The industrial production of chlorine dioxide mainly adopts the R2 method.

The industrial production of chlorine dioxide, that is, using sulfur dioxide, chloride ions and methanol as reducing agents, reacts with sodium chlorate under acidic conditions to prepare chlorine dioxide. Chlorine dioxide is prepared by using sulfur dioxide as a reducing agent, and sulfur dioxide gas is entrained in the product, and CL2 is generated during the reaction, and the purity of the product is not high. When chlorine dioxide is used as a reducing agent to produce chlorine dioxide, every time Imol of chlorine dioxide is obtained, 0.5 mol of CL2 is produced, and the product needs to be specially treated. When methanol is used as a reducing agent, a degree of reduction is obtained to produce by-products such as formaldehyde, formic acid, carbon dioxide, and methanol which are not completely reacted. Methanol, formaldehyde and formic acid are all toxic substances. They bring many disadvantages to the application of chlorine dioxide. For example, bleaching will produce chlorinated organic substances. For drinking water treatment, it will produce carcinogens such as three lv methane. Come to secondary pollution.

The preparation method of the new chlorine dioxide is significantly reduced, and the yield and purity of chlorine dioxide are satisfactory. It is to accelerate and promote the large-scale promotion and application of chlorine dioxide in the field of water treatment in China. Foundation.

The future development of chlorine dioxide preparation technology mainly has the following trends:

(1) Process In the process of material conversion under normal conditions, it is difficult to create new processes due to chemical equilibrium and other conversion conditions. At the same time, greening puts new demands on the process. The conditions for the preparation of chlorine dioxide by conventional processes are generally vacuum, high temperature, and high pressure. To this end, explore some unconventional media (such as plasma, ionic liquids, supercritical CO 2, supercritical water, etc.) and extreme conditions (such as supercritical / subcritical, ultra-low temperature, microwave, ultrasonic, ultraviolet, etc.) under chlorine dioxide The production process, in order to break through the traditional chlorite and chlorate preparation of chlorine dioxide, open up a new process for the preparation of chlorine dioxide, so that the application of chlorine dioxide is rapidly promoted, may form an original industrialization Series of results.

(2) Renovation of the reactor and other related equipment in the equipment, design a more reasonable single-chamber reactor, and integrate the reaction evaporation and crystallization. Reduce investment, reduce consumption, reduce waste liquid emissions, and streamline processes. For example, since the introduction of chlorine dioxide system from the chlorate method, the problem of acid thenardite treatment in the system has been a problem, and some methods have been able to significantly reduce the output of thenardite. For example, the preparation of chlorine dioxide by the combination process of Leji, the system has almost no by-products of thenardite, solving the problem of the preparation of chlorine dioxide. At the same time, based on the new process, some new reactors, such as membrane reactors, microwave plasma reactors, photochemical reactors, microreactors, etc., have been developed.

(3) In the case of raw materials, find a more suitable and cheaper reducing agent to reduce costs. For example, a new method for preparing chlorine dioxide by using sugar or straw as a reducing agent. The outstanding advantages of this method are low cost (complete conversion of the drug) and high purity and stability of the product.

(4) Use better and more suitable stabilizers for the stability of chlorine dioxide. At present, there are many researches on the selection of stabilizers. The trend is high concentration, high stability and slow release and reduced costs.

In developed countries, chlorine dioxide is applied at a higher rate every year. So far, many water plants in the United States have applied chlorine dioxide to purify water. There are also thousands in Europe. The market demand for chlorine dioxide in China is also very high. As people's requirements for environmental quality and hygiene continue to increase, chlorine dioxide, a new type of bleaching agent, preservative and disinfectant, will have a very broad market. Therefore, accelerating the research of new production processes and their applications has very important practical significance. China's research on chlorine dioxide started late, domestic enterprises are small and scattered, and most of them introduce or imitate foreign technology, but there is no production process. Significant improvements, so the development of chlorine dioxide generation technology with independent intellectual property rights as soon as possible is an important issue facing enterprises and scientific research institutions.

China's scientific research units and institutions of higher learning should pay more attention to and strengthen the research on the new preparation process of chlorine dioxide. The state and the government should provide more funding for the research and development of chlorine dioxide preparation technology, with a view to the cost and purity of chlorine dioxide production. Breakthroughs in factors such as yield and development, and the development of chlorine dioxide generation technology with independent intellectual property rights as soon as possible, so that the application of chlorine dioxide in China has been rapidly promoted.