34 results about "Magnesium-aluminum oxide" patented technology

A treated refractory material includes a refractory material having a plurality of pores, wherein the refractory material comprises aluminum oxide, silicon oxide, magnesium oxide, chromium oxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, silicon carbide, tungsten, mullite, dolomite, magnesite, magnesium aluminum oxide, chromite, magnetite, or a combination comprising at least one of the foregoing; and a protective material disposed within the plurality of pores of the refractory material, wherein the protective material is selected from the group consisting of aluminum oxide, chromium oxide, silica, rare earth oxides, rare earth zirconates, titanium oxide, mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, and blends thereof.

An electrically conducting cermet comprises at least one transition metal element dispersed in a matrix of at least one refractory oxide selected from the group consisting of yttria, alumina, garnet, magnesium aluminum oxide, and combinations; wherein an amount of the at least one transition metal element is less than 15 volume percent of the total volume of the cermet. A device comprises the aforementioned electrically conducting cermet.

The invention provides a preparation method of a composite metal-oxide-based solid super alkali catalyst. According to the method, magnesium nitrate and aluminum nitrate with a molar ratio of [1:1]-[7:1] are prepared into a solution; 1mol / L of NaOH or KOH is used for regulating the pH to 10-12; refluxing is carried out for 12-72h; a precipitate is washed by using water with different amounts; the precipitate is dried, and is heated to 400-700 DEG C in a tube furnace under a nitrogen atmosphere; roasting is carried out for 1-5h, such that the solid super alkali catalyst with K or Na mass content of 1-20% is obtained. According to the solid super alkali catalyst preparation method, synthesizing and modification are carried out simultaneously, wherein modification object K or Na and carrier magnesium-aluminum oxide are simultaneously produced during the roasting process, such that time and energy consumption are saved. When the catalyst is applied in a Knoevenagel condensation reaction, catalyst dose is low, reaction conditions are mild, and catalytic activity is high. The catalyst can be repeatedly used through centrifugal separation.

The invention discloses a modified magnesium-aluminum composite oxide catalyst for acetone condensation, a preparation method and application thereof, and belongs to the technical field of acetone condensation. In the catalyst, the modified hydrotalcite is prepared by using a precipitant and a metal salt solution containing a rare earth element by a double-drop co-current co-precipitation method, and the modified magnesium-aluminum composite oxide catalyst is obtained after roasting. The catalyst is modified with rare earth components (La and Ce or Y and Ce) to modify the magnesium-aluminum composite oxide to effectively adjust the acid-base density and strength ratio of the catalyst surface, thereby improving its catalytic acetone self-condensation reaction activity and isotropic reaction. Selectivity of pherone. The modified catalyst achieves a single pass conversion rate of acetone of 35-42%, and a selectivity to isophorone of 72%-76%.

The invention relates to a method for removing carboxylic acid from water-containing raw materials containing carboxylic acid impurities. Mainly to solve the problem that the adsorption method in the existing deacidification technology is prone to saturation failure of the adsorbent, while the esterification deacidification method requires the addition of alcohol and water. According to the method for removing the carboxylic acid, the raw material is contacted with a catalyst at a reaction temperature of 300-600 °C to remove the carboxylic acid impurities; the catalyst includes a magnesium-aluminum composite oxide, and the magnesium-aluminum composite oxide is in a molar ratio. Calculate Mg:Al=1~5; the magnesium-aluminum composite oxide has XRD characteristic peak I at 2θ=43±2°, XRD characteristic peak II at 2θ=63±2°, and characteristic peak I and characteristic peak II The technical solution that the ratio of peak heights is 1 to 3 solves the technical problem well, and can be used in the removal and production of carboxylic acid impurities.

An electrically conducting cermet comprises at least one transition metal element dispersed in a matrix of at least one refractory oxide selected from the group consisting of yttria, alumina, garnet, magnesium aluminum oxide, and combinations; wherein an amount of the at least one transition metal element is less than 15 volume percent of the total volume of the cermet. A device comprises the aforementioned electrically conducting cermet.

A catalyst for selectively hydrogenating and dediolefinating for light hydrocarbon fractions, comprises 0.05-1.0 wgt% Pd as the active component and the carrier of magnesium aluminum oxide solid solution. In the magnesium aluminum oxide, the mol ration of Mg / Al is 1.0-12.0. the catalyst also contains auxiliary agents selecting from Co, Mo, Ni and Wu. The catalyst is suitable for selectively hydrogenating and dediolefinating for light C4-C6 hydrocarbon fractions.

The invention provides a method for preparing a heterogeneous catalyst in the presence of a template agent for preparing isophorone through condensation of acetone. The catalyst is a modified composite oxide based on magnesium aluminum oxide: MgO‑Al 2 o 3 -M x+ o x / 2 . The preparation method comprises the following steps: weighing a certain amount of mixed salt and dissolving it in a certain amount of water, adding a certain amount of template agent, and dropping a certain amount of precipitating agent into the mixed salt solution at a certain temperature. The catalyst is obtained after aging, filtering, washing, drying and roasting. Compared with the prior art, the preparation method of the catalyst is simple and convenient, the price is low, the bulk density is small, the activity and selectivity are high, and the stability is good. In the reaction of acetone condensation to prepare isophorone, the reaction temperature is 250℃~300℃, under normal pressure, the mass space velocity of acetone is 1~8h ‑1 , the highest conversion rate of acetone is 45%, the selectivity of isophorone is 75%, and the selectivity of mesityl oxide and isophorone is 90%. This technology is suitable for industrial production of isophorone.

The invention discloses a preparation method of propylene glycol monoalkyl ether. Propylene oxide and alcohol are used as raw materials to react under the catalysis of a modified magnetic solid base catalyst to prepare propylene glycol monoalkyl ether. The catalyst uses nickel ferrite as the magnetic core, magnesium aluminum oxide as the carrier, and cesium as the active component, and is obtained through transition metal modification. The method improves the reaction activity and selectivity, eases the operating conditions, and at the same time, the catalyst has a long service life, is easy to recycle and regenerate, has low production cost, overcomes various defects in the prior art, and can be used in industrialized production.