Device and method for catalytic oxidation of ammonia by using novel Y-shaped tube

Abstract

The invention discloses a device and method for catalytic oxidation of ammonia by using a novel Y-shaped pipe, grooves capable of filling solid reaction raw materials are arranged below the same side of two branch pipes of the novel Y-shaped pipe, openings capable of adding liquid reaction raw materials are arranged above the same side of the two branch pipes, the two branch pipes are located on the same horizontal plane, and a main pipe is connected to a drying pipe. The drying pipe is connected with a tail gas absorption device through a three-way valve. Oxygen and ammonia gas are sequentially provided through the two branch pipes of the novel Y-shaped pipe, and are fully contacted and reacted with a catalyst at the main pipe to generate nitric oxide. According to the device and the method, the ammonia-oxygen ratio is controlled through quantitative reaction, the catalytic activity is improved by adopting the composite catalyst, integration of product collection, property inspection and tail gas absorption is realized, the operation is simple, convenient and safe, the phenomenon is obvious, and the experiment success rate is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of basic chemical experimental technology, and in particular to a device and method for catalytically oxidizing ammonia using a novel Y-shaped tube. Background Art

[0002] The catalytic oxidation of ammonia is an oxidation reaction that occurs when ammonia comes into contact with air, oxygen, etc. under high temperature conditions and the action of a catalyst. Its core product, nitric oxide, is the raw material for the industrial preparation of nitric acid and can also be further used to produce nitrate nitrogen fertilizer. This reaction plays an important role in industrial and agricultural production.

[0003] The properties of ammonia and the transformations between nitrogen compounds of different valence states are key topics in high school chemistry. The catalytic oxidation of ammonia, a key experiment, connects numerous key concepts and principles and possesses significant industrial application value. It serves as a classic experiment that bridges theoretical knowledge and industrial applications, helping students intuitively understand the properties, reaction characteristics, and nitric acid preparation processes of substances such as ammonia, nitric oxide, and nitrogen dioxide. This experiment is one of the more challenging in high school chemistry. The traditional method involves aerating air and ammonia vaporized from concentrated aqueous ammonia in a specific ratio. Under the high-temperature catalysis of chromium oxide, the reaction produces nitric oxide gas, which then rapidly transforms into reddish-brown nitrogen dioxide gas. This method suffers from challenges such as difficulty controlling the aeration frequency and ammonia-oxygen ratio, a strong odor, difficulty obtaining and contaminating catalysts, difficulty controlling the catalytic temperature, the generation of white smoke, and a low success rate. While numerous improvements have been proposed, they all suffer from complex setup, the need for multiple alcohol lamps, which increase safety risks, catalyst toxicity, and the lack of quantification of reactants.

[0004] To solve the above problems, an integrated experimental device and method were designed and developed with simple experimental operation, safe and easy-to-obtain catalysts, controllable conditions, obvious phenomena and high success rate to achieve the catalytic oxidation of ammonia, filling the gap in demonstration experiments in textbooks and having very important practical teaching significance and promotion value.

[0005] Invention patent content

[0006] The object of the present invention is to overcome the above-mentioned problems in the prior art and to provide a device and method for realizing catalytic oxidation of ammonia by utilizing a novel integrated Y-tube.

[0007] To achieve the above objectives, the present invention provides the following experimental device and method:

[0008] A device and method for catalytically oxidizing ammonia using a novel Y-shaped tube, comprising the novel Y-shaped tube, a stainless steel alcohol lamp, a drying tube, a three-way valve, a first syringe, and a beaker. The novel Y-shaped tube and the drying tube are fixed to an iron stand by iron clamps, and the glassware is connected by latex tubes or rubber stoppers.

[0009] Furthermore, the novel Y-shaped tube has grooves on the lower sides of the two branches, which are respectively filled with manganese dioxide solid and sodium hydroxide solid; there are openings on the upper sides of the two branches, which are respectively connected to a second syringe filled with hydrogen peroxide and a micro syringe filled with concentrated ammonia water; the two branches are on the same horizontal plane; the main tube of the novel Y-shaped tube is filled with a first glass wool wrapped in calcium chloride, a catalyst, and a second glass wool wrapped in calcium chloride in sequence.

