Showing papers on "Activated alumina published in 1990"

Alumina chemicals : science and technology handbook

Abstract: Introduction. History of Alumina Chemicals (L.D. Hart). World Production and Economics of Alumina Chemicals (L.H. Baumgardner). Fundamental Properties of Alumina Chemicals. Nomenclature, Preparation, and Properties of Aluminum Oxides, Oxide Hydroxides, and Trihydroxides (K. Wefers). Mechanical Properties of Alumina (R.C. Bradt and W.D. Scott). Colloidal Properties of Alumina (A. Bleier). Phase Equilibria of Alumina (L.P. Cook). Current Commercial Production Processes, Products, and Applications. Production Processes, Properties, and Applications for Aluminum-Containing Hydroxides (L.L. Musselman). Production Processes, Properties, and Applications for Activated and Catalytic Aluminas (K.P. Goodboy and J.C. Downing). Production Processes, Properties, and Applications for Calcined and High-Purity Aluminas (T.J. Carbone). Production Processes, Properties, and Applications for Tabular Alumina Refractory Aggregates (G. MacZura). Production Processes, Properties, and Applications for Calcium Aluminate Cements (J.E. Kopanda and G. MacZura). Gallium (A. Pearson and C.N. Cochran) Analytical Procedures for Alumina Chemicals -Editor's Note. State of the Art Assessments in Applications Utilizing Alumina Chemicals. Alumina Chemicals as Additives for Paper, Dentrifices, Paints, Coatings, Rubbers, and Plastics with Emphasis on Fire-Retardant Products (L.L. Musselman). Activated Alumina Desiccants (R.D. Woosley). Selective Adsorption Processes (H.L. Fleming and K.P. Goodboy). Water-Treatment Products and Processes (H.L. Fleming). Claus Catalysts and Alumina Catalyst Materials and Their Application (J.C. Downing and K.P. Goodboy). Monolithic Catalyst Systems (I.M. Lachman). Pelleted Catalyst Systems (W.S. Briggs). Electrical Properties of Alumina Ceramics (R.H. Insley). Electronic Ceramics (B. Schwartz). Alumina Usage in Electric Power Generation and Storage (W.T. Bakker). Alumina in Electrical Porcelain (R.H. Lester). Dinnerware Manufacture and Use in the United States (R.J. Beals). Advanced Ceramics Involving Alumina (J.B. Wachtman Jr. and R.A. Haber). Alumina as a Biomedical Material (J.W. Boretos). Alumina in Coatings (L.A. Ketron). Alumina as a Composite Material (G. Fisher). Alumina in Glasses and Glass-Ceramics (J.F. MacDowell). Alumina Powder Production by Aerosol Processes (T.T. Kodas and A. Sood). Refractory Ceramic Fiber (R.D. Smith). Fused Alumina-Pure and Alloyed-as an Abrasive and Refractory Material (P. Cichy). High-Alumina Refractories for Steelmaking in Europe (M. Koltermann). High-Alumina Refractories for Iron- and Steelmaking in Japan (N. Nameishi and T. Matsumura). Use of High-Alumina Refractories in the U.S. Steel Industry (D.H. Hubble). Petroleum and Petrochemical Applications for Refractories (M.S. Crowley and R.E. Fisher). Refractories Used for Aluminum Processing (G.E. Graddy Jr. and D.A. Weirauch Jr.). The Use of Alumina in Refractories for Melting Glass (E.A. Thomas). Refractories Used for Investment Casting of High-Temperature Alloys (M.Guerra Jr.). Alumina in Monolithic Refractories (L.P. Krietz and R.E. Fisher). Space Vehicle Thermal Protection (D.B. Leiser). Industrial Hygiene and Toxicology of Alumina Chemicals. The Aluminas and Health (B.D. Dinman). Long-Range Future Technology-The Role of Alumina Chemicals. The Future of Alumina Chemicals in Europe (P. Rothenbuehler, Y. Lazennec and L.D. Hart). Long Range Future Trends: The Role of Alumina Chemicals-The Japanese Viewpoint (H. Yanagida). The Future Role of Alumina in Ceramics Technology (M.J. Cima and H.K. Bowen). Long-Range Technology-The Role of Alumina Chemicals as Seen from the Japanese Viewpoint (S. Kazama). Present Situation and Future Technology of Alumina Chemicals in Japan (K. Yamada). A View of the Future for Alumina Chemicals (J.P. Starr). Glossary. A Glossary of Terms Most Frequently Used in Alumina Technology (S.C. Carniglia and B.J. Beadle).

