US4259169A
Expired / Lapsed
US
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Process for the separation of n-paraffins from hydrocarbon oils
Assignee: Chevron Belgium NV
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Filing: 1979-05-25
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Granted: 1981-03-31
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Expires: 1999-05-25
Abstract
Abstract A process for the separation of n-paraffins from hydrocarbon by means of solid urea wherein the formation of the adduct of n-paraffins with urea is carried out in a fluidized bed.
Inventors
- 👤 Sidney T. G. Gale
- 👤 Paula J. J. Spreutels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:47
CPC Classifications
C; C10; C10G; C10G73/00; C10G73/02; C10G73/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
181 words
A process for forming an adduct of urea and a normal paraffin which comprises passing a liquid hydrocarbon mixture comprising n-paraffins having at least 6 carbon atoms per molecule, non adduct-forming hydrocarbons, and from 1 to 3 volume percent of a monohydric alcohol having from 1 to 2 carbon atoms per molecule upwardly through a contacting zone into contact with solid particles of urea at a flow rate sufficient to fluidize said particles of urea without substantial entrainment in said liquid hydrocarbon mixture thereby maintaining a dense phase fluidized bed of solid urea particles in said contacting zone, said bed having a distinct upper level below the outlet for the treated hydrocarbon mixture and effecting the formation of solid urea-n-paraffin adduct with at least a portion of the n-paraffins contained in said hydrocarbon mixture, said adduct tending to concentrate in the upper portion of said fluidized bed; withdrawing treated hydrocarbon mixture depleted in n-paraffins at a point above the upper level of said dense phase fluidized bed and withdrawing said adduct from the upper portion of said dense phase fluidized bed.
Claim 2
Dependent Claim
181 words
A process for forming an adduct of urea and a normal paraffin which comprises passing a liquid hydrocarbon mixture comprising n-paraffins having at least 6 carbon atoms per molecule, non adduct-forming hydrocarbons, and from 1 to 3 volume percent of a monohydric alcohol having from 1 to 2 carbon atoms per molecule upwardly through a contacting zone into contact with solid particles of urea at a flow rate sufficient to fluidize said particles of urea without substantial entrainment in said liquid hydrocarbon mixture thereby maintaining a dense phase fluidized bed of solid urea particles in said contacting zone, said bed having a distinct upper level below the outlet for the treated hydrocarbon mixture and effecting the formation of solid urea-n-paraffin adduct with at least a portion of the n-paraffins contained in said hydrocarbon mixture, said adduct tending to concentrate in the upper portion of said fluidized bed; withdrawing treated hydrocarbon mixture depleted in n-paraffins at a point above the upper level of said dense phase fluidized bed and withdrawing said adduct from the upper portion of said dense phase fluidized bed.
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein said hydrocarbon mixture comprises a middle distillate oil and a non-adduct forming light hydrocarbon diluent.
Claim 4
Dependent Claim
11 words
A process according to claim 1 wherein said alcohol is methanol.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein said alcohol is dissolved in said hydrocarbons prior to contacting said hydrocarbon mixture with urea.
Claim 6
Dependent Claim
24 words
A process according to claim 1 wherein said contacting zone is maintained at a temperature in the range of 7° C. to 21° C.
Claim 7
Dependent Claim
31 words
A process according to claim 1 wherein said hydrocarbon mixture comprises kerosene and methanol, the process is carried out at a temperature in the range of 11° C. to 13° C.
Claim 8
Dependent Claim
38 words
A process according to claim 1 wherein said hydrocarbon mixture comprises mixed iso-paraffins containing 4 to 6 carbon atoms per molecule and said reaction is maintained at a temperature in the range of 7° C. to 21° C.
Claim 9
Dependent Claim
31 words
A process according to claim 1 wherein said hydrocarbon mixture comprises a waxy gas oil and a non-adduct forming light hydrocarbon diluent containing from 3 to 6 carbon atoms per molecule.
Claim 10
Dependent Claim
32 words
A process according to claim 1 wherein said adduct recovered from said n-paraffin depleted hydrocarbon mixture is washed with a non-adduct forming hydrocarbon containing from 3 to 6 carbon atoms per molecule.
Claim 11
Dependent Claim
163 words
A process for the separation of n-paraffins from a hydrocarbon distillate containing same which comprises forming a mixture of said hydrocarbon Distillate, a non-adduct forming diluent and from 1 to 3 volume percent of a low molecular weight monohydric alcohol containing 1 to 2 carbon atoms per molecule, passing said mixture upwardly through a dense phase fluidized bed of solid urea particles having a distinct upper level, effecting removal of n-paraffins from said hydrocarbon distillate by formation of urea adduct thereby improving the pour point of said hydrocarbon distillate; withdrawing said hydrocarbon distillate of improved pour point at a point above the upper level of said dense phase fluidized bed, withdrawing solid urea and solid urea adduct from the upper portion of said fluidized bed; heating said solid urea adduct above the melting point of urea thereby decomposing said adduct and liberating n-paraffins; separating n-paraffins from said molten urea; prilling said molten urea; and returning said prilled urea to said adduct-forming fluidized bed.
Claim 12
Dependent Claim
163 words
A process for the separation of n-paraffins from a hydrocarbon distillate containing same which comprises forming a mixture of said hydrocarbon Distillate, a non-adduct forming diluent and from 1 to 3 volume percent of a low molecular weight monohydric alcohol containing 1 to 2 carbon atoms per molecule, passing said mixture upwardly through a dense phase fluidized bed of solid urea particles having a distinct upper level, effecting removal of n-paraffins from said hydrocarbon distillate by formation of urea adduct thereby improving the pour point of said hydrocarbon distillate; withdrawing said hydrocarbon distillate of improved pour point at a point above the upper level of said dense phase fluidized bed, withdrawing solid urea and solid urea adduct from the upper portion of said fluidized bed; heating said solid urea adduct above the melting point of urea thereby decomposing said adduct and liberating n-paraffins; separating n-paraffins from said molten urea; prilling said molten urea; and returning said prilled urea to said adduct-forming fluidized bed.
Claim 13
Dependent Claim
14 words
A process according to claim 10 wherein said low molecular weight alcohol is methanol.
Claim 14
Dependent Claim
34 words
A process according to claim 10 wherein said solid urea adduct is heated to a temperature in the range of 132° to 138° C. to effect decomposition of said adduct and melting of urea.
Claim 15
Dependent Claim
19 words
The process of claim 10 in which the withdrawn hydrocarbon distillate is subtantially free from urea and urea adduct.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |