Abstract: The present invention relates to a method for production of amorphous silica from particulate materials containing at least 50% elemental silicon, where the silicon-containing material is supplied to a combustion reactor which is heated by an oil- or gas burner and where amorphous silica is recovered after the outlet from the combustion reactor. At least a part of the particulate silicon containing materials are supplied to the combustion reactor in the form of an aqueous slurry. The invention further relates to an apparatus for production of amorphous silica.

Abstract: The invention relates to the use of one or more &agr;-keto carboxylic acid esters and/or aldehyde carboxylic acid esters for stabilizing hydrogen peroxide during enzyme-catalyzed or metal-catalyzed oxidation reactions in organic synthesis, as well as for stabilizing hydrogen peroxide or aqueous or organic hydrogen peroxide solutions during production, storage and transport.

Abstract: A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H2O2 starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H2O2 concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H2O2 concentration in the crystal layer is increased further.

Abstract: Hydrotreating catalyst containing one or more metal oxides and/or sulphides selected from Group VI-B and Group VIII of the Periodic Table supported on a porous refractory carrier, wherein the catalyst being in form of an angular extrudate with rounded edges.

Abstract: This invention provides a method of reactivating a catalyst for methacrylic acid production, which catalyst is used in production of methacrylic acid through vapor-phase oxidation of methacrolein or vapor-phase oxidative dehydrogenation of isobutyric acid, contains P and Mo, and exhibits reduced activity. The process comprises treating the catalyst, whose activity level has dropped (deteriorated catalyst), with a gas containing a nitrogen-containing heterocyclic compound (e.g., pyridine, piperidine, piperazine, quinoline).

Abstract: A catalyst and process for converting carbon dioxide into oxygenates. The catalyst comprises copper, zinc, aluminum, gallium, and a solid acid.

Abstract: Compositions for reduction of gas phase reduced nitrogen species and NOx generated during a partial or incomplete combustion catalytic cracking process, preferably, a fluid catalytic cracking process, are disclosed. The compositions comprise (i) an acidic metal oxide containing substantially no zeolite, (ii) an alkali metal, alkaline earth metal, and mixtures thereof, (iii) an oxygen storage component, and (iv) a noble metal component, preferably rhodium or iridium, and mixtures thereof, are disclosed. Preferably, the compositions are used as separate additives particles circulated along with the circulating FCC catalyst inventory. Reduced emissions of gas phase reduced nitrogen species and NOx in an effluent off gas of a partial or incomplete combustion FCC regenerator provide for an overall NOx reduction as the effluent gas stream is passed from the FCC regenerator to a CO boiler, whereby as CO is oxidized to CO2 a lesser amount of the reduced nitrogen species is oxidized to NOx.

Abstract: A coal liquefaction process using ionic liquefaction techniques with polar solvent solubilizing agents and water soluble inorganic compounds, produces a carbonaceous liquefaction product which is separated from the process stream by the use of methanol as a partitioning agent and the methanol and solubilizing agent are recovered separately for reuse.

Abstract: A paraffin or mixture of paraffins having from 2 to 5 carbon atoms is oxidatively dehydrogenated in the presence of a cobalt based catalyst composition which has been calcined in the absence of oxygen. The catalyst composition comprises cobalt; phosphorus; at least one promoter selected from the group consisting of zinc, titanium, zirconium, niobium, indium, lead and bismuth; at least one alkali metal and oxygen. The catalyst composition may also contain sulfur and/or a halogen. If the feed to the oxidative dehydrogenation process contains paraffins having more than two carbon atoms, some cracking of such paraffins will also occur at the conditions at which the oxidative dehydrogenation process is carried out.

Abstract: A metal catalyst carrier or support body is rolled or laminated from two alternating layers of sheet metal of different structure, wherein the sheet-metal layer, at least in some areas relative to one another, have double or multiple-wave structure, in that one of the layers has a wave structure including at least two superimposed or alternating waves of different wavelength and/or amplitude and/or both layers have wave structures of different wavelength and/or amplitude, by means of which in both cases the number of contact points between the two layers is reduced and the elasticity of the resultant structure is increased, wherein none of the wavelengths is considerably smaller than the wavelenth having the greatest amplitude.

