Composite solvent for recovering CS2 from viscose fiber waste gas by absorption process, and application thereof

Abstract

The invention discloses a composite solvent for recovering CS2 from viscose fiber waste gas by an absorption process. The composite solvent comprises polyethylene glycol dimethyl ether (NHD), N-methylpyrrolidone (NMP) or N,N-methylformamide or ethylene glycol butyl ether or 1,2,4-trimethylbenzene. CS2 in the viscose fiber waste gas is absorbed by the composite solvent to obtain a purified gas andan absorption rich solution, and the rich solution can be recycled after undergoing reduced pressure distillation regeneration. The composite solvent can effectively improve the CS2 dissolving ability, and has a higher solubility and a higher purification rate than the pure NHD solvent when applied to CS2 waste gas recovery; and compared with activated carbon for adsorption treatment of CS2 wastegas, the composite solvent has the advantages of wide application range, low process cost, high operational stability, economical property, environmental protection and long service life.

Description

technical field

[0001] The invention belongs to the technical field of industrial waste gas treatment, and relates to a composite absorbent for absorbing waste gas, in particular to an absorption method for recovering CS from viscose fiber waste gas. 2 Composite solvents and their applications. Background technique

[0002] At present, for the CS in the waste gas of viscose fiber production 2 The treatment methods mainly include condensation method, adsorption method and absorption method. The condensation method is only suitable for the treatment of high-concentration waste gas due to its limited processing capacity, and is usually only used for primary recovery or combined with other methods; although the adsorption method has a high purification rate, it has high investment costs, relatively difficult regeneration, and is easy to regenerate in the tower. Phenomena such as clogging; the absorption method is a low-concentration CS 2 Recycling technology can effectively s...

Examples

Embodiment 1

[0029] The waste gas to be treated in the present invention is derived from condensation recovery tail gas, containing 2100-2900mg / Nm 3 CS 2 , trace H 2 S and part of water vapor, due to the fact that under the existing experimental conditions, it is impossible to obtain the same CS as the actual composition of the factory 2 exhaust gas, so it is necessary for the CS used in the experiment 2 The exhaust gas is simulated, and the CS in the simulated exhaust gas 2 Content about 3000mg / m 3 , the water vapor content is about 1.0%.

[0030] Moisture content is measured using a trace moisture analyzer of the Karl Fischer method, and the calculation formula of moisture content W is:

[0031]

[0032] In the formula: W represents the water content, %; T represents the titer of Karl Fischer reagent to water, g / mL; V represents the injection volume, mL; m represents the mass of the sample, g.

[0033] Using TU-1900 double-beam ultraviolet spectrometer to CS 2 Measure the import ...

Embodiment 2

[0052] Adopt 80wt% NHD and 20wt% NMP to make composite solvent, absorb CS in viscose fiber 2 exhaust gas, which produces CS-containing 2 The absorbed rich liquid flows out from the outlet of the lower part of the absorption tower, enters the circulation tank 1, and then flows into the regeneration tower from the feed port of the lower part of the regeneration tower by the circulation tank 1 (the operating temperature of the regeneration tower is 120 ° C ~ 145 ° C, and the operating pressure is 10kPa~40kPa) under reduced pressure distillation, regenerated lean liquid (CS 2 The content is less than 0.5‰, and the water content is less than 0.5%) flows out from the outlet of the lower section of the regeneration tower, and is cooled to 18-20°C by the condenser (the cooling medium is cooling water), stored in the solvent tank, and regularly flows into the circulation tank 2 . The results are shown in Table 3.

[0053] Table 3 Repeated absorption effect

[0054]

[0055] It c...

technical field

[0001] The invention belongs to the technical field of industrial waste gas treatment, and relates to a composite absorbent for absorbing waste gas, in particular to an absorption method for recovering CS from viscose fiber waste gas. 2 Composite solvents and their applications. Background technique

[0002] At present, for the CS in the waste gas of viscose fiber production 2 The treatment methods mainly include condensation method, adsorption method and absorption method. The condensation method is only suitable for the treatment of high-concentration waste gas due to its limited processing capacity, and is usually only used for primary recovery or combined with other methods; although the adsorption method has a high purification rate, it has high investment costs, relatively difficult regeneration, and is easy to regenerate in the tower. Phenomena such as clogging; the absorption method is a low-concentration CS 2 Recycling technology can effectively s...

Examples

Embodiment 1

[0029] The waste gas to be treated in the present invention is derived from condensation recovery tail gas, containing 2100-2900mg / Nm 3 CS 2 , trace H 2 S and part of water vapor, due to the fact that under the existing experimental conditions, it is impossible to obtain the same CS as the actual composition of the factory 2 exhaust gas, so it is necessary for the CS used in the experiment 2 The exhaust gas is simulated, and the CS in the simulated exhaust gas 2 Content about 3000mg / m 3 , the water vapor content is about 1.0%.

[0030] Moisture content is measured using a trace moisture analyzer of the Karl Fischer method, and the calculation formula of moisture content W is:

[0031]

[0032] In the formula: W represents the water content, %; T represents the titer of Karl Fischer reagent to water, g / mL; V represents the injection volume, mL; m represents the mass of the sample, g.

[0033] Using TU-1900 double-beam ultraviolet spectrometer to CS 2 Measure the import ...

Embodiment 2

[0052] Adopt 80wt% NHD and 20wt% NMP to make composite solvent, absorb CS in viscose fiber 2 exhaust gas, which produces CS-containing 2 The absorbed rich liquid flows out from the outlet of the lower part of the absorption tower, enters the circulation tank 1, and then flows into the regeneration tower from the feed port of the lower part of the regeneration tower by the circulation tank 1 (the operating temperature of the regeneration tower is 120 ° C ~ 145 ° C, and the operating pressure is 10kPa~40kPa) under reduced pressure distillation, regenerated lean liquid (CS 2 The content is less than 0.5‰, and the water content is less than 0.5%) flows out from the outlet of the lower section of the regeneration tower, and is cooled to 18-20°C by the condenser (the cooling medium is cooling water), stored in the solvent tank, and regularly flows into the circulation tank 2 . The results are shown in Table 3.

[0053] Table 3 Repeated absorption effect

[0054]

[0055] It c...

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