Exhaust gas aftertreatment system for a power generator

A power generation aftertreatment system (14) includes a duct system (24), mixing vanes (48) and a straightening vane (56). The duct system (24) has a first end (26) and a second end (28) spaced from the first end (26). The duct system (24) also has an elbow (34) located between the first end (26) and the second end (28). The elbow (34) is configured to change a direction of flow (40) of a fluid contained within the duct system (24). The mixing vanes (48) are connected to the duct system (24) and are in contact with the fluid contained within the duct system (24). The straightening vane (56) is connected to the duct system (24) between the elbow (34) and the second end (28) of the duct system (24). The straightening vane (56) is in contact with the fluid contained within the duct system (24).