a method and system to reduce no x emissions from an engine connected to a fuel tank and an exhaust line , the apparatus including , a reformer to reform the fuel into hydrogen ; a fuel cell stack to convert the hydrogen into electricity ; a reduction unit disposed on the exhaust line to convert the no x into n 2 ; a first bypass line to provide a fluid communication between the first fuel tank and the fuel reformer ; a second bypass line to provide a fluid communication between the fuel reformer and the fuel cell stack ; a first reformate line to provide a fluid communication between the second bypass line and the exhaust line . the hydrogen is mixed with the no x in the exhaust line , and then the reduction unit uses the hydrogen to convert the no x into nitrogen .