SU915913A1 - Method of cleaning gas effluents from chloroprene - Google Patents

Description

The invention relates to the chemical technology of cleaning gas emissions from harmful substances, in particular to the purification of gas emissions from the production of chloroprene rubbers from chloroprene.

Known periodic carbon absorption method of trapping chloroprene from gas emissions II].

The disadvantages of this method are the formation of undesirable. wastewater, the need to treat activated carbon with an aqueous solution of Ν-nitrosodiphenylamine antipolymerizer before each desorption process and low dynamic activity, for chloroprene, equal to 2.6%.

The closest to the proposed technical essence and the achieved result is a method of cleaning gas emissions from chloroprene, including sorption of its active carbon containing 0.1-2 wt.% Wood-resin oxidizer, desorption and recovery of chloroprene. Wood resin antioxidant is used as an inhibitor of the polymerization of chloroprene. The absorption capacity of coal does not exceed 18% of chloroprene. 12].

The disadvantages of this method are the low absorption capacity of the sorbent and the complexity of the method

5 due to the periodicity of the sorption process.

The purpose of the invention is to increase the absorption capacity of the sorbent and the simplification of the method.

This goal is achieved by the fact that 10 active carbon is used in the form of a powder dispersed in high-boiling organic liquids in an amount of 5-30% by weight of the liquid.

Desorption is carried out with an inert gas or a lean-air mixture at a temperature of 150-160 ⁰ C.

The suspension is prepared from powder or dust of activated carbons in an amount of from 5 to 30% in silicone oils such as VM-5, PES, PMS, in-methylpyrrolidone, dibutyl phthalate and others with the size of molecules; blocking activated micropores

25 coals.

Wood-resin antioxidant inhibitor of chloroprene polymerization is introduced into the finished suspension in an amount of 0.1-2% by weight of activated carbon.

3

915913

four

The vapor-air mixture containing chloroprene is fed to the adsorber, where chloroprene is trapped, and the purified air is sent to the atmosphere. Chloroprene-saturated slurry: enters the stripper, where a small amount of an inert gas, for example nitrogen, is simultaneously passed through 5. Desorption is carried out at 100180 ° C, preferably at 150-160 ° C. The desorbed chloroprene is trapped 10 in a low-temperature condenser. The non-condensed part of the desorbed chloroprene after the condenser is mixed with the vapor-air mixture, which is fed into the adsorber, which prevents its entry into the atmosphere. The suspension is circulated by a centrifugal pump or desorbent stream. Chloroprene condensed in a condenser is continuously or periodically taken up for disposal.

Example 1. A 5% suspension of activated carbon – SKT brand in silicone is poured into the adsorber. oil, add 0.2% by weight of coal wood-resin antioxidant inhibitor of polymerization.

The vapor-air mixture with a chloroprene content of 70 g / m ^{3 is} countercurrently passed into the adsorber at a rate of 300 l / l-h. At a temperature of 22 ° C, the degree of purification is 99%, and the sorption capacity for chloroprene - _d 49%. Desorption is carried out at 160-165C and a nitrogen transmission rate of 60 l / lh

15

20

25

thirty

Desorbed chloroprene is caught in a condenser at -78 ° C.

PRI mme R 2. In the adsorber pour 10% suspension of activated carbon brand SKT in dibutylphthalate, 40

add 0.5% by weight of coal wood-resin antioxidant inhibitor of polymerization.

A vapor-air mixture with a chloroprene content of 3 g / m ^{3 is} counter-flowd and allowed to enter the adsorber at a rate of 300 l / l.h. At a temperature of 15-16 ° C, the degree of purification is 99.6%, and the sorption capacity for chloroprene is 49%. Desorption is carried out at 160-165 ° θ5θ and a nitrogen transmission rate of 50 liters, lh. Desorbed chloroprene is captured in a condenser containing isoamyl alcohol at -30 ° C.

Example A 20% suspension of activated carbon DAU in silicone oil is poured into the adsorber; 2% of the mass of the wood resin antioxidant polymerization inhibitor is added to 2% by weight.

The vapor-air mixture with a chloroprene content of 60 g / m ³ countercurrent is passed into the adsorber at a speed of 300 l / l.h. At 18 C, the degree of purification is 98.4%, and the sorption capacity for chloroprene is 37%. Desorption is carried out at 155-165 ⁱⁿ C and a nitrogen transmission rate of 40 l / l-h. The desorbed chloroprene is captured in a condenser containing., Holding toluene, at a temperature of -3 0 ° C .;

Example4. In the adsorber pour 30% suspension is activated -! AG-3 coal in dibutyl phthalate add 0.1% of the mass of coal from the wood resin antioxidant inhibitor of polymerization.

The vapor-air mixture with a chloroprene content of 2.7 g / m® is countercurrently passed into the adsorber at a rate of 300 l / l-h. At 30 ° C, the degree of purification is 99.2%, and the sorption capacity for chloroprene is 27%. Desorption is carried out at 160 ° 0 and the transmission rate of nitrogen! 15 l / l * h Desorbed chloroprene is caught as in Example 1.

The decrease in the amount of coal in suspension is less than 5 wt.%. It is impractical due to a sharp drop in the absorption capacity of the sorbent, the increase in the amount of coal more than 30% by weight of the liquid leads to a separation of the suspension.

The application of the proposed method allows to increase the absorption capacity of the sorbent from 18 to 27-49%, and also significantly simplify the capture of chloroprene from gas emissions by organizing a continuous process.

,

Claims (2)

Claim ; 1. The method of cleaning gas emissions from chloroprene, including sorption of its active carbon containing 0.1-2% wt.% Wood-resin antioxidant, desorption and recovery of chloroprene, characterized in that, in order to increase the absorption capacity of the sorbent and simplify the way activated carbon is used in the form of a powder dispersed in high-boiling organic liquids in the amount of 5-30% by weight of the liquid. 2. Method pop.1, characterized in that the desorption is carried out with an inert gas or depleted steam-air mixture at a temperature of 150-160 ° C.