Method for comprehensive treatment of volatile organic waste gas

Abstract

The invention provides a method for comprehensive treatment of volatile organic waste gas. The method mainly includes the steps that microwave radiation is introduced into a catalytic combustion treatment process of the volatile organic waste gas, radiation energy of 3000-4000 MHz is the most appropriate, if the radiation energy is too low, the activation degree of a catalyst is not enough, and nocatalyst with the excellent catalytic activity can be obtained; and if the microwave radiation energy is too high, the changes of the physical and chemical properties of the catalyst cannot be controlled due to the too high catalyst temperature, and meanwhile, energy consumption is large and the production cost is too high. In addition, microwave radiation is conducted during continuous introduction of the waste gas, the high activity of the catalyst is further maintained for a long time advantageously, and the reason is that energy of microwave radiation promotes metal ions in the catalyst to complete an oxidation-reduction cycle in the process of oxidation of adsorbed state VOCs; and after the action of microwave irradiation, the metal dispersity of the catalyst is increased, carbon deposits on the surface of the catalyst are reduced, and thus the catalyst can maintain the high activity for a long time.

Description

technical field [0001] The invention relates to a method for treating air pollution, in particular to a method for treating volatile organic waste gas. Background technique [0002] Volatile organic compounds (VOCs) generally refer to organic compounds with a boiling point of less than 260°C at standard atmospheric pressure and a vapor pressure of greater than 71Pa at room temperature. Usually, the number of carbon atoms in the molecule of VOCs is less than 12 (excluding metal organic compounds and organic acids). Most of the VOCs contain foul smell or toxicity, and even some of them have "three-caused" effects. Even if some VOCs themselves are not too harmful, they can photochemically react with NOx, HCS and oxidants to generate photochemical smog, which will also cause harm to the environment. serious hazard. The VOCs in the atmosphere mainly come from the gases discharged from chemical and petrochemical production (such as solvents, dry cleaning agents, certain oil and g...

AI Technical Summary

Problems solved by technology

And for low concentration VOCs (low concentration usually refers to the concentration of VOCs at 2000mg / m 3 Below) the treatment effect is poor through non-destructive methods, and the combustion method is generally used

Combustion treatment can be divided into direct oxidation combustion method and catalytic oxidation combustion method. Both of them have better removal rate of VOC. The direct oxidation combustion method has less one-time investment but the cost of auxiliary fuel required for later treatment of VOCs is high. Catalytic oxidation In contrast to the combustion method, the initial investment is high, but due to the use of catalysts, the incineration temperature of VOCs is reduced below 315 ° C, thereby greatly reducing the cost of auxiliary fuel

The catalytic oxidation combustion method has certain advantages in terms of continuous input costs, but it also has corresponding defects, such as the catalyst is easily affected by substances such as halogens, sulfides, and nitrogen oxides in the exhaust gas to be treated, and the catalytic activity is reduced or even deactivated