Block composite material for gas accumulation and method of manufacturing the same

Abstract

The present invention group relates to a method for manufacturing a block composite material for gas accumulation containing an organometallic coordination polymer and a carbon material having an increased injection density and a bimodal injection distribution efficient for gas storage. The proposed method comprises mixing an initial component, an organometallic coordination polymer, a carbon-containing material (microporous carbon adsorbent, carbon nanotube, graphene, graphitized black), and a binder solution such as polyvinyl alcohol, a chitosan solution in acetic acid, or oxyethylcellulose, molding the prepared mixture into a block under pressure, and drying and activating the block. The proposed block composite material enables increased efficiency and reliability of a composite gas mixture accumulation system when operating over a wide range of temperatures and pressures due to the availability of at least two pore modes, each of which can accumulate gas with maximum efficiency at specific thermodynamic parameters, namely temperature and pressure.

Description

Technology Field

[0001] The present invention group relates to the storage of gas, the storage and separation of complex gas mixtures, and a method for manufacturing materials for the storage and separation of gas. Background Technology

[0002] Up to 10,000 m 2 Due to their large surface area of ​​g / g, organometallic coordination polymers (OMCPs) may be in high demand for use in gas storage or separation. However, synthesized OMCPs are typically crystalline powders with crystal sizes ranging from nanometers to hundreds of micrometers. Using powdered adsorbents under dynamic conditions is disadvantageous due to pressure differences occurring as gases pass through layers, dust generation, wear, flow transfer, and difficulties in transportation and machining. For efficient use, synthesized OMCPs are molded into dense forms such as granules, spheres, and tablets. Furthermore, OMCPs in their pure form are mechanically and thermally unstable due to machining, shocks from adsorption-desorption cycles, and thermal effects during the adsorption process. Therefore, OMCP-based composite materials are more efficient in gas storage and separation systems.

[0003] The known invention disclosed on June 21, 2016, of US 9370771 B2, IPC B01D53 / 04; B01J31 / 16; C10L3 / 10; B01D53 / 02; B01J20 / 02; B01J20 / 22; B01J20 / 28; B01J20 / 30, provides a method for manufacturing an aluminum-based molded OMCP block obtained by solvothermal synthesis using a solvent, water (mixed with at least one additional substance), and a binder, and by extruding the obtained composition into a molded OMCP block. Analysis of the embodiments of the invention shows that the specific surface area of ​​the obtained material averages 1,000 m² 2 It shows that / g, which demonstrates a reduction in its specific surface area in relation to known data for aluminum-based OMCP.

[0004] The invention of US 9757710 B1, IPC B01J20 / 22; B01J20 / 28; B01J20 / 30; C01B3 / 00; C10L3 / 06, disclosed on September 12, 2017, provides a method for compressing OMCP powder, wherein OMCP synthesized during the application of a first solvent is filled with a solvent capable of replacing at least 10% of the first solvent in the void volume, the OMCP is then compressed and dried until the solvent is removed. The authors note that the OMCP blocks retain at least 80%-90% of the specific surface area, and the density of the blocks is less than 60% of the theoretical density of the crystal structure of the OMCP packed into blocks according to the synthesis and compression conditions. The disadvantages of the invention are a narrow range of pore characteristics and ambiguity regarding the OMCP service conditions.

[0005] The closest prior art of the claimed OMCP-based material provides a method for manufacturing a spherical molded body comprising: a composition containing an organometallic composite polymer and at least one liquid; at least one additive containing a binder selected from the group consisting of inorganic oxides, aluminum oxide, clay, bentonite, and concrete; and a mixture of additives containing an expansive agent selected from the group consisting of organic polymers, e.g., methylcellulose and polyethylene oxide, or mixtures thereof (WO 2014118054 A1 IPC B01J2 / 06; B01J2 / 14; B01J20 / 22; B01J20 / 28; B01J20 / 30 disclosed on August 7, 2014).