Abstract: Catalytic materials are modified by adding one or more electropositive and/or electronegative elements thereto in amounts sufficient to adjust the resultant geometric mean electronegativity to a value within a desired or predetermined range. The invention is particularly suited to the preparation of hydrocarbon hydroprocessing catalysts, particularly with respect to hydrodesulfurization catalysts comprising a support material containing a porous refractory oxide. With such catalysts, not only is the geometric mean electronegativity adjusted to a desired value, but if the electropositive or electronegative element added to the catalyst has pore growth promotion properties, the average pore size of the resultant catalyst is increased while its surface area, and usually also its total pore volume, is decreased.

Abstract: A novel system for the preparation of maleic anhydride by catalytic oxidation of a hydrocarbon such as butane wherein the catalyst system comprising a mixture of (1) a mixed vanadium-phosphate catalyst and (2) a noncatalytic material comprising an oxide of a Group IA-IIIA element, Pb, In, Sb, Sn, Tl, Bi or mixtures thereof.

Abstract: An improved process for dehydrating alcohols in which the catalyst used in the dehydration process is activated using an organic carboxylic acid.

Abstract: The invention relates to a vanadium/phosphorus mixed oxide catalyst, a process for its preparation and its use for the preparation of maleic anhydride.The catalyst according to the invention is prepared by reacting a vanadium(V) compound with phosphoric acid and/or a compound forming phosphoric acid with heating, optionally in the presence of water, and subsequently treating the product obtained after the reaction with organic solvents and/or diluents having reducing activity, optionally in the presence of a promoter, at an elevated temperature.

Abstract: A catalyst containing copper and silica is prepared by a process in which an aqueous alkali metal silicate solution containing from 1 to 26% by weight of SiO.sub.2 is brought to a pH of from 0.5 to 2.0 with nitric acid, an aqueous copper nitrate solution containing from 5 to 15% by weight of Cu is added, after the addition of the nitric acid, so that a clear solution containing from 0.18 to 3.0 moles of Cu per mole of SiO.sub.2 is formed, the resulting solution is mixed with an aqueous alkali metal carbonate solution at from 40.degree. to 80.degree. C., the pH of the mixture being kept at from 7.5 to 8.5, and the precipitated material is separated off, dried, calcined by heating at from 250.degree. to 400.degree. C. and pressed in a conventional manner to give catalyst moldings. The catalyst thus obtained is used for the hydrogenation of dialkyl dicarboxylates to diols.

Abstract: There is provided a method for activating preformed, crystalline aluminum phosphates by combining these aluminum phosphates with an activating metal oxide, such as silica, and water under conditions, such as mulling, sufficient to increase the acid catalytic activity of the material.

Abstract: Increased yields of liquid hydrocarbon are obtained from a carbonaceous material (e.g., coal) by a two-stage process comprising pretreatment of the carbonaceous material with an appropriate gas in a first stage, followed by pyrolysis of the pretreated carbonaceous material, in a second stage.

Abstract: Light-hardened photoresist layers are stripped by treating the layer with an aqueous solution of an organic quaternary ammonium base and, optionally a strong inorganic base. The resulting layer residues are dispersed as relatively small flakes which do not become lodged between conducting paths.

Abstract: Froth, produced by induced air flotation in the hot water process circuit for extracting bitumen from tar sand, is recycled and added to the fresh slurry being introduced to the primary separation vessel. An increase in bitumen recovered as primary froth from the circuit is produced.

Abstract: Catalyst precursor units, e.g. for ammonia synthesis catalysts, comprise an iron oxide composition in the form of sintered shaped units of substantially uniform cross section having a plurality, e.g. 13 to 50 or more, through passages of substantially uniform cross section. The passages preferably have a diameter of less than 1.5, particularly less than 0.7, mm.