Patent ID: 7608231

Claim:
A process for the continuous removal of hydrogen sulfide from a gaseous stream containing hydrogen sulfide, comprising: a) putting a gas containing H 2 S in contact with an oxidizing acidic aqueous solution of ferric nitrate which further comprises a heteropolyacid having redox properties, as such or partially salified with an alkaline metal or with ammonium, selected from those having general formula (I): H n XV y M (12-y) O 40 , (I) wherein n is an integer ranging from 3 to 6; X is selected from P, Si, As, B, and Ge; y is an integer ranging from 1 to 3; and M is selected from Mo and W; b) filtering and separating sulfur produced in a) as a result of the oxidizing effect of the ferric nitrate, which is reduced to ferrous nitrate in solution with heteropolyacid; c) oxidizing the ferrous nitrate from b) to ferric nitrate with air in an oxidation reactor thereby producing a solution comprising ferric nitrate and heteropolyacid; d) recycling the solution comprising ferric nitrate and heteropolyacid from d) to redox (a); e) subjecting a gaseous stream comprising one or more nitrogen oxides leaving the oxidation reactor in (c), to washing in a washing apparatus to the head of which is fed from 10 to 100% by weight of the reduced solution coming from sulfur separation (b), before the same is fed to the oxidation (c); and f) discharging the gaseous stream.