Copper-containing molecular sieve as well as preparation method and application thereof
By preparing copper-containing molecular sieves to activate alkanes at room temperature and pressure, the problems of high energy consumption and high carbon emissions of alkane conversion under high temperature and high pressure and poor selectivity at room temperature and normal pressure were solved, and the effect of highly selective generation of olefin products was achieved.
Patent Information
- Application Number
- CN202410259779.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-07
- Publication Date
- 2025-09-09
AI Technical Summary
The existing technology for converting alkanes into high-value-added chemicals is carried out under high temperature and high pressure, resulting in high energy consumption and high carbon emissions. In addition, the alkane oxidation activation method at room temperature and normal pressure has the problem of poor product selectivity.
Copper-containing molecular sieves are used to activate alkanes at room temperature and pressure. The H-type molecular sieve is mixed with a nitrate solution, and then a solution containing Cu ions is added. The copper-containing molecular sieve is prepared by heat treatment and reduction treatment. The copper-containing molecular sieve is used in an alkane activation reactor to react with alkanes and air to generate olefin products.
Highly selective activation of alkanes at room temperature and pressure is achieved to produce chemicals with higher added value, and the recycling performance is good, making it suitable for industrial production.
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Figure CN120607260A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of molecular sieve preparation, and in particular to a copper-containing molecular sieve and a preparation method and application thereof. Background Art
[0002] Alkanes are widely available, abundant, and inexpensive, making their conversion into higher-value chemicals of great economic value. However, existing industrial technologies for converting alkanes into high-value chemicals operate at high temperatures and pressures, resulting in high energy consumption and carbon emissions. Reducing carbon emissions from these energy-intensive and high-emission industrial processes is crucial. Therefore, exploring methods for activating alkanes under mild conditions is crucial.
[0003] The activation and conversion of alkanes into higher-value-added chemicals in the presence of oxidants (such as oxygen and nitrous oxide) is thermodynamically feasible at room temperature and atmospheric pressure, with unrestricted alkane conversion rates. However, these methods often suffer from poor product selectivity, hindering the efficient production of a single product. However, compared to non-oxidative activation methods, which are thermodynamically feasible at high temperatures, oxidative activation methods offer greater potential for efficient alkane activation and conversion at room temperature and atmospheric pressure. Therefore, developing a highly selective method for converting alkanes to single products under mild reaction conditions that overcomes the aforementioned drawbacks of oxidative conversion is crucial. Summary of the Invention
[0004] The purpose of this application is to provide a copper-containing molecular sieve and a method for preparing the same. The copper-containing molecular sieve prepared by the method of this application can activate alkanes at room temperature and pressure, and obtain higher value-added chemicals with high selectivity. The specific technical solution is as follows:
[0005] The first aspect of the present application provides a method for preparing a copper-containing molecular sieve, which comprises:
[0006] An H-type molecular sieve is mixed with a nitrate solution, stirred at 60-100° C. for 2-3 hours, and filtered to obtain a solid A; wherein the H-type molecular sieve comprises an aluminosilicate framework, the silicon-aluminum ratio of the H-type molecular sieve is 10-100:1, the mass-to-volume ratio of the H-type molecular sieve to the nitrate solution is 0.005-0.1 g:1 mL, and the concentration of the nitrate solution is 0.1-0.5 mol / L; the nitrate solution is selected from at least one of a sodium nitrate solution and a potassium nitrate solution;
[0007] adding the solid A to a solution containing Cu ions, stirring at 10-30° C. for 20-48 hours, filtering, and drying to obtain a solid B; wherein the mass volume ratio of the solid A to the solution containing Cu ions is 0.005-0.1 g:1 mL, and the concentration of the solution containing Cu ions is 0.02-0.2 mol / L; and the solution containing Cu ions is selected from at least one of a copper chloride solution, a copper acetate solution, a copper sulfate solution, and a copper nitrate solution;
[0008] The solid B is heated from 10-30° C. to 500-600° C. over 1-2 hours under an air flow at a flow rate of 30-80 mL / min, kept at this temperature for 1-2 hours, and then naturally cooled to obtain a solid C;
[0009] The solid C is heated from 10-30°C to 200-250°C over 0.2-1h under a mixed gas flow containing 5-15 vol% H2 and the balance being argon or nitrogen at a flow rate of 40-60 mL / min, kept warm for 1-2h, and then naturally cooled to obtain a copper-containing molecular sieve.
