Process for purifying a liquid hydrocarbon fuel

Abstract

The present invention relates to a process for purifying a liquid hydrocarbon fuel consisting of 5% by weight or less of high molecular weight contaminants, in which the fuel is contacted with a hydrophobic non-porous or nano-filtration membrane and the purified product stream is recovered as the permeate.

What is claimed is:  
     
         1 . A process for purifying a liquid hydrocarbon fuel comprising 5% by weight or less of high molecular weight contaminants, said process comprising: 
 contacting the fuel with a hydrophobic non-porous or nano-filtration membrane to produce a purified product stream; and,    recovering the purified product stream as permeate.    
     
     
         2 . The process of  claim 1 , in which the high molecular weight contaminants have a molecular weight in the range of from about 200 to about 900.  
     
     
         3 . The process of  claim 1 , in which the membrane comprises a hydrophobic non-porous membrane.  
     
     
         4 . The process of  claim 3 , in which the hydrophobic non-porous membrane comprises a cross-linked polysiloxane membrane.  
     
     
         5 . The process of  claim 4 , in which the cross-linked polysiloxane membrane comprises a cross-linked polydimethylsiloxane membrane.  
     
     
         6 . The process of  claim 3 , in which the hydrophobic non-porous membrane is supported on a porous support.  
     
     
         7 . The process of  claim 6 , in which the support is chosen from the group consisting of polyethylene, polypropylene, nylon, vinyl chloride polymers, aromatic polyimides, polystyrene, polysulfon, polyesters, glass fibers, inorganic supports based on alumina, and inorganic supports based on silica.  
     
     
         8 . The process of  claim 1 , in which the membrane has a thickness of from about 0.5 μm to about 30 μm.  
     
     
         9 . The process of  claim 1 , in which the membrane has a thickness of from about 1 μm to about 10 μm.  
     
     
         10 . The process of  claim 1 , in which the fuel comprises a transportation fuel.  
     
     
         11 . The process of  claim 10 , in which the fuel is selected from the group consisting of gasoline, kerosene and diesel.  
     
     
         12 . The process of  claim 1 , further comprising contacting the liquid hydrocarbon fuel with the membrane at a trans-membrane pressure in the range of from about 2 to about 80 bar, a flux of between about 200 and about 5000 kg/m 2  membrane per day and a temperature in the range of from about 10° C. to about 80° C.  
     
     
         13 . The process of  claim 12 , in which the transmembrane pressure is in the range of from about 10 mbar to about 50 mbar.  
     
     
         14 . The process of  claim 13 , in which the flux is between about 200 and about 5000 kg/m 2  per day.  
     
     
         15 . The process of  claim 14 , in which the temperature is in the range of from about 10° C. to about 40° C.