Abstract: An after-treatment system is provided, including an after-treatment module. The after-treatment module may include a housing configured to be installed in an exhaust system of an exhaust producing engine such that at least a portion of the exhaust from the engine flows through the housing. The housing may include at least one selective catalytic reduction (SCR) catalyst disposed within the housing and configured to facilitate a reduction reaction with NOx in the exhaust. In addition, the housing may include at least one NOx sensor disposed within the housing and configured to take measurements of an amount of NOx in the exhaust. Further, the housing may include a controller disposed on the housing and configured to receive the NOx measurements from the NOx sensor.

Abstract: An exhaust aftertreatment system for an engine is disclosed. The exhaust aftertreatment system including a first exhaust passage, an SCR catalyst disposed in the first exhaust passage, a second exhaust passage parallel with the first exhaust passage and fluidly coupled to the first exhaust passage upstream of the SCR catalyst and a container disposed in the second exhaust passage, the container configured to hold a volume of urea and to direct exhaust from the second exhaust passage through the volume of urea in the container.