초록 ▼

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 cosolven

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.

대표청구항 ▼

[ What is claimed as invention is:] [1.] A petroleum wax separation process for separating the wax and oil in a waxy feedstock comprising the steps of:combining a waxy feedstock at a temperature at least at about its pour point with a solvent essentially free of a cosolvent to form a feedstock/solve

[ What is claimed as invention is:] [1.] A petroleum wax separation process for separating the wax and oil in a waxy feedstock comprising the steps of:combining a waxy feedstock at a temperature at least at about its pour point with a solvent essentially free of a cosolvent to form a feedstock/solvent mixture,adding the cosolvent to the feedstock/solvent mixture to cause wax to precipitate and form a first feedstock/solvent/cosolvent slurry, said cosolvent being essentially immiscible with the wax at and below the mixing temperature, essentially immiscible with the oil, miscible with the feedstock/solvent mixture, and significantly miscible with water,filtering said first slurry at a reduced pressure to form a first wax product and a first filtrate having a lower temperature than that of said first slurry,adding cosolvent to said first filtrate to induce additional wax precipitation and form a second slurry, andfiltering said second slurry to form a second filtrate and a second wax product.