Process of Producing Chlorine Gas

A process of producing chlorine gas by catalytic oxidation of hydrogen chloride, comprising:

• A) incorporating an oxidizing agent into a gas stream of hydrogen chloride containing impurities, conducting oxidation pretreatment of said gas stream under the action of ultrasonic wave, such that said impurities in the gas stream are oxidized;
• B) the gas stream obtained after the oxidation pretreatment in step A) is allowed to pass through a separator device wherein the oxidized impurities in the form of liquid and/or the oxidized impurities in the form of solid are removed from said gas stream so as to obtain a purified gas stream of hydrogen chloride;
• and
• C) the purified gas stream of hydrogen chloride from step B) is well mixed with a gas stream containing molecular oxygen, the resultant gas mixture is preheated to a reaction temperature, and then introduced into an oxidation reactor and catalytically oxidized in the presence of a catalyst to produce chlorine gas;
• wherein the oxidizing agent used in step A) does not generate additional or new impurities in the whole reaction system;
• the impurities contained in the gas stream of hydrogen chloride are inorganic or organic compounds containing sulfur, organic compounds containing halogen, or hydrocarbons not containing halogen;
• said oxidizing agent is selected from the group consisting of hydrogen peroxide solution, ozone, hypochlorous acid, chlorine, chlorine dioxide, chlorine trioxide, and combinations thereof.