Porous ceramic filters and methods for filtering

Abstract

Disclosed herein are particulate filtration systems comprising a fuel source, a fuel burner, and a porous ceramic structure, the fuel source comprising at least one fuel additive capable of producing ash upon combustion. The resulting ash can be deposited on the porous ceramic structure in an amount sufficient to improve the filtration efficiency of the structure over a relatively short period of time or relatively short driving distances. Vehicles comprising such particulate filtration systems and methods for filtering particulate matter from a fluid stream are also disclosed herein. Further disclosed herein are methods for conditioning a particulate filter to improve the initial filtration efficiency.

1 . A particulate filtration system comprising:
 a fuel source comprising at least one fuel additive;   a fuel burner in fluid connection with the fuel source; and   a porous ceramic structure in fluid connection with the fuel burner,   wherein an exhaust stream comprising particulate matter from the fuel burner is configured to pass through the porous ceramic structure,   wherein the at least one fuel additive comprises at least one inorganic component that produces ash upon combustion, and   wherein the at least one fuel additive is capable of producing at least about 10 mg of ash per liter of fuel burned.   
     
     
         2 . The particulate filtration system of  claim 1 , wherein the at least one fuel additive is capable of producing at least about 30 mg of ash per liter of fuel burned. 
     
     
         3 . The particulate filtration system of  claim 1 , wherein the fuel source comprises diesel or gasoline fuel. 
     
     
         4 . The particulate filtration system of  claim 3 , wherein the fuel source volume ranges from about 30 liters to about 150 liters. 
     
     
         5 . The particulate filtration system of  claim 1 , wherein the fuel source comprises a fuel supply combined with the at least one fuel additive, and wherein a volumetric ratio of the fuel additive to the fuel supply ranges from about 1:25 to about 1:500. 
     
     
         6 . The particulate filtration system of  claim 1 , wherein the at least one inorganic component comprises at least one element chosen from Si, Al, Sn, Zn, Ti, Ce, Fe, Ca, Mn, Mg, Pb, Sr, V, Y, Zr, Cr, Mo, W, Co, Cu, Sn, Pr, and combinations thereof. 
     
     
         7 . The particulate filtration system of  claim 1 , wherein the fuel burner is an internal combustion engine. 
     
     
         8 . The particulate filtration system of  claim 1 , wherein the porous ceramic structure is a ceramic honeycomb comprising a plurality of channels separated by a plurality of porous interior walls. 
     
     
         9 . The particulate filtration system of  claim 1 , wherein the porous ceramic structure is coated with at least one catalyst. 
     
     
         10 . The particulate filtration system of  claim 1 , wherein the ash produced by combustion of the fuel additive is deposited on at least a portion of a surface of the porous ceramic structure. 
     
     
         11 . The particulate filtration system of  claim 10 , wherein the ash forms a membrane on at least a portion of a porous interior wall surface of the porous ceramic structure. 
     
     
         12 . The particulate filtration system of  claim 10 , wherein the ash comprises at least one oxide, sulfate, carbonate, or phosphate of Si, Al, Sn, Zn, Ti, Ce, Fe, Ca, Mn, Mg, Pb, Sr, V, Y, Zr, Cr, Mo, W, Co, Cu, Sn, Pr, or combinations thereof. 
     
     
         13 . The particulate filtration system of  claim 10 , wherein the ash is deposited in a concentration of at least about 10 mg/L, based on the total volume of the porous ceramic structure. 
     
     
         14 . The particulate filtration system of  claim 1 , wherein an initial ash concentration of the porous ceramic structure is approximately 0 mg/L. 
     
     
         15 . A vehicle comprising the particulate filtration system of  claim 1 . 
     
     
         16 . The vehicle of  claim 15 , wherein the fuel source comprises an initial fuel supply to the vehicle. 
     
     
         17 . The vehicle of  claim 15 , wherein after a driving distance of about 3000 km or less, an inorganic membrane comprising at least about 10 mg/L of ash is formed on at least a portion of a surface of the porous ceramic structure, wherein the concentration is based on a total volume of the porous ceramic structure. 
     
     
         18 . The vehicle of  claim 15 , wherein after a driving distance of about 3000 km or less, a particle number filtration efficiency of the porous ceramic structure is greater than about 80%. 
     
     
         19 . The vehicle of  claim 18 , wherein after a driving distance ranging from about 100 km to about 1000 km, a particle number filtration efficiency of the porous ceramic structure is greater than about 80%. 
     
     
         20 . (canceled) 
     
     
         21 . A method for filtering particulates from a fluid, the method comprising flowing the fluid through the particulate filtration system of  claim 1 . 
     
     
         22 .- 36 . (canceled)