Patent ID: 8136345
Filing Date: 2012-03-20
Classification: F01N,Y02T

Abstract:
1. Apparatus for reducing oxides of nitrogen (NOx) in the exhaust of an internal combustion engine which has a source of fuel and generates exhaust in an exhaust pipe, comprising: first and second NOx traps which reduce NOx in exhaust that passes therethrough; a single exhaust valve having two outlets and at least one inlet, said exhaust pipe connected to said one inlet, said valve having at least a first position in which substantially all of the exhaust flowing in said exhaust pipe is directed through a first one of said outlets to said first one of said NOx traps and a second position in which substantially all of the exhaust flowing in said exhaust pipe is directed through a second one of said outlets to a second one of said NOx traps; a respective hydrocarbon fuel reformer disposed between each of said outlets and each of said NOx traps, each reformer receiving fuel from said source; and a pair of oxidation catalysts, each disposed in serial flow relationship between a respective one of said reformers and a related one of said outlets; said valve alternatively directing said exhaust to one or the other of said NOx traps through a corresponding one of said reformers.