Combined technique of separating and recycling VOCS (volatile organic compounds) from industrial waste gas by adsorption-desorption-rectification-pervaporation

Abstract

The invention relates to a combined technique of separating and recycling VOCS (volatile organic compounds) from industrial waste gas by adsorption-desorption-rectification-pervaporation, which comprises the following steps: drying, cooling and filtering the industrial waste gas containing the VOCS, then conveying into a plurality of adsorption-desorption groups to carry out adsorption-desorption operation, uniformly spraying through upper parts of adsorption-desorption devices by saturated vapor with the pressure at 0.15-0.5MPa, heating GAC (granular active carbon) or ACF (active carbon fiber) to desorb the adsorbed VOCS; after finishing the desorption, entering the next adsorption, using the VOCS-containing saturated vapor desorbed by the vapor in a pervaporation membrane for separation and heat supply. The combined technique provided by the invention forms an impact and enclosed circulation to sufficiently recycle the VOCS from the waste gas. The VOCS-containing saturated vapor desorbed by the saturated vapor contains large amount of latent heat and sensible heat, and the sensible heat of residual liquid on the bottom of a rectification tower is utilized sufficiently.

Description

technical field [0001] The invention relates to the field of environmental protection and chemical separation, in particular to an adsorption-desorption-rectification-pervaporation separation and recovery of volatile organic compounds (VOC) in industrial waste gas S ) combination process. Background technique [0002] Contains VOC S At present, activated carbon fiber (ACF), granular activated carbon (GAC), molecular sieve and other solid adsorbents are widely used to adsorb VOC S , Purify exhaust gas VOC S Empty up to standard. Adsorption up to VOC S After saturation, use saturated steam to heat and desorb VOC S , forming VOC-containing S Saturated water vapor, condensed and cooled with cooling water to obtain VOC-containing S The aqueous solution, some are homogeneous, and then purified by rectification or extraction to reach a given VOC S Quality standards, recycling; some are two-phase, after separating the water layer, VOC S The layer is purified and recycled by...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to propose an adsorption-desorption-rectification-pervaporation separation and recovery of VOC in industrial waste gas for the problems existing in the above-mentioned prior art. S The combination process solves the problems of high energy consumption and large equipment investment in the traditional adsorption-saturated water vapor desorption and rectification combined process, reduces the consumption of water vapor and cooling water, and realizes VOC S Energy-saving recovery, and suitable for constant boiling, near boiling VOC S - Separation of water mixture to obtain high-purity VOC S

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