Multi-engine system with on-board ammonia production

Abstract

A power system is provided having a first power source including at least one engine configured to combust a first air/fuel mixture and produce a first exhaust stream. The fuel of the first air/fuel mixture may be liquefied petroleum gas. The system also has a first exhaust passageway fluidly connected to the first power source and configured to receive the first exhaust stream. In addition, the system has a second power source including at least one engine configured to combust a second fuel/air mixture and produce a second exhaust stream. Furthermore, the system has a second exhaust passageway fluidly connected to the second power source and configured to receive the second exhaust stream. The system further has a first catalyst disposed within the first exhaust passageway to convert at least a portion of the first exhaust stream to ammonia

1 . A power system, comprising:
 a first power source including at least one engine configured to combust a first air/fuel mixture and produce a first exhaust stream, the fuel of the first air/fuel mixture being liquefied petroleum gas;   a first exhaust passageway fluidly connected to the first power source and configured to receive the first exhaust stream;   a second power source including at least one engine configured to combust a second air/fuel mixture and produce a second exhaust stream;   a second exhaust passageway fluidly connected to the second power source and configured to receive the second exhaust stream; and   a first catalyst disposed within the first exhaust passageway to convert at least a portion of the first exhaust stream to ammonia.   
   
   
       2 . The power system of  claim 1 , wherein the fuel of the second air/fuel mixture is diesel fuel. 
   
   
       3 . The power system of  claim 2 , wherein the first and second exhaust passageways are fluidly connected downstream from the first catalyst to form a merged exhaust passageway configured to receive a combined exhaust stream. 
   
   
       4 . The power system of  claim 3 , further including a second catalyst disposed within the merged exhaust passageway. 
   
   
       5 . The power system of  claim 4 , wherein the second catalyst is configured to facilitate a reaction between ammonia and NOx in the combined exhaust stream to at least partially remove NOx from the combined exhaust stream. 
   
   
       6 . The power system of  claim 5 , further including at least one sensor configured to sense a parameter indicative of an amount of NOx in the first and/or second exhaust passageways and at least one sensor configured to sense a parameter indicative of an amount of ammonia in the first exhaust passageway. 
   
   
       7 . The power system of  claim 6 , further including a controller configured to adjust the amount of NOx produced by the first and/or second power sources in response to the sensed amount of NOx and/or ammonia. 
   
   
       8 . The power system of  claim 2 , wherein the first air/fuel mixture is richer than stoichiometric condition. 
   
   
       9 . The power system of  claim 8 , wherein the second air/fuel mixture is leaner than stoichiometric condition. 
   
   
       10 . The power system of  claim 2 , wherein the first power source and the second power source are configured to power at least one of a locomotive or a marine vessel. 
   
   
       11 . A locomotive, comprising:
 a first power source configured to power the locomotive, the first power source including at least one engine configured to combust a first air/fuel mixture;   a second power source configured to power the locomotive, the second power source including at least one engine configured to combust a second air/fuel mixture;   at least one generator drivingly coupled to at least one of the first power source or the second power source, wherein the at least one generator is configured to generate electrical energy to power the locomotive;   a first exhaust passageway fluidly connected to the first power source and configured to receive a first exhaust stream;   a second exhaust passageway fluidly connected to the second power source and configured to receive a second exhaust stream; and   a first catalyst disposed within the first exhaust passageway to convert at least a portion of the first exhaust stream to ammonia.   
   
   
       12 . The locomotive of  claim 11 , wherein the fuel of the first air/fuel mixture is diesel fuel, and the fuel of the second air/fuel mixture is liquefied petroleum gas. 
   
   
       13 . The locomotive of  claim 12 , wherein the second power source receives the liquefied petroleum gas from a tender car. 
   
   
       14 . The locomotive of  claim 11 , wherein the first and second exhaust passageways are fluidly connected downstream from the first catalyst to form a merged exhaust passageway configured to receive a combined exhaust stream. 
   
   
       15 . The locomotive of  claim 14  further including a second catalyst disposed within the merged exhaust passageway. 
   
   
       16 . The locomotive of  claim 15 , wherein the second catalyst is configured to facilitate a reaction between ammonia and NOx in the combined exhaust stream to at least partially remove NOx from the combined exhaust stream. 
   
   
       17 . The locomotive of  claim 16 , further including at least one sensor configured to sense a parameter indicative of an amount of NOx in the first and/or second exhaust passageways and at least one sensor configured to sense a parameter indicative of an amount of ammonia in the first exhaust passageway. 
   
   
       18 . The locomotive of  claim 11 , wherein the first air/fuel mixture is richer than stoichiometric condition and the second air/fuel mixture is leaner than stoichiometric condition. 
   
   
       19 . A machine, comprising:
 a first power source configured to power the machine, the first power source including at least one engine configured to combust a first air/fuel mixture;   a second power source configured to power the machine, the second power source including at least one engine configured to combust a second air/fuel mixture, wherein the first power source and the second power source generate a mechanical power output;   a first exhaust passageway fluidly connected to the first power source and configured to receive the a first exhaust stream;   a second exhaust passageway fluidly connected to the second power source and configured to receive a second exhaust stream; and   a first catalyst disposed within the first exhaust passageway to convert at least a portion of the first exhaust stream to ammonia.   
   
   
       20 . The machine of  claim 19 , wherein the fuel of the first air/fuel mixture and the fuel of the second air/fuel mixture is natural gas.