[0010] Furthermore, the medicine in the first syringe is litmus solution or starch potassium iodide solution;

[0011] Furthermore, the amount of sodium hydroxide solid is 1.6-2.1 g, with 1.9 g being the best;

[0012] Furthermore, the amount of the manganese dioxide solid is 0.5 g;

[0013] Furthermore, the dosage of the concentrated ammonia solution is 0.3-0.6 ml, with 0.4 ml being the best;

[0014] Furthermore, the amount of hydrogen peroxide used is 0.8-1.2 ml, with 1 ml being the best;

[0015] Furthermore, the catalyst is composed of any one of a glass wool-loaded copper oxide / iron oxide composite catalyst, a glass wool-loaded copper oxide, and a glass wool-loaded copper oxide / manganese dioxide composite catalyst.

[0016] Furthermore, the optimal mass ratio of the composite catalyst is 1:1.

[0017] Furthermore, the method described herein has the following specific steps:

[0018] Step 1: Turn the three-way valve to Figure 2 (I) State, ignite the stainless steel alcohol lamp to preheat the catalyst for about one minute;

[0019] Step 2: First push the second syringe containing hydrogen peroxide and drip it at a constant speed for about 30 seconds. Then, slowly push the second syringe and the micro syringe at the same time. When reddish-brown gas is observed in the drying tube, stop immediately and extinguish the alcohol lamp to end the reaction.

[0020] Step 3: Turn the three-way valve to Figure 2 (II) State, draw the first syringe to verify the properties of the product.

[0021] Compared with the prior art, the present invention has the following beneficial effects: the use of a new Y-shaped tube as a reactor greatly simplifies the experimental apparatus, is easy to construct, and has simple operating steps, realizing the integration of preparation and property verification; the reaction raw materials are quantified and used in extremely small amounts, the conditions are highly controllable, the phenomenon is obvious, and the success rate is high; the catalyst or composite catalyst used in the reaction system is inexpensive, readily available, green and safe, and has a good catalytic effect; the experimental temperature is easy to control, the device has great promotional value, and is suitable as a classroom demonstration experiment to help students understand the principle of ammonia catalytic oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of the device of the present invention:

[0023] In the figure: 1. New Y-shaped tube; 2. Stainless steel alcohol lamp; 3. Drying tube; 4. Three-way valve; 5. First syringe; 6. Beaker filled with sodium hydroxide solution; 7. Iron stand; 8. Solid manganese dioxide; 9. Second syringe filled with hydrogen peroxide; 10. Solid sodium hydroxide; 11. Miniature syringe filled with concentrated ammonia solution; 12. Catalyst; 13. First glass wool wrapped with calcium chloride; 14. Second glass wool wrapped with calcium chloride.

[0024] Figure 2 It is a partial schematic diagram of the three-way valve steering. DETAILED DESCRIPTION

[0025] In order to make the purpose, experimental methods and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] The experimental device used in this embodiment is as follows: Figure 1 As shown, it includes a new Y-shaped tube 1, a stainless steel alcohol lamp 2, a drying tube 3, a three-way valve 4, a first syringe 5 and a beaker 6 filled with sodium hydroxide solution. The new Y-shaped tube 1 and the drying tube 3 are fixed on the iron stand 7 by iron clamps, and the glass instruments are connected by latex tubes or rubber stoppers. Among them, the two branches of the new Y-shaped tube 1 are made into grooves on the lower side of the same side, respectively filled with manganese dioxide solid 8 and sodium hydroxide solid 10; the upper side of the two branches is made into openings, respectively connected to the second syringe 9 filled with hydrogen peroxide and the micro syringe 11 filled with concentrated ammonia water; and the two branches are on the same horizontal plane, respectively used to provide the reaction raw materials oxygen and ammonia; the main tube of the new Y-shaped tube 1 is filled with the first glass wool 13 wrapped with calcium chloride, the catalyst 12, and the second glass wool 14 wrapped with calcium chloride in sequence, wherein the glass wool wrapped with calcium chloride is used to absorb the water produced during the reaction. The drying tube 3 receives the reaction product nitric oxide, which is then converted into reddish-brown nitrogen dioxide for observation of experimental phenomena. The three-way valve 4 is used to control the flow direction of the gas, such as Figure 2As shown in (I), the gas flows to the beaker 6 containing sodium hydroxide solution for tail gas absorption treatment; Figure 2 As shown in (II), the gas flows to the first syringe 5 for property inspection, wherein the litmus solution in the first syringe 5 is used to verify that the nitric acid produced by the reaction of nitrogen dioxide and water is acidic, and the starch-potassium iodide solution in the first syringe 5 is used to verify the strong oxidizing property of nitric acid.

