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US 2019/0367820 A1Published application
Boiling free fractionation of hydrocarbon streams utilizing a membrane cascade
AssigneeExxonMobil Research and Engineering Company
InventorsBenjamin A. McCool, Dhaval A. Bhandari, Yogesh V. Joshi
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Abstract
Methods and systems are provided herein utilizing a membrane cascade to separate a hydrocarbon feed into boiling point fractions. Also provided herein are methods for selecting membranes for said cascades to achieve the desired boiling point fraction separation.
Claims27
A process for fractionating a hydrocarbon stream into boiling point fractions, comprising:
- providing a hydrocarbon stream;
- selecting a first stage membrane effective to separate a hydrocarbon feed into a first stage permeate and a first stage retentate;
- wherein the heaviest molecule in the first stage permeate has a boiling point in the kerosene boiling range;
- selecting a second stage membrane effective to separate a hydrocarbon feed into a second stage permeate and a second stage retentate;
- wherein the heaviest molecule in the second stage permeate has a boiling point in the diesel boiling range;
- selecting a third stage membrane effective to separate a hydrocarbon feed a third stage permeate and a third stage retentate;
- wherein the heaviest molecule in the third stage permeate has a boiling point in the gas oil boiling range;
- selecting a fourth stage membrane effective to separate a hydrocarbon feed into a fourth stage permeate and a fourth stage retentate;
- wherein the heaviest molecule in the fourth stage permeate has a boiling point in the naphtha boiling range;
- and
- feeding the hydrocarbon stream to one of the first, second, third, or fourth stage membranes under effective separation conditions;
- feeding the applicable stage permeate and retentate to either a downstream refinery process or to another membrane stage;
- and
- repeating the preceding act until each of the first, second, third, and fourth stage membranes has performed a separation on the hydrocarbon stream, permeate from a previous membrane stage, or retentate from a previous membrane stage.
11 more elements
A system for fractionating a hydrocarbon stream into boiling point fractions, comprising:
- a hydrocarbon stream;
- a first stage membrane in fluid communication with the hydrocarbon stream, said first stage membrane effective to separate the hydrocarbon stream into a first stage permeate and a first stage retentate;
- wherein the heaviest molecule in the first stage permeate has a boiling point in the kerosene boiling range;
- a second stage membrane in fluid communication with the first stage retentate, said second stage membrane effective to separate the first stage retentate into a second stage permeate and a second stage retentate;
- wherein the heaviest molecule in the second stage permeate has a boiling point in the diesel boiling range;
- a third stage membrane in fluid communication with the second stage retentate, said third stage membrane effective to separation the second stage retentate into a third stage permeate and a third stage retentate;
- wherein the heaviest molecule in the third stage permeate has a boiling point in the gas oil boiling range;
- and
- a fourth stage membrane in fluid communication with the first stage permeate permeate, said fourth stage membrane effective to separate first stage permeate into a fourth stage permeate and a fourth stage retentate;
- wherein the heaviest molecule in the fourth stage permeate has a boiling point in the naptha boiling range.
7 more elements
A process for fractionating a hydrocarbon stream into boiling point fractions, comprising:
- providing a hydrocarbon stream;
- selecting one or more membranes effective to separate the hydrocarbon stream into a permeate and a retentate stream;
- contacting the hydrocarbon stream with the membrane under effective separations conditions;
- the permeate and retentate streams separated substantially into two separate boiling point fractions;
- wherein the selecting the one or more membranes comprises,
- obtaining compositional data of the hydrocarbon stream;
- said compositional data comprising one or more of API gravity, average molecular weight, aromaticity, average boiling point, density, total sulfur and nitrogen content, pour point, viscosity, metal content, total acid number (TAN), reid vapor pressure, Micro Carbon Residue content, C7 asphaltenes content, paraffin-naphthene-aromatic content, carbon to hydrogen ratio, and STAR-7 analysis;
- determining a desired diffusion of molecules through the one or more membranes;
- selecting one or more membranes based on a relationship:
- Diffusion
-
-
- of
-
-
- molecules
- ∝
- kT
- 6
-
- π
-
-
- viscosity
- *
- Radius
-
- function
-
-
- (
- Radius
- ,
- MW
- )
- where k is the Boltzmann constant, T is temperature for separation, viscosity is the viscosity of the feed, radius is the radius of each molecule in the feed, and MW is the molecular weight of each molecule in the feed;
- wherein determining the relationship comprises;
- obtaining a hydrocarbon feed of known composition;
- obtaining a membrane;
- performing a separation experiment by contacting the hydrocarbon feed of known composition with the membrane thereby forming a control permeate and a control retentate;
- analyzing the control permeate and the control retentate via one of simulated distillation, elemental analysis, and STAR7 analysis;
- establishing at least one parameter unique to the membrane as an input to the function(Radius, MW);
- and
- repeating the determining the relationship process if more than one membrane is used.
41 more elements
Dependencies are inferred from the claim text.