A vocs waste gas treatment method combining absorption and adsorption

Abstract

The invention provides a VOCs waste gas treatment method combined with absorption and adsorption, comprising the following steps: VOCs waste gas is absorbed at normal temperature and pressure in the first absorption tower, and unqualified gas is extracted from the top of the tower and passed into the runner for concentration or other methods. In the adsorption system, the purified gas is directly discharged up to the standard, and the residual VOCs in the non-standard gas is concentrated by adsorption-desorption, and then the concentrated gas containing VOCs is discharged into the second absorption tower, where the purified gas is absorbed and reaches the standard Discharge, after the first absorbent rich liquid of the first absorption tower and the second absorbent rich liquid of the second absorption tower are combined, they exchange heat with the regenerated lean liquid extracted from the bottom of the desorption tower, and then pass it into the desorption after overheating The tower is stripped and regenerated in the tower. The invention is suitable for waste gas with low, medium and high concentration, and the concentration of VOCs is 5000mg / m 3 The following exhaust gas treatment effects are remarkable.

Description

technical field [0001] The invention belongs to the technical field of waste gas treatment, and in particular relates to a VOCs waste gas treatment method combining absorption and adsorption. Background technique [0002] Industrial waste gas containing volatile organic compounds (VOCs) is one of the main sources of air pollution. At present, there are three main methods of VOCs treatment terminal control: adsorption-regeneration method, absorption-desorption separation method and oxidation destruction method. At present, the adsorption method widely uses activated carbon as the adsorbent. When the adsorption reaches the saturation of VOCs, the activated carbon needs to be desorbed by hot air, steam or pressure swing. After desorption, the steam or hot air containing VOCs is then subjected to other rectification, extraction or pervaporation operations, so that VOCs can be recycled. The adsorption method has the characteristics of high purification standard rate, but the ad...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a VOCs waste gas treatment method that combines absorption and adsorption, which can solve the problems of low absorption efficiency, large amount of absorbent, interference of water content in the air, high regeneration energy consumption, and absorbent selectivity in traditional absorption methods. , especially when the VOCs concentration is 5000mg / m 3 The effect of the following exhaust gas is remarkable, and the concentration after treatment is reduced to 50mg / m 3 The following emission standards are met, and the recovery rate of VOCs is not less than 99%.

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