120 parts, 140 parts, 160 parts, 180 parts, etc., or any range between two parts, and the adjuvant may be typically but not limited to 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, etc., or any range between two parts. Under the weight part range of each component in the solid amine honeycomb adsorbent, the solid amine loading capacity of the solid amine honeycomb adsorbent is 70kg/m ³~240kg/m³, and the adsorption capacity of the solid amine honeycomb adsorbent to CO ₂ is 70 mg/g-120 mg/g.

[ Application of solid amine honeycomb adsorbent ]

The third purpose of the embodiment of the application is to provide the solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent provided by the embodiment of the application or the application of the solid amine honeycomb adsorbent provided by the embodiment of the application in the field of CO ₂ trapping.

In some embodiments, the gas adsorption separation purification and/or capture field comprising CO ₂ includes flue gas CO ₂ capture, VOCs purification, desulfurization and denitrification, and the like.

In some embodiments, solid amine honeycomb adsorbents can be used in a rotating wheel adsorption capture technology to achieve low energy consumption gas separation.

The following description is made with reference to specific embodiments.

The embodiment provides a preparation method of a solid amine honeycomb adsorbent, which comprises the following steps:

(1) Pretreatment of a substrate: taking a glass fiber honeycomb substrate (12 mm multiplied by 20 mm), roasting at 800 ℃ for 10 hours, and keeping the oxygen content at 5% to obtain a pretreated substrate.

(2) Preparing an alcohol solution of a silane coupling agent: 2 parts by weight of N-aminoethyl-3-aminopropyl triethoxysilane is taken and added into 10 parts of methanol, and the mixture is stirred for 30min at the normal temperature and the rotating speed of 280r/min, so as to obtain the fully dispersed N-aminoethyl-3-aminopropyl triethoxysilane solution.

(3) Preparing hydroxyl modified silica sol: obtaining 12 parts by weight of neutral silica sol and 12 parts by weight of N-aminoethyl-3-aminopropyl triethoxysilane solution, stirring the neutral silica sol containing 30% by mass of silicon dioxide at 800r/min, slowly pouring the N-aminoethyl-3-aminopropyl triethoxysilane solution, waiting for the addition, stirring the mixed solution for reaction for 6h at 60 ℃ under the oil bath and 400r/min rotating speed condition, and cooling at normal temperature to obtain the hydroxyl modified silica sol.

(4) Preparing an organic gel solution: 6 parts by weight of polyacrylate and 10 parts by weight of methanol are obtained; mixing polyacrylate and methanol, and stirring at a rotation speed of 280r/min for 30min at normal temperature to obtain fully dispersed polyacrylate solution.

(5) Preparing modified silica sol: 16 parts by weight of polyacrylate solution and 14 parts by weight of hydroxyl modified silica sol are obtained, and the polyacrylate solution and the hydroxyl modified silica sol are mixed and stirred for 6 hours at the speed of 400r/min at the temperature of 60 ℃ to obtain the modified silica sol.

(6) Preparing solid amine slurry:

① Preparing an anti-precipitation solution: 1.5 parts by weight of hydroxymethyl cellulose and 110 parts by weight of deionized water are obtained, the hydroxymethyl cellulose and the deionized water are mixed, and the mixture is stirred for 30min at a rotating speed of 800r/min after the mixture is mixed, so that a transparent anti-precipitation solution is obtained.

② Preparing solid amine slurry: 111.5 parts by weight of anti-precipitation solution and 50 parts by weight of tetraethylenepentamine are obtained and mixed to obtain a mixed solution, and then the mixed solution is stirred in an oil bath at 60 ℃ for 60min at a rotating speed of 1000r/min to obtain solid amine slurry.

(7) Preparing a coating slurry:

① The weight portions are as follows: 161.5 parts of solid amine slurry, 20 parts of modified silica sol, 0.8 part of Disperbyk-191 and 0.5 part of BYK-028 are mixed to obtain mixed slurry, and the mixed slurry is stirred and dispersed in an oil bath at 60 ℃ for 60min at a rotating speed of 1000r/min to obtain milky slurry;

② And adopting ethylenediamine to adjust the pH value of the milky white slurry to 10, and continuously stirring at the rotating speed of 1000r/min for 8 hours at normal temperature to obtain the coating slurry with the viscosity of 50 mPa.s.

