Scientific Design Company, Inc.

Wojciech L Suchanek

Andrzej Rokicki

Michael Di Mare

Jean Adam

Matthew Julian

Paul E Ellis, Jr

Nabil M Rizkalla

Jason P Durand

Christelle Verrier

Rudy Anthony Morin

Nabil Rizkalla

A precursor mixture for producing a porous body, wherein the precursor mixture comprises: (i) at least one milled alpha alumina powder having a particle size of 0.1 to 6 microns, (ii) non-silicate powder that functions as a binder of the alpha alumina powders, and (iii) at least one burnout material having a particle size of 1-10 microns and a decomposition temperature of less than 550&#xb0; C., with the proviso that a burnout material having a decomposition temperature of 550&#xb0; C. or greater is excluded from the precursor mixture.

Porous bodies with enhanced pore architecture prepared without a high-temperature burnout material

A precursor mixture for producing a porous body, wherein the precursor mixture comprises: (i) milled alpha alumina powder having a particle size of 0.1 to 6 microns, (ii) boehmite powder that functions as a binder of the alpha alumina powders, and (iii) burnout materials having a particle sizes of 1-10 microns. In some embodiments, an unmilled alpha alumina powder having a particle size of 10 to 100 microns is also included in said precursor mixture. Also described herein is a method for producing a porous body in which the above-described precursor mixture is formed to a given shape, and subjected to a heat treatment step in which the formed shape is sintered to produce the porous body.

Method for producing porous bodies with enhanced properties

A porous body is provided with enhanced fluid transport properties that is capable of performing or facilitating separations, or performing reactions and/or providing areas for such separations or reactions to take place. The porous body includes at least 80 percent alpha alumina and has a pore volume from 0.3 mL/g to 1.2 mL/g and a surface area from 0.3 m/g to 3.0 m/g. The porous body further includes a pore architecture that provides at least one of a tortuosity of 7.0 or less, a constriction of 4.0 or less and a permeability of 30 mdarcys or greater. The porous body can be used in a wide variety of applications such as, for example, as a filter, as a membrane or as a catalyst carrier.

Porous bodies with enhanced pore architecture

Oxalic acid is employed in a precursor mixture containing at least one milled alpha alumina powder having a particle size of 0.1 to 6 microns, boehmite powder that functions as a binder of the alpha alumina powders, and at least one burnout material having a particle size of 1-10 microns to provide a porous body having enhanced pore architecture in which extrusion cracks can be reduced. The presence of oxalic acid in such as precursor mixture can reduce and even eliminate NOx emission during a high temperature heat treatment process.

Porous bodies with enhanced pore architecture prepared with oxalic acid

A porous body with enhanced fluid transport properties and crush strength is provided. The porous body includes the porous body includes at least 80 percent alpha alumina and having a pore volume from 0.3 mL/g to 1.2 mL/g, a surface area from 0.3 m/g to 3.0 m/g, and a pore architecture that provides at least one of a tortuosity of 7 or less, a constriction of 4 or less and a permeability of 30 mdarcys or greater, wherein the porous body is a cylinder comprising at least two spaced apart holes that extend through an entire length of the cylinder. The porous body has a flat plate crush strength improved by more than 10% over a porous body cylinder having a same outer diameter and length, but having only a single hole.

Porous bodies with enhanced crush strength

A method is provided for improving the performance of a silver-based epoxidation catalyst comprising a carrier. The carrier includes at least 80 percent alpha alumina and has a pore volume from 0.3 mL/g to 1.2 mL/g, a surface area from 0.3 m/g to 3.0 m/g, and a pore architecture that provides at least one of a tortuosity of 7 or less, a constriction of 4 or less and a permeability of 30 mdarcys or greater. A catalytic amount of silver and a promoting amount of one or more promoters is disposed on and/or in said carrier. The method further includes the steps of initiating an epoxidation reaction by reacting a feed gas composition containing ethylene and oxygen present in a ratio of from about 3.5:1 to about 12:1, in the presence of the silver-based epoxidation catalyst at a temperature of about 200&#xb0; C. to about 230&#xb0; C., and subsequently increasing the temperature either stepwise or continuously.

Epoxidation process

A silver-based ethylene epoxidation catalyst is provided that exhibits improved performance, i.e., selectivity and activity decline. The catalyst that exhibits the improved performance includes greater than about 20% by weight of silver disposed on an alpha-alumina carrier, and a promoting amount of one or more promoters disposed on the alpha-alumina carrier. The silver is present on the alpha-alumina carrier as silver particles having a diameter of greater than about 150 nm and a distribution density of about 20 particles per 1 square micron or less.

Silver catalysts with improved size and distribution density of silver particles

Silver based ethylene oxide catalysts having enhanced stability are disclosed. The enhanced stability silver based ethylene oxide catalysts include an alumina carrier which has been modified to include cavities on the surface of the carrier. The presence of the cavities on the surface of the modified carrier stops or at least impedes the motion of silver particles on the surface of the carrier during an epoxidation process. In particular, the cavities on the surface of the alumina carrier effectively trap and/or anchor silver particles and prevent them from further motion.

Modified carrier for silver based ethylene oxide catalyst

A method for producing ethylene oxide comprising: providing one or more feed components, wherein the one or more feed components contains at least ethylene obtained by dehydrating ethanol; contacting the one or more feed components with a desulfurization catalyst comprising a high surface area support and an amount of silver, wherein at least 20% of the silver is present as oxidized silver; and contacting the one or more feed components with a silver-containing epoxidation catalyst disposed inside an ethylene oxide reactor to form a reaction gas comprising ethylene oxide.

A silver-based ethylene oxide catalyst is provided that has enhanced stability. The enhanced stability is obtained in the present invention by providing a silver-based ethylene oxide catalyst that includes from 100 ppm to 1000 ppm of zinc, and from greater than 450 ppm to less than 800 ppm of cesium. Zinc and cesium are promoters that are introduced to a finished carrier either prior to, coincidentally with, or subsequent to the deposition of the silver. The silver-based ethylene oxide catalyst can be used in the epoxidation of ethylene to ethylene oxide.

Growing community of inventors

Wyckoff, NJ, United States of America

Wojciech L Suchanek