Abstract: The present invention generally relates to processes for reducing the rate of pressure drop increase in a vessel used for hydrogenation of aldehydes to alcohols. In one embodiment, the process comprises replacing a first set of catalyst pellets with a second set of catalyst pellets, wherein the second set of catalyst pellets have a higher average aspect ratio than the first set of catalyst pellets, a different shape than the first set of catalyst pellets, or a combination thereof, and wherein a void fraction of the second set of catalyst pellets is greater than the void fraction of the first set of catalyst pellets, wherein a pressure drop rate increase of the vessel partially filled with the second set of catalyst pellets is less than a pressure drop rate increase of the vessel partially filled with the first set of catalyst pellets when operated under substantially similar conditions.

Abstract: A process for preparing a silver-containing catalyst for the oxidation of ethylene to ethylene oxide (EO) including the steps of: providing a support having pores; providing a silver-containing impregnation solution; adding an amount of surfactant to the impregnation solution; contacting the support with the surfactant-containing impregnation solution; and removing at least a portion of the impregnation solution prior to fixing the silver upon the carrier in a manner which preferentially removes impregnation solution not contained in the pores. The use of the surfactant results in improved drainage of the silver impregnation solution from the carrier exteriors during the catalyst synthesis. As a result, the amount of silver-containing impregnation solution necessary for the synthesis of the EO catalyst was reduced by up to 15% without reducing the catalyst performance.

Abstract: A process for preparing a silver-containing catalyst for the oxidation of ethylene to ethylene oxide (EO) including the steps of: providing a support having pores; providing a silver-containing impregnation solution; adding an amount of surfactant to the impregnation solution; contacting the support with the surfactant-containing impregnation solution; and removing at least a portion of the impregnation solution prior to fixing the silver upon the carrier in a manner which preferentially removes impregnation solution not contained in the pores. The use of the surfactant results in improved drainage of the silver impregnation solution from the carrier exteriors during the catalyst synthesis. As a result, the amount of silver-containing impregnation solution necessary for the synthesis of the EO catalyst was reduced by up to 15% without reducing the catalyst performance.

Abstract: Porous composites of mullite and cordierite are formed by firing an acicular mullite body in the presence of a magnesium source and a silicon source. In some variations of the process, the magnesium and silicon sources are present when the acicular mullite body is formed. In other variations, the magnesium source and the silicon source are applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of mullite and cordierite alone, and have higher fracture strengths than cordierite at a similar porosity. Some of the cordierite forms at grain boundaries and/or points of intersection between mullite needles, rather than merely coating the needles. The presence of magnesium and silicon sources during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.

Abstract: Porous composites of acicular mullite and tialite are formed by firing an acicular mullite body in the presence of an oxide of titanium. In some variations of the process, the oxide of titanium is present when the acicular mullite body is formed. In other variations, the oxide of titanium is applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of acicular mullite and tialite alone. Some of the tialite is believed to form at grain boundaries and/or points of intersection between acicular mullite needles, rather than merely coating the needles. The presence of the titanium oxide(s) during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.

Abstract: Porous composites of mullite and cordierite are formed by firing an acicular mullite body in the presence of a magnesium source and a silicon source. In some variations of the process, the magnesium and silicon sources are present when the acicular mullite body is formed. In other variations, the magnesium source and the silicon source are applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of mullite and cordierite alone, and have higher fracture strengths than cordierite at a similar porosity. Some of the cordierite forms at grain boundaries and/or points of intersection between mullite needles, rather than merely coating the needles. The presence of magnesium and silicon sources during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.

Abstract: Porous composites of mullite and cordierite are formed by firing an acicular mullite body in the presence of a magnesium source and a silicon source. In some variations of the process, the magnesium and silicon sources are present when the acicular mullite body is formed. In other variations, the magnesium source and the silicon source are applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of mullite and cordierite alone, and have higher fracture strengths than cordierite at a similar porosity. Some of the cordierite forms at grain boundaries and/or points of intersection between mullite needles, rather than merely coating the needles. The presence of magnesium and silicon sources during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.

Abstract: Porous composites of acicular mullite and tialite are formed by firing an acicular mullite body in the presence of an oxide of titanium. In some variations of the process, the oxide of titanium is present when the acicular mullite body is formed. In other variations, the oxide of titanium is applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of acicular mullite and tialite alone. Some of the tialite is believed to form at grain boundaries and/or points of intersection between acicular mullite needles, rather than merely coating the needles. The presence of the titanium oxide(s) during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.

Abstract: Porous composites of mullite and cordierite are formed by firing an acicular mullite body in the presence of a magnesium source and a silicon source. In some variations of the process, the magnesium and silicon sources are present when the acicular mullite body is formed. In other variations, the magnesium source and the silicon source are applied to a previously-formed acicular mullite body. Surprisingly, the composites have coefficients of linear thermal expansion that are intermediate to those of mullite and cordierite alone, and have higher fracture strengths than cordierite at a similar porosity. Some of the cordierite forms at grain boundaries and/or points of intersection between mullite needles, rather than merely coating the needles. The presence of magnesium and silicon sources during acicular mullite formation does not significantly affect the ability to produce a highly porous network of mullite needles.