Reducing oxides of nitrogen using hydrogen generated from engine fuel and exhaust

摘要

Either (a) the exhaust ( 20 ) of an engine ( 9 ) and/or (b) inlet air ( 11 ) is sent to a hydrogen generator ( 22 ) along with diesel fuel ( 18 ) to produce hydrogen and carbon monoxide ( 26 ) for either (c) mixing with the mainstream of exhaust fed to a catalytic converter ( 28 ) or (d) regenerating a pair of NOx adsorption traps ( 35, 36 ), thereby reducing oxides of nitrogen (NOx) to provide system exhaust ( 29 ) which may have less than 0.20 grams/bhp/hr of NOx and 0.14 grams/bhp/hr of non-methane hydrocarbons. A water recovery unit ( 52, 63 ) may extract water from either the exhaust or the effluent of the NOx traps to humidify inlet air ( 11 ) for mixture with fuel. Inlet air ( 11 ) may be humidified in an air bubbling humidifier ( 72 ) that receives water from a condenser ( 76 ) that uses inlet air to cool NOx trap effluent.