Abstract: 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 vapour. 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.

Abstract: A feed gas stream containing hydrogen sulphide is subjected in a furnace 6 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 6 in a sulphur condenser 16. Residual sulphur dioxide is reduced back to hydrogen sulphide by hydrogen in a reactor 22. Water vapor is removed from the reduced gas in a quench tower 28 to form a water vapor-depleted gas stream. One part of the water vapor-depleted gas stream is sent to an adsorber vessel 30 in which hydrogen sulphide is absorbed in an absorbent. The resulting hydrogen sulphide-depleted gas stream is vented from the vessel 30 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 38 are returned as recycle streams to the furnace 6.

Abstract: 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.

Abstract: A gas stream containing at least 50% by volume of ammonia but eventually no hydrogen sulphide is burned in a reaction region which is supplied with oxygen and oxygen-enriched air. Both combustion and thermal cracking of ammonia takes place in the reaction region. The rate of supplying oxygen moleculars to the reaction region is from 75 to 98% of the stoichiometric rate required for full combustion of all combustible fluids supplied to the reaction region. Under these conditions essentially no ammonia remains in the effluent gas but formation of oxides of nitrogen can be minimized.

Abstract: 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 combustible gas 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 vapour, sulphur dioxide, and hydrogen sulphide, but essentially no residual ammonia.