SU131363A1 - The method of separation of gas mixtures in a distillation column or in a fractionation absorber - Google Patents

Description

Improved thermal processes in rectification separation columns for multicomponent mixtures, as well as in fractionation absorbers for separation of gas mixtures are known.

A common drawback of the known apparatus for carrying out such processes is the waste of heat and cold in them due to the thermodynamic irreversibility of mass transfer processes in the middle parts of the column resulting from the mismatch of the vapor composition from the feed plate with the vapor composition from the stripping section. The proposed method allows to substantially eliminate this disadvantage and differs from already known methods in that:

a) during the rectification of multicomponent mixtures, the liquid flowing from the strengthening section of the column is evaporated in a separate heat exchanger with the input of the obtained vapors into the stripping section of the column below the feed plate;

b) when separating gas mixtures in a fractionation absorber, the liquid portion of the feed is evaporated in an additional evaporator, and the resulting vapors are introduced into the middle portion of the stripping section below the feed plate;

c) when separating gas mixtures into fractionation, i.e. the absorber, the separation process is carried out by condensation of vapors from the stripping section due to cold from the outside, and the resulting liquid is used to irrigate additional strengthening colopna, and steam from the fortified column is introduced into the middle part of the absorption section is higher than the feed plate.

FIG. a flowchart of the process of separation of a multicomponent gas mixture by rectification according to the proposed method

No 131363-2 The mixture to be separated through the pipeline / fed to the distillation column 2. Liquid draining from the fixing part of this column is led through the pipeline 3 to the heat exchanger 4 heated by the coolant passing through the pipeline 5. introduced into the middle part of the stripping section of the column below the feed plate 7. The vapor from the reinforcing section of the column 2 enters the reflux condenser 8 cooled by the refrigerant passing through the pipeline 9. The condensable portion of the liquid is returned to the columns as reflux , and the gaseous part is taken as a light boiling fraction through fitting 10. Liquid from the bottom of column 2 enters the boiler //, heated by a coolant passing through pipe 12. Some of this liquid is taken from pipe 13 as a high boiling fraction, and steam from boiling point // through pipe M is returned to column 2. In FIG. 2 shows a flow chart for separation of gas mixtures in a fractionation absorber. Fluid-gas feed through the pipe / 5 is fed to the separator 16, from which the vapor through the pipe 17 is sent to the absorber 18, and the liquid to the evaporator 19. The pairs produced in this evaporator through the pipe 20 are fed to the absorber 18 below the feed plate. Through the pipe 21, the absorber is irrigated with an absorbent, and the residual gas is withdrawn through the fitting 22. The liquid from the bottom of the absorber flows into the boiler 23, with preliminary selection of the high-purity fraction from the pipe 24.

FIG. Figure 3 shows the technological scheme for separation of gas mixtures in a fractionation absorber with an additional reinforcing column.

The feed gas entering through pipe 25 is divided into two parts, of which one part through pipe 26 is directed to fractionation absorber 27, and the other part in additional column 28 is subjected to distillation by refluxing condensate formed in condenser 29 into it via pipeline 30 from the stripper section of the absorber 27. The condenser 29 is cooled with a refrigerant with the same isotherm as when the source gas and the circulating absorbent are cooled. The vapors from the column 28, together with the 29 pairs that are not condensed in the condenser, are fed to the absorber 27 above its feed plate. The absorbent in a correspondingly reduced amount is fed through pipe 3 for irrigation of the absorber. The residual gas is discharged through the nozzle 32.

The liquid from the lower part of the stripper section of the absorber 27 flows into the boiler 33. A part of this liquid is taken as the high-boiling fraction through the pipe 34.

Subject invention

Claims (3)

1. A method for separating gas mixtures in a distillation column or in a fractionation absorber with liquid or vapor-liquid feeding and with the use of intermediate heat or cold in it, characterized in that, in order to reduce the energy costs of the separation process, the liquid flowing from the upper section the columns are evaporated in a separate heat exchanger, with the vapor being introduced into the stripping section of the column below the tray, 2. A method of separating gas mixtures according to claim 1 in a fractionation absorber, characterized in that, with the purpose: reduction, energy costs, the liquid part, the power is evaporated in an additional evaporator, and the resulting steam is introduced into the middle part of the stripping section below the plate nutrition 3. The method of separation of gas mixtures according to claim 1, characterized in that, in order to reduce specific energy costs, the process the separation is carried out in a fractionation absorber with an additional reinforcing column, and the bunks from the stripping section are condensed due to cold from the outside, and the resulting liquid is used to irrigate the additional strengthening column from which the remaining vapors are introduced into the middle section of the absorption section above the feeding plate. ten J l i L /" five 12 Fig of 2