Process and device for recycling organic waste gas by refrigeration mode

Abstract

The invention relates to a process and device for recycling organic waste gas by a refrigeration mode, wherein the process and device can be used for water gas recycling in the production process of a polystyrene board in the printing industry. The device comprises a drying device, a heat exchanger, a gas conveying device, a refrigeration device and a separation tank, wherein silk screens are installed on the upper part of the separation tank; the gas conveying device is positioned between a first water cooler and a second water cooler or is positioned between the first heat exchanger and a polystyrene production line; after high-temperature waste gas is subjected to water cooling and low-temperature refrigeration, organic matters are cooled down; at the temperature of minus 60-20DEG C and under the pressure of 0-5MPa, after flash evaporation and gas and liquid separation, waste gas containing less organic matters exchanges heat with the deep-cool waste gas; after cold quantity is recycled, the waste gas is introduced to the polystyrene production line to be used as the sweep gas for recycling or discharged directly; when the treated waste gas is used as the sweep gas for recycling, the organic solvent recovery rate is greater than 99.5%; and when the treated waste gas is discharged directly, the organic solvent recovery rate is greater than 85%. According to the invention, the process and device have the advantages that process is simple, operation is convenient, recovery rate of organic waste gas is high and the like, and continuous recovery can be realized.

Description

Technical field: [0001] The invention relates to a process and a device for recovering organic waste gas by freezing, in particular to a process for recovering organic solvents in the waste gas of a PS production line in the printing industry and a device thereof. It can be used for waste gas recovery in the production process of polystyrene (PS) boards in the printing industry. Background technique: [0002] A large amount of organic solvents are used in the production of PS boards in the printing industry, such as ethylene glycol monoethyl ether, methyl ethyl ketone, methyl isobutyl ketone, chloroform, ethanol, isopropanol, butanol, propanol, ethyl acetate, butyl acetate , toluene, xylene, etc., these solvents are discharged in the form of exhaust gas through air entrainment. At present, domestic methods for treating organic waste gas mainly include adsorption recovery, biological treatment, incineration treatment, and concentrated catalytic combustion. The adsorption re...

AI Technical Summary

Problems solved by technology

The adsorption recovery method has high requirements on the adsorption material, and cannot guarantee the adsorption of all types of organic matter. In addition, the deterioration rate of the adsorbent may be accelerated according to the type of organic waste gas, resulting in frequent replacement of the adsorbent and increased operating costs; biological treatment, although in wastewater Great progress has been made in the treatment of organic matter, but it is still very difficult to treat organic matter in waste gas, and it is still in the research stage; incineration treatment and concentrated catalytic combustion methods are only suitable for small air volume and high-concentration organic waste gas treatment. The cost is high, and the solvent cannot be recycled for resource utilization

[0003] In summary, when these methods are used to treat waste gas from PS board production lines, due to the low content of organic matter and differences in the properties of organic matter, the operating cost is high or the recovery effect is not ideal, so it cannot operate normally, greatly increasing the economic burden of the enterprise and causing environmental damage. harm

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