Loading patent…
AssigneeExxon Research & Engineering Co.
InventorsTheodore H. West, David J. Martella
Estimating the term…
Solvent dewaxing of waxy hydrocarbon oils is improved by using a poly (n-C.sub.24) alkyl methacrylate polymer dewaxing aid in combination with lower melting point weight poly (C.sub.8 -C.sub.20) alkyl methacrylate polymer dewaxing aids. The solvent dewaxing processes improved using this combination dewaxing aid are the incremental and total predilution solvent type processes employing either surface chilled indirect heat exchanger means or direct chilling using cold solvent. The solvent dewaxing processes are those employing normally liquid dewaxing solvents, as exemplified by C.sub.3 -C.sub.6 ketones, such as methyl ethyl ketone, methyl isobutyl ketone and mixtures thereof, mixtures of ketones with aromatic such as MEK/toluene, halogenated C.sub.2 -C.sub.4 hydrocarbons such as tetrachloraethane, trichloro ethylene, etc. Autorefrigerative solvent dewaxing processes employing low boiling point, normally gaseous hydrocarbons, such as propane, propylene, butane, butene and mixtures of such solvents, with the aforesaid ketones, e.g., propane/MEK, are also benefited by use of the present dewaxing aid combination. Use of the combination dewaxing aid results in an improvement in feed filter rate and liquids/solids. ratio in the dewaxing process.
In solvent dewaxing process wherein a waxy hydrocarbon oil is contacted with a dewaxing solvent and a dewaxing aid and chilled so as to precipitate at least a portion of the wax present in said waxy hydrocarbon oil and the preciptated wax is removed by means of liquid/solid separation means yielding a dewaxed oil, the improvement consisting of using as the dewaxing aid a combination of (A) poly(n-C.sub.24) alkylmethacrylate polymer and (B) a lower melting point poly (C.sub.8 -C.sub.20) alkyl(meth)acrylate polymer.
Dependencies are inferred from the claim text.