[0010] In one embodiment of the present application, the H-type molecular sieve is selected from at least one of H-ZSM-5, HY, H-CHA, H-Beta, H-MCM-41 and H-SBA-15.
[0011] In one embodiment of the present application, the mass percentage of copper in the copper-containing molecular sieve is 0.3-3%.
[0012] The second aspect of the present application provides a copper-containing molecular sieve obtained according to the preparation method described in the first aspect of the present application.
[0013] A third aspect of the present application provides a method for activating alkanes, comprising:
[0014] The copper-containing molecular sieve obtained according to the preparation method described in the first aspect of the present application or the copper-containing molecular sieve described in the second aspect of the present application is placed in a reactor, and an alkane containing 1 to 5 vol% water vapor and air are introduced into the reactor, with the volume ratio of alkane to air being 0.2 to 5:1, to activate the alkane and generate an olefin product; the alkane is selected from C1-C4 alkanes.
[0015] In one embodiment of the present application, the copper-containing molecular sieve is a copper-containing molecular sieve of 20 to 60 meshes.
[0016] In a fourth aspect, the present application provides a device for alkane activation, comprising: a fixed bed reactor, an alkane intake system, an air intake system, a bubbler, an H2 intake system, a heating device, and a product collection device;
[0017] The alkane intake system is connected to the bubbler via a first pipeline, the air intake system is connected to the bubbler via a second pipeline, the H2 intake system is connected to the fixed bed reactor via a third pipeline, and the bubbler is connected to the fixed bed reactor via a fourth pipeline;
[0018] The fixed bed reactor is provided with the copper-containing molecular sieve obtained by the preparation method described in the first aspect of the present application or the copper-containing molecular sieve described in the second aspect of the present application. The fixed bed reactor is placed in the heating device, and the product collecting device is connected to the fixed bed reactor.
[0019] In one embodiment of the present application, a first control valve is provided on the first pipeline, and / or a second control valve is provided on the second pipeline, and / or a third control valve is provided on the third pipeline.
[0020] The fifth aspect of the present application provides the use of the device according to the fourth aspect of the present application in alkane activation.
[0021] In one embodiment of the present application, the alkane intake system and the air intake system are opened, and the volume ratio of alkane to air is controlled to be 0.2 to 5:1 by a first control valve on the first pipeline and a second control valve on the second pipeline; the alkane and air pass through a bubbler to form alkane and air containing 1 to 5 vol% water vapor, which flows into a fixed bed reactor for alkane activation, and the generated olefin product enters a product collection device;
[0022] After the alkane activation is completed, the alkane intake system, the air intake system and the product collection device are closed, and the H2 intake system is opened. A mixed gas flow containing 5 to 15 vol% H2 and the balance being argon or nitrogen is controlled by a third control valve on a third pipeline to enter a fixed bed reactor at a flow rate of 40 to 60 mL / min to perform a reduction reaction with the copper-containing molecular sieve after the alkane activation is completed. At the same time, a heating device is turned on to regulate the temperature of the fixed bed reactor from 10 to 30° C. to 200 to 250° C. over 0.2 to 1 hour, kept warm for 1 to 2 hours, and then naturally cooled to prepare the copper-containing molecular sieve again; then, alkane activation is performed again to obtain an olefin product; the alkane is selected from C1-C4 alkanes.
[0023] Beneficial effects of this application:
[0024] The present application provides a method for preparing a copper-containing molecular sieve, which has a simple preparation process, low cost, and is easy to industrially produce. The copper-containing molecular sieve prepared by the method of the present application can activate alkanes at room temperature and pressure, obtain higher value-added chemicals with high selectivity, and has good recycling performance, and has very good application prospects.
[0025] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.
[0027] Figure 1 A schematic diagram of an apparatus for activating alkanes according to one embodiment of the present application;
[0028] Figure 2 This is a transmission electron microscope photograph of the monovalent copper-containing molecular sieve in Example 1 of the present application.
[0029] In the figure, fixed bed reactor-1, alkane inlet system-2, air inlet system-3, bubbler-4, H2 inlet system-5, heating device-6, product collecting device-7, first control valve-8, second control valve-9, third control valve-10, copper-containing molecular sieve-11. DETAILED DESCRIPTION
[0030] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.
