Gas storage block composite material and method for producing the same

Abstract

The present invention relates to a method for preparing a block composite material for gas storage containing an organometallic coordination polymer and a carbon material, which has a high bulk density and a bimodal pore distribution that is efficient for gas storage. The proposed method includes mixing an organometallic coordination polymer, a carbon-containing material (microporous carbon adsorbent, carbon nanotubes, graphene, black graphite), a binder solution such as polyvinyl alcohol, chitosan in acetic acid, and oxyethyl cellulose as initial components, forming the prepared mixture into a block under pressure, and drying and activating the block. The proposed block composite material can improve the efficiency and reliability of storage systems for complex gas mixtures when operating over a wide range of temperatures and pressures, since at least two pore modes are available, each of which can store gas with maximum efficiency at specific thermodynamic parameters: temperature and pressure.

Description

Technical Field

[0001] This group of inventions relates to the fields of gas storage, storage and separation of composite gas mixtures, and methods for manufacturing materials for gas storage and separation.

Background Art

[0002] Up to 10,000 m 2 / g due to their large surface area, organometallic coordination polymers (OMCPs) may be in high demand for use in gas storage or separation. However, synthesized OMCPs are generally crystalline powders with crystal sizes ranging from nanometers to hundreds of micrometers. The use of powdered adsorbents under dynamic conditions is disadvantageous due to the generation of pressure differences as the gas passes through the bed, dust generation, abrasion, carry-over by flow, and difficulties in transportation and processing. Synthesized OMCPs are shaped into compact forms such as granules, spheres, tablets, etc. to be used efficiently. Furthermore, OMCPs in their pure form are mechanically and thermally unstable due to machining, the effects of adsorption / desorption cycles, and the thermal effects of the adsorption process. Therefore, OMCP-based composite materials are more efficient in gas storage and separation systems.

[0003] U.S. Patent No. 9,370,771 (B2), issued on June 21, 2016, with IPC B01D53 / 04, B01J31 / 16, C10L3 / 10, B01D53 / 02, B01J20 / 02, B01J20 / 22, B01J20 / 28, B01J20 / 30, a known invention provides a method for preparing an aluminum-based shaped OMCP block obtained by solvothermal synthesis using a solvent, water, mixing with at least one additional substance, a binder, and extruding the resulting composition into a shaped OMCP block. Analysis of the examples of this invention shows that the specific surface area of the obtained material is on average 1,000 m 2 / g, which proves a decrease in its specific surface area compared to known data for aluminum-based OMCPs.

[0004] The invention described in U.S. Patent No. 9,757,710 (B1) issued on September 12, 2017, with IPC B01J20 / 22, B01J20 / 28, B01J20 / 30, C01B3 / 00, C10L3 / 06 provides a method for compressing OMCP powder. The OMCP synthesized during the application of the first solvent is filled with a solvent that can replace at least 10% of the first solvent up to the pore volume. Then the OMCP is compressed and dried until the solvent is removed. These authors state 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 in the blocks, depending on the synthesis and compression conditions. The disadvantages of this invention are the narrow range of pore characteristics and the ambiguity of the OMCP usage conditions.

[0005] The background art closest to the OMCP - based material described in the claims provides a method for manufacturing spherical shaped bodies, which includes mixing a composition containing an organometallic composite polymer and at least one liquid, and at least one additive containing a binder selected from the group consisting of non - organic oxides, aluminum oxide, clay, bentonite, and concrete, and an additive containing a swelling agent selected from the group consisting of organic polymers, for example, from the group consisting of methyl cellulose and polyethylene oxide or mixtures thereof (International Publication No. 2014 / 118054 (A1) issued on August 7, 2014, IPC B01J2 / 06, B01J2 / 14, B01J20 / 22, B01J20 / 28, B01J20 / 30).

[0006] Such an approach enables the creation of composite materials containing spherical OMCP granules with increased OMCP and bulk density. When a foaming agent is used during the compression of OMCP, additional porosity is generated by the foaming agent, so that the degradation of the porous structure caused by machining (pressing, extrusion) and pore filling with a binder can be adjusted step by step. The drawback of this method is that the pores formed by the foaming agent are related to macropores and mesopores, so the specific surface area of the pores decreases, and as a result, the gas storage efficiency decreases, that is, they are insufficient for the adsorption and storage of complex gas mixtures.