Exhaust gas purifying catalyst excellent in thermal resistance and method of production thereof

Abstract: A catalyst which is used for purifying exhaust gas of an internal-combustion engine of an automobile or the like and can exhibit an excellent performance of purification even after a prolonged, high-temperature service. The catalyst is composed of a catalytic component comprising at least one platinum group element, activated alumina, cerium oxide, a coprecipitated oxide of zirconium stabilized by cerium, and optionally a zirconium compound carried on a monolithic support. This catalyst is produced by preparing activated alumina containing at least one platinum group element, adding thereto cerium oxide, a coprecipitated oxide of zirconium stabilized by cerium, and optionally a zirconium compound to prepare a slurry, and applying the slurry on a monolithic support, followed by firing.

On-line preconcentration of silver on activated alumina and determination in borehole water by flow injection atomic absorption spectrophotometry

Abstract: A micro column of activated alumina in the basic form was used in conjunction with flame atomic absorption for the preconcentration and determination of silver in borehole water. The silver was accumulated on the alumina column by pumping sample solution at pH 4 through the column at a rate of 5 cm3 min-1 for 5 min. By incorporating an injection valve and a simple interfacing device into the system, silver was determined by elution into the nebulizer of an atomic absorption spectrophotometer with 500 μl of 2 mol l-1 nitric acid. Regeneration of the alumina to its basic form was achieved by 0.15 mol l-1 ammonia solution pumped through the column at 5 ml min-1 for 2 min. A detection limit of 4 μg l-1 was measured, based on a sample volume of 25 ml. The relative standard deviation was less than ±5% at concentration levels above 10 μg l-1.

Process for rearranging allylic geminal dihalogen compounds

Abstract: Cis- and trans-1,3-dichloropropenes and their homologs and 1,3-dibromopropenes can be prepared by isomerizing the corresponding 3,3-dihalopropene or homolog thereof in a simple, high yield process by contacting the latter with an effective silica, alumina, or zeolite catalyst. Thus, a mixture of cis- and trans-1,3-dichloropropenes is produced in good yield and with good selectivity when a mixture of 3,3-dichloropropene with other chlorinated hydrocarbons, principally 1,2-dichloropropane, is contacted with an acidic activated alumina catalyst at a temperature of about 100° C.

Exhaust gas-purifying catalyst excellent in heat resistance and process for preparation thereof

Abstract: This invention relates to a purifying-catalyst for exhaust gas emitted from internal combustion engines such as automobiles, and the object is to provide a catalyst which exhibits excellent exhaust gas purification performance at lower temperature compared to usual catalysts, even after high temperature aging, and a process for preparation thereof. This object has been attained by an exhaust gas-purifying catalyst containing on a support having a monolithic structure as catalytic components at least one element of the platinum group, activated alumina, cerium, a coprecipitated ceria-stabilized zirconia oxide and optionally a zirconium compound, and a process for preparation of the above exhaust gas-purifying catalyst which comprises (a) preparing activated alumina containing at least one element of the platinum group, (b) preparing a slurry containing this prepared platinum group element-containing activated alumina, cerium oxide, the coprecipitated ceria-stabilized zirconia and optionally the zirconium compound, and (c) coating the slurry onto the support having a monolithic structure and calcining it.

