Showing papers on "Activated alumina published in 1991"
Patent•
20 Feb 1991
TL;DR: In this paper, a filter for removing contaminants from a gas contains a support material and a first component which is an oxide, a hydroxide or a mixture of an oxide and hydroxides of Al, Si, Ti, Fe or Zn, containing at least about 0.5% by weight of water.
Abstract: A filter for removing contaminants from a gas contains a support material and, deposited on the support material, a first component which is an oxide, a hydroxide or a mixture of an oxide and hydroxide of Al, Si, Ti, Fe or Zn, containing at least about 0.5% by weight of water. The first component is deposited onto the filter preferably from a colloidal sol solution of a compound of the metal of that component. The first component acts as an adsorbent to remove contaminants from a gas, such as air. The filter may contain a second component, such as an alkali metal, alkaline earth metal, permanganate(s), or a mixture thereof. The filter may also contain a third component, such as an adsorbent, in the form of separate particles, e.g., activated charcoal, potassium permanganate, activated alumina, optionally treated with an alkali metal or alkaline earth metal compound(s), zeolites, and alumino-silicate compositions. The filter is preferably used to remove contaminants from the air in central forced air systems in residential and commercial construction.
53 citations
Patent•
20 Mar 1991
TL;DR: In this paper, a tri-disperse structure was used for the removal of heavy metal ions, halocarbons, aromatic organics, radon and microbiological substances from water.
Abstract: A very effective adsorption composition has been produced for the removal of heavy metal ions, halocarbons, aromatic organics, radon and microbiological substances from water. This adsorption composition consists of up to 7 different components. These include aluminum silicate, diatomite, granulated activated carbon, catalytic chlorine removal media, tri-sodium phosphate, bone charcoal and activated alumina. This adsorption composition has a tri-disperse structure. By this it is meant it has three different types of pores. The adsorption composition is utilized by being packaged into cartridges, containers and alike where it is held in place while contaminated water passes through the adsorption composition and the contaminants are removed.
40 citations
Patent•
11 Jun 1991
TL;DR: In this paper, a gas containing NO x in a low concentration is brought into contact with an activated alumina-based adsorbent containing 0.3-40wt.% of an oxide of at least one element selected from iron, copper, cobalt, nickel, and manganese.
Abstract: PURPOSE: To remove NO x by drying a gas containing NO x in a low concentration of about 50ppm at the highest by using an adsorbent. CONSTITUTION: A gas containing NO x in a low concentration is brought into contact with an activated alumina-based adsorbent containing 0.3-40wt.% of oxide of a least one element selected from sodium, potassium, magnesium, and calcium to adsorb and remove NO x and the adsorbent adsorbing NO x is treated with hot air at 150-600°C to regenerate it. The NO x removal becomes effective when 0.3-10wt.% of an oxide of at least one element selected from iron, copper, cobalt, nickel, and manganese is contained in the absorbent. COPYRIGHT: (C)1992,JPO&Japio
27 citations
Patent•
20 Dec 1991
TL;DR: An exhaust gas purifying catalyst suppressing the generation of hydrogen sulfide obtained by coating and supporting on a honeycomb carrier of a monolithic structure is defined in this paper, which is an example of such an approach.
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.
20 citations
Patent•
12 Aug 1991
TL;DR: In this paper, a method for purifying an exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment which comprises previously passing the gas through a layer packed with a highly activated alumina to remove the catalyst poison (s); and an apparatus for Purifying exhaust gas consisting of catalytic poison (catalyst poison).
Abstract: A method for purifying an exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment which comprises previously passing the gas through a layer packed with a highly activated alumina to remove the catalyst poison(s); and an apparatus for purifying exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment, wherein a layer packed with a highly activated alumina for removal of the catalyst poison(s) and a layer packed with an oxidation catalyst for removal of harmful substances in the gas are separately arranged.
12 citations
Patent•
12 Feb 1991TL;DR: The process for the preparation of the said agglomerates is characterised in that it consists in carrying out the maturing of activated alumina aggregates, at atmospheric pressure, in the presence of a complexing agent of the Al cation and then subjecting the said aggregates to a thermal treatment at a temperature of between approximately 100 DEGC and approximately 500 DEG C.
Abstract: Activated alumina agglomerates which exhibit good adsorption properties and improved mechanical properties. The process for the preparation of the said agglomerates is characterised in that it consists in carrying out the maturing of activated alumina agglomerates, at atmospheric pressure, in the presence of a complexing agent of the Al cation and then in subjecting the said agglomerates to a thermal treatment at a temperature of between approximately 100 DEG C and approximately 500 DEG C. The alumina agglomerates which are preferentially in the form of beads are well adapted for being used as adsorbents in processes for the removal of impurities contained in a fluid.
8 citations
Patent•
11 Mar 1991
TL;DR: In this paper, the surface of a metal carrier base material composed of an aluminum-containing heat resistant metallic material or a heat-resistant metal material having a metal aluminum layer on the surface thereof is coated with a coating material composed with activated alumina (coating method to be used: a known method such as a wash coat method).
Abstract: PURPOSE:To simultaneously perform the baking of a coating layer and the formation of alumina whiskers and to obtain a catalyst carrier good in the adhesion and heat conductivity between a catalyst support layer and a metal base material according to a short manufacturing process by coating the surface of a metallic carrier base material composed of an aluminum-containing heat- resistant metallic material with a coating material and heat-treating the coated base material in oxygen-containing gas. CONSTITUTION:The surface of a metal carrier base material composed of an aluminum-containing heat-resistant metallic material or a heat-resistant metal material having a metal aluminum layer on the surface thereof is coated with a coating material composed of activated alumina (coating method to be used: a known method such as a wash coat method). Subsequently, the obtained coated metallic base material is heat-treated at 850 - 1,000 deg.C. By this method, both of the baking of activated alumina and the formation of alumina whiskers are performed simultaneously and an excellent metallic carrier for a catalyst without such problem as release is obtained. A catalyst component for purifying exhaust gas is supported by this carrier to form a catalyst used in the purifica tion of a harmful component.
8 citations
Patent•
19 Jul 1991
TL;DR: In this article, the authors proposed a title sheet having adequate mechanical strength even with a small amount of binder, with the pores of the activated carbon fiber unclosed, high in adsorptivity, good in air permeability, thus suitable for filters, containing microfibrous cellulose and activated carbon fibre.
Abstract: PURPOSE:To provide the title sheet having adequate mechanical strength even with a small amount of binder, with the pores of the activated carbon fiber unclosed, high in adsorptivity, good in air permeability, thus suitable for filters, containing microfibrous cellulose and activated carbon fiber. CONSTITUTION:The objective sheet containing (A) 0.5-30 (pref. 5-20) wt.% of microfibrous cellulose (e.g. produced by microfibrillation of cellulose using a homogenizer) and (B) activated carbon fiber. Furthermore, it is preferable that the present sheet contain 1-50wt.% of at least one material selected from adsorptive materials including zeolite, activated alumina, acid clay, silica gel, diatomaceous earth and granular activated carbon.
6 citations
Patent•
04 Jun 1991
TL;DR: In this paper, the authors proposed a catalyst for diesel exhaust gas purification, which is capable of reducing the discharge amount of diesel particulate, reducing the sulfate and preventing the poisoning of a catalytic metal.
Abstract: PURPOSE: To provide a catalyst purifying HC, CO and SOF, capable of reducing the discharge amount of a diesel particulate, also reducing the discharge amount of sulfate and preventing the poisoning of a catalytic metal. CONSTITUTION: A catalyst for purifying the exhaust gas of a diesel engine consists of a carrier base material 1, the activated alumina layer 2 formed to the surface of the base material 1, the catalytic metal 3 supported on the alumina layer 2 and the oxide membrane 4 composed of at least one oxide selected from SiO 2 , TiO 2 and ZrO 2 and formed to the surface of the alumina layer 2 by CVD(chemical vapor deposition). COPYRIGHT: (C)1992,JPO&Japio
6 citations
Patent•
03 Jul 1991TL;DR: A process for producing acid adsorbents is described in this article, which consists of treating activated alumina with a solution of an alkali metal silicate followed by an alkyl metal aluminate, and forming agglomerates of the treated alumina at a temperature below about 90 °C.
Abstract: The invention relates to alumina-containing acid adsorbents and process for producing same. Activated alumina has been used as an acid adsorbent, but it is not very long-lived. The adsorbents of the invention comprise activated alumina having internal pores and an amorphous alkali (preferably sodium) aluminum silicate coating the inner surfaces of the pores. The ratio of Si:Al in the amorphous alkali 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 and they have a greater effective life than activated alumina itself.
6 citations
Patent•
18 Dec 1991
TL;DR: In this article, a stable anti-bacterial composition having strong antibacterial activity with a small requirement of bactericidal metal was obtained by forming a film of aluminosilicate containing metallic ion having bactericidal action on the surface of alumiua.
Abstract: PURPOSE:To obtain a stable anti-bacterial composition having strong anti-bacterial activity with a small requirement of bactericidal metal by forming a film of aluminosilicate containing metallic ion having bactericidal action on the surface of alumiua. CONSTITUTION:Porous activated alumina having 0.4-1.2cm /g pore volume, >=20Angstrom , especially >=50Angstrom pore diameter and >=80m /g, especially >=100 m /g is treated with an alkali solution and a silica-containing solution to form a coating film of aluminosilicate containing metal capable of ion exchange (preferably having 1.3-30 molar ratio of SiO2/Al2O3) on activated surface of pores or macroscopic holes and metallic ion having bactericidal action is carried in the film of aluminosilicate by ion exchange. As the metallic ion having bactericidal action, metallic ion selected from Ag, Cu, Zn, Hg, Sn, Pb, Bi, Cd and Cr is used and made to exist in an amount of >=0.002mmol, preferably >=0.005mmol per 100cm surface area of the composition.