(8) Preparation of solid amine honeycomb adsorbent:

① And (3) putting the pretreated substrate into coating slurry for first impregnation for 10min.

② Taking out the base material after the first impregnation, and airing for 4 hours under natural conditions.

③ And (3) continuously putting the dried base material into coating slurry, and repeating the steps of dipping and drying for 2 times, wherein the dipping time is 5min and the drying time is 4h. I.e. the pretreated substrate was impregnated a total of 3 times.

④ Taking out the repeatedly immersed base material (i.e. wet material), dripping for 30min under natural conditions, purging the base material with 0.5MPa compressed air, and continuing to air-dry under natural conditions for 8h after purging.

⑤ And drying the naturally dried wet material for 12 hours under the vacuum condition of 90 ℃ to obtain the solid amine honeycomb adsorbent.

The embodiment also provides a solid amine honeycomb adsorbent, which is prepared by adopting the preparation method of the solid amine honeycomb adsorbent, wherein the load of solid amine raw powder is 154.6 kg/m;

The solid amine honeycomb adsorbent was 12mm by 20mm in size.

The embodiment provides a preparation method of a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, which comprises the following steps of: the parts of the solid amine raw powder in the step (6) are 40 parts.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: the part of the solid amine raw powder in the step (6) is 60 parts.

The embodiment provides a preparation method of a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, which comprises the following steps of: in the impregnation step, the number of impregnation was 2.

The embodiment provides a preparation method of a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, which comprises the following steps of: in the dipping step, the number of dipping times was 8.

The embodiment provides a preparation method of a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, which comprises the following steps of: the weight portion of the neutral silica sol is 20 portions.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: the weight portion of the neutral silica sol is 10 portions.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: the weight part of the N-aminoethyl-3-aminopropyl triethoxysilane (aminosilane coupling agent) is 1 part.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: the weight part of N-aminoethyl-3-aminopropyl triethoxysilane (aminosilane coupling agent) is 5 parts.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: the weight portion of polyacrylate (organic glue) is 1 portion.

The present example provides a method for preparing a solid amine honeycomb adsorbent, comprising the steps substantially identical to those of example 1, except that: 10 parts of polyacrylate (organic gel).

Comparative example 1

This comparative example provides 50 parts by weight of solid amine raw powder of tetraethylenepentamine as CO ₂ adsorbent.

Comparative example 2

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: step (1) of pre-treating the substrate is not included.

Comparative example 3

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: at point ⑤ in step (8), the wet material is dried without vacuum.

Comparative example 4

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: at point ④ in step (8), the substrate is not purged after impregnation.

Comparative example 5

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight part of tetraethylenepentamine (solid amine raw powder) is 30 parts.

Comparative example 6

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight part of tetraethylenepentamine (solid amine raw powder) is 100 parts.

Comparative example 7

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight portion of the neutral silica sol is 30 portions.

Comparative example 8

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight portion of the neutral silica sol is 5 portions.

Comparative example 9

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight part of the N-aminoethyl-3-aminopropyl triethoxysilane (aminosilane coupling agent) is 10 parts.

Comparative example 10

This comparative example proposes a method for preparing a solid amine honeycomb adsorbent and the solid amine honeycomb adsorbent prepared by the same, comprising the steps substantially identical to those of example 1, except that: the weight portion of polyacrylate is 12 portions.

Comparative example 11

The comparative example provides a spherical solid amine CO ₂ adsorbing material, which is formed by taking polyethyleneimine as a matrix and then crosslinking and curing the polyethyleneimine with a crosslinking agent, wherein the matrix comprises a thermosensitive group introduced by Michael addition; the particle diameter D50 of the spherical solid amine CO ₂ adsorption material is 2-5 mu m, and the swelling ratio is 110-270%; the provision of a temperature sensitive group includes N-isopropylacrylamide; the cross-linking agent comprises ethylene glycol diglycidyl ether; the molecular weight of the polyethyleneimine was 70000.

In order to verify the advancement of the embodiment of the present application, the following verification tests are performed on the solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent provided in the above embodiments 1 to 11, the solid amine raw powder provided in the comparative embodiment 1, the solid amine honeycomb adsorbent provided in the comparative embodiment 2 to 10, and the spherical solid amine CO ₂ adsorbent provided in the comparative embodiment 11, respectively, and the following verification tests are performed, including the following steps:

1: and taking out the adsorbent after drying to observe whether the bottom is blocked, cutting off 0.5cm when the bottom is blocked, and judging whether the bottom is not blocked, if so, continuing cutting off the adsorbent at 0.5cm increments until the bottom is not blocked.