Exhaust gas purification catalyst

Abstract: PURPOSE:To obtain an exhaust gas purification catalyst having a high activity and durability by depositing platinum group metals in the carrier contg. a multiple oxide of perovskite type and the ceria of a high specific surface area having O2 storage ability. CONSTITUTION:The surface of a monolith carrier substrate is provided with a coating layer consisting of the powder of the partially stabilized rare earth zirconia with an oxidating activating multiple oxide of perovskite type shown by the formula I (wherein A is Sr or Ba, B is Pt or Pd, E is Mn or Cu, x is 0.1-0.5 and y is 0.001-0.01) deposited thereon, the activated alumina powder contg. platinum deposited cerium and the ceria powder of a high specific surface area. On this layer is provided a coating layer consisting of the aforesaid zirconia powder with a reduction activating multiple oxide of perovskite type shown by the formula II (wherein C is Ba or Sr, D is Pd or Ru, E is Mn or Cu, z is 0.1-0.5 and u is 0.04-0.06) deposited thereon, the activated alumina powder contg. palladium deposited zirconia and the aforesaid ceria power.

Production of catalyst carrier for purification of exhaust gas

Abstract: PURPOSE:To enhance the adhesion of a metal honeycomb to an alumina coating layer by coating a metal substrate with activated alumina powder by electrophoresis or electrodeposition to form a catalyst carrier for purification of exhaust gas. CONSTITUTION:A metal substrate is coated with activated alumina powder by electrophoresis or electrodeposition to produce a catalyst carrier for purification of exhaust gas. Otherwise, the metal substrate may be coated with activated alumina powder treated with a rare earth metal oxide by electrophoresis or electrodeposition to produce a catalyst for purification of exhaust gas. The surface of the substrate is preferably pretreated by etching or sandblast so as to increase the specific surface area. The pref. grain size of the activated alumina powder is 1-5mum.

Alumina-alkali metal aluminum silicate agglomerate acid adsorbents

Abstract: Alumina-containing acid adsorbents and process for producing same. The adsorbents comprise activated alumina and an amorphous alkali (preferably sodium) aluminum silicate. The ratio of Si:Al in the amorphous material is preferably 0.25-100:1 by weight. A process for producing such adsorbents comprises treating activated alumina with a solution of an alkali metal silicate followed by an alkali metal aluminate, and forming agglomerates of the treated alumina at a temperature below about 90° C., aging the agglomerates at a temperature in the range of 20°-90° C., and calcining the aged agglomerates at a temperature in the range of 200°-500° C. The adsorbent can be used to remove acidic materials from gases and liquids during industrial processes.

Method for separating and recovering carbon monoxide

Abstract: PURPOSE:To separate and recover CO in high purity and recovery ratio by adsorbing CO2 from a mixed gas of CO and CO2 using activated alumina or silica gel and then adsorbing the CO on an adsorbent carrying copper chloride, etc, on active carbon CONSTITUTION:CO is separated from a mixed gas containing CO and CO2 by a pressure swing adsorption(PSA) method In the process, the CO2 is initially adsorbed together with water using activated alumina or silica gel as a pretreating adsorbent so as to provide <=15wt% concentration thereof CO is then adsorbed using a post-treating adsorbent carrying copper (I) chloride or an aluminum tetrachloride complex on active carbon The resultant CO is subsequently desorbed and recovered from the above-mentioned adsorbent

Production of catalyst for purifying exhaust gas

Abstract: PURPOSE:To obtain an exhaust gas purifying catalyst excellent in durability, by a method wherein a platinum group catalyst is supported on a highly active ceria powder and the supported ceria powder is mixed with an activated alumina powder to prepare a slurry which is, in turn, applied to a carrier and a platinum group catalyst is further supported on the coated carrier. CONSTITUTION:A solution containing a platinum group catalytic metal compound such as a platinum compound or a rhodium compound is brought into contact with a highly active ceria powder having a specific surface area of 100m /g or more and the impregnated ceria powder is subsequently baked to obtain a platinum group catalyst supported ceria catalyst powder. Next, this ceria catalyst powder and an activated alumina powder are mixed to prepare a slurry which is, in turn, applied to a carrier base material and the coated one is baked. A platinum group catalytic metal is further supported on the catalyst support layer. The catalyst thus obtained is enhanced in HC and CO purifying capacity while it keeps NOX purifying capacity.

