Nano hydrolysis catalyst carrier and chemical synthesis method and application thereof

Abstract

The invention discloses a nanocrystallization hydrolysis catalyst carrier and a chemical synthesis method and application thereof.The nanocrystallization hydrolysis catalyst carrier is synthesized with hexadecyl trimethyl ammonium bromide, aluminum nitrate and ammonium bicarbonate as raw materials, and the chemical synthesis method comprises the following steps that a hexadecyl trimethyl ammonium bromide solution is prepared from ultrapure water; respectively dissolving aluminum nitrate and ammonium bicarbonate in the hexadecyl trimethyl ammonium bromide solution to obtain an aluminum nitrate solution and an ammonium bicarbonate solution; slowly dropwise adding the ammonium bicarbonate solution into the vigorously stirred aluminum nitrate solution, stopping dropwise adding when the reaction solution generates a sol-like substance, continuously stirring for at least one hour, and standing and aging at room temperature to form gel; and fully drying the gel at 60-80 DEG C, granulating the dried gel, and calcining in a high-temperature furnace to obtain the nanocrystallization hydrolysis catalyst carrier. By increasing the specific surface area and mesopore ratio of the catalyst carrier, the purification effect on COS in blast furnace gas is improved, and the service life of the hydrolysis catalyst is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst carriers, and particularly relates to a nanometer hydrolysis catalyst carrier and a chemical synthesis method and application thereof. Background Art

[0002] At present, my country's steel smelting technology is mainly based on blast furnace ironmaking, accounting for more than 90%, and electric furnace steelmaking is less than 10%. Each ton of pig iron produced can generate 1600-2000m 3 The calorific value of blast furnace gas is about 3000~4200kJ / m 3 The main uses include providing energy for coke ovens, hot blast stoves and steel rolling heating furnaces, as well as gas power generation. In addition to carbon dioxide (6-12%), carbon monoxide (28-33%), hydrogen (1-4%), and nitrogen (55-60%), blast furnace gas also contains some sulfur-containing substances, the main components of which are organic sulfur and inorganic sulfur. The components are shown in Table 1.

[0003] Table 1 Typical sulfur components in blast furnace gas (mg / m 3 )

[0004]

[0005] In recent years, the state and local governments have successively issued a series of policies on blast furnace gas desulfurization, stipulating that blast furnace gas and coke oven gas should be refined desulfurized and the concentration of hydrogen sulfide in the gas should be less than 20mg / m 3 ; The concentration of hydrogen sulfide in blast furnace gas of steel enterprises is ≤20mg / Nm 3 , and encourages decarbonyl sulfide (COS).

[0006] Traditional methods for removing COS include adsorption, hydrogenation conversion, organic amine solvent absorption, etc., but these methods are costly and suitable for fine removal of small amounts of tail gas, but not suitable for fine removal of COS in large amounts of blast furnace gas; another method is hydrolysis conversion + dry desulfurization, which has become a widely recognized COS conversion and removal technology in the steel industry because it can adapt to the working conditions of blast furnace gas. The selection of hydrolysis catalyst is crucial to the entire process. However, existing hydrolysis catalysts have the problems of low hydrolysis conversion rate and short service life, which restricts the purification effect.

[0007] Therefore, how to further improve the catalytic efficiency and service life of the hydrolysis catalyst in COS conversion and removal is a problem that needs to be solved. Summary of the invention

[0008] In order to overcome the problems of low hydrolysis conversion rate and short service life of the catalyst in the existing COS removal, the present invention proposes a nano-hydrolysis catalyst carrier and its chemical synthesis method and application, by increasing the specific surface area and mesopore ratio of the catalyst carrier, thereby improving the purification effect of COS in blast furnace gas and extending the service life of the hydrolysis catalyst.

