The Boc Group, Inc.

Richard William Watson

Stephen Rhys Graville

Vijay Ramanand Balse

Jason Scott Norman

John Allen Wainford

Oxygen or oxygen-enriched air is employed to support combustion in furnaces () and () of part of the hydrogen sulphide content of a first feed gas stream. Sulphur vapour is extracted in condenser () from the resulting gas mixture so as to form a sulphur vapour depleted gas stream. The sulphur vapour depleted gas stream is passed into a catalytic reduction reactor () in which all the residual sulphur dioxide is reduced to hydrogen sulphide. This reduced gas mixture has water vapour extracted therefrom in a quench tower (). The resulting water vapour depleted gas stream flows to a Claus plant for treatment typically together with a second feed gas steam comprising hydrogen sulphide. Employing both furnaces () and () makes it possible to obtain effective conversions to sulphur of the hydrogen sulphide in the feed gas without having the recycle any of the water vapour depleted gas.

Process and apparatus for recovering sulphur from a gas stream containing sulphide

Oxygen or oxygen-enriched air is employed to support combustion in furnace () of part of the hydrogen sulphide content of a first feed gas stream. Sulphur is extracted from the resulting gas stream in a sulphur condenser (). Catalyst Claus reaction between hydrogen sulphide and sulphur dioxide in the resulting sulphur vapour depleted gas stream takes place in a catalytic reactor (). Sulphur is extracted in a further sulphur condenser (). The resulting sulphur vapour depleted gas stream is passed into a catalytic reduction reactor () in which all the residual sulphur dioxide and any sulphur vapour are reduced to hydrogen sulphide. The resulting reduced gas mixture has water vapour extracted there from in a quench tower (). The resulting water vapour depleted gas stream flows to a Claus plant for further treatment typically together with a second feed gas stream.

Process and apparatus for recovering sulphur from a gas stream containing hydrogen sulphide

An air-oxygen hydrogen sulphide burner ( ) fires into a furnace ( ). The burner comprises a main passage for combustion-supporting gas containing air ( ), a multiplicity of spaced apart outer elongate fluid-conducting open ended tubes extending in parallel with each other along the main passage, each of the outlet tubes surrounding at least at the distal end of the burner a respective inner elongate fluid-conducting open ended tube, the inner tubes extending in parallel with one another, a first inlet to the burner for oxygen or oxygen-enriched air, and a second inlet to the burner for feed gas containing hydrogen sulphide, the first inlet communicating with the inner tubs, and the second inlets communicating with the outer tubes.

Partial oxidation of hydrogen sulphide

Sour gas containing hydrogen sulphide has hydrogen sulphide absorbed therefrom in an absorbent in a vessel . A hydrogen sulphide rich gas stream is formed by desorbing hydrogen sulphide from the absorbent in a vessel . The resulting hydrogen sulphide rich gas stream is partially burned in a furnace . Resulting sulphur dioxide reacts therein with residual hydrogen sulphide to form sulphur vapor which is extracted in a condenser . Residual sulphur dioxide and sulphur vapor are reduced to hydrogen sulphide in catalyst stage of a reactor . Water vapor is removed from the resulting reduced gas stream by direct contact with water in a quench tower . At least part of the resulting water vapor depleted gas stream is sent to the vessel with the incoming sour gas stream.

Treatment of a gas stream containing hydrogen sulphide

A process and apparatus for recovering sulphur from a combustible gas stream comprising hydrogen sulphide, air, commercially pure oxygen or oxygen-enriched air. The combustible gas stream are fed to a burner which fires into an elongate furnace. A longitudinally extending flame is created which as a relatively oxygen-poor endothermic hydrogen sulphide dissociation region, and a relatively oxygen-rich, intense hydrogen sulphide combustion region. Residual hydrogen sulphide reacts with sulphur dioxide formed by the combustion to produce sulphur vapor. The furnace has an aspect ratio of about 8:1. The flame diverges from its root to occupy at its maximum cross-sectional area at least about 80% of the cross-sectional area of the furnace interior coplanar therewith.