[0031] The first aspect of the present application provides a method for preparing a copper-containing molecular sieve, which comprises:
[0032] An H-type molecular sieve is mixed with a nitrate solution, stirred at 60-100° C. for 2-3 hours, and filtered to obtain a solid A; wherein the H-type molecular sieve comprises an aluminosilicate framework, the silicon-aluminum ratio of the H-type molecular sieve is 10-100:1, the mass-to-volume ratio of the H-type molecular sieve to the nitrate solution is 0.005-0.1 g:1 mL, and the concentration of the nitrate solution is 0.1-0.5 mol / L; the nitrate solution is selected from at least one of a sodium nitrate solution and a potassium nitrate solution;
[0033] adding the solid A to a solution containing Cu ions, stirring at 10-30° C. for 20-48 hours, filtering, and drying to obtain a solid B; wherein the mass volume ratio of the solid A to the solution containing Cu ions is 0.005-0.1 g:1 mL, and the concentration of the solution containing Cu ions is 0.02-0.2 mol / L; and the solution containing Cu ions is selected from at least one of a copper chloride solution, a copper acetate solution, a copper sulfate solution, and a copper nitrate solution;
[0034] The solid B is heated from 10-30° C. to 500-600° C. over 1-2 hours under an air flow at a flow rate of 30-80 mL / min, kept at this temperature for 1-2 hours, and then naturally cooled to obtain a solid C;
[0035] The solid C is heated from 10-30°C to 200-250°C over 0.2-1h under a mixed gas flow containing 5-15 vol% H2 and the balance being argon or nitrogen at a flow rate of 40-60 mL / min, kept warm for 1-2h, and then naturally cooled to obtain a copper-containing molecular sieve.
[0036] The inventors found in their research that the preparation method of the copper-containing molecular sieve of the present application is simple, low-cost, and easy to industrially produce; the copper-containing molecular sieve prepared by the method of the present application has good circulation performance, can be used for alkane activation at room temperature and pressure, and obtains higher value-added chemicals with high selectivity.
[0037] In one embodiment of the present application, the H-type molecular sieve is selected from at least one of H-ZSM-5, HY, H-CHA, H-Beta, H-MCM-41 and H-SBA-15.
[0038] In one embodiment of the present application, the mass percentage of copper in the copper-containing molecular sieve is 0.3-3%.
[0039] The inventors have discovered that a copper content of 1% to 3% by mass of the copper-containing molecular sieve within the range of the present application results in a high alkane activation activity per copper atom in the copper-containing molecular sieve. Preferably, a copper content of 1% to 3% by mass of the copper-containing molecular sieve results in a higher alkane activation activity per copper atom in the copper-containing molecular sieve.
[0040] In the present application, there is no particular limitation on the filtering method, as long as the purpose of the present application can be achieved. For example, suction filtration and washing with deionized water 3 to 5 times can be used.
[0041] In the present application, the drying method is not particularly limited, as long as the purpose of the present application can be achieved, for example, drying in an oven at 80-120° C. for 2-3 hours.
[0042] In the present application, the step of introducing a mixed gas flow containing 5 to 15 vol% H2 with the remainder being argon or nitrogen can be carried out in a tubular furnace or a fixed bed reactor, and is not particularly limited in the present application.
[0043] The second aspect of the present application provides a copper-containing molecular sieve obtained according to the preparation method described in the first aspect of the present application.
[0044] In the present application, the copper-containing molecular sieve comprises an aluminosilicate framework, copper ions that balance the negative charge of the framework, and other cations that may be adsorbed on the negatively charged molecular sieve framework during the preparation process, such as hydrogen ions, sodium ions, etc.
[0045] A third aspect of the present application provides a method for activating alkanes, comprising:
[0046] The copper-containing molecular sieve obtained according to the preparation method described in the first aspect of the present application or the copper-containing molecular sieve described in the second aspect of the present application is placed in a reactor, and an alkane containing 1 to 5 vol% water vapor and air are introduced into the reactor, with the volume ratio of alkane to air being 0.2 to 5:1, to activate the alkane and generate an olefin product; the alkane is selected from C1-C4 alkanes.
[0047] In one embodiment of the present application, the copper-containing molecular sieve is a copper-containing molecular sieve of 20 to 60 meshes.
[0048] In the present application, the preparation method of the 20-60 mesh copper-containing molecular sieve is not particularly limited, as long as the purpose of the present application can be achieved, for example, by extrusion molding or extrusion molding.
