Method for recovering organic solvent from organic water gas

Abstract

The invention belongs to the technical field of treatment of organic waste gas, and relates to a method for recovering an organic solvent from organic waste gas. The method comprises the following steps of: adsorbing the organic solvent in the organic waste gas into active carbon, purifying, and discharge within controlling indexes of a national standard; when the active carbon is saturated by adsorbing, heating the residual organic waste gas in a pipeline, desorbing the organic solvent which is absorbed by the active carbon, and regenerating the active carbon; performing heat exchange on thedesorbed organic solvent gas, condensing into liquid, and recovering; and heating condensed waste gas, reentering the desorbed saturated active carbon again, circulating, and finishing one-time desorption. The method has the advantages of simple process flow, convenience for operating, saving in energy, reduction in production cost, lowering of the organic substance content of the waste gas to reach an environmentally-friendly emission standard, capability of recycling organic substances in the waste gas as resources, regeneration of active carbon, no emission of secondary pollutants, remarkable economic benefit and wide application field.

Description

technical field [0001] The invention belongs to the technical field of organic waste gas treatment, and relates to a combined method for recovering organic solvents in organic waste gas through combined operations of activated carbon adsorption-hot air desorption-freezing recovery. Background technique [0002] Due to the wide variety of organic solvents, which are widely used and used in huge quantities, organic solvent gases are discharged into the atmosphere without treatment, which not only has toxic and side effects, but also produces acid smog and photochemical smog in the troposphere of the atmosphere, depleting ozone in the stratosphere of the atmosphere, and eventually It will endanger the life safety of human beings, animals and plants. However, although the mixed gas of the recovered organic solvent and air can be detoxified through flame combustion or flameless catalytic combustion, it will still produce a large amount of greenhouse gas carbon dioxide. Therefore...

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Problems solved by technology

[0003] However, the liquid absorption method will produce a large amount of wastewater, and the cost of wastewater treatment is relatively high; the solid adsorption method uses activated carbon adsorption. Although this method is currently the best and most widely used in the adsorption of organic waste gas, when the activated carbon is saturated, the activated carbon will lose. For the adsorption capacity of organic pollutants, at this time, the activated carbon must be replaced or regenerated and reused. The replacement of activated carbon is not only costly, but also labor-intensive. However, the traditional water vapor desorption process is used to regenerate activated carbon. It will cause waste water and secondary pollution; although the recovery of solvent by freezing condensation method has high purity, the recovery effect is not great when the concentration of organic solvent is low, and this method is often used as pretreatment of absorption method and adsorption method

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