Combustion Filter Use & Regeneration Methods to Control Particulate Deposition & Extend High-performance Lifetime

Technology #15944

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Victor Wong
Department of Mechanical Engineering, MIT
Alexander Sappok
Department of Mechanical Engineering, MIT
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Particulate Filter Control System and Method

US Patent 9,334,772
In-Situ Optical Analysis of Ash Formation and Transport in Diesel Particulate Filters During Active and Passive DPF Regeneration Processes
SAE International, DOI 10.4271/2013-01-0519


These methods can be used generally on any filters that are fouled by mixed particulate systems, but are especially geared towards combustion filters that are clogged with soot and ash - diesel particulate filters (DPF), gasoline particulate filters (GPF), or other similar systems.

Problem Addressed

When fuel is burned, both soot (combustible particles) and ash (incombustible particles) build up on the filter walls and pores, blocking the air flow resulting in increased backpressure and reduced engine efficiency. To minimize this effect, the filter is regenerated by oxidizing away the soot. However, the resulting ash will eventually compromise the filter. This technology details an optimal method of engine use to strategically build up distinct layers of ash and soot that are better regenerated and extended filter lifetime.


The new and novel elements of this disclosure center around the manipulation of soot and ash levels at the start of the regeneration event, combined with control of flow rates through the filter during the regeneration event to control the resulting ash agglomerate size and transport, as well as the spatial distribution of the accumulated material. An initial thin layer of ash prohibits complete pore blocking by soot particles. A carefully grown soot layer can trap smaller ash nanoparticles and agglomerate them for cleaner removal. Also, a controlled regeneration temperature and airflow can better oxidize the soot and peel the underlying ash layer, creating a much cleaner, regenerated filter.


  • Methods require no physical change to existing combustion setups; instead, the methods are applied through airlfow control and correct timing to build the needed ash and soot strata
  • Better filter regeneration improves engine performance and reduces replacement costs