[0006] This approach enables the production of OMCP and composite materials containing spherical OMCP granules with increased pour density. The use of an expanding agent during OMCP compression allows for the grading of the porous structure degradation caused by machining (pressurization, extrusion) and the filling of pores into the binder due to the additional porosity generated by the expanding agent. The disadvantage of this method is the reduction in the specific surface area of ​​the pores and, consequently, the reduction in gas accumulation efficiency, which is attributed to the fact that the pores formed by the expanding agent are macropores and mesopores, meaning they are insufficient for the adsorption and storage of complex gas mixtures.

[0007] The closest equivalent to the claimed gas mixture storage method recommended for use in storage systems for gas mixtures, particularly natural gas and methane, is RU 2650012, IPC F17C 11 / 00 (2006.01); B82B 1 / 00 ​​(2006.01), published on April 6, 2018, wherein a nanoporous material having an average effective pore width of 0.6 to 1.2 nm is used during the operation of an accumulator vessel at an operating pressure of 3.5 MPa and a temperature of plus 10°C to plus 30°C. A nanoporous material having an average effective pore width of 0.5 to 1.0 nm is used during the operation of an accumulator vessel at an operating pressure of 7 MPa and the same temperature. When operating an accumulator vessel in a low temperature range of minus 30°C to minus 10°C, efficient accumulation can be achieved if an adsorbent having wider pores of 0.9 to 2 nm is used. As a result, the volume (W0) of the adsorbent pores in the accumulation system will be maximized. A disadvantage of this known method is that the storage efficiency of the complex gas mixture is low because each of the proposed materials has a small operating range of efficient process parameters (temperature and pressure).

[0008] To address the problem of efficient gas storage and the maximum complete accumulation of different components of complex gases, the creation of composite materials based on adsorbents having a bimodal pore distribution is provided. Such composite materials can be used, for example, in the case of natural gas adsorption, where the smaller mode will mainly accumulate methane and the larger mode will accumulate heavier hydrocarbons. The modes correspond to the effective inner diameter (nm) of the micropores. However, it is difficult to achieve a bimodal pore distribution in a manner where the two modes have an effective inner diameter of less than 2.0 nm and their pore volumes are relatively equal. Composite materials based on OMCP and carbon adsorbents can solve this problem, and at specific ratios of the components and parameters of the porous structure, they can ensure the optimal adsorption rate and mechanical properties required for use in gas storage and separation systems.

[0009] Accordingly, the objective of the present invention group is to obtain a mechanically strong composite material having a pore size efficient for the accumulation of gases and mixtures, which has an internal surface developed to flexibly adapt to changes in the phase composition and other properties of the composite gas mixture when operating over a wide range of temperatures and pressures.

[0010] The technical results to be achieved by the present invention group are as follows:

[0011] - Increasing the injection density of block composite materials by molding that preserves the developed internal surface enables increasing the specific volume of gas accumulation in units of storage system volume, thereby ensuring the design possibility of a denser gas storage system;

[0012] - To ensure the industrial applicability of OMCP under steamed aerodynamic load conditions, the hardness of the obtained block composite material is increased by optimizing the composition formulation and its mixing technology;

[0013] - Reduces gas loss from temperature and pressure disturbances in gas storage systems through the bimodal pore size distribution of block composite materials.

[0014] The above technical result is achieved by the following facts, namely, a method for manufacturing a block composite material for gas accumulation comprising mixing components with a binder, forming the obtained mixture into a block, and subsequently drying the same; using as components an organometallic coordination polymer and a nanoporous carbon adsorbent or an adsorbent based on carbon nanotubes mixed in a ratio of 30 / 70 to 95 / 5 weight%; the effective inner diameters of the micropores of the mixed components differ from each other by at least 0.4 nm and at most 0.8 nm; using a 2-15% aqueous solution of a compound such as polyvinyl alcohol, a chitosan solution in acetic acid, or oxyethylcellulose as a binder; forming the obtained mixture into a block under pressure with a loading force of 25 to 75 kN within 1-2 minutes; placing the block into a drying chamber under normal conditions; This is achieved by a manufacturing method in which the temperature is then increased to 110°C-120°C at a rate of up to 60°C / hour and dried for a minimum of 12 hours and a maximum of 36 hours; subsequently, the block is activated in a thermal vacuum chamber at a temperature of 120°C for a minimum of 6 hours at a residual pressure of 0.26 kPa.