[0009] The object of the present invention is achieved in that:

[0010] The first aspect of the present invention provides a chemical synthesis method of a nano-sized hydrolysis catalyst carrier, which is synthesized using hexadecyltrimethylammonium bromide, aluminum nitrate and ammonium bicarbonate as raw materials, and comprises the following steps:

[0011] (1) preparing a cetyltrimethylammonium bromide solution with ultrapure water, and then dissolving aluminum nitrate and ammonium bicarbonate in the cetyltrimethylammonium bromide solution respectively to obtain an aluminum nitrate solution and an ammonium bicarbonate solution;

[0012] (2) slowly adding the ammonium bicarbonate solution dropwise to the vigorously stirred aluminum nitrate solution until the reaction solution produces a sol-like substance, then stopping the dropping and continuing stirring for at least one hour, and allowing the solution to stand at room temperature for aging to form a gel;

[0013] (3) The gel is fully dried at 60-80° C., the dried gel is granulated, and calcined in a high-temperature furnace to obtain a nano-sized hydrolysis catalyst carrier.

[0014] Furthermore, the mass concentration of the hexadecyltrimethylammonium bromide solution in step (1) is 0.5-2 g / L.

[0015] Furthermore, in step (1), the mass concentrations of aluminum nitrate and ammonium bicarbonate in the aluminum nitrate solution and the ammonium bicarbonate solution are 20-35% and 10-15%, respectively.

[0016] Furthermore, in step (3), the particle size of the granulation is 0.5-0.7 mm, and the calcination conditions are: heating at 5° C. per minute to 400-500° C. and maintaining the temperature for 2-4 hours.

[0017] The second aspect of the present invention provides a nano-sized hydrolysis catalyst carrier, which is synthesized by the above method.

[0018] Furthermore, the specific surface area of ​​the catalyst carrier is 323.35 to 377.78 m 2 / g, and the strength is 90~135.4.

[0019] The third aspect of the present invention provides the use of the nano-sized hydrolysis catalyst carrier in the removal of carbonyl sulfide. The advantages and beneficial effects of the present invention are:

[0020] The invention uses hexadecyltrimethylammonium bromide, aluminum nitrate and ammonium bicarbonate as raw materials and utilizes a chemical synthesis method to prepare a nano hydrolysis catalyst carrier, which is beneficial to increasing the specific surface area and mesopore ratio of the finished catalyst, thereby improving the purification effect of COS in blast furnace gas and extending the service life of the hydrolysis catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 is a flow chart of the chemical synthesis method of the nano-hydrolysis catalyst carrier according to the embodiment of the present invention;

[0023] Figure 2 This is a graph comparing the conversion efficiencies of three nano-sized hydrolysis catalyst supports in Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0024] The implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the scope of protection of the present invention. In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. Unless otherwise specified, the methods used in the embodiments are common techniques in the art.

[0025] For numerical ranges, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be deemed to be specifically disclosed herein.

[0026] The detection method according to the embodiment of the present invention includes:

[0027] Specific surface area determination method: BET specific surface area test method (GB / T 6609.35);

[0028] Strength determination method: Use catalyst strength tester for determination.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment provides a chemical synthesis method of a nano-hydrolysis catalyst carrier, which is synthesized using hexadecyltrimethylammonium bromide, aluminum nitrate, and ammonium bicarbonate as raw materials, and includes the following steps:

[0031] Step 1: Measure 1L ultrapure water into a 3L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of aluminum nitrate and dissolve it in the above hexadecyltrimethylammonium bromide solution to a concentration of 23%, and stir for about 30 minutes to completely dissolve.

[0032] Step 2: Measure 400 mL of ultrapure water in a 1L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of ammonium bicarbonate and dissolve it in the above hexadecyltrimethylammonium bromide to a concentration of 14%, and stir for about 30 minutes to completely dissolve.

[0033] Step 3: The ammonium bicarbonate solution obtained in step 2 is slowly added to the aluminum nitrate solution obtained in step 1 in batches, and stirred vigorously for 1 hour to allow it to react fully. When the solution becomes slightly turbid, stirring is stopped, and the solution is allowed to stand and age for 48 hours to obtain a wet gel.