2: The monolithic adsorbent cut-out pieces prepared in the examples were subjected to carbon dioxide adsorption isotherm characterization tests using a BET machine (machine autosorb iQ) on all the adsorbents of the examples and comparative examples. The adsorption isotherm of CO ₂ at 90 ℃ was measured by a static adsorption method, and all samples were vacuum degassed at 100 ℃ for 8 hours before adsorption to demonstrate the adsorption capacity, wherein the mass of the adsorbent was converted to the mass of pure solid amine.

3: The adsorbents of examples and comparative examples were placed in a CO ₂ dynamic adsorption platform for CO ₂ adsorption evaluation, and the adsorbents were activated with nitrogen (1L/min) at 120℃for 30 min before adsorption. After the activation, cooling to the adsorption temperature of 90 ℃ below zero, and switching to raw material gas, wherein the concentration of CO ₂ in the raw material gas is 40% (volume fraction), the rest is N ₂, and the flow rate of the raw material gas is 100ml/min; and (3) introducing the adsorbed tail gas taking part into an analyzer to detect the concentration of CO ₂, and exhausting the residual part after the residual part is fed into a tail gas treatment device, wherein the concentration of the tail gas CO ₂ is recovered to the initial concentration and is stable, so that the adsorption penetration can be considered.

4: The pressure sensor is used for detecting the pressure difference before and after the adsorbent in the CO ₂ dynamic adsorption test process to test the piezoresistance of the adsorbent, and the gas flow rate is 0.01m/s according to the gas flow rate and the sectional area of the adsorption column.

5: The section of the adsorbent in the example was taken, the mass at this time was recorded, the white paper was laid on the bottom, the honeycomb adsorbent was allowed to freely fall at a distance of 40cm from the white paper, and then weighing was performed and whether or not powder remained on the white paper was observed.

6: The adsorbent of example 1 was placed in a direct air trap stage for adsorption evaluation, and the adsorbent was activated with nitrogen (1L/min) at 120℃for 30min before adsorption. After the activation is finished, nitrogen is used for blowing and cooling to the adsorption temperature of 25 ℃ below zero, and then the air is switched into air, wherein the air inlet flow is 40L/min; introducing the adsorbed tail gas extraction part into an analyzer to detect the concentration of CO ₂, introducing the rest part into a tail gas treatment device, then evacuating, and after the concentration of the tail gas CO ₂ is recovered to the initial concentration and stabilized, considering adsorption penetration; and heating the adsorbent subjected to adsorption saturation to 120 ℃ for desorption, collecting desorbed gas to an air bag by using a vacuum pump, and introducing the gas to a CO ₂ gas analyzer for analysis.

For comparison, the parameters of the changes of examples 1 to 11 and comparative examples 1 to 11 are listed to form the following table 1. The solid amine honeycomb adsorbents prepared by the preparation methods of the solid amine honeycomb adsorbents provided by examples 1-11 and the solid amine raw powder provided by comparative example 1, the solid amine honeycomb adsorbents provided by comparative examples 2-14, the spherical solid amine CO ₂ adsorbent provided by comparative example 15 are shown in the following table 2 for the unit equilibrium adsorption amount, the total equilibrium adsorption amount, the load, the piezoresistance, the powder dropping condition, the adsorbent pore blocking condition and the like of CO ₂. The adsorption isotherms of the solid amine honeycomb adsorbent prepared by the preparation method of examples 1-11, the solid amine raw powder provided in comparative example 1, and the CO ₂ adsorption of the solid amine particle adsorbent prepared by comparative examples 2-11 are shown in FIG. 3. The solid amine honeycomb adsorbent obtained in example 1 was used to directly capture carbon dioxide in air from the above test step 6, and the breakthrough adsorption curve of CO ₂ was shown in fig. 4.

TABLE 1

TABLE 2

Note that: in tables 1 and 2, "-" indicates that the physical quantity content is the same as in example 1; "\" indicates that the physical quantity is not present.

As can be seen from table 2, fig. 3 and 4, above:

(1) The adsorption capacity of the solid amine honeycomb adsorbent in example 1 and comparative example 1 for CO ₂ is not greatly different from that of the solid amine raw powder, which indicates that the solid amine honeycomb adsorbent prepared by the preparation method of the embodiment of the application does not excessively reduce the adsorption capacity of CO ₂.