[0015] The above technical result is achieved by the following fact, namely, a block composite material for gas accumulation comprising an organometallic coordination polymer in a ratio of 30 / 70 to 95 / 5 weight% each, a nanoporous carbon adsorbent or an adsorbent based on carbon nanotubes, and a binder comprising a 2-15% aqueous solution of a compound such as polyvinyl alcohol, a chitosan solution in acetic acid, or oxyethylcellulose, wherein the pour density of the block composite material is 0.540 to 1.220 g / cm³ 3This is achieved by a block composite material for gas accumulation, characterized in that the nanoporous structure is bimodal, the effective inner diameter of the micropores is similar to the initial component and differs from each other by at least 0.4 nm and at most 0.8 nm, and the material is used at a temperature of minus 30°C to plus 60°C and a pressure of up to 10 MPa.

[0016] T1, T6, and CNT microporous carbon adsorbents were used as the carbon components of the composite material. T1 and T6 were obtained from peat by mixing peat with potassium sulfide, followed by granulation and carbonization using exhaust gas or pyrolysis gas, then performing an activation process at a temperature of 800°C, and milling to a crushing size of >0.2 mm. The microporous-mesoporous CNT carbon adsorbent containing carbon nanotubes was manufactured by "NanoTechCenter" Ltd. (Tambov) under the commercial name MPU-007. The porous structure parameters of the specified carbon components are presented in Table 1.

[0017] A diluted (2%-5%) solution of PVAL, chitosan, and oxycellulose was used as a composite material binder to ensure minimal inhibition of block composite material micropores by the binder while providing its acceptable strength.

[0018] The essence of the present invention group is explained by the detailed description of specific exemplary embodiments and the accompanying drawings and tables, but these do not limit the present invention group.

[0019] Table 1 - Parameters of the porous structure of carbon materials used for molding composite adsorbents, where S BET = Specific surface area according to the BET method (m 2 / g); W0 = specific micropore volume (cm²) 3 / g); D = Effective inner diameter of micropores (nm); a0 = Adsorption limit value in micropores (mmol / g); E0 = Nitrogen adsorption characteristic energy (kJ / mol); E = Benzene adsorption characteristic energy (kJ / mol); W s = Summarized pore volume (cm²) 3 / g); W me = Mesopore volume (cm²) 3 / g); S me = Mesopore area (m 2 / g).

[0020] Table 2 - Characteristics of composite materials based on OMCP and carbon adsorbents molded using a binder, where S BET = Specific surface area according to the BET method (m 2 / g); W0 = specific volume of micropores (cm³) 3 / g); P = Molding pressure (kN); t = Molding time (min); ρ = Injection density (g / cm³) 3 W0 = specific volume of micropores (cm²) 3 / g); D = Effective inner diameter of micropores (nm); HA = Hardness (Shore) (ShA); HB = Hardness (Brinell) (kg / mm²) 2 ). Brief explanation of the drawing

[0021] Fig. 1: Photographic image of F-18 block composite material; Fig. 2: Specific amount of methane that can be accumulated by the F-18 block composite material at the following temperature (°C): 1 = minus 30; 2 = 0; 3 = plus 20; 4 = plus 40, and 5 = plus 60; Fig. 3: Bimodal micropore size distribution of samples of F-18 and F-63 composite materials (Table 2), determined by the NLDFT method according to the isotherm of standard nitrogen vapor at 77 K, where d 11 , 12 , d 21 , 22= Mode sizes of the F-18 and F-63, respectively; Fig. 4: Photographic image of F-41 block composite material; Fig. 5: Specific amounts of a) methane, b) CO2 accumulated by the F-41 block composite material at the following temperatures (°C): 1 = minus 30; 2 = 0; 3 = plus 20; 4 = plus 40, and 5 = plus 60; Fig. 6: Photographic image of F-27 block composite material; Fig. 7 - Specific amount of methane that can be accumulated by the F-27 block composite material at the following temperature (°C): 1 = minus 30; 2 = 0; 3 = plus 20; 4 = plus 40, and 5 = plus 60; Fig. 8: Adsorption of a mixture of methane and n-propane at 95% / 5% volume concentrations on composite materials: a) F-27; b) F-41 at plus 20°C and plus 60°C. Specific details for implementing the invention