[0027] The method for catalytic oxidation of ammonia based on the above experimental device specifically includes the following steps:

[0028] Step 1: Add a certain amount of reaction raw materials to the above experimental device, wherein 0.5g of manganese dioxide solid and 1.9g of sodium hydroxide solid are added to the two grooves of the new Y-shaped tube 1 respectively, 1ml of hydrogen peroxide is added to the corresponding second syringe 9, and 0.4ml of concentrated ammonia water is added to the micro syringe 11; the catalyst 12 filled in the main tube of the new Y-shaped tube 1 is a copper oxide / iron oxide composite catalyst loaded with glass wool, and the mass ratio is 1:1; the drying tube 3 is kept dry; and litmus solution is added to the first syringe 5.

[0029] Step 2: Turn the three-way valve 4 to Figure 2 (I) state, ignite the stainless steel alcohol lamp 2 to preheat the catalyst 12 for about one minute;

[0030] Step 3: First, push the second syringe 9 filled with hydrogen peroxide and drip it at a constant speed for about 30 seconds. Then, slowly push the second syringe 9 and the micro syringe 11 at the same time. When reddish-brown gas is observed in the drying tube 3, stop immediately and extinguish the stainless steel alcohol lamp 2 to end the reaction.

[0031] Step 4: Turn the three-way valve 4 to Figure 2 (II) state, pumping the first syringe 5 to verify the acidity of the product;

[0032] Step 5: Turn the three-way valve 4 to Figure 2 (I) state, replace the solution in the first syringe 5 with starch-potassium iodide solution, and then rotate the three-way valve 4 to Figure 2 (II) state, draw the first syringe 5 to verify the strong oxidizing property of the product; after completion, rotate the three-way valve 4 to Figure 2 (I) State, absorbing the exhaust gas.

[0033] Although the present invention has been described herein with reference to a preferred embodiment thereof, it should be understood that numerous other modifications and implementations can be devised by those skilled in the art that will fall within the scope of the principles disclosed herein.

Claims

1. A device and method for catalytic oxidation of ammonia using a novel Y-shaped tube, characterized in that: The device consists of a new Y-shaped tube 1, a stainless steel alcohol lamp 2, a drying tube 3, a three-way valve 4, a first syringe 5, and a beaker 6. The new Y-shaped tube 1 and the drying tube 5 are fixed on an iron stand 7 by iron clamps, and the glassware are connected by latex tubes or rubber stoppers.

2. The novel Y-shaped tube according to claim 1, characterized in that: There is a groove at the bottom of the same side of the two branches, which is respectively filled with manganese dioxide solid 8 and sodium hydroxide solid 10; there is an opening at the top of the same side of the two branches, which is connected to a second syringe 9 filled with hydrogen peroxide and a micro syringe 11 filled with concentrated ammonia water; the two branches are on the same horizontal plane; the main pipe of the new Y-shaped tube 1 is filled with a first glass wool 13 wrapped in calcium chloride, a catalyst 12, and a second glass wool 14 wrapped in calcium chloride in sequence.

3. The method according to claim 1, wherein The following steps are involved: the three-way valve is rotated to the state shown in FIG2(I), the stainless steel alcohol lamp 2 is ignited to preheat the catalyst 12 for about one minute, the second syringe 9 filled with hydrogen peroxide is first pushed to drip at a constant speed for about 30 seconds, and then the second syringe 9 and the micro syringe 11 are slowly pushed at the same time. When a reddish-brown gas is observed to be generated in the drying tube 3, the reaction is stopped immediately, and the alcohol lamp is extinguished to terminate the reaction; finally, the three-way valve is rotated to the state shown in FIG2(II), and the first syringe 5 is pumped to verify the properties of the product.

4. The method according to claim 1, wherein: The medicine in the first syringe 5 is litmus solution or starch potassium iodide solution.

5. As claimed in claim 2, it is characterized in that The amount of sodium hydroxide solid 10 used is 1.8-2.0 g, with 1.9 g being the best.

6. As claimed in claim 2, it is characterized in that The amount of manganese dioxide solid 8 used is 0.5 g.

7. The method according to claim 3, wherein The dosage of concentrated ammonia water is 0.3-0.6ml, with 0.4ml being the best.

8. The method according to claim 3, wherein The dosage of hydrogen peroxide is 0.8-1.2ml, with 1ml being the best.

9. The method according to claim 3, wherein The catalyst 12 is composed of any one of a glass wool-loaded copper oxide / iron oxide composite catalyst, a glass wool-loaded copper oxide, and a glass wool-loaded copper oxide / manganese dioxide composite catalyst.

10. The catalyst according to claim 8, characterized in that The optimal mass ratio of the composite catalyst is 1:1.

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