DE1643757C3 - Process for the production of a condensate containing acetylene, xthane, ethylene and C deep 3 to C deep 5 hydrocarbons - Google Patents

Description

proportions as well as the sulfur, which is in the form of Hydrogen sulfide is present, in a known manner by washing, / .. B. with an aqueous solution of alkali metal / s of amino acids. If necessary, this laundry, in which the;> The main amount of carbon dioxide is separated off together with the hydrogen sulphide. still a fine cleaning for carbon dioxide nachgesciiaiici will. This fine cleaning is expedient by washing with a dilute alkali metal hydroxide solution made.

The fission gases freed from carbon dioxide and hydrogen sulphide are on it before the condensation dried. This drying can, for. B. in a known manner by scrubbing the gases with Di- or triethylene glycol take place. In addition to this drying process, the laundry has also been made with anhydrous Methanol or a saturation with methanol vapor proved to be suitable.

The condensation itself is generally Iv i = -> a pressure of 5 to 40 at.

The condensate can be used for washing the gas mixture after cooling to 82 to 120 ° C Use that obtained when cooling down after animal washing at 140 to 17o C. will. However, if necessary, additional quantities ν can also be added to this washing liquid and or supply Athan, which comes from other oucüe come.

To cool the gas mixture, you can use the in the condensation columns or, if necessary, in a single condensation stage before washing the tub relax the separated condensates and evaporate in the countercurrent warning exchange.

From the condensates combined with the washing liquid from the sump ocr Athvienwäschen the acetylene and ethylene together with alcohol and methane can be obtained from a liquid fraction, which contains all of the C to C hydrocarbons and otherwise Contains carbon oxysulfide and carbon disulfide, are separated.

example

In a system that is shown in the figure again- 4; given is. enter through line 1 14 000NmMi Fission gas that frees from CO., And H., S; and dried by an upstream methanol wash was, under a pressure of S at and with a temperature of ■■ (■ 20 C in the heat exchanger 2 a. The gas has the following composition:

Volume percentage

H "29.37

N .; 0.59

40.10

0.20

3.96

6.46

0.49

3.84

2.46

4.S9

6.05

IN THE -

CO

O.

CH ₁
CH ₄ .
C ₂ H ₆ ..
C ₃ H ₆ ..
C ₅ H ₈ ..
C ₄ H ₁₀ .
CH, ..
CH ₁ OH

separates: the remaining gas is passed through a heat exchanger via line 4 and cooled to I Io C. and iir separator 6 for condensate. The roasting gas flows through line 7 into the column 8. where it by a counter-current wash with a mixture of acetylene consisting essentially of liquid ethylene and ethane so far freed λ ird. that the acetylene content in line 9. based on the mixture of acetylene and ethylene, below I ".. so that as the cooling continues No excretion on Ito C in the heat exchanger Iß of solid acetylene can occur. Gas and liquid are separated in the separator. The gas with a residual ethylene content of 2 () l) ppm and acetylene of less than 10 ppm is passed with line 12 through the heat exchanger IO and heated to a temperature of 125 ° C. in countercurrent to the gas flow in the line and the F.nispannungsiurbinc 13 supplied. In her w: rd the gas under performance of external work from 7.8 relaxed to 1.4 at, whereby it is at 16 ^ C cools down.

This cold gas is heated to a temperature of -Io C through line 14 through the heat exchangers 10, 5 and 2 in the GeüeiWrom / u the media flowing through lines 1, 4 and 9. The amount of continuous seeds accumulating in separator i S is fed by pump 15 and through line 16 into heat exchanger 10 to give off the sensible heat and is added to washing column 8 at a temperature of 23 ° C. In addition to this scrubbing liquid, 2NONm ¹ h of ethylene-ethane mixture is fed in from the outside as bulk through line 17 and the column 8 is also added after it has entered the heat exchangers 2 and 5

120 Γ have been cooled. The loaded washing liquid from the bottom of the column 8 is with the .Abscheider 6 resulting condensate mixed and after lntspannuim to 1.4 at Line 18 passed through ilen heat exchanger 5, then with the from separator J duith line 19 coming condensate mixed and through line 20 for further delivery of latent and sensible heat passed through heat exchanger 2 in countercurrent to the incoming gas streams. In The compressor 21 this hydrocrslolfgemiseh is compressed to 1 (S at and the pressure distillation fed.

This gas mixture has the following composition:

Volume percentage

H.,

CO.

O"

CH ₁

CH ₄

CH,

c; h ,;

C ₁ H,

C ₁ H,

0.28
0.06
1.70
0.03
LlO

33.43
1.30

14.00
8.90

17.60

21.60

The gas is cooled to 20 ° C. The resulting condensate is in the separator 3 · aiu ".- FJ-; i ,! he described mode of operation of the separation plant with an intermediate ash with ethylene in The column S is not observed to be precipitated even during continuous operation.

