Showing papers on "Activated alumina published in 1989"

Field Experience With Point-of-Use Treatment Systems for Arsenic Removal

Abstract: Point-of-use (POU) treatment devices can be effective for removing inorganic contaminants. This article describes the investigation of POU treatment systems used for arsenic removal in four homes in Alaska and Oregon. Small systems utilizing activated alumina, ion exchange, and reverse osmosis techniques were field-tested on waters naturally contaminated with arsenic. The waters contained arsenic in concentrations ranging from 0.1 to 1.0 mg/L, which were successfully lowered to below the 0.05mg/L maximum contaminant level.

Adsorption methods for treating organically coloured upland waters

Abstract: Conventional methods for treating highly coloured upland raw waters for potable water supply are relatively inefficient. Adsorption of organic colour either by activated carbon, activated alumina or bone char, particularly after preozonation of the raw water, is a possible alternative method that may be more cost‐effective. This paper summarises the properties of each adsorbent and discusses their relative performance and suitability as methods for removing organic colour from highly coloured raw waters.

Catalyst for purifying exhaust gas and preparation thereof

Abstract: PURPOSE: To obtain a palladium/rhodium catalyst prevented from the sintering of palladium and having good purifying capacity by supporting activated alumina, palladium, rhodium, cerium and barium on a monolithic honeycomb carrier. CONSTITUTION: After activated alumina is applied to a monolithic honeycomb carrier, cerium, palladium and rhodium are bonded to the carrier. This carrier is immersed in a water-soluble barium compound solution to bond barium to the carrier. When barium is added to palladium as mentioned above, palladium is always set to an oxidizing state and the sintering thereof is prevented. Therefore, a palladium/rhodium catalyst showing high purifying capacity by the same amount of palladium as platinum is obtained. COPYRIGHT: (C)1991,JPO&Japio

Agent and process for cleaning gases and exhaust gases and process for producing said agent

Abstract: Surfactants such as activated charcoal, brown coal open-hearth coke, activated alumina and silica gel are admixed, in finely divided form, with the water required for slaking quick lime. The Ca(OH)2 obtained is particularly suitable for removing Hg from gases and exhaust gases. Residual HCl, SO2 and NOx can also be removed. The surfactants can also be admixed with the quick lime before slaking or with the Ca(OH)2. The surfactants may be charged with catalytically active heavy metals, e.g. vanadium, or with substances which bind heavy metals, e.g. sodium sulfphide. The surfactants used are activated charcoal, brown coal open-hearth coke, silica gel, diatomaceous earth and/or activated alumina.

Activated Alumina for Removing Dissolved Organic Compounds

Abstract: Adsorption of natural organic matter on activated alumina (AA) improved when the organic matter was preoxidized with either ozone or hydrogen peroxide. The alumina was effectively regenerated in the laboratory with 0.1 percent (or greater) NaOH solutions, i.e., more than 8 X 10"4 mol NaOH/g AA. The spent regenerant could be reused several times to reduce the quantity of process waste. The use of AA before granular activated carbon (GAC), combined with in situ regeneration of the AA, resulted in an 80 percent higher capacity of GAC for an organic micropollutant- 2,4, -dichlorophenol. Presumably there was reduced competition for adsorption sites on the GAC because the dichlorophenol was not adsorbed by the AA. Pilot tests of AA adsorbers in parallel with GAC adsorbers showed that GAC had a higher capacity and could adsorb a larger percentage of natural organics than AA, that AA did not adsorb the semivolatile organics (analyzable by gas chromatography-mass spectroscopy) in a surface water, and that preozonation improved removal by AA and GAC. Activated alumina (AA) has been used to remove various inorganic substances1"4 from drinking water supplies. The use of AA has also been suggested for the removal of organic acids, surfactants, and dissolved humic substances.5"9 It was recently reported that more dissolved humic substances can be adsorbed on AA after they have been preoxidized with ozone.10 Adsorption capacity increased as pH decreased and ozone dosage increased. The increase in adsorption caused by ozonation is consistent with several earlier studies that showed color, particles, organic compounds, and trihalomethane (THM) precursors were more effectively removed after ozonation by coagulation with aluminum salts11"13 or adsorption on AA.14 An explanation of the increased adsorption capacity is that the increased molecular polarity caused by ozonation results in stronger adsorption bonds with the polar alumina surfaces. This study examined the adsorption efficiency of AA for humic substances, with and without preoxidation with ozone and ozone plus hydrogen peroxide, in comparison with granular activated carbon (GAC). Regeneration of AA with NaOH was studied to determine the factors that affect regeneration effi

