Abstract: A crossflow membrane device that receives a feedstock at a feed end face and separates the feedstock into permeate and retentate. The device has a membrane support containing at least one monolith of porous material defining a plurality of passageways extending longitudinally from the feed end face of the monolith to a retentate end face of the monolith through which the feedstock flows to pass retentate from the device. A permselective membrane coating of finer pore size than that of the porous material is applied to the passageway wall surfaces of the monolith. At least one permeate conduit is formed within the monolith, the conduit containing a plurality of longitudinal permeate chambers communicating with a means of permeate introduction at or near the feed end face and permeate withdrawal at or near the retentate end face.

Abstract: A porous ceramic support for a gas separation membrane formed by sintering a green body containing grains of a refractory ceramic oxide with a high coefficient of thermal expansion and grains of a reactive binder precursor. Upon sintering, the reactive binder precursor reacts with at least one gaseous, liquid or solid reactant to create a reaction bond that binds the refractory ceramic oxide grains. The support configuration can be a tubular, flat plate, hollow fiber, or multiple-passageway monolith structure.

Abstract: A crossflow membrane device that receives a feedstock at a feed end face and separates the feedstock into permeate and retentate. The device has a membrane support containing at least one monolith of porous material defining a plurality of passageways extending longitudinally from the feed end face of the monolith to a retentate end face of the monolith through which the feedstock flows to pass retentate from the device. A permselective membrane coating of finer pore size than that of the porous material is applied to the passageway wall surfaces of the monolith. At least one permeate conduit is formed within the monolith, the conduit containing a plurality of longitudinal permeate chambers communicating with a means of permeate introduction at or near the feed end face and permeate withdrawal at or near the retentate end face.

Abstract: A submerged, vertically-mounted membrane device, the device receiving a gas-sparged feed stock at a bottom feed inlet to provide airlift circulation of the feed stock through the device and separating the feed stock into filtrate and residual gas-containing retentate which passes from the top end of the device. The device comprises a structure of one or more monolith segments of porous material each monolith segment defining a plurality of passageways extending longitudinally from a bottom feed end face to a top retentate end face. A porous membrane is applied to the walls of the monolith segment passageways to provide a separating barrier. At least one filtrate conduit within the device carries filtrate from within the device toward a filtrate collection zone of the device, and the filtrate conduit provides a path of lower flow resistance than that of alternative flow paths through the porous material. A seal is provided to separate feed stock and retentate from the filtrate collection zone.

Abstract: A reaction-bonded &agr;-alumina filter element is provided. The filter element includes a monolith of porous material having multiple passageways extending from one end face to an opposing end face. The monolith is extruded from a mixture containing at least aluminum metal and alumina powders in a proportion such that on sintering the volume change of the monolith is minimized. The filter body can be used as a filter or as a membrane support for crossflow or dead end flow filter elements. A method for making the filter element is also provided.

Abstract: A cross-flow filtration device which receives a feed stock at a feed end face and separates the feed stock into filtrate and retentate. The device has a structure formed from a plurality of substantially parallel monolith segments of porous material, each segment having a plurality of passageways which extend longitudinally from the feed end face to a retentate end face of the structure. The structure contains a filtrate conduit network comprised of both an intersegment filtrate conduit, formed by the arrangement of the segments, and at least one intrasegment filtrate conduit formed within at least one segment. The filtrate conduit network provides low pressure drop flow paths for filtrate flow through the porous material from the passageways to nearby filtrate conduits, and at least some of the passageways are separated from filtrate conduits by intervening passageways, thereby enabling a high ratio of passageway surface area to volume of the device and a high rate of filtrate removal.

Abstract: A process and system for the production of inorganic nanoparticles by precipitating the inorganic nanoparticles by a precipitating agent from a microemulsion with a continuous and a non-continuous phase; and concentrating the precipitated nanoparticles employing an ultrafiltration membrane.

Abstract: A diesel engine exhaust gas recirculation system for control of NO.sub.x emissions is disclosed in hi h total particulate (soot, condensed polynuclear aromatic and aliphatic hydrocarbons, and ash) control system is employed to filter the exhaust gas prior to reintroduction to the diesel engine. By cleaning the recirculated exhaust gas of substantially all particulates, wear on the engine due to particulate abrasion is minimized, and NO.sub.x and particulate emissions are reduced. The particulate control system includes a high efficiency ceramic monolith trap that is periodically regenerated by one or more pulses of high-pressure air that move in the opposite direction of the engine exhaust flow through the trap. In one embodiment, a portion of the filtered diesel exhaust is recirculated to the engine. In a further embodiment, the particulate control system filters a portion of the diesel exhaust in the recirculation flow path. The system can retrofit any existing diesel-powered equipment.

Abstract: A back-flushable filtration device is provided. The device includes a monolith of porous material having an inlet end and an outlet end. The passageways of the monolith are plugged at the inlet and outlet ends of the monolith, thereby preventing direct passage of feed stock through the passageways from the inlet end to the outlet end. A microporous membrane of mean pore size smaller than the mean pore size of the monolith material covers the surface of the passageways. Methods for making the back-flushable filter as well as methods for using the back-flushable filter also are provided.

Abstract: A cross-flow filtration device which receives a feed stock at a feed end face and separates the feed stock into filtrate and retentate, the device having a structure, preferably a monolith, formed of porous material and defining a number of passageways which extend longitudinally from the feed end face to a retentate end face of the structure. The structure further includes a number of longitudinal filtrate chambers and a filtrate collection volume extending into the structure and communicating with the filtrate chambers. The filtrate chambers are distributed among the passageways to provide low pressure drop flow paths for filtrate flow through the porous material from the passageways to nearby filtrate chambers, and at least some of the passageways are separated from filtrate chambers by intervening passageways, thereby enabling a high ratio of passageway surface area to volume of the device and a high rate of filtrate removal.

Abstract: A porous inorganic membrane for use with a membrane device having a porous support, the membrane including refractory particles bound to each other and to the support by a thermally reactive inorganic binder which reacts at a temperature below that at which the refractory particles react. Further, a method of forming a porous inorganic membrane on a support by applying a coating of a mixture of refractory particles and a thermally reactive inorganic binder to the support. The inorganic binder reacts at a first temperature lower than a second temperature at which the refractory particles sinter. The method further includes firing the support to a firing temperature at least as high as the first temperature and less than the second temperature to react the inorganic binder, and cooling the support to form the porous membrane.

Abstract: A cross-flow filtration device which receives a feed stock at a feed end face and separates the feed stock into filtrate and retentate, the device having a monolith with at least one filtrate network. The monolith is formed of porous material and defines a number of passageways which extend longitudinally from the feed end face to a retentate end face of the monolith. The filtrate network includes a number of longitudinal filtrate chambers and one or more filtrate channels which transect the chambers. The filtrate channel communicates with at least one filtrate duct that discharges filtrate from one or both end faces of the monolith. The filtrate chambers are distributed among the passageways to provide low pressure drop flow paths for filtrate flow through the porous material from the passageways to nearby filtrate chambers.

Abstract: A porous inorganic membrane for use with a membrane device having a porous support, the membrane including refractory particles bound to each other and to the support by a thermally reactive inorganic binder which reacts at a temperature below that at which the refractory particles react. Further, a method of forming a porous inorganic membrane on a support by applying a coating of a mixture of refractory particles and a thermally reactive inorganic binder to the support. The inorganic binder reacts at a first temperature lower than a second temperature at which the refractory particles sinter. The method further includes firing the support to a firing temperature at least as high as the first temperature and less than the second temperature to react the inorganic binder, and cooling the support to form the porous membrane.