Abstract: Nitrogen oxides and carbon monoxide are removed from the exhaust of an internal combustion engine which operates on a methane-containing fuel by reacting the carbon monoxide, nitrogen oxides, and oxygen in the exhaust gas with methane in the presence of a catalyst comprising a crystalline zeolite having a silicon to aluminum ratio of equal to or greater than about 2.5 which is exchanged with a cation selected from the group consisting of cobalt, nickel, iron, chromium, rhodium, gallium, and manganese. Methane for the reaction is provided as a portion of the methane-containing fuel.

Abstract: A turbocharged or supercharged internal combustion motive system for utilization of gaseous fuel stored as a liquid wherein the liquefied gaseous fuel is vaporized and warmed at least partially with heat removed from the compressed intake combustion air in the turbocharger or supercharger aftercooler. In a preferred embodiment, the compressed intake combustion air is first cooled in an aftercooler against an ambiently cooled coolant and is subsequently cooled in further aftercooler heat exchange passages against an intermediate coolant which transfers heat removed from the compressed intake combustion air to the liquefied gaseous fuel.