US 11,655,431 B2
Method for upgrading low-value and waste fats, oils, and greases
David A. Slade, Ames, IA (US); Ramin Abhari, Bixby, OK (US); Martin Haverly, Ames, IA (US); and Peter Z. Havlik, Tulsa, OK (US)
Assigned to REG Synthetic Fuels, LLC, Ames, IA (US)
Filed by REG SYNTHETIC FUELS, LLC, Ames, IA (US)
Filed on Aug. 18, 2021, as Appl. No. 17/405,819.
Application 17/405,819 is a continuation of application No. 16/399,728, filed on Apr. 30, 2019, granted, now 11,118,133.
Claims priority of provisional application 62/665,991, filed on May 2, 2018.
Prior Publication US 2021/0371771 A1, Dec. 2, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. C11B 3/06 (2006.01); C11B 3/10 (2006.01); C11B 13/00 (2006.01); C11B 3/04 (2006.01); C11B 3/00 (2006.01)
CPC C11B 3/06 (2013.01) [C11B 3/001 (2013.01); C11B 3/008 (2013.01); C11B 3/04 (2013.01); C11B 3/10 (2013.01); C11B 13/00 (2013.01); C10G 2300/1011 (2013.01); C10G 2300/1014 (2013.01); C10G 2300/1018 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
contacting a composition with a caustic solution to produce a first mixture;
separating from the first mixture a caustic-treated composition and producing an aqueous waste with a pH from about 2.0 to about 5.0, wherein the separating comprises the use of a disc-stack centrifuge;
combining the caustic-treated composition with silica particles to produce a slurry; and
removing the silica particles from the slurry to produce a treated composition;
wherein:
the composition comprises:
one or more of animal fats, animal oils, plant fats, plant oils, vegetable fats, vegetable oils, greases, and used cooking oil,
about 10 wppm or more of total metals;
about 8 wppm or more of phosphorus;
about 10 wppm or more of sulfur;
about 20 wppm or more of nitrogen;
about 5 wt. % or more of free fatty acids; and
has an acid number from about 10 mg KOH/g to about 150 mg KOH/g;
the treated composition comprises:
a wt. % of free fatty acids about that of the composition; and
less total metals, phosphorus, sulfur, and nitrogen than the composition; and
the silica particles have an average particle size from about 10 microns to about 50 microns and a BET surface area from about 200 m2/g to about 1000 m2/g.