VOCs removing method based on photocatalytic free radical advanced oxidation

Abstract

The invention relates to a VOCs removing method based on photocatalytic free radical advanced oxidation. According to the method, strongly oxidative hydroxyl or sulfate free radicals are produced by decomposing peroxide with a combination of ultraviolet light and a catalyst; and the free radicals are used for oxidizing and removing VOCs in an impinging bed. According to the invention, a part of flue gas from an emission source and a part of catalyst particles are mixed and sprayed into the impinging bed with a high-speed nozzle; the other part of flue gas and the other part of catalyst particles are mixed and sprayed into the impinging bed with a coaxially oppositely arranged high-speed nozzle; at a same time, a peroxide solution is sprayed into the impinging bed with a sprayer; the three streams of gas-liquid-solid mixtures are fully mixed in the impinging bed; with the combination of ultraviolet light and the catalyst, the peroxide is decomposed to produce hydroxyl or sulfate free radicals; and VOCs are degraded into harmless CO2 and H2O. With the system, a removal rate of 100% can be realized. The method has a good development prospect.

Description

technical field [0001] The invention relates to the field of combustion flue gas pollution control, in particular to a VOCs removal method based on photocatalytic free radical advanced oxidation. Background technique [0002] A large number of studies have shown that after VOCs (volatile organic compounds) enter the human body through the respiratory tract and skin, they can cause temporary and permanent lesions to human breathing, blood, liver and other organs. Various organic waste gases are produced in industrial production, mainly including various hydrocarbons, alcohols, aldehydes, acids, ketones and amines, etc. These organic waste gases will cause air pollution and endanger human health. With the rapid development of the economy and the improvement of people's awareness of environmental protection, the problem of VOCs removal in exhaust gas has attracted more and more attention. At the same time, the country has also formulated corresponding laws and regulations to s...

AI Technical Summary

Problems solved by technology

[0006] The catalytic combustion method is to convert the exhaust gas into harmless and odorless carbon dioxide and water through catalytic combustion. This method has low ignition temperature, energy saving, high purification rate, convenient operation, small footprint, and is suitable for high temperature or high concentration. Organic waste gas, but the catalyst is easily poisoned and deactivated, and the stability is poor

The removal efficiency of the activated carbon adsorption method can reach 95%, the equipment is simple, and the investment is small, but the activated carbon is replaced frequently, which increases the working procedures of loading, unloading, transportation, and replacement, resulting in increased operating costs

Therefore, so far, although a variety of VOCs removal technologies have been developed and utilized, each technology has almost limited application range and many disadvantages.

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