Process for producing an oligomerization catalyst
The invention relates to a process for producing an oligomerization catalyst comprising nickel oxide and a silicon-alumina support material, wherein the silica-alumina support material is in the ammonium form. The present invention further relates to a process for oligomerization of C3- to C6-olefins using the oligomerization catalyst produced according to the invention.
1. A process for producing an oligomerization catalyst, comprising at least the steps of:
a) mixing an amorphous silica-alumina support material comprising from 10% to 20% by weight of Al 2 O 3 and from 80% to 90% by weight of SiO 2 , an Al-containing and Si-free or Al-free and Si-containing binder, at least a portion of a nickel source comprising an aqueous, ammonia-free nickel solution of a nickel compound, an aqueous, ammonia-free nickel paste of a nickel compound or a combination of the abovementioned nickel solution and the abovementioned nickel paste, wherein the nickel compound is selected from the group consisting of nickel nitrate (Ni(NO 3 ) 2 ), nickel acetate (Ni(ac) 2 ), nickel acetylacetonate (Ni(acac) 2 ), nickel sulfate (NiSO 4 ), nickel citrate or nickel carbonate (NiCO 3 ), and granulating the resulting mixture, wherein the amorphous silica-alumina support material in step a) is in the ammonia form;
b) treating the granulate produced in step a) with at least another portion of a nickel source as defined for step a); and
c) calcining the granulate to produce the oligomerization catalyst.
2. The process according to claim 1 , wherein step a) comprises employing an oxidic aluminum material as the Al-containing and Si-free binder or silicon dioxide as the Al-free and Si-containing bind.
3. The process according to claim 2 , wherein the oxidic aluminum is selected from the group consisting of aluminum oxide, aluminum hydroxide and aluminum oxide hydroxide.
4. The process according to claim 3 , wherein the nickel source of step a) and/or b) comprises the aqueous, ammonia-free nickel paste which comprises between 30% and 50% by weight of nickel based on the total weight of the nickel paste.
5. The process according to claim 3 , wherein the nickel source of step a) and/or b) comprises the aqueous, ammonia-free nickel solution which comprises nickel in an amount in the range of from 1 % to 2 0% by weight based on the total weight of the solution.
6. The process according to claim 3 , wherein the calcination in step c) is performed at a temperature between 400° C. and 800° C.
7. The process according to claim 3 , wherein the oligomerization catalyst has a final composition of from 15% to 30% by weight of NiO, from 10% to 30% by weight of Al 2 O 3 , from 55% to 70% by weight of SiO 2 and optionally from 0.01% to 2.5% by weight of an alkali metal oxide.
8. A process for oligomerization of C3- to C6-olefins comprising contacting an olefin-containing feed mixture containing the C3- to C6-olefins with a catalyst comprising the oligomerization catalyst of claim 3 in a reaction zone.
9. The process according to claim 1 , wherein the nickel source of step a) and/or b) comprises the aqueous, ammonia-free nickel paste which comprises between 30% and 50% by weight of nickel based on the total weight of the nickel paste.
10. The process according to claim 9 , wherein the paste is composed of nickel carbonate and water as solvent, wherein the nickel is present as carbonate/hydroxide.
11. The process according to claim 1 , wherein the nickel source of step a) and/or b) comprises the aqueous, ammonia-free nickel solution which comprises nickel in an amount in the range of from 1% to 20% by weight based on the total weight of the solution.
12. The process according to claim 11 , wherein Ni(CO 3 or Ni(NO 3 ) 2 solution is used as the aqueous, ammonia-free nickel solution.
13. The process according to claim 11 , wherein the calcination in step c) is performed in a nitrogen stream.
14. The process according to claim 1 , wherein the calcination in step c) is performed at a temperature between 400° C. and 800° C.
15. The process according to claim 1 , wherein the oligomerization catalyst has a final composition of from 15% to 40% by weight of NiO, from 10% to 30% by weight of Al 2 O 3 , from 55% to 70% by weight of SiO 2 and optionally from 0.01% to 2.5% by weight of an alkali metal oxide.
16. The process according to claim 1 , wherein an alkali metal is added in step a) such that the oligomerization catalyst has a final composition of from 15% to 30% by weight of NiO and from 0.01% to 2.5% by weight of an alkali metal oxide.
17. A process for oligomerization of C3- to C6-olefins comprising contacting an olefin-containing feed mixture containing the C3- to C6-olefins with a catalyst comprising the oligomerization catalyst of claim 1 in a reaction zone.
18. The process for oligomerization according to claim 17 , wherein the olefin-containing feed mixture contains less than 2% by weight of branched olefins.
19. The process for oligomerization according to claim 17 , wherein the contacting takes place in the liquid phase.
20. The process for oligomerization according to claim 17 , wherein the contacting is carried out at a pressure of 10 to 70 bar and a temperature of from 50° C. to 200° C., wherein if the contacting is carried out in the liquid phase, the pressure and temperature are chosen such that the olefin-containing feed mixture is in the liquid phase.