A method for producing chlorine dioxide gas

Abstract

This invention provides a method for preparing chlorine dioxide gas, belonging to the technical field of disinfectant preparation. The method involves adding an acidic solution and / or sodium persulfate solution to a solid preparation containing chlorite, conducting a redox reaction to obtain chlorine dioxide gas. The addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min; the solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4–6 g: 8–15 mL. This invention controls the generation rate of chlorine dioxide gas by controlling the quantitative and rate-controlled liquid addition, avoiding spontaneous combustion caused by excessively high chlorine dioxide concentrations. Simultaneously, it maintains an excess solid state in the reaction system, reducing the dissolution of chlorine dioxide gas and improving the preparation efficiency of chlorine dioxide gas.

Description

Technical Field

[0001] This invention belongs to the field of disinfectant preparation technology, specifically relating to a method for preparing chlorine dioxide gas. Background Technology

[0002] Chlorine dioxide has strong bactericidal, disinfectant, and bleaching effects. It is a broad-spectrum disinfectant recommended by the World Health Organization for microbial disinfection and sterilization, and its applications cover multiple fields such as water treatment, papermaking, food, and medical and health care.

[0003] Chlorine dioxide is inherently unstable and readily soluble in water, so gaseous chlorine dioxide generally needs to be prepared on-site. Currently, there are two main methods for generating chlorine dioxide gas: gas-solid reactions and liquid-liquid reactions. The gas-solid reaction involves the reaction of chlorine gas with sodium chlorite to produce chlorine dioxide. In this reaction, chlorine gas is highly toxic, posing safety hazards during use. The liquid-liquid reaction involves the reaction of sodium chlorite solution with an oxidizing agent solution or an acid solution. After the solution reaches saturation, chlorine dioxide is released into the air. This reaction has a relatively low yield of gaseous chlorine dioxide. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing chlorine dioxide gas, which is safe in preparation process and has high preparation efficiency of chlorine dioxide gas.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing chlorine dioxide gas, comprising the following steps: adding an acidic solution and / or sodium persulfate solution to a solid preparation containing chlorite, and carrying out an oxidation-reduction reaction to obtain chlorine dioxide gas;

[0007] The addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min;

[0008] The solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4-6 g: 8-15 mL.

[0009] Preferably, the chlorite is one or both of sodium chlorite and potassium chlorite.

[0010] Preferably, the solid dosage form contains 80-95 wt% chlorite.

[0011] Preferably, the solid dosage form further includes one or more of a wetting agent, a binder, a disintegrant, and a lubricant.

[0012] Preferably, the wetting agent is one or both of distilled water and ethanol;

[0013] The binder is one or more of glucose, starch, dextrin, and sucrose;

[0014] The disintegrant is one or both of sodium hydroxymethyl starch and croscarmellose sodium;

[0015] The lubricant is one or both of magnesium stearate and talc.

[0016] Preferably, the acidic solution is one or more of sulfuric acid solution, hydrochloric acid solution, citric acid solution, ascorbic acid solution, and sodium bisulfate solution.

[0017] Preferably, when the acidic solution includes a sulfuric acid solution, the concentration of the sulfuric acid solution is 1-2 mol / L;

[0018] When the acidic solution includes a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 1-2 mol / L;

[0019] When the acidic solution includes a citric acid solution, the concentration of the citric acid solution is 150–300 g / L;

[0020] When the acidic solution includes an ascorbic acid solution, the concentration of the ascorbic acid solution is 150–300 g / L;

[0021] When the acidic solution includes a sodium bisulfate solution, the concentration of the sodium bisulfate solution is 300–670 g / L.

[0022] Preferably, the concentration of the sodium persulfate solution is 10–20 g / L.

[0023] Preferably, the redox reaction takes 8 to 12 minutes.

[0024] Preferably, the addition method is dripping or spraying.

[0025] This invention provides a method for preparing chlorine dioxide gas. An acidic solution and / or sodium persulfate solution are added to a solid preparation containing chlorite to carry out a redox reaction, yielding chlorine dioxide gas. The addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min. The solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4–6 g: 8–15 mL. This invention, by controlling the quantitative and rate-controlled liquid addition, controls the generation rate of chlorine dioxide gas, thereby avoiding spontaneous combustion caused by excessively high chlorine dioxide concentrations, and ensuring production safety by avoiding the use of toxic chlorine gas. Furthermore, it ensures that the reaction system is in a state of solid excess, minimizing the dissolution of chlorine dioxide gas due to the minimal amount of solution, and allowing the chlorine dioxide produced in the reaction to be directly released into the air, thus improving the preparation efficiency of chlorine dioxide gas. Results from the examples show that using the preparation method of this invention, 1 g of sodium chlorite can release 480–512 mg of chlorine dioxide gas upon complete reaction, improving the yield of chlorine dioxide. Detailed Implementation

[0026] This invention provides a method for preparing chlorine dioxide gas, which involves adding an acidic solution and / or sodium persulfate solution to a solid preparation containing chlorite to carry out a redox reaction to obtain chlorine dioxide gas;

[0027] The addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min;

[0028] The solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4-6 g: 8-15 mL.

[0029] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.

[0030] The present invention involves adding an acidic solution and / or sodium persulfate solution to a solid preparation containing chlorite to carry out a redox reaction, thereby obtaining chlorine dioxide gas.

[0031] In this invention, the chlorite is preferably one or both of sodium chlorite and potassium chlorite, more preferably sodium chlorite.

[0032] In this invention, the mass content of chlorite in the solid preparation is preferably 80-95 wt%, more preferably 85-90 wt%.

[0033] In this invention, the solid dosage form preferably further includes one or more of sodium sulfate, a wetting agent, a binder, a disintegrant, and a lubricant, more preferably a single dosage form of chlorite. In this invention, when the solid dosage form is a single dosage form of chlorite, the aforementioned mass content refers to the purity of the chlorite.

[0034] In this invention, the wetting agent is preferably one or both of distilled water and ethanol, and when it is a mixture of the two, the volume concentration of ethanol is preferably 75%; the binder is preferably one or more of glucose, starch, dextrin, and sucrose, more preferably dextrin; when the binder is dextrin, the mass of the dextrin is preferably 2% of the mass of the solid dosage form; the disintegrant is preferably one or both of sodium hydroxymethyl starch and croscarmellose sodium, more preferably sodium hydroxymethyl starch; when the disintegrant is sodium hydroxymethyl starch, the mass of the sodium hydroxymethyl starch is preferably 3% of the mass of the solid dosage form; the lubricant is preferably one or both of magnesium stearate and talc, more preferably magnesium stearate, and when the lubricant is magnesium stearate, the mass of the magnesium stearate is preferably 0.1% of the mass of the solid dosage form.

[0035] In this invention, the solid preparation is preferably in the form of powder or compressed into solids of different shapes, and more preferably in the form of powder.

[0036] In this invention, the acidic solution is preferably one or more of sulfuric acid solution, hydrochloric acid solution, citric acid solution, ascorbic acid solution and sodium bisulfate solution, more preferably one or two of sulfuric acid solution and sodium bisulfate solution.

[0037] In this invention, when the acidic solution includes a sulfuric acid solution, the concentration of the sulfuric acid solution is preferably 1-2 mol / L, more preferably 1.5 mol / L; when the acidic solution includes a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 1-2 mol / L, more preferably 1.5 mol / L; when the acidic solution is preferably a combination of sulfuric acid and hydrochloric acid solutions, when the solution concentration is too high, the reaction intensifies, causing an explosion, while the amount of chlorine dioxide generated decreases.

[0038] In this invention, when the acidic solution includes a citric acid solution, the concentration of the citric acid solution is 150-300 g / L, more preferably 200-250 g / L; when the acidic solution includes an ascorbic acid solution, the concentration of the ascorbic acid solution is 150-300 g / L, more preferably 200-250 g / L.

[0039] In this invention, when the acidic solution includes a sodium bisulfate solution, the concentration of the sodium bisulfate solution is 300–670 g / L, more preferably 550–620 g / L, and even more preferably 600 g / L. As the concentration of sodium bisulfate increases, the amount of chlorine dioxide generated increases. When the concentration of the sodium bisulfate solution is 600 g / L, the amount of chlorine dioxide generated reaches its maximum. Further increases in the concentration of the sodium bisulfate solution do not change the amount of chlorine dioxide generated. When the concentration reaches 670 g / L, the sodium bisulfate solution is saturated.

[0040] In this invention, the concentration of the sodium persulfate solution is preferably 10-20 g / L, more preferably 15 g / L.

[0041] In this invention, the preferred method of addition is dripping or spraying, and the preferred device for adding the solution is a constant-speed, quantitative pipetting device.

[0042] In this invention, the addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min, preferably 0.3–0.7 mL / min, and more preferably 0.5 mL / min. A low addition rate results in a long reaction time. When the addition rate exceeds 0.8 mL / min, excessively high local concentrations of chlorine dioxide can lead to explosions. Firstly, the explosions decompose chlorine dioxide gas; secondly, intensified explosions can cause sodium chlorite solids to scatter, making the reaction uncontrollable and impossible to proceed.

[0043] In this invention, the solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4-6 g: 8-15 mL, preferably 5 g: 10 mL.

[0044] In this invention, the redox reaction time is preferably 8 to 12 minutes, more preferably 10 minutes. The redox reaction time is calculated from the moment the acidic solution and / or sodium persulfate solution are completely added.

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to specific examples. The described embodiments are only some embodiments of the present invention, and not all embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the embodiments of the present invention based on the technical essence and general principles of the present invention without creative effort should be within the protection scope of the present invention.

[0046] Example 1

[0047] 5g of 80wt% sodium chlorite was placed in a container, and 10mL of 600g / L sodium bisulfate aqueous solution was added dropwise at a rate of 0.5mL / min. After addition, the mixture was allowed to react for 10min. The concentration of chlorine dioxide gas in the air was measured using a chlorine dioxide sensor, and the amount of chlorine dioxide generated was calculated based on the volume of the reaction chamber. The final measured amount of chlorine dioxide generated was 2523mg.

[0048] Example 2

[0049] 10 mL of a 500 g / L sodium bisulfate aqueous solution was added dropwise to the container at a rate of 0.5 mL / min. The remaining steps were the same as in Example 1. The final measured chlorine dioxide production was 2474 mg.

[0050] Example 3

[0051] 10 mL of a 670 g / L sodium bisulfate aqueous solution was added dropwise to the container at a rate of 0.5 mL / min. The remaining steps were the same as in Example 1. The final measured chlorine dioxide production was 2489 mg.

[0052] Example 4

[0053] 10 mL of a 600 g / L sodium bisulfate aqueous solution was added dropwise to the container at a rate of 0.3 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 2511 mg.

[0054] Example 5

[0055] 10 mL of a 600 g / L sodium bisulfate aqueous solution was added dropwise to the container at a rate of 0.7 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 2504 mg.

[0056] Example 6

[0057] 10 mL of a 1 mol / L sulfuric acid aqueous solution was added dropwise to the container at a rate of 0.5 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 2227 mg.

[0058] Example 7

[0059] 10 mL of a 1 mol / L hydrochloric acid aqueous solution was added dropwise to the container at a rate of 0.5 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 2195 mg.

[0060] Example 8

[0061] 10 mL of a 300 g / L citric acid aqueous solution was added dropwise to the container at a rate of 0.5 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 501 mg.

[0062] Example 9

[0063] 10 mL of a 150 g / L ascorbic acid aqueous solution was added dropwise to the container at a rate of 0.5 mL / min, with the other steps being the same as in Example 1. The final measured amount of chlorine dioxide generated was 249 mg.

[0064] Example 10

[0065] A 10 mL, 15 g / L sodium persulfate aqueous solution was added dropwise to the container at a rate of 0.5 mL / min, with the other steps being the same as in Example 1. The final measured chlorine dioxide production was 85 mg.

[0066] Comparative Example 1

[0067] The only difference from Example 1 was that the sodium bisulfate aqueous solution was added dropwise to the container at a rate of 1.0 mL / min; all other steps were the same as in Example 1. The final measured amount of chlorine dioxide generated was 881 mg, and significant explosions accompanied the gas production.

[0068] Comparative Example 2

[0069] The only difference from Example 1 was that the concentration of the sodium bisulfate aqueous solution was 200 g / L; all other steps were the same as in Example 1. The final measured amount of chlorine dioxide generated was 813 mg.

[0070] Comparative Example 3

[0071] The only difference from Example 6 was that the concentration of the sulfuric acid aqueous solution was 2.5 mol / L; all other steps were the same as in Example 1. The final measured chlorine dioxide production was 1914 mg, with slight bursts occurring during gas generation.

