US 12,006,856 B1
Aftertreatment for alcohol fuel substituted diesel engines
Joshua Lynn Ratts, Pine Village, IN (US); Abhay Gupta, Peoria Heights, IL (US); Arnold Myoungjin Kim, Peoria, IL (US); Eric Lee Schroeder, Germantown Hills, IL (US); and Kenth I. Svensson, Peoria, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on May 17, 2023, as Appl. No. 18/319,239.
Int. Cl. F01N 3/20 (2006.01); B01D 53/94 (2006.01); F01N 3/10 (2006.01); F01N 3/28 (2006.01)
CPC F01N 3/208 (2013.01) [B01D 53/9431 (2013.01); B01D 53/9477 (2013.01); B01D 53/9495 (2013.01); F01N 3/106 (2013.01); F01N 3/2803 (2013.01); F01N 3/2892 (2013.01); B01D 2251/2062 (2013.01); B01D 2255/102 (2013.01); B01D 2255/904 (2013.01); F01N 2370/02 (2013.01); F01N 2610/03 (2013.01); F01N 2610/05 (2013.01); F01N 2900/1402 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An internal combustion engine system, comprising:
an internal combustion engine configured to combust diesel fuel and a second fuel, wherein a portion of an exhaust of the combustion engine comprises nitrogen dioxide (NO2) and nitric oxide (NO);
a diesel oxidation catalyst (DOC) configured to receive the exhaust of the internal combustion engine and, in a first stage, decrease a concentration of the NO2 at a first concentration to a second concentration using an additive and reducing a portion of the NO2 to NO and, in a second stage, increase the concentration of the NO2 from the second concentration to a third concentration by oxidizing a portion of the NO to NO2, wherein the third concentration of the NO2 is less than the first concentration; and
a selective catalytic reduction (SCR) system configured to receive the NO2 and NO from the DOC and react the NO2 and NO with anhydrous ammonia (NH3) to produce nitrogen and water as an emission from the internal combustion engine system.