[0049] like Figure 1 As shown, the fourth aspect of the present application provides a device for alkane activation, which includes: a fixed bed reactor 1, an alkane intake system 2, an air intake system 3, a bubbler 4, an H2 intake system 5, a heating device 6 and a product collecting device 7;
[0050] The alkane intake system 2 is connected to the bubbler 4 via a first pipeline, the air intake system 3 is connected to the bubbler 4 via a second pipeline, the H2 intake system 5 is connected to the fixed bed reactor 1 via a third pipeline, and the bubbler 4 is connected to the fixed bed reactor 1 via a fourth pipeline;
[0051] The fixed bed reactor 1 is provided with the copper-containing molecular sieve 11 obtained by the preparation method described in the first aspect of the present application or the copper-containing molecular sieve 11 described in the second aspect of the present application. The fixed bed reactor 1 is placed in the heating device 6, and the product collecting device 7 is connected to the fixed bed reactor 1.
[0052] In one embodiment of the present application, a first control valve 8 is provided on the first pipeline, and / or a second control valve 9 is provided on the second pipeline, and / or a third control valve 10 is provided on the third pipeline.
[0053] The fifth aspect of the present application provides the use of the device according to the fourth aspect of the present application in alkane activation.
[0054] In one embodiment of the present application, the alkane intake system 2 and the air intake system 3 are opened, and the volume ratio of alkane to air is controlled to be 0.2 to 5:1 by a first control valve 8 on the first pipeline and a second control valve 9 on the second pipeline; the alkane and air pass through a bubbler 4 to form alkane and air containing 1 to 5 vol% water vapor, which flows into the fixed bed reactor 1 for alkane activation, and the generated olefin product enters the product collection device 7;
[0055] After the activation of the alkane is completed, the alkane intake system 2, the air intake system 3 and the product collecting device 7 are closed, and the H2 intake system 5 is opened. The third control valve 10 on the third pipeline controls a mixed flow containing 5-15 vol% H2 and the balance being argon or nitrogen to enter the fixed bed reactor 1 at a flow rate of 40-60 mL / min to carry out a reduction reaction with the copper-containing molecular sieve after the alkane activation is completed. At the same time, the heating device 6 is turned on to regulate the temperature of the fixed bed reactor 1 from 10-30° C. to 200-250° C. over 0.2-1 h, and then kept warm for 1-2 h, and then naturally cooled to prepare the copper-containing molecular sieve 11 again; then the alkane activation is carried out again to obtain an olefin product; the alkane is selected from C1-C4 alkanes.
[0056] In the present application, the copper-containing molecular sieve is a molecular sieve loaded with monovalent copper ions. Since monovalent copper ions, with the assistance of water vapor, can activate oxygen at 10 to 30°C to form highly active oxygen-containing species that can capture the CH bonds of alkanes, the molecular sieve loaded with monovalent copper ions can be used for alkane activation.
[0057] The inventors found in their research that the copper-containing molecular sieve of the present application can maintain a stable yield when the alkane activation process is cycled for more than 5 times.
[0058] In one embodiment of the present application, the temperature for activating the alkane is 10-30° C., and the pressure is 80-120 KPa.
[0059] The copper-containing molecular sieve provided in this application can activate alkanes at room temperature and pressure, obtain higher value-added chemicals with high selectivity, and has good circulation performance.
[0060] Example
[0061] The following examples further illustrate the embodiments of the present invention. Various tests and evaluations were performed according to the following methods. Unless otherwise specified, "parts" and "%" are by mass, with room temperature being 10-30°C, and normal temperature and pressure being 10-30°C and 80-120 kPa.
[0062] Example 1
[0063] like Figure 1 As shown, the device for activating alkanes includes: a fixed bed reactor 1, an alkane intake system 2, an air intake system 3, a bubbler 4, an H2 intake system 5, a heating device 6 and a product collecting device 7; the alkane intake system 2 is connected to the bubbler 4 through a first pipeline, the air intake system 3 is connected to the bubbler 4 through a second pipeline, the H2 intake system 5 is connected to the fixed bed reactor 1 through a third pipeline, and the bubbler 4 is connected to the fixed bed reactor 1 through a fourth pipeline; a copper-containing molecular sieve 11 is placed in the fixed bed reactor 1, the fixed bed reactor 1 is placed in the heating device 6, and the product collecting device 7 is connected to the fixed bed reactor 1; the first pipeline is provided with a first control valve 8, the second pipeline is provided with a second control valve 9, and the third pipeline is provided with a third control valve 10.
[0064] (1) 1 g of H-ZSM-5 (Si:Al ratio 15, Tianjin Nantian New Materials Research Center Co., Ltd.) was dissolved in 50 mL of 0.3 mol / L NaNO3 aqueous solution, heated and stirred in a water bath at 80°C for 3 h, filtered, and washed three times with deionized water to obtain Na-ZSM-5.
[0065] (2) The Na-ZSM-5 obtained above was added to 50 mL of a 0.1 mol / L CuCl2 aqueous solution, stirred at room temperature for 20 h, filtered, washed three times with deionized water, and dried in a 95°C oven for 3 h to obtain CuNa-ZSM-5;
[0066] (3) The CuNa-ZSM-5 obtained above was heated from room temperature to 550°C for 1 hour under a 40 mL / min air flow, kept warm for 2 hours, and then cooled naturally. The obtained solid was heated from room temperature to 230°C for 0.5 hours under a 40 mL / min 10 vol% H2 (the remaining gas was argon) flow, kept warm for 1 hour, and then cooled naturally to obtain a monovalent copper molecular sieve sample with a copper loading of 1.8 wt% (such as Figure 2 shown);
[0067] (4) Take 0.1 g of the above-obtained copper-containing molecular sieve sample with a copper loading of 1.8 wt% and prepare it into 40-60 mesh particles by pressing or extrusion molding; place it in Figure 1In the fixed-bed reactor 1 shown, the alkane inlet system 2 and the air inlet system 3 are opened, the propane flow rate is controlled to 2 mL / min by the first control valve 8 on the first pipeline, and the air flow rate is controlled to 4 mL / min by the second control valve 9 on the second pipeline. The alkane and air pass through the bubbler 4 to form propane and air with 3 vol% water vapor, which are then introduced into the fixed-bed reactor 1 at room temperature and pressure for propane activation. The production of propylene is detected by gas chromatography.
[0068] Example 2
[0069] (1) 1 g of HY (model X12H014, Si / Al ratio 10, company: Thermo Fisher Scientific) was dissolved in 50 mL of 0.3 mol / L NaNO3 aqueous solution, heated and stirred in a water bath at 80°C for 3 h, filtered, and washed three times with deionized water to obtain Na-Y;
[0070] (2) The Na-Y obtained above was added to 50 mL of a 0.1 mol / L CuCl2 aqueous solution, stirred at room temperature for 24 h, filtered, washed three times with deionized water, and dried in a 95°C oven for 3 h to obtain CuNa-Y;
[0071] (3) The CuNa-Y obtained above was heated from room temperature to 550°C for 1 hour under a 60 mL / min air flow, kept warm for 2 hours, and then naturally cooled. The obtained solid was heated from room temperature to 230°C for 0.5 hours under a 40 mL / min 10 vol% H2 (the remaining gas was argon) flow, kept warm for 1 hour, and then naturally cooled to obtain a monovalent copper molecular sieve sample with a copper loading of 2.0 wt%;
[0072] (4) Take 0.1 g of the above-obtained copper-containing molecular sieve sample with a copper loading of 2.0 wt% and prepare it into 40-60 mesh particles by pressing or extrusion molding; place it in Figure 1 In the fixed-bed reactor 1 shown, the alkane inlet system 2 and the air inlet system 3 are opened, the propane flow rate is controlled to 2 mL / min by the first control valve 8 on the first pipeline, and the air flow rate is controlled to 4 mL / min by the second control valve 9 on the second pipeline. The alkane and air pass through the bubbler 4 to form propane and air with 3 vol% water vapor, which are then introduced into the fixed-bed reactor 1 at room temperature and pressure for propane activation. The production of propylene is detected by gas chromatography.
[0073] Example 3
[0074] (1) 1 g of H-ZSM-5 (Si:Al ratio 27, Tianjin Nantian New Materials Research Center Co., Ltd.) was dissolved in 50 mL of 0.3 mol / L NaNO3 aqueous solution, heated and stirred in a water bath at 80°C for 3 h, filtered, and washed three times with deionized water to obtain Na-ZSM-5;
[0075] (2) The Na-ZSM-5 obtained above was added to 50 mL of a 0.06 mol / L CuCl2 aqueous solution, stirred at room temperature for 20 h, filtered, washed three times with deionized water, and dried in a 95°C oven for 3 h to obtain CuNa-ZSM-5;
[0076] (3) The CuNa-ZSM-5 obtained above was heated from room temperature to 550°C for 1 hour under an air flow of 40 mL / min, kept warm for 2 hours, and then naturally cooled. The obtained solid was heated from room temperature to 230°C for 0.5 hours under a 10 vol% H2 (the remaining gas was argon) flow of 40 mL / min, kept warm for 1 hour, and then naturally cooled to obtain a monovalent copper molecular sieve sample with a copper loading of 0.6 wt%;
[0077] (4) Take 0.1 g of the above-obtained copper-containing molecular sieve sample with a copper loading of 0.6 wt% and prepare it into 40-60 mesh particles by pressing or extrusion molding; place it in Figure 1 In the fixed-bed reactor 1 shown, the alkane inlet system 2 and the air inlet system 3 are opened, the ethane flow rate is controlled to 2 mL / min by the first control valve 8 on the first pipeline, and the air flow rate is controlled to 4 mL / min by the second control valve 9 on the second pipeline. The alkane and air pass through the bubbler 4 to form ethane and air with 3 vol% water vapor, which is then introduced into the fixed-bed reactor 1 at room temperature and pressure for ethane activation. The production of ethylene is detected by gas chromatography.
