A Method and System for Freeze Protecting Liquid NOx Reductants for Vehicle Application

A method and system for freeze protecting liquid NOx reductants in which a liquid NOx reductant carried onboard a vehicle that could be exposed to cold weather conditions is heated by existing thermal energy generated by compressing the fuel used to power an engine of the vehicle. The heated fuel 14 heats the potentially frozen reductant 20 and the liquid reductant 20 is supplied to an exhaust gas pipe 56 in front of a catalyst for reducing NOx on the surface of the catalyst and catalytically converting into environmentally safe nitrogen and water.