[0034] Step 4: After the wet gel is dried at 70°C, the sample is completely converted from the gel state to the solid state. The dried powder is ground and then granulated. The speed of the disc granulator is adjusted to 60r / min and the inclination is 45 degrees. Dry powder is first added to the disc, and then water is sprayed with a sprayer. The spheres are observed to gradually form and become larger. When the diameter is about 0.5-0.7mm, the spheres are taken out. Calcination is carried out in a muffle furnace. The calcination conditions are: heating at 5°C per minute, heating to 450°C and keeping warm for 3 hours, and a nano-hydrolysis catalyst carrier is prepared, which is called sample 1.

[0035] Example 2

[0036] This embodiment provides a chemical synthesis method of a nano-sized hydrolysis catalyst carrier, which is synthesized using hexadecyltrimethylammonium bromide, aluminum nitrate, and ammonium bicarbonate as raw materials, and includes the following steps:

[0037] Step 1: Measure 1L ultrapure water into a 3L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of aluminum nitrate and dissolve it in the above hexadecyltrimethylammonium bromide solution to a concentration of 27%, and stir for about 30 minutes to completely dissolve.

[0038] Step 2: Measure 400 mL of ultrapure water in a 1L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of ammonium bicarbonate and dissolve it in the above hexadecyltrimethylammonium bromide solution to a concentration of 12%, and stir for about 30 minutes to completely dissolve.

[0039] Step 3: The ammonium bicarbonate solution obtained in step 2 is slowly added to the aluminum nitrate solution obtained in step 1 in batches, and stirred vigorously for 1 hour to allow it to react fully. When the solution becomes slightly turbid, stirring is stopped, and the solution is allowed to stand and age for 48 hours to obtain a wet gel.

[0040] Step 4: After the wet gel is dried at 70°C, the sample is completely converted from a gel state to a solid state and granulated (the steps are the same as in Example 1). It is calcined in a muffle furnace. The calcination conditions are: heating at 5°C per minute, heating to 450°C and keeping warm for 3 hours to prepare a nano-hydrolysis catalyst carrier, which is called Sample 2.

[0041] Example 3

[0042] This embodiment provides a chemical synthesis method of a nano-sized hydrolysis catalyst carrier, which is synthesized using hexadecyltrimethylammonium bromide, aluminum nitrate, and ammonium bicarbonate as raw materials, and includes the following steps:

[0043] Step 1: Measure 1L ultrapure water into a 3L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of aluminum nitrate and dissolve it in the above hexadecyltrimethylammonium bromide solution to a concentration of 27%, and stir for about 30 minutes to completely dissolve.

[0044] Step 2: Measure 400 mL of ultrapure water in a 1L beaker, weigh a certain amount of hexadecyltrimethylammonium bromide and dissolve it in the ultrapure water to a concentration of 1g / L, and stir for about 15 minutes to completely dissolve. Then weigh a certain amount of ammonium bicarbonate and dissolve it in the above hexadecyltrimethylammonium bromide solution to a concentration of 12%, and stir for about 30 minutes to completely dissolve.

[0045] Step 3: slowly add the ammonium bicarbonate solution in step 2 to the aluminum nitrate solvent in step 1 in batches, stir vigorously for 1 hour to allow it to react fully, stop stirring when the solution becomes slightly turbid, add 2% silicate at this time, and let the solution stand and age for 48 hours to obtain a wet gel.

[0046] Step 4: After the wet gel is dried at 70°C, the sample is completely converted from a gel state to a solid state and granulated (the steps are the same as in Example 1). It is calcined in a muffle furnace. The calcination conditions are: heating at 5°C per minute, heating to 450°C and keeping warm for 3 hours to prepare a nano-hydrolysis catalyst carrier, which is called Sample 3.