Patent•
24 Jul 1991
TL;DR: In this article, a method for purifying an exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment which comprises previously passing the gas through a layer packed with a highly activated alumina to remove the catalyst poison (s); and an apparatus for Purifying exhaust gas consisting of catalytic poison (catalyst poison).
Abstract: of EP0437901A method for purifying an exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment which comprises previously passing the gas through a layer packed with a highly activated alumina to remove the catalyst poison(s); and an apparatus for purifying exhaust gas containing catalyst poison(s) by subjecting the gas to a catalytic treatment, wherein a layer packed with a highly activated alumina for removal of the catalyst poison(s) and a layer packed with an oxidation catalyst for removal of harmful substances in the gas are separately arranged.
Patent•
11 Sep 1991
TL;DR: In this article, the authors proposed a method to purify HC, CO and SOF to reduce the discharge amount of diesel particulate and to prevent poisoning of a catalytic metal.
Abstract: PURPOSE:To purify HC, CO and SOF, to reduce not only the discharge amount of a diesel particulate but also the discharge amount of sulfate and to prevent the poisoning of a catalytic metal. CONSTITUTION:A catalyst consists of a carrier base material 1, the activated alumina layer 2 formed to the surface of the carrier base material, the catalytic metal 3 supported on the activated alumina layer 2 and the coating layer 4 formed to the surface of the activated alumina layer 2 and composed of at least one component selected from alumina, titania and silica and oxide of at least one kind of a metal selected from Mn, Co, Sn, Fe, Ca, Ni, Ce, Zr, Mg and Cu is added to the coating layer 4.
Patent•
20 Dec 1991
TL;DR: In this article, a spherical activated alumina carrier with 0.1-50mum average particle diameter and 1-20m /g specific surface area is produced by a method for atomizing aluminum and classifying the obtained powder with a screen, etc.
Abstract: PURPOSE:To obtain a spherical activated alumina carrier, having a large specific surface area and excellent in coloring matter adsorptivity by treating spherical metallic Al having a specified average particle diameter and specific surface area with an alkali within a specific pH range, then drying and burning the resultant substance. CONSTITUTION:Spherical metallic aluminum having 0.1-50mum average particle diameter and 1-20m /g specific surface area is produced by a method for atomizing aluminum and classifying the obtained powder with a screen, etc. The resultant spherical metallic aluminum is then treated with an alkali at pH7.1-11 and subsequently dried and/or burned to afford a spherical activated alumina carrier having 0.1-50mum average grain diameter and 30-350m /g specific surface area. An organic coloring matter can be then adsorbed on the resultant spherical activated alumina carrier to produce a combination pigment excellent in brightness, saturation, water, solvent and weather resistance and safety, etc. The obtained combination pigment is preferably used as coatings, cosmetics, etc.
Patent•
18 Dec 1991
TL;DR: In this article, a perovskite type compound oxide of formula I was used to purify aldehydes included in an exhaust gas even in an atmosphere contg sulfur by incorporating both a silver contg compound oxide and an oxide with a high specific surface area in an alumina-coated layer contg Pd.
Abstract: PURPOSE:To purify efficiently and at low temp aldehydes included in an exhaust gas even in an atmosphere contg sulfur by incorporating both a silver-contg compound oxide and an oxide with a high specific surface area in an alumina- coated layer contg Pd CONSTITUTION:The surface of a monolithic carrier is coated with an activated alumina contg a base metal compound oxide contg silver, an oxide with oxygen storage ability and a high specific surface area such as cerium oxide and palladium The silver-contg compound oxide used here is a perovskite type compound oxide of formula I (wherein x is 01 or 02; y is 01, 02 or 03; delta is 10 or smaller) Thus, an alumina-coated layer contg Pd with oxidation catalystic activity incorporated with a silver contg compound oxide with low temp oxidation activity, heat resistance and resistance to sulfur exposure and a cerium oxide with strong oxygen storage ability and a high specific surface area purifies at low temp and efficiently aldehydes in an exhaust gas
Patent•
19 Jul 1991
TL;DR: In this paper, a process for removing heavy metals from a silver nitrate solution is described, which comprises the step of bringing said silver nitrates solution into contact with activated alumina having a surface acidity of at least 8 and an average pore diameter of not more than 50 Å.
Abstract: A process for removing heavy metals from a silver nitrate solution is disclosed. The process comprises the step of bringing said silver nitrate solution into contact with activated alumina having a surface acidity of at least 8 and an average pore diameter of not more than 50 Å.
TL;DR: A wide variety of aliphatic acid chlorides including an optically active one has been efficiently converted to their t-butyl esters under very mild reaction conditions by employing activated alumina as a catalyst as mentioned in this paper.
Abstract: A wide variety of aliphatic acid chlorides including an optically active one has been efficiently converted to their t-butyl esters under very mild reaction conditions by employing activated alumina as a catalyst.