CN1185417A

CN1185417A - Method for production of stable chlorine dioxide

Info

Publication number: CN1185417A
Application number: CN96118919A
Authority: CN
Inventors: 丁章迅; 丁文洁
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-18
Filing date: 1996-12-18
Publication date: 1998-06-24
Anticipated expiration: 2016-12-18
Also published as: CN1052957C

Abstract

The production method of stable chlorinedioxide is characterized by that the whole production process is implement under the liquid-phase state, i. e. the prepared reactant solution capable of producing chlorinedioxide gas is added in a reactor in which liquid paraffin or aromatic hydrocarbon or solvent gasoline as extracting agent is held, stirred to make reaction, then the chlorinedioxide is directly absorbed by extracting agent, and after the reaction is completed, stood still and layered, other resultant solution of reaction is discharged, then sodium carbonate or sodium percarbonate or sodium perborate solution as stabilizing agent is added, and hydrogen peroxide is added, mixed and stirred to absorb chlorinedioxide from extracting agent, and after separated from extracting agent, the high-concentration product capable of long-term storing can be made up.

Description

Production method of stable chlorine dioxide

The invention relates to a process for producing stable chlorine dioxide.

Chlorine dioxide, as a novel disinfectant, is gaining importance and popularity in people's daily life. However, chlorine dioxide is an unstable gas, which is soluble in water, easily decomposed and difficult to store, and is prepared into liquid stable chlorine dioxide for storage and application except for on-site use, and is acidified (also called activated) by adding organic acid or inorganic acid to release chlorine dioxide gas when the chlorine dioxide is used.

The existing technology for producing stable chlorine dioxide generally adopts a chemical reaction method, pure chlorine dioxide gas is firstly prepared, and then the prepared gas is introduced into liquid serving as a stabilizerto be absorbed to form liquid stable chlorine dioxide. For example, the invention of patent application No. 93111608.2 entitled "method for producing stable chlorine dioxide" is created by reacting sodium chloride with sulfuric acid, using hydrogen peroxide as a reducing agent to produce chlorine dioxide gas, and then introducing 5% sodium carbonate solution as a stabilizer to absorb the chlorine dioxide gas to produce stable chlorine dioxide. Since chlorine dioxide is soluble in water, it is difficult and not completely removed to remove chlorine dioxide gas during the reaction. Meanwhile, chlorine dioxide gas is extremely unstable, and the explosion is possible when the content of the chlorine dioxide gas in the air exceeds 10 percent, and the production condition and the process technical requirement of the production method for preparing stable chlorine dioxide by dissolving gaseous chlorine dioxide in stabilizer liquid are very strict.

The invention aims to disclose a method for producing stable chlorine dioxide, which has simple production process, safety, reliability and high product concentration.

The technological key points of the present invention are that the whole production process of the product is carried out in liquid phase state, that is, reactant solution capable of generating chlorine dioxide gas is prepared and added into a reactor containing liquid alkane or aromatic hydrocarbon or solvent gasoline for stirring reaction, after the reaction is finished, the liquid benzene-taking agent in the container is changed from colorless to yellow green, and is layered with other reaction product solution, other reaction product solution is discharged, then sodium carbonate solution or sodium percarbonate solution or perboric acid solution as stabilizer is added with hydrogen peroxide, and is added into a container containing the extractant dissolved withchlorine dioxide for stirring, when the yellow green extractant is changed to colorless, namely, the original dissolved chlorine dioxide is absorbed by the stabilizer, the stirring is stopped, after the standing and layering, the original stabilizer absorbed by chlorine dioxide is prepared into stable, separating the extract from the extractant, and storing in a lightproof sealed container to obtain the product.

The whole production process of the stable chlorine dioxide is carried out in a liquid phase state, so that the generation of gaseous chlorine dioxide is avoided, and the selected extracting agent can not dissolve reactants participating in the generation of chlorine dioxide and other reaction products except the chlorine dioxide, can not dissolve non-aqueous phase substances in the stabilizing agent participating in the absorption of the chlorine dioxide, and can not chemically react with the substances. The chlorine dioxide dissolved in the extracting agent has high purity, and the chlorine dioxide dissolved in the extracting agent can be completely absorbed by the used stabilizing agent and a proper amount of hydrogen peroxide as an accelerating agent. More particularly, the same part of stabilizing agent can absorb chlorine dioxide from the extraction solution dissolved with chlorine dioxide for a plurality of times, thereby preparing high-concentration stable chlorine dioxide with the concentration of more than 6 percent, which is incomparable with other stable chlorine dioxide production process methods known at present. The preservation period can reach more than one year.

Specific embodiments of the invention are detailed below:

the chemical reactions that produce chlorine dioxide that meet the hygiene standards are several:

1. the reaction equation of sodium chlorite and hydrochloric acid is as follows:

2. the reaction equation of sodium chlorite and sulfuric acid is:

3. sodium chloride and sulfuric acid are used for reducing sodium chlorate to generate chlorine dioxide, and the reaction equation is as follows:

4. the chlorine dioxide is generated by reducing sodium chlorate by hydrochloric acid, and the reaction equation is as follows:

5. oxidizing sodium chlorite with sodium hypochlorite to produce chlorine dioxide, the reaction equation of which is:

among these, the chemical reaction of sodium chlorite with hydrochloric acid to produce chlorine dioxide is preferred for use in the present invention. All reactants were used after being formulated as aqueous solutions. For example, sodium chlorite and water are prepared into a solution with the concentration of 10-20%, and the concentration of hydrochloric acid is 7.5-20% generally; firstly, putting prepared hydrochloric acid and an extracting agent into a reactor provided with a stirrer according to the ratio of 1: 1-4 of the solution amount, starting the stirrer, then pouring sodium chlorite solution with the same amount as the hydrochloric acid into the reactor for 3-5 times at intervals of 2-3 minutes each time, after the sodium chlorite solution is put into the reactor for the last time, continuing stirring for 5-10 minutes, dissolving chlorine dioxide generated by the reaction of the sodium chlorite and the hydrochloric acid into the extracting agent, and changing the color of the extracting agent from colorless to yellowish green. Stopping stirring, allowing the liquid in the reactor to stand for layering, and allowing the extracting agent dissolved with chlorine dioxide to float on the reaction product liquid. The separated reaction product liquid can be placed in a sealed lightproof container to be extracted for the second time. The liquid alkane in the extractant can be cyclohexane or cyclopentane, and the liquid arene can be xylene, chlorobenzene and the like, so long as the working condition that the liquid alkane is always liquid is ensured. Of course, solvent gasoline is the most economical and most suitable extractant.

The preparation of the stabilizer is ideally carried out by three schemes: firstly, dissolving sodium carbonate in water to prepare an aqueous solution with the concentration of 3-12%, taking the amount according to the proportion of the aqueous solution of the sodium carbonate to an extracting agent of 2-1/2: 1, mixing the aqueous solution of the sodium carbonate with the extracting agent absorbing chlorine dioxide, firstly adding 1/2-3/4 of hydrogen peroxide, starting a stirrer, if the extracting agent is changed from yellow green to colorless, pouring the rest of hydrogen peroxide, or gradually adding 1/4-1/3 of hydrogen peroxide until the extracting agent is completely colorless, stopping stirring, standing for layering, and then releasing stable chlorine dioxide; dissolving sodium percarbonate into water to prepare an aqueous solution with the concentration of 5-18% before use, taking the amount of the aqueous solution according to the proportion of 2-1/2: 1 to the extracting agent, preparing hydrogen peroxide with the weight equal to that of pure sodium percarbonate, mixing the aqueous solution of sodium percarbonate and the extracting agent absorbing chlorine dioxide, stirring until the extracting agent absorbing chlorine dioxide is changed from yellow green to colorless, and then adding the standby hydrogen peroxide into the mixture without adding any other spare hydrogen peroxide, or gradually adding a proper amount of hydrogen peroxide until the extracting agent is completely colorless; dissolving sodium perborate in water to prepare an aqueous solution with the concentration of 5-20% before use, preparing hydrogen peroxide with the same amount as the pure sodium perborate, and mixing and stirring the sodium perborate aqueous solution and the extracting agent according to the proportion of 2-1/2: 1, wherein if the extracting agent absorbing chlorine dioxide is changed from yellow green to colorless, the hydrogen peroxide is not required to be added, otherwise, a proper amount of hydrogen peroxide is gradually poured into the extracting agent and stirred until the extracting agent is completely changed to colorless.

The same stabilizer is matched with hydrogen peroxide to absorb chlorine dioxide from the extracting agent absorbing chlorine dioxide for many times so as to prepare a high-concentration stable chlorine dioxide product. Two or more reactors provided with stirrers can be connected into a production line, and each reactor is fixed to work with a dose of extractant, so that continuous reaction and production are realized.

When in use, the chlorine dioxide can be released by adding organic acid or inorganic acid into the stable chlorine dioxide to acidify the stable chlorine dioxide, thereby achieving the purpose of disinfection and sterilization.

Claims

1. A method for producing stabilized chlorine dioxide, comprising: mixing reactant solution capable of generating chlorine dioxide gas, successively adding the reactant solution into a reactor containing liquid alkane or aromatic hydrocarbon or solvent gasoline as an extracting agent, stirring and reacting, after the reaction is finished, the liquid extracting agent in the reactor is changed from colorless to yellow-green, and is layered with other reaction product solutions, discharging other reaction product solutions, then adding sodium carbonate solution or sodium percarbonate solution or sodium perborate solution as a stabilizing agent, and adding hydrogen peroxide, successively adding the mixture into the reactor containing the extracting agent absorbing chlorine dioxide, stirring until the extracting agent is changed from yellow-green to colorless, standing and layering, then preparing the original stabilizing agent absorbing chlorine dioxide into stable chlorine dioxide, separating the stable chlorine dioxide from the extracting agent, and filling the stable chlorine dioxide into a lightproof sealed container.

2. The method for producing stabilized chlorine dioxide as claimed in claim 1, wherein: the reactant capable of generating chlorine dioxide gas can be sodium chlorite and hydrochloric acid, or sodium chlorite and sulfuric acid, or sodium chlorate can be reduced by sodium chloride and sulfuric acid, or sodium chlorate can be reduced by hydrochloric acid, or sodium chlorite can be oxidized by hypochlorous acid.