Fuel fractionation using membrane distillation

Patent metadata

Field	Value
Publication number	US-9541000-B2
Application number	US-201314071732-A
Country	US
Kind code	B2
Filing date	Nov 5, 2013
Priority date	Sep 15, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A method for reducing emissions from an engine includes generating a light hydrocarbon fuel fraction and combusting the light hydrocarbon fuel fraction in place of the fuel. The light hydrocarbon fuel fraction is generated by heating the fuel and flowing the fuel through a plurality of hollow fiber superhydrophobic membranes in a membrane module. Each hollow superhydrophobic membrane comprises a porous support and a superhydrophobic layer free of pores that extend from one side of the superhydrophobic layer to the other. Vapor from the fuel permeates the superhydrophobic membranes and enters a distillate collection chamber, producing a distilled fuel in the distillate collection chamber and a residual fuel within the hollow fiber superhydrophobic membranes. The residual fuel is removed from the membrane module and cooled to produce a cooled residual fuel. The cooled residual fuel flows through a plurality of hollow tubes in the membrane module and the distilled fuel is removed from the distillate collection chamber to produce the light hydrocarbon fuel fraction.

First claim

The invention claimed is:

1. A method for reducing emissions from an engine, the method comprising:
generating a light hydrocarbon fuel fraction by:
heating a fuel;
flowing the fuel through a plurality of hollow superhydrophobic membranes in a membrane module, wherein each hollow superhydrophobic membrane comprises a porous support and a superhydrophobic layer free of pores that extend from one side of the superhydrophobic layer to the other, and wherein vapor from the fuel permeates the hydrophobic membranes and enters a distillate collection chamber, producing a distilled fuel in the distillate collection chamber and a residual fuel within the hollow superhydrophobic membranes;
removing the residual fuel from the membrane module;
cooling the residual fuel to produce a cooled residual fuel;
flowing the cooled residual fuel through a plurality of hollow tubes in the membrane module; and
removing the distilled fuel from the distillate collection chamber to produce the light hydrocarbon fuel fraction; and

combusting the light hydrocarbon fuel fraction in the engine in place of the fuel, wherein combusting the light hydrocarbon fuel fraction generates fewer particulate emissions than combusting the fuel.

2. The method of claim 1 , wherein the light hydrocarbon fuel fraction is combusted in the engine during aircraft take off or cold engine starting.

3. The method of claim 1 , further comprising:
storing the light hydrocarbon fuel fraction prior to combusting the light hydrocarbon fuel fraction in the engine.

4. The method of claim 1 , wherein the step of generating the light hydrocarbon fuel fraction is carried out onboard an aircraft.

5. The method of claim 1 , wherein the superhydrophobic layer is selected from the group consisting of polytetrafluoroethylenes, parylenes and combinations thereof.

6. The method of claim 1 , wherein the hollow fiber support is porous and has an average pore diameter between about 0.1 microns and about 0.6 microns, and wherein the superhydrophobic layer has a thickness between about 0.01 microns and about 0.1 microns.

7. The method of claim 1 , wherein the superhydrophobic layer is applied to the hollow fiber support by a process selected from the group consisting of vapor phase deposition, slurry coating, surface polymerization and combinations thereof.

8. The method of claim 1 , wherein the fuel has a surface tension and the superhydrophobic layer has a surface energy density lower than the fuel surface tension.

9. The method of claim 1 , wherein a surface of the hollow fiber support is textured to reduce the surface energy of the superhydrophobic layer.

10. The method of claim 1 , wherein the fuel is heated to a temperature between about 70° C. and about 90° C., and wherein the residual fuel is cooled to a temperature between about 15° C. and about 30° C.

11. The method of claim 1 , wherein the distilled fuel condenses on exterior surfaces of the hollow superhydrophobic membranes.

12. The method of claim 1 , wherein the fuel comprises fuel hydrocarbons and the distilled fuel comprises distilled fuel hydrocarbons, and wherein the distilled fuel hydrocarbons have an average carbon number lower than the fuel hydrocarbons.

Assignees

• United Technologies Corp

Inventors

• Ma Zidu
• Sangiovanni Joseph J
• Dardas Zissis A
• Colket Iii Meredith B

Classifications

• B01D61/366

  Apparatus therefor · CPC title

• C10G7/00

  Distillation of hydrocarbon oils · CPC title

• F02C3/20 Primary

  using a special fuel, oxidant, or dilution fluid to generate the combustion products · CPC title

• C10G2400/02

  Gasoline · CPC title

• C10G31/11

  by dialysis · CPC title