Oxygen conducting membranes, preparation method thereof, and reactor and method using same
View Patent ↗The invention relates to an oxygen conducting membrane includes a dense, mixed-conducting, multi-metallic oxide membrane having one surface which is coated with dispersed particles based on noble metals or magnesium oxide.
1. An oxygen conducting membrane, comprising:
a mixed conducting dense membrane of multimetal oxide, one surface of which is covered with dispersed particles containing magnesium oxide or noble metals,
wherein the mixed conducting dense membrane is a layer comprising a multimetal oxide compound having a formula:
Ba x Sr 1-x Co 1-y Fe y O 3-z
where 0≦x≦1,
0≦y≦1, and
z is a number which renders a charge of the compound neutral and which defines oxygen deficiency, and
the particles based on magnesium oxide or noble metals represent from 0.01 to 0.1% by weight of the dense membrane.
2. The membrane according to claim 1 , in which the particles containing magnesium oxide or noble metals have a diameter of between 5 and 3000 nm.
3. The membrane according to claim 1 , in which the mixed conducting dense membrane of multimetal oxide has a perovskite structure.
4. The membrane according to claim 1 , in which the multimetal oxide comprises Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-z .
5. The membrane according to claim 1 , in which the mixed conducting dense membrane of multimetal oxide has a thickness of between 0.5 and 10 mm.
6. The membrane according to claim 1 , in which the particles are containing magnesium oxide.
7. The membrane according to claim 6 , in which the particles containing magnesium oxide are doped using vanadium.
8. The membrane according to claim 1 , in which the particles are particles of noble metals or alloys thereof.
9. The membrane according to claim 1 , in which the noble metals are selected from the group consisting of Pd, Pt, Rh, Ag, Au, Ru and Ir.
10. A method for preparing the oxygen conducting membrane as defined according to claim 1 , comprising:
a) providing the mixed conducting dense membrane;
b) preparing a colloidal suspension containing the magnesium oxide in an organic solvent;
c) placing the suspension obtained in contact with the mixed conducting dense membrane; and
d) calcining the membrane obtained.
11. A method for preparing the oxygen conducting membrane as defined according to claim 1 , comprising:
a) providing the dense membrane of multimetal oxide; and
b) depositing the particles of noble metals or alloys thereof by means of laser vaporisation.
12. A membrane reactor comprising an oxidation zone and a reduction zone which are separated by the oxygen conducting membrane as defined in claim 1 .
13. The membrane reactor according to claim 12 , in which the oxidation zone is in contact with the surface of the membrane coated with dispersed particles containing magnesium oxide or noble metals.
14. A method for oxidising a reactant gas, comprising:
i) providing the membrane reactor according to claim 12 ;
ii) introducing the reactant gas into the oxidation zone;
iii) introducing the gas containing oxygen into the reduction zone; and
iv) heating the membrane which separates the oxidation and reduction zones to an operating temperature.
15. The method according to claim 12 , in which the reactant gas is a light hydrocarbon which is oxidised into alkene.
16. The method according to claim 12 , in which the light hydrocarbon is ethane which is oxidised into ethylene.