Treatment of a combustible gas stream

A feed gas stream containing hydrogen sulphide is subjected in a furnace to reactions in which part of the hydrogen sulphide is burned to form sulphur dioxide, and is which the sulphur dioxide reacts with residual hydrogen sulphide to form sulphur vapor. The sulphur vapor is condensed from the gas stream exiting the furnace in a sulphur condenser . Residual sulphur dioxide is reduced back to hydrogen sulphide by hydrogen in a reactor . Water vapor is removed from the reduced gas in a quench tower to form a water vapor-depleted gas stream. One part of the water vapor-depleted gas stream is sent to an adsorber vessel in which hydrogen sulphide is absorbed in an absorbent. The resulting hydrogen sulphide-depleted gas stream is vented from the vessel as a purge stream. Another part of the water vapor-depleted gas stream and a hydrogen sulphide-rich gas formed by desorbing hydrogen sulphide from the absorbent in a vessel are returned as recycle streams to the furnace

Treatment of gas streams containing hydrogen sulphide

Sulphur is recovered from a first gas stream comprising hydrogen sulphide and at least 50% by volume of ammonia and from a second gas stream comprising hydrogen sulphide but essentially no ammonia, the first gas stream, the second gas stream, and combustion supporting gas comprising at least one stream of essentially pure oxygen or oxygen-enriched air are fed to a single combustion zone or a plurality of combustion zones in parallel with each other without premixing of first gas stream or the second gas stream with oxygen or air, and creating in the or each combustion zone at least one region in which thermal cracking of ammonia takes place, and taking from the reactor an effluent gas stream including sulphur vapor, sulphur dioxide, and hydrogen sulphide, but essentially no residual ammonia.

Sulphur recovery

Sulfur vapor is formed by partial oxidation of hydrogen sulphide. A burner is operated so as to establish a flame in a furnace in or into which the burner fires. There is supplied to the flame from the first region of the mouth of the burner at least one flow of a first combustible gas comprising hydrogen sulfide. At least one second flow of a first oxidizing gas is caused to issue from the mouth of the burner and mix in the flame with the first combustible gas. There is supplied to the flame from a second region of the mouth of the burner surrounding and spaced from the said first region at least one third flow of a second combustible gas comprising hydrogen sulfide. At least one fourth flow of a second oxidizing gas is caused to issue from a region or regions of the mouth of the burner surrounded by said second region and mix in the flame with the second combustible gas. At least one fifth, outermost flow of a third oxidizing gas is caused to mix in the flame with the second combustible gas. A resultant gas mixture including sulfur vapor, water vapor, sulfur dioxide, hydrogen and residual hydrogen sulfide is withdrawn from the furnace.

Partial combustion of hydrogen sulphide

Apparatus for recovering sulphur from a combustible gas stream comprising hydrogen sulphide is provided. The combustible gas stream, air and oxygen, or an oxygen-rich stream, are fed via a coaxial burner into an elongate furnace thereby creating a longitudinally-extending flame which has one or more relatively oxygen-rich, intense, combustion regions wherein hydrogen sulphide is combusted to form sulphur dioxide and one or more relatively oxygen-poor, endothermic, thermal dissociation regions. Residual hydrogen sulphide reacts with sulphur dioxide formed by the combustion to produce sulphur vapor. The apparatus includes a waste heat boiler to reduce the temperature of the furnace effluent and a condenser to remove sulphur therefrom. The furnace has an aspect ratio of about 8:1. The flame diverges from its root to occupy at its maximum cross-sectional area at least about 80% of the cross-sectional area of the furnace interior coplanar therewith.

Apparatus for burning a combustible gas containing hydrogen sulfide

A method is provided for converting the hydrogen sulfide in a hydrogen sulfide containing feed gas into elemental sulfur by oxidizing the hydrogen sulfide with an oxygen containing gas to produce elemental sulfur in a Claus plant, wherein the oxygen containing gas is axially introduced into an end portion of the reaction cylinder of the Claus plant and the hydrogen sulfide containing gas is introduced through at least one gas inlet in the side wall of the reaction cylinder at an oblique or perpendicular angle with respect to the direction of the flow of the oxygen containing gas so that the hydrogen sulfide containing gas introduced through the side wall surrounds and swirls about the oxygen containing gas, thereby allowing higher combustion temperatures to be achieved within the reaction cylinder which enhances the efficiency of the combustion and enhances the efficiency of decomposing any ammonia in the gas while keeping the very hot zones away from the refractory material lining the interior of the reaction cylinder.