Purification of jojoba oil

Abstract: PURPOSE:To obtain a colorless, transparent and virtually oderless purified oil, optimum as a cosmetic base and useful as a medical raw material by treating a low-boiling hydrocarbon solution of jojoba oil with a column packed with a cation exchange resin to be used for non-aqueous solution. CONSTITUTION:Firstly, jojoba oil is dissolved in a low-boiling hydrocarbon such as m-pentane, n-hexane or n-heptane so as to be 5-95wt.% in concentration. Thence, the resultant solution is treated through a column packed with a strongly acidic cation exchange resin having pref. sulfonic acid group to be used for non-aqueous solution and an adsorbent consisting of activated alumina or activated carbon at the weight ratio pref. 1:(0.5-3), thus obtaining the objective purified product.

Production of catalyst for purification of exhaust gas

Abstract: PURPOSE:To improve the heat resistance of a catalyst by coating the surface of a catalyst carrier with a slurry prepd. by mixing combined powder consisting of alumina, Zr and Ba with a Ce soln. and by supporting a catalytic component on the resulting coating layer. CONSTITUTION:Activated alumina is mixed with Zr and Ba solns., this mixture is dried and crushed and the resulting combined powder is mixed with a Ce soln. to prepare a slurry. The surface of a catalyst carrier is coated with the slurry and a coating layer is formed on the surface of the carrier by calcining. A catalytic component is then impregnated into or supported on the coating layer to produce a catalyst for purification of exhaust gas. Since heat resistant Zr and Ba coexist closely with activated alumina in the catalyst, the activated alumina is hardly heated to a high temp. even by exposure to the heat of exhaust gas and the deterioration of the alumina by the heat of exhaust gas is nearly prevented.

Manufacture of carrier for combustion catalyst

Abstract: PURPOSE:To form a catalyst carrier having improved low temperature ignitablity by immersing a laminated carrier of alumina fiber composed mainly of activated alumina into a dinitrodiamine platinum nitric acid solution containing reducing agents to immobilize platinum CONSTITUTION:Carriers comprising lamination layers of alumina fibers composed mainly of activated alumina are immersed into a dinitrodiamine platinum nitric acid solution to which reducing agents are added, following which, immobilizing treatment of platinum is carried out in said solution to prepare catalysts in which platinum is carried by inorganic fibrous lamination layers or moldings by drying and burning the immobilized platinum As an alternative, after said laminated carriers are immersed into dinitrodiamine platinum nitric acid solution to which reducing agents and cationic surfactants have been added, platinum is immobilized in the solution Catalysts thus obtained have improved low temperature ignitability in particular and have a uniform distribution of platinum

Manufacture of gaseous emission cleanup catalyst

Abstract: PURPOSE:To maintain gaseous emission cleanup ability by forming on the surface of a substrate a binder layer, on which an activated alumina layer is formed. CONSTITUTION:A metallic substrate is coated with a first dispersing liquid to form a binder layer on its surface. This binder layer is then coated with a second dispersing liquid consisting mainly of activated alumina. After drying, this coat is baked together with the binder layer to form an activated alumina layer. Preferably, the thickness of the binder layer may be 3-10mum, an average particle diameter of metal powder 3-5mum and an average particle diameter of alumina sol 10-100mum. Due to the above-mentioned features, the activated alumina layer can exert its catalytic effect over an extended period of time.

Degradation of desiccants upon contamination: An experimental study

Abstract: Experiments were conducted to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. A test apparatus was used to thermally cycle several desiccant samples and expose them to ambient or contaminated humid air. The source of contamination was cigarette smoke. Six different solid desiccants were tested: two types of silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. The exposed desiccant samples were removed after 0.5, 1, 2, 4, or 11 months of exposure and their moisture capacities were measured. Other tests were conducted to characterize pollutants deposited on the exposed samples or to evaluate impact of exposure on internal structure of the samples. Compared to fresh samples, the capacity loss due to thermal cycling with ambient air was generally 10% to 30%. The capacity loss due to only cigarette smoke was generally between 20% to 50%. 7 refs., 8 figs., 3 tabs.