[0072] Comparative Example 4

[0073] The only difference from Example 6 was that the sulfuric acid aqueous solution was added dropwise to the container at a rate of 1.0 mL / min; all other steps were the same as in Example 1. The final measured amount of chlorine dioxide generated was 1803 mg, and significant explosions accompanied the gas production.

[0074] Comparative Example 5

[0075] The only difference from Example 1 is that 5g of 80wt% sodium chlorite was dissolved in 10mL of water to make a solution, and all other conditions were the same. The final measured amount of chlorine dioxide generated was 498mg.

[0076] Comparative Example 6

[0077] The only difference from Example 1 is that 10 mL of a 600 g / L sodium bisulfate aqueous solution was added to the container all at once, while all other conditions remained the same. The final measured amount of chlorine dioxide generated was 612 mg, and the gas was accompanied by obvious explosions.

[0078] The reaction conditions and chlorine dioxide production amounts for the examples and comparative examples are shown in Table 1.

[0079] Table 1. Results of chlorine dioxide generation tests in Examples 1-10 and Comparative Examples 1-6

[0080]

[0081]

[0082] As shown in Table 1, the data from Examples 1, 6, and Comparative Examples 1-4 indicate that when the solution concentration is too high, the reaction rate of the acidic solution accelerates, the reaction intensifies, and an explosion occurs, leading to uncontrollable reaction and a decrease in chlorine dioxide production. When the addition rate exceeds 0.8 mL / min, chlorine dioxide is generated too quickly, resulting in excessively high local concentrations, causing an explosion and reducing the amount of chlorine dioxide produced. Furthermore, the results from Examples 1 and 5 show that, compared to liquid-liquid reactions, the present invention employs a liquid-solid reaction method, which significantly improves the yield of chlorine dioxide gas. The results from Examples 1 and 6 show that, by controlling the addition rate of the acidic solution, the present invention controls the generation rate of chlorine dioxide gas, thereby avoiding spontaneous explosions caused by excessively high chlorine dioxide concentrations. On the other hand, it also ensures that the reaction system is in a state of solid excess, minimizing the dissolution of chlorine dioxide gas with minimal solution, allowing the chlorine dioxide produced in the reaction to be directly released into the air, thus improving the preparation efficiency of chlorine dioxide gas.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing chlorine dioxide gas, characterized in that, Includes the following steps: An acidic solution and / or sodium persulfate solution are added to a solid preparation containing chlorite to carry out a redox reaction, yielding chlorine dioxide gas. The addition rate of the acidic solution and / or sodium persulfate solution is ≤0.8 mL / min; The solid-liquid ratio of the solid preparation containing chlorite to the acidic solution and / or sodium persulfate solution is 4-6 g: 8-15 mL; The acidic solution is one or more of hydrochloric acid solution, citric acid solution, ascorbic acid solution, and sodium bisulfate solution; When the acidic solution includes a hydrochloric acid solution, the concentration of the hydrochloric acid solution is 1-2 mol / L; When the acidic solution includes a citric acid solution, the concentration of the citric acid solution is 150–300 g / L; When the acidic solution includes an ascorbic acid solution, the concentration of the ascorbic acid solution is 150–300 g / L; When the acidic solution includes a sodium bisulfate solution, the concentration of the sodium bisulfate solution is 300–670 g / L; The concentration of the sodium persulfate solution is 10–20 g / L.

2. The preparation method according to claim 1, characterized in that, The chlorite is one or both of sodium chlorite and potassium chlorite.

3. According to the preparation method of claim 1 or 2, the mass content of chlorite in the solid preparation is 80-95 wt%.

4. The preparation method according to claim 1, characterized in that, The solid dosage form also includes one or more of wetting agents, binders, disintegrants and lubricants.

5. The preparation method according to claim 4, characterized in that, The wetting agent is one or both of distilled water and ethanol; The binder is one or more of glucose, starch, dextrin, and sucrose; The disintegrant is one or both of sodium hydroxymethyl starch and croscarmellose sodium; The lubricant is one or both of magnesium stearate and talc.

6. The preparation method according to claim 1, characterized in that, The redox reaction takes 8–12 minutes.

7. The preparation method according to claim 1, characterized in that, The method of addition is dripping or spraying.

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