[0007] The gas mixture storage method described in the claims, which is most recommended for use in a gas mixture, especially a natural gas and methane storage system, is the Russian Patent Invention No. 2650012 issued on April 6, 2018, IPC F17C11 / 00 (2006.01), B82B1 / 00 (2006.01). Here, a nanoporous material with an average effective pore width of 0.6 - 1.2 nm is used during the operation of an accumulator vessel at an operating pressure of 3.5 MPa and a temperature of +10 to +30 °C. A nanoporous material with an average effective pore width of 0.5 - 1.0 nm is used during the operation of an accumulator vessel at an operating pressure of 7 MPa and the same temperature. When the accumulator vessel is operated in the low temperature range of -30 to -10 °C, using an adsorbent with wider pores of 0.9 - 2 nm may result in efficient storage. Thereby, the volume W0 of the pores of the adsorbent in the storage system is maximized as much as possible. The drawback of this known method is that the operating range of the process parameters (temperature and pressure) for which each of the proposed materials is efficient is narrow, so the storage efficiency of complex gas mixtures is low.

Summary of the Invention

[0008] The creation of composite materials based on adsorbents with a bimodal pore distribution is provided to solve the problems of efficient gas storage and maximum complete accumulation of various components of complex gases. Such composite materials can be used, for example, in the case of natural gas adsorption, where the small mode mainly accumulates methane and the large mode accumulates heavier hydrocarbons. The mode corresponds to the effective inner diameter of the micropores, in nm. However, it is difficult to achieve a bimodal pore distribution where the two modes have an effective inner diameter of less than 2.0 nm and the volumes of those pores are relatively equal. Composite materials based on OMCP and carbon adsorbents may solve this problem, and with specific ratios and parameters of the components of the porous structure, they can ensure the optimal adsorption rate and mechanical properties required for use in gas storage and separation systems.

[0009] Therefore, the problem of this group of inventions is to obtain a mechanically tough composite material that has an efficient pore size for the accumulation of gases and mixtures, has a developed inner surface, and can flexibly adapt to changes in the phase composition and other properties of complex gas mixtures when operating over a wide range of temperatures and pressures.

[0010] The technical result achieved by this group of inventions is · By shaping while maintaining a developed inner surface, the bulk density of the block composite material can be increased, thereby making it possible to increase the specific volume of gas storage per unit volume of the storage system, ensuring the possibility of designing a more compact gas storage system. · To ensure the possibility of industrial application of OMCP under conditions of increased aerodynamic load, by optimizing the composition formulation and its mixing technology, the hardness of the obtained block composite material is increased. · To reduce gas losses due to temperature and pressure disturbances in the gas storage system due to the bimodal pore size distribution of the block composite material. That's it.

[0011] This technical achievement is that the manufacturing method of the block composite material for gas storage includes mixing components with a binder, molding the obtained mixture into blocks, and then drying. The organometallic coordination polymer and the nanoporous carbon adsorbent or the carbon nanotube-based adsorbent are mixed at a ratio of 30 / 70 to 95 / 5 wt% and used as components. 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. An aqueous solution of 2 to 15% of a compound such as polyvinyl alcohol, an acetic acid solution of chitosan, or oxyethyl cellulose is used as a binder. The obtained mixture is molded into blocks under pressure within 1 to 2 minutes with a loading force of 25 to 75 kN. The blocks are placed in a drying chamber in a normal state, and then the temperature is raised to 110 to 120 °C at a maximum rate of 60 °C / h and dried for at least 12 hours and at most 36 hours. Next, it is achieved by activating the blocks in a hot vacuum chamber at a temperature of 120 °C, for at least 6 hours, and a residual pressure of 0.26 kPa.

[0012] This technical achievement is that the block composite material for gas storage containing an organometallic coordination polymer, a nanoporous carbon adsorbent, or a carbon nanotube-based adsorbent at a ratio of 30 / 70 to 95 / 5 wt% respectively, and containing an aqueous solution of 2 to 15% of a compound such as polyvinyl alcohol, an acetic acid solution of chitosan, or oxyethyl cellulose as a binder, has a bulk density of the block composite material in the range of 0.540 to 1.220 g / cm 3 and has a bimodal nanoporous structure, the effective inner diameters of the micropores are the same as those of the initial components and differ from each other by at least 0.4 nm and at most 0.8 nm, and the material is used at a temperature of -30 to +60 °C and a maximum pressure of 10 MPa.

