Metallgesellschaft Aktiengesellschaft

Linde Aktiengesellschaft

Gerhard Grunewald

Manfred Kriebel

Emil Alunic

Emil Supp

Friedemann Marschner

Heinz Hiller

Gerhard Hochgesand

Hans-J Fritzsche

Hans Kammerer

A scrubbing solution boiling above 100.degree. C. under atmospheric pressure is used for removing H.sub.2 S and CO.sub.2 from a gas stream at a temperature from 5.degree. to 70.degree. C. The solution is thus laden with at least CO.sub.2 and H.sub.2 S. For regeneration, the laden scrubbing solution under a pressure of at least 2 bars and at a temperature of at least 60.degree. C. is supplied to an expansion zone and is expanded therein. A flashed-off gas which is rich in H.sub.2 S is withdrawn from the expansion zone. The scrubbing solution from the expansion zone is subjected to a hot regeneration, by which the scrubbing solution at a temperature below its boiling temperature is stripped with an inert gas so that its residual loading is substantially removed. Mixed gases which contain inert gas are withdrawn from the hot regeneration and are contacted with scrubbing solution.

Process of regenerating a high-boiling scrubbing solution which contains

Two absorbent solution streams are laden with CO.sub.2 and optionally with COS, which are physically dissolved. The COS content of the second absorbent solution stream is at least three times the COS content of the first absorbent solution stream. For regeneration, the first absorbent solution stream is pressure-relieved into a first pressure relief zone so as to reduce the pressure by at least 2 bars and to flash off a gas which contains CO.sub.2. The second absorbent solution stream is pressure-relieved at least in part into a second pressure relief zone, which contains exchange-promoting elements. The flashed-off gas from the first pressure relief zone is passed through the second pressure relief zone in a countercurrent to the second absorbent solution stream. The second pressure relief zone is preferably disposed over the first pressure relief zone and the second absorbent solution stream flows first through the second and then through the first pressure relief zone.

Process for regenerating absorbents containing CO.sub.2 and COS

A gas which contains CO.sub.2 and at least one of the valuable gases methane, hydrogen or carbon monoxide is purified by means of an absorbent solution in a scrubbing zone under a pressure of at least 5 bars. The laden absorbent solution has absorbed CO.sub.2 and at least one of the valuable gases by physical dissolution. For a recovery of the valuable gas or gases, the laden absorbent solution is pressure-relieved to an intermediate pressure in the stripping zone and is stripped in the stripping zone with a gas which predominantly consists of CO.sub.2. A gas mixture which contains a valuable gas is withdrawn from the stripping zone. The absorbent solution is pressure-relieved further in a succeeding pressure-relief zone, from which a flashed-off gas consisting predominantly of CO.sub.2 is withdrawn. The laden absorbent solution is pressure-relieved to a first intermediate pressure in a pressure-relief zone which precedes the stripping zone and the laden absorbent solution is then supplied to the stripping zone. The gas which has been flashed off in the succeeding pressure-relief zone may be fed to the stripping zone as a stripping gas.

Process for treating CO.sub.2 -containing absorbent solution

Two absorbent solution streams which come from different gas-scrubbing zones and have absorbed carbon dioxide and at least one of the valuable gases carbon monoxide, hydrogen or methane by physical dissolution under pressures from 10 to 100 bars are treated for a recovery of the valuable gases. For that purpose the first absorbent solution stream is pressure-relieved into a first pressure-relief zone with a pressure reduction by at least 5 bars so that a high-CO.sub.2 gas is flashed off. The second absorbent solution stream is partly pressure-relieved into a second pressure-relief zone, which contains exchange-promoting elements. The flashed-off gas from the first pressure relief zone is passed upwardly through the second pressure relief zone in a countercurrent to the second absorbent solution stream. A gas mixture containing CO.sub.2 and at least one valuable gas is withdrawn at the top of the second pressure relief zone. The two scrubbing solution streams which have left the pressure-relief zones are then regenerated. The second absorbent solution stream which has left the second pressure relief zone is preferably fed to the first pressure relief zone.

Process for treating scrubbing solutions

Two different gases, which contain sulfur compounds and Co.sub.2, are desulfurized with a physically acting solvent. The first gas is treated with the solvent in a first scrubbing zone, in which the sulfur compounds, particularly H.sub.2 S and COS, are substantially completely removed and part of the Co.sub.2 content in the gas is dissolved. At least part of the laden solvent leaving the first scrubbing zone is fed to a second scrubbing zone, which is supplied with the second gas, which has a lower CO.sub.2 content than the first gas. The second gas is partly desulfurized in the second scrubbing zone and in a third scrubbing zone is subsequently treated with a solvent which is virtually free of sulfur compounds. The laden solvent leaving the third scrubbing zone is preferably fed to the second scrubbing zone.

Process for desulfurizing CO.sub.2 -containing gases

An apparatus for the regenerating of absorbent is disclosed wherein the apparatus comprises a regenerating column provided with mass transfer-promoting elements. The regenerating column comprises an upper regenerating zone which can be shut down and is provided with at least one shutoff valve-controlled inlet for laden absorbent and a lower second regenerating zone provided with a second shutoff valve-controlled inlet for the same laden absorbent, the volume ratio of the second regenerating zone to the upper regenerating zone being at least about 1.5:1. A process for regenerating laden absorbent is also disclosed.

Apparatus for regenerating absorbent and method of operating the

Methanol is produced by a process wherein

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Mainz-Gonsenheim, Germany

Gerhard Grunewald