A process for conversion of aqueous hydrogen sulfide to sulfuric acid

A process for purification of an aqueous solution comprising hydrogen sulfide comprising the steps of

• a. directing an amount of recycle gas to contact the aqueous solution comprising hydrogen sulfide, to separate a gas comprising hydrogen sulfide from the aqueous solution comprising hydrogen sulfide,
• b. optionally heating said gas comprising hydrogen sulfide optionally after addition of a source of oxygen to provide a process feed gas,
• c. in a hydrogen sulfide oxidation step directing said process feed gas optionally after addition of a source of oxygen under conditions efficient in oxidation of hydrogen sulfide to sulfur dioxide, to provide a sulfur dioxide rich gas,
• d. in a sulfur dioxide oxidation step directing said sulfur dioxide rich gas optionally after addition of a source of oxygen to contact a material catalytically active in oxidation of sulfur dioxide to sulfur trioxide under conditions efficient in catalytic oxidation of sulfur dioxide to sulfur trioxide, to provide a sulfur trioxide rich gas
• e. in a condensation step cooling said sulfur trioxide rich gas by heat exchange with a condenser heat exchange medium, to enable hydration of sulfur trioxide and condensation of sulfuric acid to provide a stream of concentrated sulfuric acid and a purified process gas, and
• f. in a recycling step, directing at least a part of the purified process gas as said recycle gas.