[0022] The essence of the present invention group is explained by the following parameters:

[0023] Example 1

[0024] A CuBTC organometallic coordination polymer with an effective micropore inner diameter of 0.68 nm was mixed with a T6 nanoporous carbon adsorbent with an effective micropore inner diameter of 1.34 nm in a 30 / 70 wt% ratio, a 5% aqueous solution of polyvinyl alcohol as a binder was added, and after homogenization, the mixture was molded under pressure with a loading force of 50 kN within 1 minute. The block of the obtained composite material was placed in a drying chamber at room temperature, the temperature was increased to plus 120°C at a rate of up to 60°C / hour and maintained for up to 36 hours, and then activated in a thermal vacuum chamber at a temperature of 120°C for up to 6 hours at a residual pressure of up to 0.26 kPa.

[0025] The obtained F-18 block composite material (Fig. 1) has a bimodal porous structure of the initial mixture components and 0.65 g / cm³ 3 It has an injection density. Thermal vacuum activation enables the preservation of the characteristics of the initial composite component's inherent porous bimodal structure in the most prudent manner and the cleaning of the material's inner surface for its intended subsequent use as an accumulator of gas mixtures. The amount of methane accumulated by this adsorbent within a temperature range of minus 30°C to plus 60°C at a pressure of up to 10 MPa is shown in Fig. 2; the characteristics of the carbon component used are presented in Table 1; and the characteristics of the OMCP and the obtained F-18 composite material are presented in Table 2.

[0026] Example 2

[0027] An AlBTC organometallic coordination polymer with an effective micropore inner diameter of 1.74 nm was mixed with a T6 nanoporous carbon adsorbent with an effective micropore inner diameter of 1.34 nm in a 50 / 50 wt% ratio, a 5% aqueous solution of polyvinyl alcohol as a binder was added, and after homogenization, the mixture was molded under pressure with a loading force of 75 kN within 2 minutes. The block of the obtained composite material was placed in a drying chamber at room temperature, the temperature was increased to plus 110°C at a rate of up to 60°C / hour and maintained for up to 24 hours, and then activated in a thermal vacuum chamber at a temperature of 110°C for up to 8 hours at a residual pressure of up to 0.26 kPa.

[0028] The obtained F-41 block composite material (Fig. 4) has a bimodal porous structure of the initial mixture components, and its injection density is 0.65 g / cm³ 3 The amount of methane accumulated by this adsorbent in the temperature range of minus 40°C to plus 50°C at a pressure of up to 10 MPa is shown in FIG. 4; the characteristics of the carbon component used are presented in Table 1; and the characteristics of the OMCP and the obtained F-41 composite material are presented in Table 2.

[0029] Example 3

[0030] A CuBTC organometallic coordination polymer with an effective micropore inner diameter of 0.68 nm was mixed with a CNT nanoporous carbon adsorbent with an effective micropore inner diameter of 1.48 nm in a 90 / 10 wt% ratio, a 5% aqueous solution of polyvinyl alcohol as a binder was added, and after homogenization, the mixture was molded under pressure with a loading force of 75 kN within 1 minute. The block of the obtained composite material was placed in a drying chamber at room temperature, the temperature was increased to plus 120°C at a rate of up to 60°C / hour, and it was dried within 36 hours, and then activated in a thermal vacuum chamber at a temperature of 120°C within 10 hours at a residual pressure of up to 0.26 kPa.

