Sulfur recovery process including removal of residual sulfur from Claus catalyst after regeneration
AssigneeAmoco Corporation
InventorBoyd E. Cabanaw
Life of this patent
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Abstract
A portion of the acid gas feedstream to a Claus plant is passed through Claus catalyst to strip residual sulfur and sulfur compounds from the catalyst. The resulting gas-in-process containing the stripped compounds can then be provided to a Claus conversion step.
Claims26
In a Process for the recovery of sulfur comprising passing an acid gas feedstream having as a sulfur species essentially only hydrogen sulfide therein to a Claus plant comprising a thermal conversion zone and at least one Claus catalytic reaction zone operated under adsorption conditions including temperature for forming and depositing a preponderance of sulfur formed on catalyst therein, the steps of:
- vaporizing deposited sulfur from the resulting sulfur-laden catalyst in said Claus catalytic reaction zone in the presence of a gas-in process richer in hydrogen sulfide and sulfur dioxide than the gas contacting the catalyst under said adsorption conditions, then
- stripping residual sulfur and sulfur compounds from the catalyst resulting from such vaporizing step by passing a portion of the acid gas feedstream comprising as a sulfur species essentially only hydrogen sulfide through catalyst in said Claus catalytic conversion zone at a inlet temperature less than the inlet temperature of gas into said catalytic conversion zone during adsorption conditions and at a rate and for a time effective for stripping residual sulfur and sulfur compounds from the catalyst to a level such that emissions from such zone after being placed on-stream with a feedstream leaner in sulfur and sulfur compounds than utilized before thus passing the portion of the acid gas feedstream to the Claus plant therethrough at least do not exceed the quantity of sulfur atoms entering such zone;
- providing the resulting gas-in-process containing the thus stripped sulfur and sulfur compounds to a Claus conversion step;
- and
- returning the catalytic reaction zone having catalyst thus stripped of residual sulfur and sulfur compounds to adsorption conditions with a feedstream leaner in hydrogen sulfide and sulfur dioxide than utilized during the vaporizing step, thereby preventing emissions from such zone after being placed on stream with such feedstream from exceeding the quantity of sulfur atoms entering such zone during adsorption.
In a sulfur recovery process comprising passing an acid gas feedstream, having H.sub.2 S as essentially the only sulfur species therein, to a Claus plant comprising (a) a thermal conversion zone, and (b) at least two Claus catalytic reaction zones, at least one of which is operated under adsorption conditions including temperature, for forming and depositing a preponderance of sulfur formed on a catalyst therein, while another catalytic reaction zone is being regenerated and/or cooled, the improvement comprising:
- (1) regenerating the Claus catalyst in a first catalytic reactor zone by vaporizing sulfur deposited on the catalyst using a stream of gas-in-process whose temperature is above the sulfur dewpoint and whose composition is richer in H.sub.2 S and SO.sub.2 than the gas contacting the catalyst under said adsorption conditions;
- (2) cooling the regenerated catalyst and stripping residual sulfur and sulfur compounds from the regenerated catalyst by passing a portion of the acid gas feedstream through the regenerated catalyst in said Claus catalytic conversion zone at an inlet temperature below the inlet temperature of gas during the adsorption conditions and at a rate and for a time sufficient to cool the catalyst and to strip the sulfur and sulfur compounds from the catalyst;
- and
- (3) providing the resulting gas-in-process from step (2) containing the residual sulfur and sulfur compounds to a second Claus catalytic reaction zone.
Process for the recovery of sulfur from an acid gas feedstream comprising as a sulfur species essentially only hydrogen sulfide, the processing comprising:
- partially combusting hydrogen sulfide in the acid gas feedstream to sulfur dioxide in a thermal conversion zone and then reacting resulting sulfur dioxide with hydrogen sulfide in a Claus catalytic conversion zone in the presence of an effective Claus conversion catalyst for production of sulfur by the Claus reaction under adsorption conditions including temperature for forming and depositing a preponderance of the sulfur on catalyst therein;
- then vaporizing thus deposited sulfur from the resulting sulfur-laden catalyst in the presence of a gas-in-process richer in hydrogen sulfide and sulfur dioxide than in the gas contacting the catalyst under said adsorption conditions;
- then stripping residual sulfur and sulfur compounds from the catalyst freshly denuded of sulfur by passing a portion of the acid gas feedstream comprising as a sulfur species essentially only hydrogen sulfide through catalyst in said catalytic conversion zone at an inlet temperature less than the inlet temperature to said catalytic conversion zone during said adsorption conditions;
- and
- then returning the thus regenerated and conditioned catalyst to operation in a final position of a series of one or more Claus catalytic reaction zones operated under adsorption conditions, the feedstream being introduced into such zone under adsorption conditions being leaner in hydrogen sulfide and sulfur dioxide than the gas used for vaporizing elemental sulfur from the catalyst.
In a sulfur recovery process comprising passing an acid feed gas feedstream, having H.sub.2 S as essentially the only sulfur species therein, to a Claus plant comprising (a) a thermal conversion zone, and (b) at least two Claus catalytic reaction zones, at least one of which is operated under adsorption conditions, including temperature, for forming and depositing a preponderance of sulfur formed on a catalyst therein while another catalytic reaction zone is being regenerated and/or cooled, the improvement comprising:
- (1) regenerating the Claus catalyst in a first catalytic reactor zone by vaporizing sulfur deposited on the catalyst using a stream of gas-in-process whose temperature is above the sulfur dewpoint and whose composition is richer in H.sub.2 S and SO.sub.2 than the gas contacting the catalyst under said adsorption condition;
- (2) cooling the regenerated catalyst and stripping residual sulfur and sulfur compound from the regenerated catalyst by passing a portion of the acid gas feedstream through the regenerated catalyst in said Claus catalytic conversion zone at an inlet temperature below the inlet temperature of gas during the adsorption conditions and at a rate and for a time sufficient to cool the catalyst and to strip the sulfur and sulfur compounds from the catalyst;
- (3) providing the resulting gas-in-process from step (2) containing the residual sulfur and sulfur compounds to a second Claus catalytic reaction zone;
- and
- (4) returning the catalytic reactor zone containing this thus regenerated and conditioned catalyst to operation in a final position of a series of two or more Claus catalytic reaction zones operated under adsorption conditions.
Dependencies are inferred from the claim text.