1 sheet of drawings

Claims (1)

I 643 Claim: Process for obtaining an acetylene. Alhan. Ethylene and C ₁ - to C. Kolilenw asserstolle containing condensate from an acetylene. Ethane. Ethylene, C ₁ to C _s hydrocarbons. Dried cracked gas containing carbon monoxide, hydrogen and methane, which is obtained during the cracking of petroleum or petroleum fractions by a flame burning below the surface of the liquid and from which carbon dioxide and hydrogen sulphide have been removed, with separation of carbon monoxide, hydrogen and methane, characterized in that: the cracked gas is cooled in one or more condensation stages to a temperature which is still above the fixed point temperature of the acetylene in the mixture with the other condensed constituents, at pressures of 5 to 40 al to 82 to Ί 20 C, after the acetylene obtained has been separated off. Ethane. Ethylene and condensate containing C. to C. hydrocarbons, the remaining gas mixture containing small amounts of acenia is freed from acetylene in a scrubbing column by washing with liquid ethylene and / or ethane 140 to 170 C cooled gas after renewed condensate separation in countercurrent / u the gas leaving the ethylene scrubbing is heated to 130 to 100 C and the gas mixture heated to 130 to 100 C is expanded in an expansion machine with the performance of external work, whereby the gas mixture is cooled and for countercurrent cooling is used in the condensation stages. 40 When splitting crude oil or hydrocarbon fractions in a flame burning under the surface of the liquid (immersion flame) a cracked gas is obtained which, in addition to acetylene and ethylene, still contains hydrogen as the main component. Carbon monoxide. Carbon dioxide in addition to various sulfur compounds and methane. Ethane as well as C, - to ^ -hydrocarbons contains. It is known that gas mixtures of this type can be broken down into their constituents in stages, generally first separating the C ₁ to C hydrocarbons by washing with oil and then removing the acetylene from the remaining gas mixture by washing with N-methylpyrrolidone. For the separation of the ethylene from the remaining gas mixture, which still contains carbon monoxide and hydrogen as essential components, a Ro condensation at low temperatures is necessary. However, this procedure also has the disadvantage that the preceding step-by-step separation of the C ₁ - to C. fractions by oil scrubbing and the separation of the acetylene content requires disproportionately large equipment, since in both stages the main part of the gas is still in the form of hydrogen and carbon monoxide is carried. In addition, the sulfur compounds contained in the cracked gas, provided they are not in the form of hydrogen sulphide and have previously been removed by selective hydrogen sulphide scrubbing, are distributed among the acetylene fraction and the mixture of hydrogen and carbon monoxide. In any case, this requires a sulfur purification of the acetylene fraction and a further sulfur purification of the hydrogen-carbon monoxide mixture, if this is to be used for synthesis purposes. It has now been found that acetylene, ethane. Ethylene and C ₁ to C hydrocarbons containing condensate from an acetylene, ethane, ethylene, C 1 to C hydrocarbons, carbon monoxide. Rockneten fission gas containing hydrogen and methane, which is generated during the cracking of petroleum or petroleum fractions by a flame burning below the surface of the liquid and from which carbon dioxide and hydrogen sulphide have been removed, with the separation of carbon monoxide. Hydrogen and methane can advantageously be obtained if the cracked gas is cooled in one or more condensation stages to a temperature which is still above the fixed point temperature of the acetylene mixed with the other condensed constituents, at pressures of 5 to 40 atmospheres to -82 to 120 ° C , after separating off the acetylene obtained. Ethane. Ethylene and C ₁ - to ^ .- hydrocarbons containing condensate, the remaining, still small amounts of acetylene-containing gas mixture freed in a scrubbing column by washing with liquid ethylene and / or ethane from acetylene, then the acetylene-free gas mixture is further cooled to 140 to 170 C, the 140 to 170 C cooled gas after renewed condensate separation in countercurrent to the gas leaving the ethylene scrubbing heated to 130 to KO C and that to - 130 to Cias mixture heated to 100 C in a relaxation machine relaxed under the performance of external work, the gas mixture cools down and is used for countercurrent cooling in the condensation stages. When cooling the cracked gas to 82 bis 120 C are the C ₁ - to C. hydrocarbons, sulfur compounds such as carbon oxysulphide and carbon disulfide, as well as the main amount of acetylene. z. B. 50 to 95 ". Condensed in the total amount of Acelylen. The condensate contains an additional 30 to 80" 0 of the ethylene and the atane and small amounts of methane. That after the condensation at 82 to ■ - 120 '"" C remaining gas is washed with ethylene or ethane or their mixture. After the remaining acetylene has been removed from the cracked gas by scrubbing, is the gas mixture further to -140 to -170 "C cooled, the remaining ethylene and ethane being removed. It is a particular advantage of the process according to the invention that the acetylene content in the Residual gas is reduced so far that a separation of solid acetylene during further cooling of the residual gas, e.g. B. in expansion turbines, can no longer occur. When carrying out the process, the necessary preliminary separation of the carbon dioxide