§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US3850740A Expired / Lapsed US ⏱️ 0.0 years remaining

Partial predilution dilution chilling

Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1972-08-29
•
Granted: 1974-11-26
•
Expires: 1992-08-29
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A dewaxing process is described wherein a residual waxy petroleum oil stock characterized by having a viscosity greater than about 75 SUS at 210*F. and containing less than about 10 percent of material boiling below about 950*F., is mixed with at least about 0.3 volumes of a dewaxing solvent per volume of residual waxy oil stock, thereby depressing the cloud point of same. In one embodiment of the invention, the resultant mixture is introduced into a cooling zone, at a temperature above the depressed cloud point of the oil. Precooled dewaxing solvent is incrementally added to the cooling zone which is divided into a plurality of stages with agitation means present in each of the stages. The resultant solvent-oil mixture is cooled and agitated as it passes through the cooling zone, thereby reducing the temperature of the oil to below its depressed cloud point and precipitating at least a portion of the wax therefrom. A residual oil stock of diminished wax content is thereafter recovered. In a second embodiment of the invention, the waxy oil stock is introduced into the cooling zone in the absence of solvent at a temperature above the cloud point of the oil. Precooled dewaxing solvent is introduced incrementally into the initial stages of the cooling zone, coming into contact with the waxy oil and depressing its cloud point. The oil is gradually cooled to a temperature no less than the depressed cloud point of the oil whereupon additional precooled dewaxing solvent is added to the oil in the remaining stages of the cooling zone, thereby gradually cooling the oil to a temperature below the depressed cloud point and precipitating at least a portion of the wax therefrom.

Inventors

  • 👤 D Gudelis
  • 👤 D Shaw

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 22:15
CPC Classifications
C; C10; C10G; C10G73/00; C10G73/02; C10G73/06; C10G73/32

