Patent classifications
B01J27/188
Methods for making supported chromium catalysts with increased polymerization activity
Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.
Methods for making supported chromium catalysts with increased polymerization activity
Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.
Methods for Making Supported Chromium Catalysts with Increased Polymerization Activity
Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.
Methods for Making Supported Chromium Catalysts with Increased Polymerization Activity
Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.
Methods for Preparing Diol
Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.
Methods for Preparing Diol
Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.
CATALYST FOR GLYCERIN DEHYDRATION, PREPARATION METHOD THEREFOR, AND ACROLEIN PREPARATION METHOD USING CATALYST
The present invention relates to: a catalyst for glycerin dehydration; a preparation method therefor; and an acrolein preparation method using the catalyst. According to one embodiment of the present invention, the catalyst is used in glycerin dehydration so as to exhibit high catalytic activity, a high yield and high acrolein selectivity, and has a characteristic in which carbon is not readily deposited, thereby having a long lifetime compared with that of a conventional catalyst.
CATALYST FOR GLYCERIN DEHYDRATION, PREPARATION METHOD THEREFOR, AND ACROLEIN PREPARATION METHOD USING CATALYST
The present invention relates to: a catalyst for glycerin dehydration; a preparation method therefor; and an acrolein preparation method using the catalyst. According to one embodiment of the present invention, the catalyst is used in glycerin dehydration so as to exhibit high catalytic activity, a high yield and high acrolein selectivity, and has a characteristic in which carbon is not readily deposited, thereby having a long lifetime compared with that of a conventional catalyst.
Prevention of tissue ischemia and related methods
Provided herein are compositions for preventing, ameliorating, and/or reducing tissue ischemia and/or tissue damage due to ischemia, increasing blood vessel diameter, blood flow and tissue perfusion in the presence of vascular disease including peripheral vascular disease, atherosclerotic vascular disease, coronary artery disease, stroke and influencing other conditions, by suppressing CD47 and/or blocking TSP1 and/or CD47 activity or interaction. Influencing the interaction of CD47-TSP1 in blood vessels allows for control of blood vessel diameter and blood flow, and permits modification of blood pressure and cardiac function. Under conditions of decreased blood flow, for instance through injury or atherosclerosis, blocking TSP1-CD47 interaction allows blood vessels to dilate and increases blood flow, tissue perfusion and tissue survival.
Prevention of tissue ischemia and related methods
Provided herein are compositions for preventing, ameliorating, and/or reducing tissue ischemia and/or tissue damage due to ischemia, increasing blood vessel diameter, blood flow and tissue perfusion in the presence of vascular disease including peripheral vascular disease, atherosclerotic vascular disease, coronary artery disease, stroke and influencing other conditions, by suppressing CD47 and/or blocking TSP1 and/or CD47 activity or interaction. Influencing the interaction of CD47-TSP1 in blood vessels allows for control of blood vessel diameter and blood flow, and permits modification of blood pressure and cardiac function. Under conditions of decreased blood flow, for instance through injury or atherosclerosis, blocking TSP1-CD47 interaction allows blood vessels to dilate and increases blood flow, tissue perfusion and tissue survival.