[0078] Example 4
[0079] (1) 1 g of H-ZSM-5 (Si:Al ratio 15, Tianjin Nantian New Materials Research Center Co., Ltd.) was dissolved in 50 mL of 0.3 mol / L NaNO3 aqueous solution, heated and stirred in a water bath at 80°C for 3 h, filtered, and washed three times with deionized water to obtain Na-ZSM-5.
[0080] (2) The Na-ZSM-5 obtained above was added to 50 mL of a 0.02 mol / L CuCl2 aqueous solution, stirred at room temperature for 20 h, filtered, washed three times with deionized water, and dried in a 95°C oven for 3 h to obtain CuNa-ZSM-5;
[0081] (3) The CuNa-ZSM-5 obtained above was heated from room temperature to 550°C for 1 hour under a 50 mL / min air flow, kept warm for 2 hours, and then naturally cooled. The obtained solid was heated from room temperature to 230°C for 0.5 hours under a 40 mL / min 10 vol% H2 (the remaining gas was argon) flow, kept warm for 1 hour, and then naturally cooled to obtain a monovalent copper molecular sieve sample with a copper loading of 0.34 wt%;
[0082] (4) Take 0.1 g of the above-obtained copper-containing molecular sieve sample with a copper loading of 0.34 wt% and prepare it into 40-60 mesh particles by pressing or extrusion molding; place it in Figure 1 In the fixed-bed reactor 1 shown, the alkane inlet system 2 and the air inlet system 3 are opened, the propane flow rate is controlled to 2 mL / min by the first control valve 8 on the first pipeline, and the air flow rate is controlled to 4 mL / min by the second control valve 9 on the second pipeline. The alkane and air pass through the bubbler 4 to form propane and air with 3 vol% water vapor, which are then introduced into the fixed-bed reactor 1 at room temperature and pressure for propane activation. The production of propylene is detected by gas chromatography.
[0083] Example 5
[0084] (1) 1 g of H-ZSM-5 (Si:Al ratio 15, Tianjin Nantian New Materials Research Center Co., Ltd.) was dissolved in 50 mL of 0.3 mol / L NaNO3 aqueous solution, heated and stirred in a water bath at 80°C for 3 h, filtered, and washed three times with deionized water to obtain Na-ZSM-5.
[0085] (2) The Na-ZSM-5 obtained above was added to 50 mL of a 0.2 mol / L CuCl2 aqueous solution, stirred at room temperature for 48 h, filtered, washed three times with deionized water, and dried in a 95°C oven for 3 h to obtain CuNa-ZSM-5;
[0086] (3) The CuNa-ZSM-5 obtained above was heated from room temperature to 550°C for 1 hour under a 50 mL / min air flow, kept warm for 2 hours, and then naturally cooled. The obtained solid was heated from room temperature to 230°C for 0.5 hours under a 10 vol% H2 (the remaining gas was argon) flow at 40 mL / min, kept warm for 1 hour, and then naturally cooled to obtain a monovalent copper molecular sieve sample with a copper loading of 2.7 wt%;
[0087] (4) Take 0.1 g of the above-obtained copper-containing molecular sieve sample with a copper loading of 2.7 wt% and prepare it into 40-60 mesh particles by pressing or extrusion molding; place it in Figure 1In the fixed-bed reactor 1 shown, the alkane inlet system 2 and the air inlet system 3 are opened, the propane flow rate is controlled to 2 mL / min by the first control valve 8 on the first pipeline, and the air flow rate is controlled to 4 mL / min by the second control valve 9 on the second pipeline. The alkane and air pass through the bubbler 4 to form propane and air with 3 vol% water vapor, which are then introduced into the fixed-bed reactor 1 at room temperature and pressure for propane activation. The production of propylene is detected by gas chromatography.
