Abstract: A storage vessel for emission control liquids such as aqueous solutions of urea is equipped with phase change materials that are calibrated to help maintain the liquid within a proper temperature range. Multiple phase change materials having phase transition temperatures of fifty to seventy degrees Celsius and seventy to one hundred degrees Celsius provide staged high-temperature stability for the urea solutions. Phase change materials can be included that also provide low temperature stability by changing from liquids to solids when freezing of the aqueous solution is threatened. Containers of phase change materials are applied to the interior or exterior surfaces of the storage vessel. Alternatively the storage vessel is included within and surrounded by a housing that forms an annular space with the storage vessel, and phase change materials are installed within the annular space. A method for using the storage vessel in an emissions control system also is presented.

Abstract: A fuel tank has phase change material located within its interior and in a heat transferring relationship with the contents of the tank. Thermal energy is transferred from the contents of the tank to the phase change material (PCM) when tank temperatures increase to the phase transition temperature (PTT) of the PCM. The PCM then transforms from solid to liquid to absorb substantial thermal energy and thereby helps to reduce vapor emissions. PCM also can be applied to the exterior of the tank. The fuel tank is particularly useful in automotive applications and also can be used in boats, motorcycles, and smaller powered equipment.