Societe Nationale Elf Aquitaine (production)

Societe Nationale Elf Aquitaine

Elf Aquitaine Production

Georges Kvasnikoff

Andre Philippe

Jean Nougayrede

Robert Voirin

Claude Blanc

Guy Desgrandchamps

Removal of sulfur compounds in claus type residual gases with sulfur

A process is provided for the production of sulphur from at least one sour gas containing H.sub.2 S and a gaseous or liquid fuel effluent, of the type comprising a thermal reaction step, wherein the thermal reaction step is conducted by performing the combustion of the gaseous or liquid fuel effluent in a first zone of the thermal reaction stage with a quantity of a gas containing free oxygen in excess in relation to the theoretical quantity needed for a complete combustion of the fuel effluent, the excess being smaller than the theoretical proportion of gas containing free oxygen needed to oxidize to SO.sub.2 approximately one third of the H.sub.2 S of the total flow of sour gas into the combustion fumes of the fuel effluent which are present in the first zone of the thermal reaction stage, by burning incompletely a second stream of sour gas in a second zone of the thermal reaction stage, which receives the gaseous products from the first zone, with a controlled quantity of gas containing free oxygen, such that the H.sub.2 S:SO.sub.2 molar ratio in the gases originating from the catalytic reaction step has a predetermined value, and by adjusting the flow rates of the first and second sour gas streams so that the temperature obtained during the incomplete combustion of the second sour gas stream in the second zone of the thermal reaction stage has a value higher than 850.degree. C.

Process for the production of sulphur from at least one sour gas

A process is provided for the improvement of the sulphur yield of an assembly which produces sulphur from H.sub.2 S and which consists of a sulphur plant (1), an oxidation and hydrolysis unit (2) and a purification unit (3). The sulphur plant in producing sulphur provides a residual gas which incorporates H.sub.2 O, COS and/or CS.sub.2 and H.sub.2 S and SO.sub.2 in a mol ratio of H.sub.2 S:SO.sub.2 &gt;2:1. The residual gas passes into the hydrolysis unit on a H.sub.2 S oxidation and COS and CS.sub.2 hydrolysis catalyst which functions between 180.degree. C. and 700.degree. C., in the presence of air, thus producing a residual gas free of COS and CS and incorporating H.sub.2 S and SO.sub.2 in a mol ratio which is kept equal to 2:1 by regulating the air flow. The residual gas is introduced into the purification unit in which H.sub.2 S and SO.sub.2 are made to react in order to produce sulphur and to obtain a purified residual gas.

Process for improving the sulphur yield of a complex for producing

A process is provided for improving the sulphur yield of a sulphur production unit using an acid gas containing H.sub.2 S and wherein said unit is comprised of a sulphur plant with a downstream purification unit. The H.sub.2 S resulting from hydrolysis of COS and CS.sub.2 is almost entirely recovered in the form of sulphur in the purification unit resulting in an improved sulphur output of the overall installation.

Process for improving the sulphur yield of a complex for the production

Process for removing sulphur-containing compounds from a residual gas with recovery of said compounds in the form of sulphur, wherein the residual gas is subjected to a treatment comprising a hydrogenation and a hydrolysis phase to provide the sulphur-containing compounds in the unique form of H.sub.2 S, a cooling step with water condensation, a catalytic oxidation of H.sub.2 S in CLAUS stoechiometry and a catalytic CLAUS reaction phase with deposition of sulphur on the CLAUS catalyst and periodic regeneration of the sulphur-laden catalyst and cooling of the regenerated catalyst. The gas used for the regeneration and for the cooling is tapped from the gas effluent supplied to the catalytic oxidation and the gas issued from the regeneration is reintroduced at least in part into said gas effluent after separation of the sulphur containing therein. Application to the purification of residual gases issued from CLAUS sulphur units.

Process for removing sulphur compounds from a residual gas

Process for removing sulfur compounds contained in a residual gas with recovery of said compounds in the form of sulfur, wherein a gas obtained from a residual gas containing H.sub.s S and SO.sub.2 and having a temperature lower than 160.degree. C. is subjected to a catalytic CLAUS reaction phase with deposition of sulfur on the catalyst and periodic regeneration of the sulfur-laden catalyst and cooling of the regenerated catalyst. The gas brought in contact with the CLAUS catalyst is produced by subjecting the residual gas to a hydrogenation and hydrolysis treatment to provide the sulfur compounds in the unique form of H.sub.2 S and to cooling with water separation by condensation and then to catalytic oxidation of H.sub.2 S in CLAUS stoichiometry with cooling of the gas stream obtained from the oxidation step under 160.degree. C. in order to separate the sulfur by condensation. Application to the purification of the residual gases emitted by CLAUS sulfur plants.

Process for removing sulphur compounds contained in a residual gas

Catalytic process for producing sulphur from H.sub.2 S-containing acid gas wherein the acid gas is subjected to a catalytic oxidation in CLAUS stoichiometry and to a catalytic CLAUS reaction phase with deposition of sulphur on the catalyst with periodic regeneration of the sulphur-laden catalyst and cooling of the regenerated catalyst. The gas used for the regeneration and for the cooling is tapped from the acid gas supplied to the catalytic oxidation and the gas issued from the regeneration is reintroduced into said acid gas after separation of the sulphur contained therein. The process is particularly applicable to the treatment.

Catalytic process for producing sulphur from H.sub.2 S containing sour

A process to produce sulphur from two acid gases both containing hydrogen sulphide and one of which contains ammonia, using a modified Claus technique. The acid gas containing ammonia is burnt in the presence of air under substoichiometric conditions in a first heat-reaction chamber, while the ammonia-free acid gas is burnt in a second heat-reaction chamber, forming a series with the first chamber, with the right quantity of air to provide a molar ratio of H.sub.2 S to SO.sub.2 of approximately 2/1 at the catalytic reaction stage inlet. The mixed effluents from both heat-reaction chambers may pass through a high-temperature residence chamber before being conveyed to the heat-recovery stage. Gas effluents from the heat-reaction stage contain H.sub.2 S and SO.sub.2 in the right ratio for the catalytic reaction stage, and no hydrocarbons or harmful quantities of NH.sub.3 and NO.

Apparatus for burning hydrogen sulphide

Improved process for the production of sulphur from a gas containing H.sub.2 S, SO.sub.2, H.sub.2 and/or CO, in which the gas is caused to pass through a CLAUS catalyst in a primary catalytic stage operating at between 200.degree. and 460.degree. C. in order to form sulphur, and thereafter the sulphur contained in the reaction mixture issuing from this stage is condensed through indirect heat exchange with water to produce steam. The improved process consists in constituting at least the final eighth of the catalyst volume in this stage by a composite mass formed from a refractory oxide on which is fixed a transition metal compound, for example Co and/or Mo, and in entering into contact the gas with this composite mass at between 300.degree. and 460.degree. C. in order to oxidize H.sub.2 and CO. The energy resulting from this oxidation is recovered in the form of a supplementary quantity of steam during the sulphur condensation.

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Monein, France

Georges Kvasnikoff