Method of reacting hydrogen sulfide to produce sulfur

An improved oxygen-enhanced Claus process for the recovery of sulphur from an acid gas comprising hydrogen sulphide as a furnace in which a part of the hydrogen sulphide content of the acid gas is burned to form sulphur dioxide. The sulphur dioxide then reacts with residual hydrogen sulphide to form sulphur vapor which is condensed out of the resulting gas mixture. One part of the residual gas mixture is then subjected to catalytic stages to bring the reaction between the hydrogen sulphide and sulphur dioxide close to completion. The improvement resides in sending a second part of the gas mixture to an incinerator to convert all its hydrogen sulphide content to sulphur dioxide. After removal of water, the sulphur dioxide is returned to the furnace.

Treatment of gases

A part of the hydrogen sulphide content of a feed gas stream comprising hydrogen sulphide is burned by a burner that fires into a furnace. The combustion is supported by a stream of oxygen or oxygen-enriched air. Resulting sulphur dioxide reacts with residual hydrogen sulphide in the furnace to form sulphur vapor. Sulphur is condensed out of the resulting gas mixture in a sulphur condenser. At least part of the sulphur-free gas mixture flows through a reactor in which its sulphur dioxide content is reduced to hydrogen sulphide. Water vapor is removed from the resulting gas stream in a water condenser. At least part of the gas stream now essentially free of water vapor is recycled to the furnace. A purge stream is taken either from immediately downstream of the sulphur condenser or from intermediate the water condenser and the furnace, or from the furnace and, if desired, subjected to further treatment to remove sulphur-containing gases therefrom.

Treatment of gas streams

A hydrogen sulphide containing feed gas stream (typically including at least 70% by volume of hydrogen sulphide) is divided into a minor stream and a major stream. The minor stream is burnt in a first combustion region to form sulphur dioxide and water vapor. The resulting gas mixture is cooled in a heat exchanger and is employed in a second combustion region in which a portion of the hydrogen sulphide content of the major stream is burnt to form sulphur dioxide and water vapor. Reaction between the sulphur dioxide and remaining hydrogen sulphide takes place in a thermal reaction region to form sulphur vapor and water vapor. The proportions of sulphur burnt in the respective combustion regions and are chosen such that about one-third of the total hydrogen sulphide content of the feed gas stream is burnt to sulphur dioxide in these regions. Subsequent reaction between hydrogen sulpide and sulphur dioxide typically takes place in one or more catalytic reaction regions resulting with sulphur vapor being extracted in sulphur condensers. By using substantially pure oxygen to support combustion in the second combustion region, a relatively large flow rate of feed gas mixture may be handled in a plant of given size.

An oxygen enhanced split feedstream sulfur recovery process

A feed gas stream containing at least 60% by volume of hydrogen sulphide is burnt in a first combustion region to form water vapor and sulphur dioxide. Oxygen is employed to support combustion is the region. Thermal reaction then takes place in a thermal reaction region between hydrogen sulphide and sulphur dioxide to form sulphur vapor and water vapor. The resulting gas mixture is then cooled and sulphur vapor is extracted in a condenser. The gas mixture then passes into a second combustion region in which a further portion of the hydrogen sulphide is burnt in the presence of oxygen to form further sulphur dioxide and to adjust the mole ratio of hydrogen sulphide to sulphur dioxide to about 2:1. Further reaction between hydrogen sulphide and sulphur dioxide may be conducted in a further thermal reaction region and in catalytic reactors with further sulphur extraction in further condensers. The mole ratio of hydrogen sulphide to oxygen entering the first combustion region per unit time is greater than 2:1 and the mole ratio of hydrogen sulphide to fluid(s) (if any) other than oxygen being introduced into the first combustion region is greater than 3:2 and preferably greater than 4:1. By using substantially pure oxygen to support combustion of the hydrogen sulphide, a relatively large flow rate of feed gas mixture may be handled in a plant of given size.

Double combustion oxygen enhanced sulfur recovery process

A gas mixture including sulphur dioxide is recovered from sulphate waste material by burning a fuel to form a flame zone, introducing sulphate waste material into the zone and introducing pure oxygen or other oxygen-rich gas into the flame zone to support combustion of the fuel and to generate a flame of sufficient temperature to crack solid sulphate waste material and thereby liberate sulphur dioxide therefrom. Solids exiting the flame zone are separated from the gaseous combustion products. The sulphate waste material may be taken from a plant for making titanium dioxide pigment by the sulphate route.

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Near Ilkley, United Kingdom

Richard William Watson