Effect of pretreatments on the two-stage hydrogreatment of coal liquid vacuum residue.

Abstract: The two-stage hydrotreatment of Morwell coal liquid vacuum residue (CLVR) were examined using an autoclave and a commercial Ni-Mo/Al2O3 catalyst under the conditions of 390°C-2h and 430°C-2h, before and after the solvent fractionation with THF or the pretreatment with HCl/THF. The THF soluble fraction of CLVR was further treated using a cation-exchange resin or an activated alumina column chromatography. The pretreatment of whole CLVR with HCl/THF was more effective in the recovery and maintaining the catalytic activity of nitrogen removal than the THF extraction through the selective removal of specific nitrogen-containing compounds. The catalytic activity for the aluminatreated CLVR-THFS was maintained at the higher level in nitrogen removal than that for cation-exchange treated one, although the recovery was much higher in the latter than the former treatment. Based on the above results, the mechanism of catalyst deactivation is discussed.

Exhaust gas cleanup catalyst

Abstract: PURPOSE:To provide a catalyst for controlling the evolution of H2S while maintaining a ternary catalytic characteristic by providing an activated alumina with precious metals deposited thereon and adding alkali metal and cerium oxide thereon. CONSTITUTION:In a catalyst for cleanup of exhaust gases emitted from a vehicle, there is provided an activated alumina of 1 - 20g on which platinum and/or palladium of 5 - 30wt.% and rhodium of 1 - 20wt.% are deposited. A honeycomb carrier is covered with a cerium oxide of 10 - 150g, an activated alumina of 50 - 200g and an alkali metal such as Na and K of 0.5 - 30g per liter of catalyst. The catalyst thus formed controls the reduction of SOx to H2S, being excellent in the cleanup performance of hydrocarbon, CO, NOx, etc.

Manufacture of catalyst carrier for use in purifying waste gas

Abstract: PURPOSE:To provide a catalyst carrier wherein alumina coating is not separated from the carrier due to thermal shock under operating conditions by applying coating of activated alumina powder to the surface of a metal substrate by dry-powder electrostatic method to improve the adhesion between a metal honeycomb and the alumina coating layer. CONSTITUTION:Powder of activated alumina containing activated alumina or rare earth metal oxides is applied to the surface of a metal substrate from the end of a gun for use in electrostatic coating, while voltage is being applied to said powder. The metal substrate is formed into a corrugated shape or a three dimensional construction, following which said activated alumina is impregnated with aqueous solutions of rare earth metal salts so that the rare earth metal salts are thermally decomposed into rare earth oxides. In this manner, catalyst carriers for use in purification of waste gas having improved adhesion between a metal honeycomb and alumina coating layer can be provided.

Pretreatment agent of exhaust gas

Abstract: PURPOSE:To obtain a pretreatment agent for exhaust gas being pressure drop smaller and having pretreatment effect higher than a conventional pretreatment agent by carrying activate alumina on a carrier made of an inorganic fiber aggregate. CONSTITUTION:Activated alumina slurry is carried on an aggregate of ceramic fiber preferably a honeycomb structural body whose wall surface has holes of diameter not smaller than 5000Angstrom at >=0.1cc/g by an ordinary method, e.g., the method for immersing the honeycomb structural body in activated alumina slurry liquid. Then excess activated alumina slurry is blown off by air and activated alumina is stuck at 50-100g/l so that the hollows of the honeycomb catalytic structural body are not lost as thoroughly as possible. This honeycomb structural body is dried and calcined to obtain a pretreating agent of exhaust gas. Even when a crack is generated in activated alumina, the obtained pretreatment agent is not peeled off and separated.