Preparation method of chlorine dioxide without production of solids

Abstract

The invention discloses a preparation method of chlorine dioxide without production of solids. The method comprises the following steps: filtering a concentrated sodium chlorate solution sent from an electrolytic bath, then injecting into a generator to form a reaction mother solution, circulating in the generator and a circulating pipeline under the action of a circulating pump, maintaining the reaction mother solution at a certain density and temperature, then adding hydrochloric acid sent from a hydrochloric acid system, reacting to generate chlorine gas, chlorine dioxide gas and sodium chloride, cooling the chlorine dioxide gas, then absorbing the chlorine dioxide gas by low-temperature chilled water to obtain a chlorine dioxide water solution, sending the chlorine gas produced by reaction into a hydrochloric acid furnace to be burned with hydrogen gas produced in the electrolytic bath to prepare hydrochloric acid, and returning a dilute sodium chlorate solution after reaction into the electrolytic bath by a pump for re-preparing the concentrated sodium chlorate solution for recycling. According to the method disclosed by the invention, the production of the solids can be prevented in the whole reaction process and scaling of equipment can be avoided, so that sodium chloride and sodium dichromate can be completely recycled and do not need to be supplemented basically.

Description

technical field [0001] The invention relates to the field of chlorine dioxide production, in particular to a method for preparing chlorine dioxide without generating solids. technical background [0002] Chlorine dioxide is a strong oxidizing agent. Stable chlorine dioxide has been considered by the World Health Organization as a fungicide with good effect and a bactericidal disinfectant with excellent performance, and it is also a good paper bleaching agent. Since the 1930s, industrial production has begun, and there are currently about 1,000 chlorine dioxide production plants in North America and Europe. At present, my country has realized the localization of the methanol-based chlorine dioxide production system for pulp bleaching. However, the hydrochloric acid-based chlorine dioxide production system is still in the research and development stage in China. The existing paper-making enterprises adopt the hydrochloric acid-based chlorine dioxide production system. For comp...

AI Technical Summary

Problems solved by technology

Since the 1970s, foreign countries have successively developed a new method of electrolytically synthesizing chlorine dioxide using sodium chloride, sodium chlorate and sodium chlorite as electrolytes. This method requires a large investment in equipment and complicated processes, and has not yet been promoted.

Because sodium chloride crystals are produced during the reaction process, it will cause scaling problems in the reactor and reboiler. Scaling will lead to a decrease in heat exchange efficiency. Regular descaling is necessary. Descaling will inevitably lead to loss of sodium chloride and material imbalance. , need to add salt

In addition, because the electrolytic cell needs to add a small amount of sodium dichromate to reduce the electrolytic oxygen content, however, the sodium chlorate solution electrolyzed by the R6 method will not return after being sent to the generator, and the sodium dichromate cannot be returned to the electrolytic cell, so The electrolytic cell has to be supplemented with sodium dichromate all the time, and the sodium dichromate will accumulate in the generator, and to a certain extent, it will fly off along with the exhaust foam, enter the chlorine dioxide solution, and part of it will be discharged to the chlorine dioxide solution during descaling. sewers, pollution

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