[0047] Test Case

[0048] The three nano-sized hydrolysis catalyst supports synthesized in Examples 1-3 were subjected to strength testing and specific surface area testing (BET). The results are shown in the following table.

[0049] project Sample 1 Sample 2 Sample 3 <![CDATA[Specific surface area (m 2 / g)]]> 323.35 343.85 377.78 strength 134.3 135.4 90

[0050] Catalyst samples A, B and C were prepared using the three nano-sized hydrolysis catalyst supports (samples 1-3) of Examples 1-3 respectively under the same preparation process, and COS conversion and removal were carried out on a laboratory device to determine the hydrolysis conversion efficiency.

[0051] Equal volumes of carriers (samples 1-3) and commercially available hydrolysis catalysts were immersed in 8% potassium carbonate solution for 4 hours, then dried at 120°C for 5 hours, and calcined at 550°C for 3 hours to finally obtain carrier-loaded catalyst samples A, B, and C.

[0052] Catalyst detection method: Gas distribution system parameters: COS: 300-400ppm, hydrogen sulfide: 60-80ppm, oxygen: 1%, the rest is N2;

[0053] Gas flow rate: 1L / min;

[0054] Catalyst: 10mL;

[0055] Reactor temperature: 120°C;

[0056] Airspeed: 6000h -1 .

[0057]

[0058] like Figure 2 The test results show that the hydrolysis conversion efficiency of the three is: sample C>sample B>sample A, but due to the lower strength of sample C, it may be pulverized and damaged in actual operation, affecting the service life. In summary, the catalyst sample B loaded by the carrier sample 1 described in Example 2 is the best solution.

[0059] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred arrangement scheme, a person skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A chemical synthesis method of a nano hydrolysis catalyst carrier, characterized in that: The synthesis is carried out using hexadecyltrimethylammonium bromide, aluminum nitrate and ammonium bicarbonate as raw materials, and comprises the following steps: (1) preparing a cetyltrimethylammonium bromide solution with ultrapure water, and then dissolving aluminum nitrate and ammonium bicarbonate in the cetyltrimethylammonium bromide solution respectively to obtain an aluminum nitrate solution and an ammonium bicarbonate solution; (2) slowly adding the ammonium bicarbonate solution dropwise to the vigorously stirred aluminum nitrate solution until the reaction solution produces a sol-like substance, then stopping the dropping and continuing stirring for at least one hour, and allowing the solution to stand at room temperature for aging to form a gel; (3) The gel is fully dried at 60-80° C., the dried gel is granulated, and calcined in a high-temperature furnace to obtain a nano-sized hydrolysis catalyst carrier.

2. The chemical synthesis method of the nano-hydrolysis catalyst carrier according to claim 1, characterized in that: The mass concentration of the hexadecyltrimethylammonium bromide solution in step (1) is 0.5-2 g / L.

3. The chemical synthesis method of the nano-hydrolysis catalyst carrier according to claim 1, characterized in that: In step (1), the mass concentrations of aluminum nitrate and ammonium bicarbonate in the aluminum nitrate solution and the ammonium bicarbonate solution are 20-35% and 10-15%, respectively.

4. The chemical synthesis method of the nano-hydrolysis catalyst carrier according to claim 1, characterized in that: In step (3), the particle size of the granulation is 0.5-0.7 mm, and the calcination conditions are: heating at 5° C. per minute to 400-500° C. and maintaining the temperature for 2-4 hours.

5. A nano-hydrolysis catalyst carrier, characterized in that: The catalyst carrier is synthesized by the method according to any one of claims 1 to 4.

6. The nano-hydrolysis catalyst carrier according to claim 5, characterized in that: The specific surface area of ​​the catalyst carrier is 323.35 to 377.78 m 2 / g, and the strength is 90~135.

4.

7. Use of the nano-sized hydrolysis catalyst carrier according to claim 5 or 6 in the removal of carbonyl sulfide.

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