US 12,202,914 B2
Rapid activation process and activation treatments for chromium catalysts for producing high melt index polyethylenes
Max P. McDaniel, Bartlesville, OK (US); Kathy S. Clear, Bartlesville, OK (US); William C. Ellis, Bartlesville, OK (US); Deloris R. Gagan, Ramona, OK (US); and Ted H. Cymbaluk, Seabrook, TX (US)
Assigned to Chevron Phillips Chemical Company LP, The Woodlands, TX (US)
Filed by Chevron Phillips Chemical Company LP, The Woodlands, TX (US)
Filed on Sep. 20, 2021, as Appl. No. 17/480,025.
Application 17/480,025 is a continuation of application No. 16/577,423, filed on Sep. 20, 2019, granted, now 11,149,098.
Claims priority of provisional application 62/735,999, filed on Sep. 25, 2018.
Prior Publication US 2022/0017661 A1, Jan. 20, 2022
Int. Cl. C08F 4/02 (2006.01); C08F 4/24 (2006.01); C08F 10/02 (2006.01); C08F 110/02 (2006.01); C08F 210/16 (2006.01)
CPC C08F 10/02 (2013.01) [C08F 4/24 (2013.01); C08F 110/02 (2013.01); C08F 4/025 (2013.01); C08F 210/16 (2013.01); C08F 2500/12 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A process for preparing a supported chromium catalyst, the process comprising:
(a) calcining a silicon oxide at a first temperature to provide a calcined silicon oxide comprising siloxane moieties, wherein the first temperature is above 600° C.;
(b) contacting the calcined silicon oxide with a chromium composition comprising a chromium source in an anhydrous, aprotic solvent, to form a chromium-treated silicon oxide comprising a residual solvent, the chromium source comprising a compound of chromium (VI); and
(c) heating the chromium-treated silicon oxide to a second temperature to remove the residual solvent and form the supported chromium catalyst, wherein the second temperature is less than the first temperature.