Alumina aglomerates preparation process

Abstract: The present invention relates to a process for the manufacture of activated alumina agglomerates and to the agglomerates obtained according to this process. It relates more particularly to a process consisting in forming an alumina body by agglomerating an alumina powder obtained by a fast dehydration of an aluminium hydroxide, characterised in that it consists: (i) in aging these alumina bodies in an atmosphere with a controlled degree of humidity, (ii) in impregnating the aged bodies with a solution of one or more acids (iii) in subjecting these impregnated bodies to a hydrothermal treatment in a confined atmosphere, and (iv) in drying and calcining these bodies. The process of the invention makes it possible to preserve the pore distribution during the aging and autoclaving stages. The agglomerates of the invention are useful especially as supports for a catalyst or adsorbent.

Production of polymer

Abstract: PURPOSE: To remove readily and efficiently the catalyst components in the polymerization reaction mixture and obtain the polymer which is useful as an optical material by treating the reaction mixture resulting metathesis ring- opening polymerization of a specific monomer with an adsorbent. CONSTITUTION: The metathesis ring-opening polymerization of a monomer mixture of (A) (i) a monomer of the formula (A, B are H, 1 to 10C hydrocarbon; halogen atom; m is 0, 1) or a mixture thereof with another monomer copolymerizable with component (i) is carried out in a solvent and the reaction mixture is treated with (B) an adsorbent such as activated clay, activated carbon, kieselguhr, activated alumina, zeolite or the like in the presence of (C) a compound of R-OH (R is H, 1 to 6C hydrocarbon) to give the subject polymer. COPYRIGHT: (C)1991,JPO&Japio

Purification of sulfuryl fluroide by selective adsorption

Abstract: Many impurities of sulfuryl fluroide are removed by selective adsorption on activated alumina and activated carbon. Thionyl fluoride, hydrogen fluoride, hydrogen chloride, and water are removed by treating contaminated sulfuryl fluoride with activated alumina. Sulfur dioxide and 1,2-dichloroethane are removed by treating contaminated sulfuryl fluoride with activated carbon. When sulfuryl fluoride is treated with the two adsorbents in sequence, sulfuryl fluoride of exceptionally high purity is obtained.

Catalyst for purification of exhaust gas and production thereof

Abstract: PURPOSE:To improve the heat resistance of a catalyst by forming a second coating layer consisting of Pd and combined powder having Zr and La fixed on the surface of Ce on a first coating layer of activated alumina contg. Pt and Rh formed on a catalyst carrier. CONSTITUTION:Ce is mixed with Zr and La solns., this mixture is dried and the resulting solid body is crushed to prepare combined powder having Zr and La fixed on the surface of Ce. A first coating layer 3 based on activated alumina contg. Pt and Rh is formed on the surface of a catalyst carrier 2 and a second coating layer 4 based on the prepd. combined powder and Pd is formed on the layer 3 to produce a catalyst 1 for purification of exhaust gas. Since the Zr and La are fixed on the surface of the Ce, the thermal deterioration of the Ce in the catalyst is prevented.

IR study of chlorination of alumina employing mixtures of gaseous chlorine and carbon monoxide

Abstract: The chlorination of an alumina with BET surface area of 100 m2/g has been studied in situ by transmission IR measurements at about 670 K. The chlorinating gases consisting of Cl2 and CO were employed individually and in equimolar proportion. The IR results do not reveal the presence of a phosgene surface species which could support the only mechanism proposed so far to explain the chlorination. A detailed alternative reaction mechanism is suggested for the high temperature chlorination reaction, taking into account the IR results, together with the known electron donor-acceptor properties of the activated alumina and the reaction gases: Cl2 molecules accept electrons from oxide ions with a lower coordination number on the alumina surface, leading to the formation of Cl−and Oad. While Cl− yields AlCl3, Oad reacts further with CO producing CO2.