[0013] T1, T6, and CNT microporous carbon adsorbents were used as the carbon component of the composite material. T1 and T6 were obtained from peat by mixing peat with potassium sulfide, followed by granulation and carbonization with exhaust gas or pyrolysis gas, then an activation process at a temperature of 800 °C and grinding to a crushing size of >0.2 mm. The microporous-mesoporous CNT carbon adsorbent containing carbon nanotubes was manufactured under the trade name MPU-007 by "NanoTechCenter" Limited (Tambov). The porous structure parameters of the specific carbon components are shown in Table 1.

[0014] Dilute (2-5%) solutions of PVAL, chitosan, and oxycellulose were used as the composite material binder, minimizing the inhibition of the micropores of the block composite material by the binder when providing acceptable strength.

[0015] The essence of the inventive group is explained by the detailed description of specific exemplary embodiments, as well as the attached drawings and tables, but these do not limit the inventive group.

[0016] Table 1 shows the parameters of the porous structure of the carbon material used for the molding of the composite adsorbent, where S BET is the specific surface area by the BET method, m 2 / g, W0 is the specific micropore volume, cm 3 / g, D is the effective inner diameter of the micropores, nm, а0 is the adsorption limit value in the micropores, mmol / g, E0 is the adsorption characteristic energy of nitrogen, kJ / mol, E is the adsorption characteristic energy of benzene, kJ / mol, W s is the total pore volume, cm 3 / g, W me is the mesopore volume, cm 3 / g, S me is the mesopore area, m 2 / g.

[0017] Table 2 shows the properties of the composite material based on OMCP and the carbon adsorbent molded using a binder, where S BET is the specific surface area by the BET method, m 2 / g, W0 is the specific micropore volume, cm 3 / g, P is the molding pressure, kN, t is the molding time, minutes, ρ is the bulk density, g / cm 3 , W0 is the specific micropore volume, cm 3 / g, D is the effective inner diameter of the micropores, nm, HA is the hardness (Shore), ShA, HB is the hardness (Brinell), kg / mm 2 is as follows.

Brief Description of the Drawings

[0018]

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Modes for Carrying Out the Invention

[0019] The essence of the invention group is explained by the following parameters.

Example

[0020] A CuBTC organometallic coordination polymer with an effective inner diameter of the micropores of 0.68 nm was mixed with a T6 nanoporous carbon adsorbent with an effective inner diameter of the micropores of 1.34 nm at a ratio of 30 / 70% by weight, and a 5% aqueous solution of polyvinyl alcohol as a binder was added and homogenized. Then, the mixture was pressure-molded within a range of a load force of 50 kN for 1 minute. The obtained composite material block was placed in a drying chamber at room temperature, the temperature was raised to +120 °C at a maximum rate of 60 °C / h, held within a range of 36 hours, and then activated in a thermal vacuum chamber at a temperature of 120 °C, within a range of 6 hours, at a residual pressure of a maximum of 0.26 kPa.

[0021] The obtained F-18 block composite material, Figure 1, had a bimodal porous structure of the initial mixed components, and the bulk density was 0.65 g / cm 3 It was. Thermal vacuum activation makes it possible to preserve the characteristics of the porous bimodal structure inherent in the initial composite components in the most careful way and to clean the inner surface of the material in preparation for its use as an accumulator for subsequent gas mixtures. The amount of methane accumulated in this adsorbent within a temperature range of -30 to +60 °C and at a maximum pressure of 10 MPa is shown in Figure 2, the characteristics of the carbon components used are shown in Table 1, and the characteristics of the OMCP and the obtained F-18 composite material are shown in Table 2.

Example

[0022] An AlBTC organometallic coordination polymer with an effective inner diameter of the micropores of 1.74 nm was mixed with a T6 nanoporous carbon adsorbent with an effective inner diameter of the micropores of 1.34 nm at a ratio of 50 / 50% by weight, and a 5% aqueous solution of polyvinyl alcohol as a binder was added and homogenized. Then, the mixture was pressure-molded within a load force of 75 kN for 2 minutes. The obtained composite material block was placed in a drying chamber at room temperature, the temperature was raised to +110 °C at a maximum rate of 60 °C / h, held within 24 hours, and then activated in a thermal vacuum chamber at a temperature of 110 °C, within 8 hours, at a residual pressure of a maximum of 0.26 kPa.

[0023] The obtained F-41 block composite material, shown in Figure 4, has a bimodal porous structure of the initial mixed components, and its bulk density was 0.65 g / cm 3 The amount of methane accumulated in this adsorbent within a temperature range of -40 to +50 °C and at a maximum pressure of 10 MPa is shown in Figure 4, the characteristics of the carbon components used are shown in Table 1, and the characteristics of the OMCP and the obtained F-41 composite material are shown in Table 2.

