Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.
Type:
Grant
Filed:
December 28, 1998
Date of Patent:
February 15, 2000
Assignees:
Advanced Refining Technologies, Inc., University of Arkansas
Inventors:
Michael D. Ackerson, Seyed-Hamid Arabshahi, Robert E. Babcock
Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.
Type:
Grant
Filed:
April 14, 1997
Date of Patent:
December 29, 1998
Assignees:
University of Arkansas, Advanced Refining Technologies, Inc.
Inventors:
Michael D. Ackerson, Seyed-Hamid Arabshahi, Robert E. Babcock
Abstract: A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.
Type:
Grant
Filed:
July 25, 1994
Date of Patent:
December 12, 1995
Assignees:
University of Arkansas, Advanced Refining Technologies, Inc.
Inventors:
Michael D. Ackerson, Seyed-Hamid Arabshahi, Robert E. Babcock