SBIR-STTR Award

Ceramic cross-flow filters have been designed to provide hightemperature, high pressure removal of particulates from hot gasstreams in coal fueled power systems, with the benefit of highsurface area per unit volume. However, further ceramic technologyis needed on cross-flow filters to improve both effectiveness andreliability. An important need has been identified as a one-piecemonolithic ceramic cross-flow filter, rather than the presentsegmented filter that has been known to delaminate in service. This delamination allows particulates to bypass the filter, whichcould lead to costly damage to downstream turbines and subsequentfailure to meet environmental regulations pertaining to stack gasemissions. Current ceramic technology has proved incapable offorming a complex one-piece shape of this nature with anacceptable permeable, porous ceramic material. A unique andproprietary injection mold ceramic forming process has been usedfor years to produce complex one piece monolithic shapescommercially, but of a non-permeable nature. The development of apermeable ceramic composition for this process represents asignificant effort. In Phase I, the aim is to demonstrate thefeasibility of a novel technology where a permeable, porousceramic material is formed with this process, targeted to meetthe filtration and environmental requirements of cross-flowfilters. With this material and process, a much more reliable,effective monolithic ceramic cross-flow filter can evolve.Anticipated Results /Potential Commercial Applications as described by the awardee: Phase I results are expected to showwhich of several ceramic composition variations produce favorablepermeability and hot strength properties suitable for cross-flowfilter application. The Phase II objective will be prototypeproduction and field testing of monolithic ceramic cross-flowfilters to demonstrate a new level of effective, reliable removalof particulates in hot gas streams, in coal fired power systems.The new filter design is expected to significantly reduce stackemissions and reduce costly downstream turbine damage anddowntime in coal-fired power systems.

Ceramic cross-flow filters are designed to provide high temperature, high pressure removal of particulates from hot gas streams in coal fueled power systems with the benefit of high surface area per unit volume. An important need has been identified for a one-piece monolithic ceramic cross-flow filter, rather than the present segmented filter that has been known to delaminate or separate in service. This delamination allows particulates to by-pass the filter, which can lead to costly damage to downstream turbines and subsequent failure to meet environmental regulations pertaining to stack gas emissions. Further, an effective hot gas stream filtration system is expected to result in greater use of plentiful coal and conservation of other less abundant fossil fuels. Current ceramic technology has proved incapable of forming such a complex one-piece shape with an acceptable permeable porous ceramic material. A unique injection mold ceramic forming process has commercially produced complex shapes of this nature for many years, but of a nonpermeable ceramic. In Phase I feasibility was demonstrated for using this process on a laboratory scale to form permeable, porous ceramic shapes of new compositions targeted to meet the filtration requirements of ceramic cross-flow filters. In Phase II the ceramic composition data and laboratory scale process techniques established in Phase I will be used as the basis for prototype production of full size one-piece monolithic ceramic cross-flow filters. Also, these prototypes will be subjected to filtration testing followed by post-test characterization. This monolithic ceramic cross-flow filter technology is expected to result in a much more effective hot gas stream filtration system for coal-fueled power stations.Anticipated Results/Potential Commercial Applications as described by the awardee: Phase II results will determine manufacturability and filtration performance of the prototype full size monolithic ceramic cross-flow filters made in Phase I. The commercial application for this technology is hot gas stream particulate filtration for various types of coal-fueled power systems.