Catalyst for exhaust gas purification

Abstract: PURPOSE:To improve the ability to convert CO and NO2 into harmless substances, by fixing Pt, Pd and CeO2 on a carrier consisting of either alumina cement, molten silica and activated alumina or hydraulic alumina and lithium composite oxide. CONSTITUTION:A heat-resistant porous carrier is prepared which has a high specific surface area and consists mainly of either alumina cement, molten silica and activated alumina or hydraulic alumina and lithium composite oxide. On this heat-resistant porous carrier, three kinds of catalyst metals, i.e., Pd, Pt and CeO2, are fixed to give a catalyst for purification of exhaust gases. This catalyst has improved ability to convert CO and NO2 into harmless substances, because of the large specific surface area of the carrier and the increased effective interaction between the carrier components and the catalyst metals. Further, the life of the catalytic ability is long and the deterioration of the ability can be prevented.

Exhaust gas purifying catalyst suppressing the generation of hydrogen sulfide

Abstract: An exhaust gas purifying catalyst suppressing the generation of hydrogen sulfide obtained by coating and supporting on a honeycomb carrier of a monolithic structure a catalyst composition containing (a) activated alumina supporting platinum and/or palladium in the range of 5 to 30 weight % and rhodium in the range of 1 to 20 weight %, (b) a cerium oxide and (c) activated alumina, and optionally (d) an alkali metal and/or (e) a nickel oxide.

Catalytic material adsorbing low molecular gas

Abstract: PURPOSE:To enhance the ability of a catalytic material adsorbing low molecular gas to maintain the freshness of perishables and to provide dehumidifying, deodorizing and antibacterial abilities to the material by combining a microporous material in the form of granules, etc, with an org acid compd to form the catalytic material CONSTITUTION:A granular microporous material is mixed with a granular org acid compd or treated with an aq soln of the compd to form a catalytic material adsorbing low molecular gas The microporous material may be activated carbon, silica gel, activated alumina, synthetic or natural zeolite or calcium carbonate The org acid compd may be carboxylic acid, sulfonic acid or sulfinic acid The formed catalytic material is utilized for maintaining the freshness of perishables and can also be utilized as deodorizing, dehumidifying and antibacterial materials

Flaky activated alumina carrier, production thereof and combined pigment using same

Abstract: PURPOSE: To render superior characteristics as the carrier of a pigment to a flaky activated alumina carrier and to make the alumina carrier suitable for cosmetics by specifying the average diameter, aspect ratio and specific surface area of the alumina carrier. CONSTITUTION: This flaky activated alumina carrier has 0.1-50μm average diameter, 10-100 aspect ratio and 30-350m 2 /g specific surface area. The pH of a suspension of this carrier is 3.0-5.0. Flaky metallic Al having 0.1-50μm average diameter, 10-100 aspect ratio and 2-20m 2 /g specific surface area is subjected to alkali treatment at pH 7.1-11.0 and dried and/or fired to produce the alumina carrier. Org. coloring matter is adsorbed on the carrier and the surface of the carrier is hydrothermally treated to obtain a combined pigment. COPYRIGHT: (C)1991,JPO&Japio

Method of refining oil containing gamma-linolenic acid

Abstract: PURPOSE:To prepare a transparent and odorless refined oil having a low gamma- linolenic acid content, by treating a soln. of an oil contg. gamma-linolenic acid in a low-boiling hydrocarbon with a column packed with a cation exchange resin for a nonaqueous soln. and a particular adsorbent. CONSTITUTION:A soln. of an oil contg. gamma-linolenic acid in a low-boiling hydrocarbon (e.g., a solution of evening primrose seed oil, lettuce seed oil, black current seed oil, or the like having a high gamma-linolenic acid content in n-pentane, n-hexane, or the like) is treated with a column packed with a cation exchange resin for a nonaqueous soln. (pref. a strongly acidic cation exchange resin) and activated alumina or activated carbon as an adsorbent. The refined oil prepd. by this treatment has a low free fatty acid content and improved hue and odor and exhibits little loss of gamma-linolenic acid caused by adsorption. Since the refined oil is transparent and has mild odor, it is suitable for use not only as a base material for cosmetic preparations but also as a raw material of medicine and health-promoting foods.