[0088] Test Example 1
[0089] The yields of the products generated in Examples 1-5 were determined by gas chromatography and calculated using the external standard method. The specific method is as follows:
[0090] 1. Gas chromatography conditions:
[0091] Chromatographic column: HPPLOT Al2O3 column (Agilent J&W); column temperature: 60℃-150℃; stationary phase: Al2O3; mobile phase: He; elution program: 0-5 min, 60℃; 5-14 min, 60℃ to 150℃; carrier gas: He; flow rate: 5.5 mL / min; injection port temperature: 250℃; injection volume: 0.25 mL; injection method: quantitative loop injection.
[0092] 2. The results are shown in Table 1:
[0093] Table 1
[0094] Alkanes product Yield (μmol / g) Example 1 Propane Propylene 42 Example 2 Propane Propylene 15 Example 3 Ethane Ethylene 8.5 Example 4 Propane Propylene 8.0 Example 5 Propane Propylene 40
[0095] As can be seen from Table 1, in Example 1, 0.1g of a sample containing a monovalent copper molecular sieve with a copper loading of 1.8wt% was prepared into 40-60 mesh particles and placed in a fixed reaction bed for propane activation, and the propylene yield was 42μmol / g; in Example 2, 0.1g of a sample containing a monovalent copper molecular sieve with a copper loading of 2.0wt% was prepared into 40-60 mesh particles and placed in a fixed reaction bed for propane activation, and the propylene yield was 15μmol / g; in Example 3, 0.1g of a sample containing a monovalent copper molecular sieve with a copper loading of 0.6wt% was prepared into 40-60 mesh particles were placed in a fixed reaction bed for ethane activation, and the ethylene yield was 8.5 μmol / g; in Example 4, 0.1 g of a monovalent copper molecular sieve sample with a copper loading of 0.34 wt% was prepared into 40-60 mesh particles and placed in a fixed reaction bed for propane activation, and the propylene yield was 8.0 μmol / g; in Example 5, 0.1 g of a monovalent copper molecular sieve sample with a copper loading of 2.7 wt% was prepared into 40-60 mesh particles and placed in a fixed reaction bed for propane activation, and the propylene yield was 40 μmol / g. It can be seen that the copper-containing molecular sieve prepared in this application can oxidatively activate alkanes under gas phase conditions at room temperature and pressure, and the alkane molecules only remove one molecule of hydrogen and are highly selectively converted into single olefin products, with a yield of up to 42 μmol / g.
[0096] Test Example 2
[0097] After the activation of the alkane in Example 1 was completed, the alkane intake system 2, the air intake system 3 and the product collecting device 7 were closed, and the H2 intake system 5 was opened. A gas flow containing 10 vol% H2 (the remaining gas was argon) was controlled by the third control valve 10 on the third pipeline to enter the fixed bed reactor 1 at a flow rate of 50 mL / min to carry out a reduction reaction with the copper-containing molecular sieve after the alkane activation was completed. At the same time, the heating device 6 was turned on to regulate the temperature of the fixed bed reactor 1 from room temperature to 230° C. over 0.5 h, kept warm for 1 h, and then naturally cooled to prepare a monovalent copper molecular sieve sample again; then, the alkane activation was performed again to obtain an olefin product, which was counted as "cycle 1". In this cycle, the product yield after 5 cycles is shown in Table 2.
[0098] Table 2
[0099]
[0100] As can be seen from Table 2, the copper-containing molecular sieve obtained by the preparation method of the present application can maintain stability and even obtain a higher yield after the alkane activation process is cycled 5 times.
[0101] In summary, the preparation method of the copper-containing molecular sieve provided in the present application has a simple preparation process, low cost, and is easy to industrially produce; the copper-containing molecular sieve prepared by the method of the present application can activate alkanes at room temperature and pressure, obtain higher value-added chemicals with high selectivity, and has good recycling performance, and has very good application prospects.
[0102] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.
[0103] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.
