Methods for monitoring and regenerating selective catalytic reduction filter devices

Abstract

Methods for monitoring and/or regenerating a selective catalytic reduction particulate filter (SCRF) are provided. The SCRF comprises a porous filter substrate and a catalytic composition capable of reducing NOx applied thereto. Methods include determining a SCRF pressure differential (dP) and determining the SCRF soot loading using a 1st SCRF dP map if the SCRF has not been degreened, or a 2nd SCRF dP map if the SCRF has been degreened. The SCRF has been degreened if one or more of a degreening cumulative time and temperature threshold has been achieved and a filter regeneration count threshold has been achieved. The 1st and 2nd SCRF dP maps correlate SCRF dP and one or more of SCRF temperature, exhaust mass flow, and exhaust volumetric flow to a SCRF soot loading. The method can optionally further include initiating a filter regeneration if the determined SCRF soot loading is above a soot loading threshold.

Dependencies are inferred from the claim text.