Aqueous methods for titanating a chromium/silica catalyst with an alkali metal

Patent metadata

Field	Value
Publication number	US-12570770-B2
Application number	US-202519069382-A
Country	US
Kind code	B2
Filing date	Mar 4, 2025
Priority date	Apr 26, 2022
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

Methods for making titanated silica supports, titanated chromium/silica pre-catalysts, and activated titanated chromium/silica catalysts are disclosed in which hydrogen peroxide and an alkali metal precursor are used during catalyst preparation. Resulting titanated chromium/silica pre-catalysts often contain silica, 0.1 to 5 wt. % chromium, 0.1 to 10 wt. % titanium, and less than or equal to 4 wt. % carbon, and further contain an alkali metal or zinc at a molar ratio of alkali metal:titanium or zinc:titanium from 0.02:1 to 3:1 and/or at an amount in a range from 0.01 to 2 mmol of alkali metal or zinc per gram of the silica. High melt index potential activated titanated chromium/silica catalysts can be used to polymerize olefins to produce, for example, ethylene based homopolymers and copolymers having HLMI values of greater than 30 g/10 min.

First claim

We claim:

1 . A process for preparing a titanated silica support, the process comprising:
(i) contacting water, a peroxide compound, and a titanium precursor to form a first mixture; (ii) contacting a silica with the first mixture under conditions sufficient for titanium to adsorb onto the silica and form a second mixture; (iii) isolating a solid fraction from the second mixture and washing the solid fraction; wherein: isolating the solid fraction comprises filtering and/or centrifuging; and washing the solid fraction comprises contacting the solid fraction with a wash solution containing water; and (iv) drying the solid fraction to form the titanated silica support.

2 . The process of claim 1 , wherein:
step (i) comprises contacting water, hydrogen peroxide, a sodium precursor, a nitrogen-containing compound, and the titanium precursor to form the first mixture; and the second mixture is subjected to a reaction temperature in a range from 40 to 100° C. before isolating the solid fraction.

3 . The process of claim 2 , wherein:
the silica is a preformed silica.

4 . The process of claim 1 , wherein:
step (i) comprises contacting water, hydrogen peroxide, a sodium precursor, and the titanium precursor to form the first mixture; and the second mixture is subjected to a reaction temperature in a range from 40 to 100° C. before isolating the solid fraction.

5 . The process of claim 4 , wherein:
the silica is a preformed silica.

6 . The process of claim 1 , wherein the process further comprises a step of adjusting a pH of the first mixture to within a range from 3 to 12, prior to contacting the silica with the first mixture.

7 . A process for preparing a titanated chromium/silica pre-catalyst, the process comprising:
performing the process for preparing a titanated silica support of claim 1 ; and contacting a chromium precursor with the first mixture or the second mixture in any step prior to the step of isolating the solid fraction from the second mixture.

8 . A process for preparing a titanated chromium/silica catalyst, the process comprising:
performing the process for preparing a titanated chromium/silica pre-catalyst of claim 7 ; and activating the titanated chromium/silica pre-catalyst to form the titanated chromium/silica catalyst.

9 . A process for preparing a titanated chromium/silica pre-catalyst, the process comprising:
performing the process for preparing a titanated silica support of claim 1 ; and contacting a chromium precursor with the solid fraction after isolating the solid fraction from the second mixture.

10 . A process for preparing a titanated chromium/silica catalyst, the process comprising:
performing the process for preparing the titanated chromium/silica pre-catalyst of claim 9 ; and activating the titanated chromium/silica pre-catalyst to form the titanated chromium/silica catalyst.

11 . A process for preparing a titanated chromium/silica pre-catalyst, the process comprising:
performing the process for preparing a titanated silica support of claim 1 , except instead of contacting the silica with the first mixture, contacting a chromium/silica pre-catalyst with the first mixture.

12 . The process of claim 1 , wherein
a weight ratio of titanium of the titanium precursor to the water (Ti:H 2 O) is in a range from 0.0001:1 to 0.02:1; and a weight ratio of the silica to the water (silica:H 2 O) is in a range from 0.001:1 to 1:1.

13 . The process of claim 12 , wherein the silica is a preformed silica.

14 . The process of claim 12 , wherein the silica is a silica hydrogel.

15 . The process of claim 12 , wherein a molar ratio of the peroxide compound to the titanium precursor is in a range from 0.5:1 to 100:1.

16 . The process of claim 1 , wherein drying comprises spray drying or flash drying.

17 . The process of claim 1 , wherein a sodium precursor is added in step (ii) after the silica is contacted with the first mixture.

18 . The process of claim 17 , wherein a molar ratio of the sodium precursor to the titanium precursor is in a range from 0.1:1 to 300:1.

19 . The process of claim 18 , wherein the silica is a preformed silica.

20 . The process of claim 18 , wherein the silica is a silica hydrogel.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Ramanathan Anand
• Mcdaniel Max P
• Barr Jared
• Blagg Andrew
• Wittner Christopher E
• Solenberger Alan L
• Kilpatrick Zachary T
• Stevens Micheal P

Classifications

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• C08F4/78

  selected from chromium, molybdenum or tungsten · CPC title

• B01J2523/00

  Constitutive chemical elements of heterogeneous catalysts · CPC title

• C08F10/02

  Ethene · CPC title

• B01J37/0203

  the impregnation liquid containing organic compounds · CPC title