Claims
1. A method for preparing a copper-containing molecular sieve, comprising: An H-type molecular sieve is mixed with a nitrate solution, stirred at 60-100° C. for 2-3 hours, and filtered to obtain a solid A; wherein the H-type molecular sieve comprises an aluminosilicate framework, the silicon-aluminum ratio of the H-type molecular sieve is 10-100:1, the mass-to-volume ratio of the H-type molecular sieve to the nitrate solution is 0.005-0.1 g:1 mL, and the concentration of the nitrate solution is 0.1-0.5 mol / L; the nitrate solution is selected from at least one of a sodium nitrate solution and a potassium nitrate solution; adding the solid A to a solution containing Cu ions, stirring at 10-30° C. for 20-48 hours, filtering, and drying to obtain a solid B; wherein the mass volume ratio of the solid A to the solution containing Cu ions is 0.005-0.1 g:1 mL, and the concentration of the solution containing Cu ions is 0.02-0.2 mol / L; and the solution containing Cu ions is selected from at least one of a copper chloride solution, a copper acetate solution, a copper sulfate solution, and a copper nitrate solution; The solid B is heated from 10-30° C. to 500-600° C. over 1-2 hours under an air flow at a flow rate of 30-80 mL / min, kept at this temperature for 1-2 hours, and then naturally cooled to obtain a solid C; The solid C is heated from 10-30°C to 200-250°C over 0.2-1h under a mixed gas flow containing 5-15 vol% H2 and the balance being argon or nitrogen at a flow rate of 40-60 mL / min, kept warm for 1-2h, and then naturally cooled to obtain a copper-containing molecular sieve.
2. The preparation method according to claim 1, wherein The H-type molecular sieve is selected from at least one of H-ZSM-5, HY, H-CHA, H-Beta, H-MCM-41 and H-SBA-15.
3. The preparation method according to any one of claims 1 to 2, wherein The mass percentage of copper in the copper-containing molecular sieve is 0.3-3%.
4. The copper-containing molecular sieve obtained by the preparation method according to any one of claims 1 to 3.
5. A method for activating an alkane, comprising: The copper-containing molecular sieve obtained by the preparation method according to any one of claims 1 to 3 or the copper-containing molecular sieve according to claim 4 is placed in a reactor, and an alkane containing 1 to 5 vol% water vapor and air are introduced into the reactor, with the volume ratio of alkane to air being 0.2 to 5:1, to activate the alkane and generate an olefin product; the alkane is selected from C1-C4 alkanes.
6. The method according to claim 5, wherein: The copper-containing molecular sieve is a copper-containing molecular sieve of 20 to 60 meshes.
7. A device for activating alkanes, comprising: Fixed bed reactor, alkane inlet system, air inlet system, bubbler, H2 inlet system, heating device and product collection device; The alkane intake system is connected to the bubbler via a first pipeline, the air intake system is connected to the bubbler via a second pipeline, the H2 intake system is connected to the fixed bed reactor via a third pipeline, and the bubbler is connected to the fixed bed reactor via a fourth pipeline; The copper-containing molecular sieve obtained by the preparation method according to any one of claims 1 to 3 or the copper-containing molecular sieve according to claim 4 is placed in the fixed bed reactor, the fixed bed reactor is placed in the heating device, and the product collecting device is connected to the fixed bed reactor.
8. The device according to claim 7, wherein The first pipeline is provided with a first control valve, and / or the second pipeline is provided with a second control valve, and / or the third pipeline is provided with a third control valve.
9. Use of the device according to any one of claims 7-8 in alkane activation.
10. The use according to claim 9, wherein: The alkane inlet system and the air inlet system are opened, and the volume ratio of alkane to air is controlled to be 0.2 to 5:1 by a first control valve on the first pipeline and a second control valve on the second pipeline; the alkane and air are passed through a bubbler to form alkane and air containing 1 to 5 vol% water vapor, which flows into a fixed bed reactor for alkane activation, and the generated olefin product enters a product collection device; After the alkane activation is completed, the alkane intake system, the air intake system and the product collection device are closed, and the H2 intake system is opened. A mixed gas flow containing 5 to 15 vol% H2 and the balance being argon or nitrogen is controlled by a third control valve on a third pipeline to enter a fixed bed reactor at a flow rate of 40 to 60 mL / min to perform a reduction reaction with the copper-containing molecular sieve after the alkane activation is completed. At the same time, a heating device is turned on to regulate the temperature of the fixed bed reactor from 10 to 30° C. to 200 to 250° C. over 0.2 to 1 hour, kept warm for 1 to 2 hours, and then naturally cooled to prepare the copper-containing molecular sieve again; then, alkane activation is performed again to obtain an olefin product; the alkane is selected from C1-C4 alkanes.