Catalyst design and preparation process for steam-reforming catalysts
View Patent ↗A catalyst with large surface area structure, in particular for steam-reforming catalysts, which is characterized in that the large surface area structure is formed of a large number of round or parallel penetrating holes of polygonal cross-section, wherein the catalyst carrier is prepared in the injection molding process, coated with a washcoat and then impregnated with the active component. The catalyst carrier includes at least one sinterable material and has a lateral pressure resistance of at least 700 N. Also, a process for the preparation of such catalysts and the use thereof in a reactor.
1. Catalyst with large surface area structure, characterised in that the large surface area structure is a honeycomb-shaped structure formed of a large number of parallel penetrating holes of round or polygonal cross-section, the honeycomb-shaped structure having 10 to 300 clear penetrating holes per cm 2 face area, where the catalyst contains 10 to 99 wt. % of at least one sinterable material and has a lateral pressure resistance of at least 700 N, wherein the at least one sinterable material is selected from the group consisting of metal oxides and ceramics.
2. Catalyst according to claim 1 , wherein the cross-sections of the penetrating holes are round, triangular, rectangular and/or hexagonal.
3. Catalyst according to claim 1 , wherein the at least one sinterable material is selected from aluminate, silicate, titanate, titanium dioxide, aluminium oxide, magnesium oxide, zirconium oxide, aluminium titanate, piezo ceramics, technical porcelain, steatite, cordierite, mullite ceramics, carbides, silicon carbide, boron carbide, nitrides, silicon nitride, aluminium nitride, silicon aluminium oxynitride, calcium aluminate, potassium aluminate or magnesium aluminate or combinations of the aforesaid.
4. Catalyst according to claim 1 , wherein the at least one sinterable material includes a catalytically active material.
5. Catalyst according to claim 4 , wherein the catalytically active material is selected from nickel, platinum, palladium, rhodium, ruthenium, copper, silver, gold, cobalt, manganese or iron.
6. Catalyst according to claim 1 , wherein the catalyst additionally includes a washcoat coating.
7. Catalyst according to claim 6 , wherein the washcoat coating has a large BET surface area and contains rare earths, preferably cerium/lanthanum and/or potassium/strontium.
8. Catalyst according to claim 6 , wherein the washcoat includes a binder for increasing the washcoat adhesion.
9. Catalyst according to claim 8 , wherein the binder is a sol and/or a metal salt solution.
10. Catalyst according to claim 9 , wherein the sol is a sol of aluminium or cerium compounds.
11. Catalyst according to claim 10 , wherein the metal salt solution is a saturated aluminium nitrate solution.
12. Catalyst according to claim 6 , wherein the coating includes a catalytically active material, selected from nickel, platinum, palladium, rhodium, ruthenium, copper, silver, gold, cobalt, manganese or iron.
13. A process of steam reforming comprising catalyzing a steam reforming reaction with the catalyst according to claim 1 .
14. A reactor, comprising the catalyst of claim 1 .
15. The reactor according to claim 14 , comprising a fixed bed, tubular or tube bundle reactor.
16. The reactor according to claim 14 , wherein the catalyst is honeycomb-shaped or has another large surface-area structure and is present in the reactor in the form of a loose packing.
17. Process for the preparation of a catalyst with honeycomb-shaped structure having a lateral pressure resistance of at least 700 N comprising the steps of:
a.) Grinding of a sinterable material to a powder, wherein the at least one sinterable material is selected from the group consisting of metal oxides and ceramics;
b.) Treatment of the sinterable material with a dispersant;
c.) Heating and mixing of the resulting composition so as to obtain a plastic mixture;
d.) Injection of the plastic mixture into an injection mould;
e.) Cooling, removal from mould and calcination of the mixture to form a catalyst comprising 10 to 99 wt. % of the sinterable material.
18. Process according to claim 17 , wherein after the calcination of step e) a coating is applied onto the catalyst.
19. Process according to claim 18 , wherein the coating of the catalyst is effected with a washcoat.
20. Process according to claim 18 , wherein the catalyst is calcined after the coating.
21. Process according to claim 18 , wherein a catalytically active material is fixed on the solid fraction of the washcoat before the coating.
22. Process according to claim 21 , wherein the catalytically active material is selected from nickel, platinum, palladium, rhodium, ruthenium, copper, silver, gold, cobalt, manganese or iron.
23. Process according to claim 17 , wherein the at least one sinterable material is selected from aluminate, silicate, titanate, titanium dioxide, aluminium oxide, magnesium oxide, zirconium oxide, aluminium titanate, piezo ceramics, technical porcelain, steatite, cordierite, mullite ceramics, carbides, silicon carbide, boron carbide, nitrides, silicon nitride, aluminium nitride, silicon aluminium oxynitride, calcium aluminate, potassium aluminate, magnesium aluminate or combinations of the aforesaid.
24. Process according to claim 17 , wherein the at least one sinterable material also includes a catalytically active material.
25. Process according to claim 24 , wherein the catalytically active material is selected from nickel, platinum, palladium, rhodium, ruthenium, copper, silver, gold, cobalt, manganese or iron.
26. Process according to claim 17 , wherein the dispersant includes paraffin oil.
27. Process according to claim 17 , wherein the heating of the composition is effected at 30 to 150° C.
28. Process according to claim 17 , wherein the heating and mixing of the composition to obtain the plastic mixture is effected in an extruder.