Catalyst for purification of exhaust gas from diesel

Abstract: PURPOSE:To facilitate the combustion of fine C particles in exhaust gas by supporting a fireproof inorg base material (a), Pt, Pd or Rh (b) and manganese oxide (c) on a fireproof three-dimensional structure and specifying the ratio of (b) to (c) in the surface layer CONSTITUTION:A fireproof inorg base material (a), at least one kind of metal (b) selected among Pt, Pd and Rh and manganese oxide (c) are supported on a fireproof three-dimensional structure having the function of a gas filter to form a catalyst for purification of exhaust gas from a diesel In the catalyst, the molar ratio of the component (b) to the component (c) in the surface layer of <=10mum thickness is regulated to 003-100 Ceramic foam or metal mesh is suitable for use as the three-dimensional structure and activated alumina, silica or titania as the component (a)

Catalyst for purifying discharge gas

Abstract: PURPOSE:To efficiently remove CH, CO and NOx, by carrying on the catalytic constituents including at least either of Pt or Pd and Rh, carried by activated alumina, cerium oxide and an activated alumina on a honeycomb structure. CONSTITUTION:At least either of Pt or Pd in an amount within the range of 5-30% by weight and Rh in an amount within the range of 1-20% by weight are carried by activated alumina. An aqueous slurry is prepared by mixing together this activated alumina carrying these noble metals, cerium oxide and a noncarrying activated aluminum. This aqueous slurry, carried by a honeycomb structure, is formed into a catalyst for cleaning up exhaust gases. It is appropriate for this catalyst to contain 1-20g noble metal carrying activated alumina per 1 liter carrier, 50-200g activated alumina and 10-150g cerium oxide in an amount in terms of CeO2.

Production of dichlorosilane

Abstract: PURPOSE:To obtain dichlorosilane in good yield even at a relatively low temperature, by subjecting trichlorosilane to disproportionation reaction in the presence of a specific reaction product thereof, etc., with hexamethylphosphoryltriamide as a catalyst. CONSTITUTION:Trichlorosilane is subjected to disproportionation reaction in the presence of a reaction product solid substance of at least one of silicon tetrachloride, aluminum chloride, phosphorus oxytrichloride and the trichlorosilane as a catalyst to afford the aimed dichlorosilane. The above- mentioned reaction product solid substance can be directly used as the catalyst for the disproportionation reaction of the trichlorosilane, but may be supported on a carrier, such as silica gel or activated alumina, for use. Although the silica gel or activated alumina may be powder or a spherical or pellet form and the method for supporting the reaction product solid substance may be carried out in an ether. The resultant supported catalyst exhibits high catalyst activity without any peeling property.

Agent and process for cleaning gases and exhaust gases and process for producing said agent

Abstract: Surfactants such as activated coal, lignite hearth furnace coke, activated aluminum oxide and silica gel are added in finely divided form in water for the extinction of the quicklime. Ca (OH) 2 obtained is particularly suitable for removing Hg from gases and exhaust gases. HCl residual contents, SO2 and NOx can also be eliminated. Surfactants may also be mixed with quicklime prior to its termination or Ca (OH) 2. Surfactants may be loaded with heavy catalytically active metals, e.g., vanadium, or to substances which bind heavy metals, for example sodium sulphide. The surfactants used are activated carbon, the hearth furnace lignite coke, silica gel, diatomaceous earth and / or activated alumina.

