Method of changing compositions of circulating solvent in solvent dewaxing
AssigneeMobil Oil Corporation
InventorLyle A. Leach
Life of this patent
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Abstract
An improved solvent dewaxing process in which a method and apparatus for continuous hot wash of a dewaxing filter is disclosed. A hot wash solvent is continuously sprayed below the doctor blade followed by a cold solvent spray below the hot solvent spray. Additionally, a solvent management process for changing the proportions of the solvent in response to different viscosity feedstocks thereby increasing filtration efficiency is also disclosed.
Claims11
A process for changing the composition of total circulating solvent in an MEK dewaxing unit including a dewaxing filter comprising the steps of:
- subjecting a petroleum feedstock to solvent dewaxing and thereafter recovering solvent from dewaxed filtrate and separated wax by evaporation and stripping;
- dehydrating the recovered solvent from said evaporation and stripping to form a dry solvent and recycling said dry solvent to the dewaxing unit;
- passing a portion of said dry solvent into a dry solvent tank;
- splitting said dry solvent from the dry solvent tank in a solvent splitter into an MEK rich fraction and a toluene rich fraction and storing each fraction in a separate tank;
- and
- replacing the dry solvent portion passed to the dry solvent tank with an amount of MEK rich fraction recovered from the solvent splitter.
A process for changing the composition of total circulating solvent comprising a first solvent and a second solvent in a solvent dewaxing unit including a dewaxing filter comprising the steps of:
- subjecting a petroleum feedstock to solvent dewaxing and thereafter recovering solvent from dewaxed filtrate and separated wax by evaporation and stripping;
- dehydrating the recovered solvent from said evaporation and stripping to form a dry solvent and recycling said dry solvent to the dewaxing unit;
- passing a portion of said dry solvent into a dry solvent tank;
- splitting said dry solvent from the dry solvent tank in a solvent splitter into a first solvent rich fraction and a second solvent rich fraction and storing each fraction in a separate tank;
- and
- replacing the dry solvent portion passed to the dry solvent tank with an amount of first solvent rich fraction recovered from the solvent splitter.
Dependencies are inferred from the claim text.