Abstract:
A process for removing sulfur from a gas containing sulfur compounds as H2S, SO2, COS, CS2 . . . , in a quantity of up to 15% wt; particularly gases emanating from the Claus process: A first hydrogenation of the sulfur compounds into H2S, the hydrogenation gas being used to regenerate a deactivated bed of oxidation catalyst, both being carried out at 200-500° C. After sulfur removal, the resulting gas undergoes a second hydrogenation step and then a direct oxidation step, said step being operated under the dew point of sulfur to trap the formed sulfur in the catalyst. In the further cycle, the gas streams are switched so as to regenerate the catalyst in run which is deactivated.
Abstract:
A process for the removal of hydrogen sulfide and sulfur recovery from a H2S-containing gas stream by catalytic direct oxidation and Claus reaction through two or more serially connected catalytic reactors, wherein a specific control of the oxygen supplement is operated. The control and improvement of the process is obtained by complementing, in each major step of the process, the H2S-containing gas stream by a suitable flow of oxygen, namely before the H2S-containing gas stream enters the Claus furnace, in the first reactor of the process and in the last reactor of the process. Especially in application in a SubDewPoint sulfur recovery process the H2S/SO2 ratio is kept constant also during switch-over of the reactors R1 and R by adding the last auxiliary oxygen containing gas directly upstream the last reactor R so that the H2S/SO2 ratio can follow the signal of the ADA within a few seconds.
Abstract:
The present invention is directed to a process for the removal of aromatic hydrocarbons from a lean acid gas containing less than 20 mol. % of H2S, comprising:a) contacting the lean acid gas stream (1) with a H2S-selective liquid absorbent solution (29) in a first absorption zone (2) to produce a gas stream depleted in H2S (3) and an absorbent solution enriched in H2S (4),b) introducing the absorbent solution (4) into a non-thermic stripping zone (8) where it is contacted with a stripping gas stream (7) to obtain an absorbent solution depleted in C4+ aliphatic and aromatic hydrocarbons (9) and a stripping gas stream enriched in aromatic and C4+ aliphatic hydrocarbons (10),c) contacting the stripping gas stream (10) obtained in step b) with a H2S-selective liquid absorbent solution (28) in a second absorption zone (12) to obtain a stripping gas stream depleted in H2S (13), and an absorbent solution enriched in H2S (14)d) introducing the absorbent solution (9) obtained in step b) into a desorption zone (16) wherein the H2S-selective liquid absorbent solution (17) is recovered and a lean acid gas is produced.