Integrated system for reducing fuel consumption and emissions in an internal combustion engine

Abstract

An integrated NOx after-treatment system for an internal combustion engine includes (a) a fuel supply subsystem for supplying an inlet fuel stream to the engine fuel intake, (b) an air supply subsystem for supplying an inlet oxygen-containing air stream to the engine air intake, (c) a fuel processor to which a fuel stream having substantially the same composition of the engine inlet fuel stream is directed, the fuel processor converting the fuel stream directed to the fuel processor to an outlet stream comprising H 2 and CO, (d) an adsorbent bed subsystem that cycles between an adsorbent state in which constituents from the engine exhaust stream are adsorbed and a desorption state in which the constituents are desorbed and converted to at least one of SO 2 and an environmentally-benign component selected from the group consisting of N 2 , H 2 O and CO 2 , and (e) a recirculation stream for directing at least some of the fuel processor output stream to the engine air intake.

1 . An integrated NOx after-treatment system for an internal combustion engine, the system comprising: 
 (a) a fuel supply subsystem for supplying an inlet fuel stream to the engine fuel intake;    (b) an air supply subsystem for supplying an inlet oxygen-containing air stream to the engine air intake;    (c) a fuel processor to which a fuel stream having substantially the same composition of the engine inlet fuel stream is directed, the fuel processor converting the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO;    (d) a catalyst/adsorbent material bed subsystem that cycles between a trapping state in which constituents from the engine exhaust stream are trapped and a regenerating state in which the constituents are desorbed and converted to at least one of SO 2  and an environmentally-benign component selected from the group consisting of N 2 , H 2 O and CO 2 ;    (e) a recirculation stream for directing at least some of the fuel processor output stream to the engine air intake.    
   
   
       2 . The system of  claim 1  wherein conversion of the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO is promoted by thermal means.  
   
   
       3 . The system of  claim 1  wherein conversion of the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO is promoted by a catalyst material.  
   
   
       4 . The system of  claim 3  wherein the catalyst material adsorbs CO.  
   
   
       5 . The system of  claim 4  wherein the catalyst material comprises platinum.  
   
   
       6 . The system of  claim 5  wherein the platinum-containing catalyst material is disposed on a supporting substrate.  
   
   
       7 . The system of  claim 6  wherein the supporting substrate is a ceramic substrate.  
   
   
       8 . The system of  claim 7  wherein the ceramic support is selected from the group consisting of zirconia and alumina.  
   
   
       9 . The system of  claim 1  wherein the fuel processor outlet stream molar concentration of each of H 2  and CO is in the range of 5-30 percent.  
   
   
       10 . The system of  claim 1  wherein the fuel processor outlet stream comprising H 2  and CO is passed periodically through the catalyst/adsorbent bed to evolve adsorbed NOx at a temperature lower than the NOx desorption temperature of stream compositions other than that of the fuel processor outlet stream.  
   
   
       11 . The system of  claim 1  wherein the fuel processor outlet comprising H 2  and CO is passed periodically through the catalyst/adsorbent bed to evolve adsorbed SOx at a temperature lower than the SOx desorption temperature of stream compositions other than that of the fuel processor outlet stream.  
   
   
       12 . A method for reducing NOx emissions and fuel consumption in an internal combustion engine, the method comprising: 
 (a) supplying an inlet fuel stream to the engine fuel intake;    (b) supplying an inlet oxygen-containing air stream to the engine air intake;    (c) directing a fuel stream having substantially the same composition of the engine inlet fuel stream to a fuel processor;    (d) converting the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO;    (e) cycling an adsorbent bed between an adsorbent state in which constituents from the engine exhaust stream are adsorbed and a desorption state in which the constituents are desorbed and converted to at least one of SO 2  and an environmentally-benign component selected from the group consisting of N 2 , H 2 O and CO 2 ;    (f) directing at least some of the fuel processor output stream to the engine air intake.    
   
   
       13 . The method of  claim 12  wherein fuel injection timing is advanced in relation to fuel injection timing that is retarded to reduce NOx emissions.  
   
   
       14 . The method of  claim 12  wherein conversion of the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO is promoted by thermal means.  
   
   
       15 . The method of  claim 12  wherein conversion of the fuel stream directed to the fuel processor to an outlet stream comprising H 2  and CO is promoted by a catalyst material.  
   
   
       16 . The method of  claim 15  wherein the catalyst material adsorbs CO.  
   
   
       17 . The method of  claim 16  wherein the catalyst material comprises platinum.  
   
   
       18 . The method of  claim 17  wherein the platinum-containing catalyst material is disposed on a supporting substrate.  
   
   
       19 . The method of  claim 18  wherein the supporting substrate is a ceramic substrate.  
   
   
       20 . The method of  claim 19  wherein the ceramic support is selected from the group consisting of zirconia and alumina.  
   
   
       21 . The method of  claim 12  wherein the fuel processor outlet stream molar concentration of each of H 2  and CO is in the range of 5-30 percent.  
   
   
       22 . The method of  claim 12  wherein the fuel processor outlet stream comprising H 2  and CO is passed periodically through the catalyst/adsorbent bed to evolve adsorbed NOx at a temperature lower than the NOx desorption temperature of stream compositions other than that of the fuel processor outlet stream.  
   
   
       23 . The method of  claim 12  wherein the fuel processor outlet comprising H 2  and CO is passed periodically through the catalyst/adsorbent bed to evolve adsorbed SOx at a temperature lower than the SOx desorption temperature of stream compositions other than that of the fuel processor outlet stream.