A process for production of elemental sulfur from a feedstock gas including from 15% to 100 vol % H2S and a stream of sulfuric acid, the process including: a) providing a Claus reaction furnace feed stream substoichiometric oxygen with respect to the Claus reaction, b) directing to a reaction furnace zone operating at elevated temperature such as above 900 C., c) directing to a sulfuric acid evaporation zone downstream said reaction furnace zone, d) cooling to provide a cooled Claus converter feed gas, e) directing to contact a material catalytically active in the Claus reaction, f) withdrawing a Claus tail gas and elemental sulfur, g) directing to a Claus tail gas treatment plant, with the associated benefit of a process involving injection of sulfuric acid in a sulfuric acid evaporation zone allowing high temperature combustion of said feedstock gas, including impurities, without cooling from evaporation and decomposition of sulfuric acid.

A system and method for producing hydrogen, including converting sulfur vapor and oxygen gas in a first zone of furnace into sulfur monoxide, injecting water into a second zone of the furnace, converting the sulfur monoxide and the water in the second zone into hydrogen gas and sulfur dioxide, discharging furnace exhaust gas (including the hydrogen gas) from the furnace, condensing sulfur vapor in the furnace exhaust gas into liquid sulfur in a condenser (heat exchanger) downstream of the furnace, and discharging the liquid sulfur from the condenser to a vessel.

A system and method for producing hydrogen, including converting sulfur vapor and oxygen gas in a first zone of furnace into sulfur monoxide, injecting water into a second zone of the furnace, converting the sulfur monoxide and the water in the second zone into hydrogen gas and sulfur dioxide, discharging furnace exhaust gas (including the hydrogen gas) from the furnace, condensing sulfur vapor in the furnace exhaust gas into liquid sulfur in a condenser (heat exchanger) downstream of the furnace, and discharging the liquid sulfur from the condenser to a vessel.