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US 2007/0178033 A1Published application
Process for the removal of hydrogen sulfide, by means of its oxidation in the presence of hetero polyacids
AssigneeENI S.p.A.
InventorsAlberto De Angelis, Giuseppe Bellussi, Paolo Pollesel, Ugo Romano, Carlo Perego
Life of this patent
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Abstract
Hydrogen sulfide is oxidized to sulfur by means of treatment with an aqueous acid solution containing trivalent iron and a hetero polyacid having formula (I): HnXVyM(12-y)O40; or a sole hetero polyacid having formula (II): HnMeM12O40; wherein the symbols X, M Me n and y are specified in the text. At the end of the oxidation, the solution is treated with gas containing oxygen to re-oxidize the reduced metal.
Claims14
A process for the oxidation of hydrogen sulfide, comprising:
- a) contacting a gas containing H2S with an aqueous acid solution of trivalent iron and containing a hetero polyacid having redox properties, as such or partially salified with an alkaline metal or with ammonium, selected from those having general formula (I):
- HnXVyM(12-y)O40 (I)
- wherein n is an integer ranging from 3 to 6, X is an element selected from P, Si, As, B, Ge, y is an integer ranging from 1 to 3 and M consists of Mo or W.
- b) filtering and separating the sulfur produced due to the oxidizing effect of the trivalent iron which is reduced to bivalent iron;
- c) re-oxidizing the bivalent iron to trivalent iron with a gaseous stream containing oxygen;
- and
- d) recycling the solution containing trivalent iron and the hetero polyacid to the oxidation step (a).
4 more elements
A process for the oxidation of hydrogen sulfide, comprising:
- a1) contacting a gas containing H2S with an aqueous acid solution containing a hetero polyacid having redox properties, as such or partially salified, with an alkaline metal or with ammonium, selected from those having general formula (II):
- HnMeM12O40 (II)
- wherein n is an integer, ranging from 2 to 7, Me is selected from Fe, Co, Mn, Cu, Cr whereas M consists of Mo or W.
- b1) filtering and separating the sulfur produced due to the oxidizing effect of the element Me which is reduced;
- c1) re-oxidizing the element Me with a gaseous stream containing oxygen;
- and
- d1) recycling the re-oxidized solution to the oxidation step (a).
4 more elements
Dependencies are inferred from the claim text.