(2) The piezoresistance of the solid amine honeycomb adsorbents in example 1 and comparative example 11 is much lower than that of the solid amine raw powder and the spherical adsorbent, which indicates that the solid amine honeycomb adsorbent prepared by the preparation method of the embodiment of the application has lower piezoresistance.

(3) As can be seen from comparison of example 1 and comparative example 2, most of the organic matters in the pretreated substrate volatilize to generate a large number of macroscopic holes, which is favorable for loading the solid amine honeycomb adsorbent, and the loading of the pretreated substrate is larger than that of the substrate which is not pretreated, and finally, the advantages of the pretreated substrate on the total adsorption amount are reflected.

(4) As can be seen from a comparison of example 1 and comparative example 3, the solid amine honeycomb adsorbents of the present invention must be oxygen-insulated at high temperatures, otherwise the adsorbents would be oxidized and deactivated, resulting in a dramatic decrease in the unit adsorption.

(5) As can be seen from a comparison of example 1 and comparative example 4, the lack of purging after impregnation resulted in a portion of the excess slurry accumulating at the bottom of the solid amine honeycomb adsorbent due to surface tension, resulting in deeper plugging, and increased cost for industrial applications.

(6) As can be seen from the comparison of examples 1 to 11 and comparative examples 5 to 6, reducing the fraction of solid amine resulted in a reduction in the amount of solid amine supported, and although the unit adsorption amount of the solid amine honeycomb adsorbent was not greatly affected, the reduction in the amount of supported resulted in a substantial reduction in the total adsorption amount. However, even if the amount of solid amine powder is excessively increased, the solid amine in the solid amine powder cannot be contacted with CO ₂, a large amount of solid amine honeycomb adsorbent is not fully utilized, the unit adsorption amount is reduced, the viscosity of slurry is rapidly increased due to the excessive increase of the solid amine powder, the wall thickness of a pore canal is increased, the piezoresistance is increased, the hole blocking depth is greatly increased, the load strength is greatly reduced due to the mismatching of the parts of the solid amine and the parts of the binder, and the powder dropping rate is increased.

(7) As can be seen from the comparison of examples 1-11 and comparative examples 7-8, an excessive increase in the amount of silica sol, even though increasing the loading, can also cause the blocking of a large amount of solid amine powder by the sol, resulting in a decrease in the unit adsorption amount, and an excessive increase in the silica sol can cause an increase in the viscosity of the slurry, resulting in an increase in the wall thickness of the pore canal, resulting in an increase in the piezoresistance and a large increase in the blocking depth. The reduction of the silica sol dosage can lead to the reduction of the load capacity, and because the phenomenon of increasing the powder dropping rate is not enough in the bonding capacity, a part of silica sol is not enough crosslinked with the silica sol after the hydrolysis of the silane, so that a small part of the silane is hydrolyzed to form paste, the viscosity of the slurry is increased, the unit adsorption capacity is reduced due to the blocking of the pore canal of a part of solid amine powder, the problem of increasing the blocking depth is also caused due to the overlarge viscosity, the silica sol content is further reduced, so that most of the aminosilane coupling agent is not enough crosslinked with the silica sol after the hydrolysis, the slurry is hard settled, and the result of incapability of coating is caused.

(8) As is clear from the comparison between examples 1 to 11 and comparative example 9, reducing the amount of the aminosilane coupling agent resulted in that a part of the silica sol and the organic compound could not form a crosslink with the aminosilane coupling agent, a sufficient three-dimensional network could not be formed, the load was reduced, and the powder dropping rate was increased. The increase of the dosage of the aminosilane coupling agent can lead to severe silane hydrolysis, a part of silane is hydrolyzed and then is not crosslinked with enough silica sol and organic glue, so that paste is formed after the part of silane is hydrolyzed or slurry is solidified, the viscosity of the slurry is increased and cannot be coated, the pore canal of a part of solid amine powder is blocked to cause the reduction of unit adsorption quantity, the problem of the increase of the blocking depth due to the overlarge viscosity is solved, the coating of the solid amine on a substrate is uneven, and the problem of piezoresistance increase is solved.

