Showing papers on "Pseudoboehmite published in 1998"

Copper–cobalt oxide spinel supported on high-temperature aluminosilicate carriers as catalyst for CO–O2 and CO–NO reactions

Abstract: A copper–cobalt oxide spinel supported on high-temperature aluminosilicate carriers (90 wt% boehmite (pseudoboehmite)+10 wt% activated bentonite, calcined at Tcalcin=800, 1000, 1050 or 1150°C) has been prepared, characterized and tested in CO–O2 and CO–NO reactions. X-ray diffraction (XRD) has shown the presence of different forms of Al2O3 in the carriers: γ-Al2O3 for B800; γ-Al2O3+δ-Al2O3 for the B1000, δ-Al2O3+θ-Al2O3+α-Al2O3 for the B1050 and α-Al2O3 for the carrier B1150. The carriers have very high mechanical strength. With increasing Tcalcin the surface area of carriers changes from 133 to 13 m2/g. XRD has shown the presence of a spinel phase for all Cu–Co supported samples. The adsorption capacity of Al2O3 supports towards Cu ions is related to the surface area of carriers and is of essential importance for the Cu and Co loading. The amounts of loaded metals Cu and Co change in an opposite manner with increasing Tcalcin. However, the total amount of loaded metals (Cu+Co) is almost constant. The weight ratio Co : Cu increases to almost that of the closer to the stoichiometric value for the CuCo2O4 spinel. It is suggested that the whole amount of Co is engaged in the formation of Cu–Co spinel phase observed by XRD. The catalysts have shown high activity towards both CO–O2 and NO–CO reactions. The same order of activity of catalysts SB800

Metal-exchanged carboxylato-alumoxanes and process of making metal-doped alumina

Abstract: A method has been developed for the solution-based metal exchange of carboxylato-alumoxanes [Al(O)x(OH)y(O2CR)z]n with a wide range of metal cations. Metal-exchanged carboxylato-alumoxanes are new, particularly those in which about 10% to about 50% or more of the Al ions are exchanged for other metal ions. Additionally, the carboxylic acid ligands can be stripped from the boehmite core of metal-exchanged carboxylato-alumoxanes at low temperature leading to the formation of metal-exchanged boebmite particles. These new material phases can be used as intermediates for preparation of mixed metal aluminum oxide materials. Thermolysis of the metal-exchanged carboxylato-alumoxanes or metal-exchanged boehmite particles results in doped aluminas (M/Al2O3), binary (MAlOx), ternary (MM′AlOx) and even more complex metal aluminum oxide compounds, where M and M′ are metal ions other than those of aluminum and are preferably those of Lanthanide metals or transition metals. The method allows preparation of pure phase materials as well as the preparation of metastable metal aluminum oxide phases. The carboxylato-alumoxanes are prepared by the reaction of boehmite (or pseudoboehmite) with carboxylic acids in a suitable solvent. Up to at least half of the aluminum cations in the boehmite lattice of the carboxylato-alumoxanes can be replaced by the reaction of metal acetylacetonates with the carboxylato-alumoxane in a suitable solvent. The metal exchange reaction can also be carried out by reaction with soluble metal salts. Reactions of boehmite with the metal acetylacetonates (or soluble metal salts) do not lead to the metal exchange reaction observed for the carboxylato-alumoxanes.

Aluminum material excellent in resistance to heat cracking and corrosion

Abstract: PROBLEM TO BE SOLVED: To provide an Al material coated with an anodic oxide film excellent in resistance to the corrosion of gas and plasma without the anodic oxide film being cracked even in the corrosive environment of gas and plasma in a high- temp. heat cycle. SOLUTION: An Al material with the anodic oxide film A having a porous layer 4 and a nonporous layer 5 formed on the surface is used as the Al material excellent in resistance to heat cracking and corrosion. In this case, the diameter of the pore 3 of the layer 4 on the surface side W 1 is made smaller than that on the Al alloy substrate side W 2 , and boehmite and/or pseudoboehmite 6 are formed in the film. COPYRIGHT: (C)1999,JPO

Pseudoboehmite powder for catalyst carrier and process for preparing the same

Abstract: An aluminum salt solution and an alkali aluminate solution are subjected to a neutralization reaction to precipitate and form a pseudo-boehmite powder. The neutralization reaction is performed under a condition in which the reaction temperature is within a range of 55 to 71° C., pH is within a range of 8.5 to 9.5, and the solution feed time is within a range of 7 to 25 minutes. The obtained pseudo-boehmite is as follows. That is, the pore volume concerning pores having a pore diameter ranging from 20 to 600 Å is within a range of 0.8 to 1.8 cc/g as measured by the nitrogen adsorption method, and the maximum value of variation ratio dV/dD of the pore volume with respect to the pore diameter as measured by the BJH method is not more than 0.018 cc/g•Å. When the pseudo-boehmite is used, it is possible to produce a catalyst carrier for hydrogenation refining, which has a sharp pore diameter distribution and which suffers less decrease in strength upon impregnation with a catalyst solution.

Catalyst for hydrodemetalization of heavy oil

Abstract: A catalyst for hydrodemetalization of heavy oil, especially residuum oil, and a process for preparing the same, wherein said catalyst comprises the metal elements of Groups VIII and/or VIB as active components supported on an alumina carrier having large pores. The total pore volume of said carrier is in the range of 0.80˜1.20 ml/g (by mercury porosimetry method), the specific surface area in the range of 110˜200 m2/g, the peak pore diameter in the range of 15˜20 nm, and the bulk density in the range of 0.50˜0.60 g/ml. In the process of the invention, a physical pore-enlarging agent and a chemical pore-enlarging agent are added simultaneously during the mixing of the pseudoboehmite to a plastic mass, then extruding, drying, calcining, the carrier is obtained, then impregnating with active components by spraying onto the carrier, after drying and calcining, the catalyst is obtained. The catalyst of the invention is suitable for the hydrodemetalization and/or hydrodesulfurization of heavy oil, particularly residuum oil.

Manufacturing of raw materials for the catalyst industry

Abstract: As known from modern catalytic surface science the nature and quality of the carrier material is a key part of catalysis. Defined properties and consistent quality of the carrier material are pre-requisites for a successful catalyst. This paper will demonstrate the possibilities and flexibility of CONDES's alkoxide technology in terms of manufacturing aluminas, silica-aluminas and other mixed oxides as raw materials for the catalyst industry. The CONDEA group operates two different types of processes for the manufacture of alkoxide derived alumians and related products, the Ziegler-ALFOL process and CONDEA's On-Purpose Process. The Ziegler process is a co-production process of linear fatty alcohols and alumina, using aluminum organic compounds as intermediates, CONDEA's own On- Purpose technology is based on the formation of aluminum alkoxide from aluminum metal and alcohol. In both processes the formation of alumina is achieved by hydrolysis of aluminum alcoholates with water.AI(OR) 3 + 2 H 2 0 → A1OOH + 3 ROH Alumina from the hydrolysis of alcoholates is typically obtained in the form of boehmite or pseudoboehmite. It is important to mention that both processes give products of equivalent quality. Subsequent processing steps lead to a variety of different alumina products of high purity and defined physical properties such as. • beohmite aluminas of different crystallite size, porosity, particle size and peptisation or dispersion behavior or • calcined aluminas of different phase compositions (gamma, delta/theta, alpha), porosities, surface areas, particle sizes and attrition resistance. Besides boehmite and boehmite derived calcined alumina phases bayerite and eta alumina can also be produced via this technology. Also accessible is an almost unlimited variety of high purity mixed oxides such as silica aluminas and doped aluminas. Even other catalytic carrier materials for example, MgO can be obtained. A key concept in CONDEA's product development process is the controlled scale-up or new products from laboratory to commercial production. The gap between pilot production and full scale commercial production, typical for the manufacturing industry, is being bridged by a flexible multi-purpose semi-commercial unit of approx. 1200 mt per year capacity, where large scale commercial samples can be manufactured during the developmental stage. This concept reduces scale-up factors to a reasonable ratio and helps to shorten the development of new raw materials for catalytic applications.

Method of producing nickel catalyst for hydrogenation

Abstract: FIELD: catalytic chemistry. SUBSTANCE: invention relates to methods of producing nickel catalyst for hydrogenation of carbon oxides, oxygen and aromatic hydrocarbons. Method involves mixing basic nickel carbonate with alumooxide carrier in the presence of ammonium hydroxide aqueous solution followed by drying, calcination, grinding, mixing with graphite and tabletting. Alumooxide carrier: a mixture of high- and low-temperature forms of aluminium oxide at ratio from 0.05: 0.95 to 0.50:0.50 (as measured for Al 2 O 3 ). Boehmite, pseudoboehmite, hydrargilite, gamma-Al 2 O 3 or ρ-Al 2 O 3 were used as low-temperature form of aluminium oxide and alpha-Al 2 O 3 or theta-Al 2 O 3 - as high-temperature form. EFFECT: high activity of catalyst. 1 tblt

Method for revealing light hydrocarbon traces

Abstract: FIELD: chromatographic analysis. SUBSTANCE: light hydrocarbons in concentrations 0.1 ppm and below are revealed by way of separating traces of these substances from matrix substances, accumulating them on adsorbent, and subjecting them to gas- chromatographic analysis. Adsorbent employs microporous substances, in particular, carbon molecular sieves or carbon fibers with micropore volume 0.30-0.45 cm/g, or mixture of carbon fibers and pseudoboehmite at ratio 9:1. EFFECT: improved accuracy of analysis. 2 cl, 2 dwg, 4 tbla