Catalyst for purifying exhaust gas of automobile

Abstract: PURPOSE:To enlarge exhaust gas treatment capacity by allowing a heat resistant carrier to be covered with oxide of one or more kinds of Fe, Co, Ni and allowing the upper part thereof to be covered with activated alumina incorporating one or more kinds of noble metal selected from among Pt, Pd and Rh. CONSTITUTION:A catalyst for purifying exhaust gas is formed by allowing a heat resistant carrier to be covered with oxide of one or more kinds of metal selected from Fe, Co and Ni and furthermore allowing the upper part thereof to be covered with activated alumina and also carrying the component of at least one or more kinds of metal selected from among Pt, Pd and Rh on this activated alumina. The noble metal component can be used in a state of metal compd. such as nitrate. In the obtained catalyst for purifying exhaust gas, exhaust gas treatment capacity of the noble metal component is little inhibited by denaturation of activated alumina carried therewith and excellent treatment capacity is exhibited even under high pump.

Assaying aluminium in drinking water.

Abstract: The aluminium content in a water supply is determined by a method which involves forming the aluminium in a sample stream of the water into a complex with added fluoride and sensing the fluoride content electrically. Equipment for carrying out the invention comprises means (10) to mix a sample stream (in 1) with a standard sodium fluoride solution (in 9), warm it (in 12) and sense the PD generated between electrodes 13 and 14. Solutions of known aluminium concentration can be drawn from reservoirs 3 and 4 to calibrate the fluoride ion selective electrode 14.

Phase composition and structure of cobalt-, nickel-, and copper-containing oxide catalysts based on activated alumina

Abstract: 1. Aluminum hydroxide and oxide supports, obtained by interaction with water of aluminum activated by indium or gallium, are multiphasic systems containing in the first case PB, BR, and In, and in the second, γ-Al2O3, In2O3, and In. 2. The presence of Co and Ni as alloys with activated aluminum determined the x-ray amorphous character of the Co- and Ni-containing phases at all stages, including the thermal treatment of the hydroxide and oxide systems. In the case of the copper alloy, only with thermal treatment does the partial crystallization of the CuO phase occur. 3. Introduction of the Co, Ni, and Cu ions into the aluminum oxide or hydroxide matrices, obtained from activated aluminum, show a definite effect on the formation of the Co3O4, CoAl2O4, and NiAl2O4 phases after thermal treatment. For the Cu-containing catalysts, the Cu2O and CuO phases are formed even before thermal treatment.

Production of 1,1,1,2-tetrafluoroethane

Abstract: PURPOSE:To produce the subject compound useful as a refrigerant in high selectivity and yield, by reacting HFC-114a containing CFC-114 as a starting material with hydrogen in the presence of a palladium catalyst supported on activated alumina while controlling reaction temperature. CONSTITUTION:HFC-114a, i.e. 1,1-dichloro-1,2,2,2-tetrafluoroethane containing CFC-114, i.e. 1,2-dichloro-1,1,2,2-tetrafluoroethane as a raw material is reacted with hydrogen in the presence of a palladium catalyst supported on activated alumina at a temperature within the range of 120-<200 deg.C to afford 1,1,1,2- tetrafluoroethane. The content of the CFC-114 in the raw material HFC-114a is preferably within the range of about 10-25%. The amount of the Pd in the catalyst is preferably within the range of 0.2-5%.

Oil filtering adsorbent

Abstract: PURPOSE:To obtain the title adsorbent appropriate to filter edible oil used in cooking by composing the adsorbent essentially of activated alumina and/or attapulgite, controlling the content to >=40wt%, and adding =40wt%, and <=60wt% perlite and/or bentonite in total is added and uniformly mixed to obtain an oil filtering adsorbent Since the adsorbent does not blacken the surroundings unlike activated carbon and has excellent deodorizing property, decoloring property, and peroxide removing property, the adsorbent is appropriately used for filtering the edible oil used in cooking In addition, the adsorbent is preferably composed of 35-70%, by weight, activated alumina, 40-60% attapulgite, 3-20% perlite, and 3-15% bentonite