Consolidation of DOC and DPF Functions into a Single Component
Diesel Particulate Filters (DPFs) are in common use in many applications for particulate matter (PM) control. Most examples of DPF usage follow a Diesel Oxidation Catalyst (DOC) providing NO2 for passive soot oxidation and fuel burning for active soot regeneration. The DPF is often catalyzed, (CDPF) to enhance passive regeneration by NO2, and to assist active regeneration by burning CO resulting from soot oxidation and any hydrocarbons passing through the DOC. Some applications with favorable NOx to PM ratios can operate without active regeneration, including applications with only CDPF for cost and packaging space savings. However, eliminating the DOC for applications that require both types of regeneration is difficult, as active regeneration must be accomplished by burning fuel within the CDPF, while adequately burning soot near the front.