[0031] The obtained F-27 block composite material (a photographic image of which is shown in Fig. 6) has a bimodal porous structure of the initial mixture components. Its injection density is 0.77 g / cm³. 3 The amount of methane that can be accumulated by this adsorbent within a temperature range of minus 40°C to plus 50°C at a pressure of up to 10 MPa is shown in FIG. 6; the characteristics of the carbon component used are presented in Table 1; and the characteristics of the OMCP and the obtained F-27 composite material are presented in Table 2.

[0032] Example 4

[0033] It differs from Example 1 in that a 2% aqueous solution of chitosan was added to the adsorbent mixture. The obtained block composite material has the same adsorption characteristics as one of the materials in Example 1. Its injection density is 0.760 g / cm³. 3 The characteristics of the carbon components used are presented in Table 1; and the characteristics of the OMCP and the obtained F-111 composite material are presented in Table 2.

[0034] Example 5

[0035] It differs from Example 1 in that a 2% solution of oxycellulose was added to the adsorbent mixture and molded with a loading force of 75 kN. The obtained block composite material has the same adsorption characteristics as one of the materials in Example 1. Its injection density is 1.200 g / cm³. 3 The characteristics of the carbon components used are presented in Table 1; and the characteristics of the OMCP and the obtained F-116 composite material are presented in Table 2.

[0036] The composite materials obtained by the present invention group have a bimodal porous structure having micropores and mesopores, and by press-forming them into dense blocks having strength that enables them to be used as accumulators for gases and gas mixtures, e.g., methane, nitrogen, carbon dioxide, natural gas, and related petroleum gas, the claimed technical results can be achieved. The bimodal pore distribution facilitates the rapid adaptation of gas storage to changes in the phase composition of the complex gas mixture caused by process operation or changes in climatic conditions, as different pore modes are used in this case. As a result, gas loss due to discharge from safety valves is reduced. Increasing the injection density of the block composite material makes it possible to increase the specific volume of gas accumulation per unit of storage system volume, thereby enabling the design and construction of a denser storage system for the complex gas mixture.

[0037]

[0038]

[0039]

Claims

Claim 1 A method for manufacturing a block composite material for gas accumulation, comprising mixing components with a binder, forming the obtained mixture into a block, and subsequently drying the mixture, wherein an organometallic coordination polymer and a nanoporous carbon adsorbent or an adsorbent based on carbon nanotubes are used as components, mixed in a ratio of 30 / 70 to 95 / 5 weight%; the effective inner diameters of the micropores of the mixed components differ from each other by at least 0.4 nm and at most 0.8 nm; and a 2-15% aqueous solution of a compound selected from the group consisting of polyvinyl alcohol, a chitosan solution in acetic acid, and oxyethylcellulose is used as a binder; forming the obtained mixture into a block under pressure with a loading force of 25 to 75 kN within 1-2 minutes; and placing the block into a drying chamber under normal conditions. A method for manufacturing a block composite material for gas accumulation, characterized by: then increasing the temperature to 110°C-120°C at a rate of up to 60°C / hour and drying for a minimum of 12 hours and a maximum of 36 hours; and subsequently activating the block in a thermal vacuum chamber at a temperature of 120°C for a minimum of 6 hours at a residual pressure of 0.26 kPa. Claim 2 A block composite material for gas accumulation comprising a binder comprising an organometallic coordination polymer in a ratio of 30 / 70 to 95 / 5 weight% each, a nanoporous carbon adsorbent or an adsorbent based on carbon nanotubes, and a 2-15% aqueous solution of a compound selected from the group consisting of polyvinyl alcohol, a chitosan solution in acetic acid, and oxyethylcellulose, wherein the pour density of the block composite material is 0.540 to 1.220 g / cm³ 3 A block composite material for gas accumulation, characterized in that the nanoporous structure is bimodal, the effective inner diameter of the micropores is similar to the initial component and differs from each other by at least 0.4 nm and at most 0.8 nm, and the material is used at a temperature of minus 30°C to plus 60°C and a pressure of up to 10 MPa.

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