Example

[0024] A CuBTC organometallic coordination polymer with an effective inner diameter of the micropores of 0.68 nm was mixed with a CNT nanoporous carbon adsorbent with an effective inner diameter of the micropores of 1.48 nm at a ratio of 90 / 10% by weight, and a 5% aqueous solution of polyvinyl alcohol as a binder was added and homogenized. Then, the mixture was pressure-molded within a load force of 75 kN for 1 minute. The obtained composite material block was placed in a drying chamber at room temperature, the temperature was raised to +120 °C at a maximum rate of 60 °C / h, 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 a maximum of 0.26 kPa.

[0025] The obtained F-27 block composite material, whose photographic image is shown in Figure 6, has a bimodal porous structure of the initial mixed components. Its bulk density is 0.77 g / cm 3It is as follows. Figure 6 shows the amount of methane that can be stored by this adsorbent within the temperature range of minus 40 to plus 50 °C and at a maximum pressure of 10 MPa. Table 1 shows the characteristics of the carbon components used, and Table 2 shows the characteristics of OMCP and the obtained F-27 composite material.

Example

[0026] This is different from Example 1 only 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 the material of Example 1. Its bulk density is 0.760 g / cm 3 It is as follows. Table 1 shows the characteristics of the carbon components used, and Table 2 shows the characteristics of OMCP and the obtained F-111 composite material.

Example

[0027] This is different from Example 1 in that a 2% solution of oxycellulose was added to the adsorbent mixture and it was molded under a load force of 75 kN. The obtained block composite material has the same adsorption characteristics as the material of Example 1. Its bulk density is 1.200 g / cm 3 It is as follows. Table 1 shows the characteristics of the carbon components used, and Table 2 shows the characteristics of OMCP and the obtained F-116 composite material.

[0028] The composite materials of the obtained invention group have a bimodal porous structure with micropores and mesopores, and are press-molded into compact blocks with sufficient strength to be used as storage materials for gases and gas mixtures such as methane, nitrogen, carbon dioxide, natural gas, and associated petroleum gas, enabling the achievement of the technical results described in the claims. The bimodal pore distribution facilitates the rapid adaptation of gas storage to changes in the phase composition of complex gas mixtures caused by changes in process operations or meteorological conditions because different pore modes are used. As a result, gas loss due to discharge from the safety valve is reduced. The increase in the bulk density of the block composite material makes it possible to increase the specific volume of gas storage per unit volume of the storage system, enabling the design and construction of a more compact storage system for complex gas mixtures.

[0029]

Table 1

[0030]

Table 2-1

[0031]

Table 2-2

Claims

1. In a method for manufacturing a block composite material for gas storage, which comprises mixing components with a binder, molding the resulting mixture into a block, and then drying it, an organometallic coordination polymer and a nanoporous carbon adsorbent or a carbon nanotube-based adsorbent are mixed at a ratio of 30 / 70 to 95 / 5 by weight and used as components, 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, an aqueous solution of 2 to 15% of a compound such as polyvinyl alcohol, an acetic acid solution of chitosan, or oxyethyl cellulose is used as a binder, the resulting mixture is molded into a block under pressure within 1 to 2 minutes with a loading force of 25 to 75 kN, the block is placed in a drying chamber in a normal state, and then the temperature is raised to 110 to 120 °C at a maximum rate of 60 °C / h and dried for a minimum of 12 hours and a maximum of 36 hours. Next, the block is activated in a hot vacuum chamber at a temperature of 120 °C for at least 6 hours and a residual pressure of 0.26 kPa. A method for manufacturing a block composite material for gas storage, characterized by the above steps.

2. An organic metal coordination polymer, a nanoporous carbon adsorbent, or a carbon nanotube-based adsorbent is each contained in a ratio of 30 / 70 to 95 / 5% by weight, and as a binder, a 2 to 15% aqueous solution of a compound such as polyvinyl alcohol, an acetic acid solution of chitosan, or oxyethyl cellulose is contained. In the block composite material for gas storage, the bulk density of the block composite material is in the range of 0.540 to 1.220 g / cm ３ and the nanoporous structure is bimodal, the effective inner diameter of the micropores is equivalent to that of the initial component and differs from each other by a minimum of 0.4 nm and a maximum of 0.8 nm, and the material is used at a temperature of -30 to +60 °C and a maximum pressure of 10 MPa. A block composite material for gas storage, characterized by this.

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