Advanced High Porosity Ceramic Honeycomb Wall Flow Filters 2008-01-0623
A new platform of advanced ceramic composite filter materials for diesel particulate matter and exhaust gas emission control has been developed. These materials exhibit high porosity, narrow pore-size distribution, robust thermo-mechanical strength, and are extruded into high cell density honeycomb structures for wall-flow filter applications. These new high porosity filters provide a structured filtration surface area and a highly connected wall pore space which is fully accessible for multi-phase catalytic reactions. The cross-linked microstructure (CLM™) pore architecture provides a large surface area to host high washcoat/catalyst loadings, such as those required for advanced multi-functional catalysts (4-way converter applications). Data from flow reactor and engine dynamometer studies conducted in house as well as at independent laboratories show low comparative pressure drop of the Composite filter materials versus standard industry powder-based ceramic filters (Cordierite and SiC). Filtration efficiency measurements have also been conducted using particle number concentration based methods, and high trapping efficiencies have been observed on steady state and transient cycles. These filters can be manufactured using GEO2's technology platform from a variety of oxide and non-oxide materials such as: Mullite, SiC and others.