(9) As can be seen from the comparison between examples 1 to 11 and comparative example 10, the reduction of the amount of the organic adhesive resulted in a reduction of the load, and the increase of the powder falling rate occurred due to insufficient adhesive ability. The increase of the organic gel can lead to the increase of the load, but excessive organic gel can block a part of pore canals of the solid amine powder, so that the unit adsorption quantity is reduced, and excessive organic gel can lead to the increase of the viscosity of the slurry, and finally, the piezoresistance and the pore blocking depth of the solid amine honeycomb adsorbent are all increased.

(10) As can be seen from the direct air trapping experiment of example 1 and fig. 4, the solid amine honeycomb adsorbent prepared by the present invention can be used for direct air trapping, and can maintain a long adsorption time, and the penetration starts after 170 min; the concentration of CO ₂ can reach 95% and the recovery rate of CO ₂ is 93% by analyzing the gas table after desorption, namely the invention can be used for direct air trapping, has larger adsorption capacity, and can carry out desorption at lower temperature, so that the concentration and recovery rate of enriched gas reach' double 90%.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. The preparation method of the solid amine honeycomb adsorbent is characterized by comprising the following steps of:

Preparing a modified silica sol by adopting raw materials comprising an aminosilane coupling agent, an organic gel and the silica sol, wherein the step of preparing the modified silica sol comprises the following steps: carrying out a first mixing reaction on an aminosilane coupling agent solution and silica sol to obtain hydroxyl modified silica sol; carrying out a second mixing reaction on the hydroxyl modified silica sol and the organic gel solution to obtain the modified silica sol;

The preparation method of the aminosilane coupling agent solution comprises the following steps: mixing an aminosilane coupling agent and a first solvent, and stirring at normal temperature at a rotating speed of 200-280 r/min for 10-30 min to obtain a fully dispersed aminosilane solution;

the first solvent comprises: at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, dichloromethane, chloroform, toluene;

2. The method for preparing a solid amine honeycomb adsorbent according to claim 1, wherein in the loading treatment step, a pH regulator is used to regulate the pH value of the coating slurry to 8-14;

And/or, in the loading treatment step, the substrate is repeatedly subjected to post-dipping drying treatment in the coating slurry.

3. The method for preparing the solid amine honeycomb adsorbent according to claim 2, wherein the aminosilane coupling agent solution is 6-15 parts by weight;

and/or the weight part of the silica sol is 10-20 parts.

4. The method of preparing a solid amine honeycomb adsorbent of claim 1 wherein the silica sol is a neutral silica sol.

5. The method for preparing a solid amine honeycomb adsorbent according to claim 2, wherein the number of times of drying treatment after impregnation is 2 to 10.

6. The preparation method of the solid amine honeycomb adsorbent according to claim 1, wherein the mass ratio of the aminosilane coupling agent, the organic gum and the silica sol in the modified silica sol is (1-5): (1-10): (10-20);

and/or the solid amine slurry comprises the following components in parts by weight: 1-2 parts of anti-settling agent, 90-120 parts of water and 40-60 parts of solid amine raw powder;

And/or, the coating slurry comprises 10-20 parts by weight of modified silica sol, 100-180 parts by weight of solid amine slurry and 0.2-2 parts by weight of auxiliary agent;

And/or the solid-to-liquid ratio of the substrate and the coating slurry is (10 g-20 g): (300-600 ml).

7. The method for preparing a solid amine honeycomb adsorbent according to any one of claims 1 to 6, wherein the organic gel comprises at least one of polyvinyl alcohol, polyurethane, polyacrylate, cyanoacrylate, silicone, phenolic resin, polyvinyl acetate, polyamide, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polystyrene, polyethylene terephthalate, polylactic acid, and polyetheretherketone.

8. The solid amine honeycomb adsorbent prepared by the preparation method of the solid amine honeycomb adsorbent according to any one of claims 1 to 7, wherein the loading amount of solid amine raw powder in the solid amine honeycomb adsorbent is 70kg/m to 240 kg/m.

9. The solid amine honeycomb adsorbent of claim 8, wherein the solid amine honeycomb adsorbent comprises, in parts by weight:

10-20 parts of modified silica sol, 131-182 parts of solid amine slurry and 0.2-2 parts of auxiliary agent.

10. Use of a solid amine honeycomb adsorbent according to any one of claims 8 to 9 in the field of gas adsorption separation purification and/or capture comprising CO ₂.