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 237 words
A PROCESS FOR THE DEWAXING OF A WAXY RESIDUAL PETROLEUM OIL STOCK HAVING A VISCOSITY RANGING BETWEEN ABOUT 125 AND 175 SUS AT 210*F, SAID PROCESS COMPRISING: A. MIXING SAID RESIDUAL OIL STOCK WITH BETWEEN ABOUT 0.3 AND 2 VOLUMES OF A PREDILUTION SOLVENT PER VOLUME OF OIL STOCK, THEREBY DEPRESSING THE CLOUD POINT OF SAID RESIDUAL OIL STOCK AND FORMING A FIRST MIXTURE COMPRISING SAID PREDILUTION SOLVENT AND SAID RESIDUAL OIL STOCK; B. INTRODUCING SAID FIRST MIXTURE AT A TEMPERATURE ABOVE THE DEPRESSED CLOUD POINT OF SAID RESIDUAL OIL STOCK INTO A COOLING ZONE DIVIDED INTO A PLURALITY OF STAGES AND PASSING SAID MIXTURE FROM STAGE TO STAGE OF SAID COOLING ZONE; C. INTRODUCING DEWAXING SOLVENT INTO AT LEAST A PORTION OF SAID STAGE OF SAID COOLING ZONE AT A PLURALITY OF SPACED POINTS THEREALONG; D. MIXING SAID DEWAXING SOLVENT WITH AT LEAST A PORTION OF SAID FIRST MIXTURE AS IT PASSES FROM STAGE TO STAGE OF SAID COOLING ZONE UNDER CONDITIONS OF HIGH AGITATION, THEREBY FORMING A SECOND MIXTURE COMPRISING SAID DEWAXING SOLVENT, SAID PREDILUTION SOLVENT AND SAID RESIDUAL OIL STOCK; AND, E. COOLING SAID RESIDUAL OIL STOCK CONTAINED IN SAID SECOND MIXTURE AS IT PASSES FROM STAGE TO STAGE OF SAID COOLING ZONE, THEREBY REDUCING THE TEMPERATURE OF SAID RESIDUAL OIL STOCK TO BELOW ITS DEPRESSED CLOUD POINT AND PRECIPITATING AT LEAST A PORTION OF SAID WAX THEREFROM UNDER SAID CONDITIONS OF HIGH AGITATION.
Claim 2
Dependent Claim 237 words
A PROCESS FOR THE DEWAXING OF A WAXY RESIDUAL PETROLEUM OIL STOCK HAVING A VISCOSITY RANGING BETWEEN ABOUT 125 AND 175 SUS AT 210*F, SAID PROCESS COMPRISING: A. MIXING SAID RESIDUAL OIL STOCK WITH BETWEEN ABOUT 0.3 AND 2 VOLUMES OF A PREDILUTION SOLVENT PER VOLUME OF OIL STOCK, THEREBY DEPRESSING THE CLOUD POINT OF SAID RESIDUAL OIL STOCK AND FORMING A FIRST MIXTURE COMPRISING SAID PREDILUTION SOLVENT AND SAID RESIDUAL OIL STOCK; B. INTRODUCING SAID FIRST MIXTURE AT A TEMPERATURE ABOVE THE DEPRESSED CLOUD POINT OF SAID RESIDUAL OIL STOCK INTO A COOLING ZONE DIVIDED INTO A PLURALITY OF STAGES AND PASSING SAID MIXTURE FROM STAGE TO STAGE OF SAID COOLING ZONE; C. INTRODUCING DEWAXING SOLVENT INTO AT LEAST A PORTION OF SAID STAGE OF SAID COOLING ZONE AT A PLURALITY OF SPACED POINTS THEREALONG; D. MIXING SAID DEWAXING SOLVENT WITH AT LEAST A PORTION OF SAID FIRST MIXTURE AS IT PASSES FROM STAGE TO STAGE OF SAID COOLING ZONE UNDER CONDITIONS OF HIGH AGITATION, THEREBY FORMING A SECOND MIXTURE COMPRISING SAID DEWAXING SOLVENT, SAID PREDILUTION SOLVENT AND SAID RESIDUAL OIL STOCK; AND, E. COOLING SAID RESIDUAL OIL STOCK CONTAINED IN SAID SECOND MIXTURE AS IT PASSES FROM STAGE TO STAGE OF SAID COOLING ZONE, THEREBY REDUCING THE TEMPERATURE OF SAID RESIDUAL OIL STOCK TO BELOW ITS DEPRESSED CLOUD POINT AND PRECIPITATING AT LEAST A PORTION OF SAID WAX THEREFROM UNDER SAID CONDITIONS OF HIGH AGITATION.
Claim 3
Dependent Claim 47 words
The process of claim 1 wherein said waxy residual petroleum oil stock is characterized by containing less than about 10 percent (weight) of material boiling below about 950*F., at atmospheric pressure, and less than about 50 percent (weight) of material boiling below about 1,050*F., at atmospheric pressure.
Claim 4
Dependent Claim 49 words
The process of claim 1 wherein the solvent in step (a) is a dewaxing solvent and is selected from the group consisting of aliphatic ketones containing from 3 to 6 carbon atoms per molecule, the lower molecular weight hydrocarbons, aromatic compounds, halogenated lower molecular weight hydrocarbons and mixtures thereof.
Claim 5
Dependent Claim 23 words
The process of claim 3 wherein said solvent is selected from the group consisting of methylethyl ketone, methylisobutyl ketone, toluene and mixtures thereof.
Claim 6
Dependent Claim 31 words
The process of claim 1 wherein the solvent used in step (a) is a dewaxing solvent and is the same as or different than the dewaxing solvent used in step (c).
Claim 7
Dependent Claim 21 words
The process of claim 1 wherein the degree of agitation is sufficient to provide substantially instantaneous mixing of solvent and oil.
Claim 8
Dependent Claim 22 words
The process of claim 1 wherein the dewaxing solvent used in step (c) is prechilled prior to introduction into said cooling zone.

References Cited (Backward Citations)

US2410483A Cited
US2486014A Cited
US3006839A Cited
US3038854A Cited
US3642609A Cited
US3644195A Cited
US3681230A Cited
US3719585A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-11-25 1978-05-27 1978-11-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-11-25 1982-05-27 1982-11-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-11-25 1986-05-27 1986-11-26 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag