Abstract: This invention relates to a method of purifying afullerenes by recrystallization of a fullerene-complexing agent complex and to a fullerene-complexing agent complex.

Abstract: The invention relates to a process for the chromatographic separation of fullerenes using a nonpolar aromatic solvent as eluant. Coke, anthracite and/or graphite are used as support material. The nonpolar solvent is the main constituent of the eluant.

Abstract: A process for the isolation of carbon nanotubes from a mixture containing carbon nanotubes and graphite is disclosed, which includes the steps of:(a) reacting the mixture with a metal compound to intercalate the metal compound into the graphite;(b) reducing the reaction mixture obtained in step (a) to convert the intercalated metal compound to elemental metal;(c) heating the reduction mixture obtained in step (b) at a temperature of 450-600.degree. C. in an oxygen-containing atmosphere to selectively oxidize the graphite and the elemental metal; and(d) contacting the heated mixture obtained in step (c) with a liquid to dissolve the oxidized metal in the liquid and to separate the carbon nanotubes as a solid phase from the oxidized metal.

Abstract: A method is provides for reducing the levels of hydrogen sulfide and organic sulfides present in gaseous hydrocarbon streams by contacting the streams with a composition comprising the reaction product of an alkanolamine with a C1 to C4 dialdehyde, especially ethanedial. The method involves delivery and storage of the reactants near the gas stream to be cleaned, forming the reaction product at a rate substantially equal to the consumption of scavenger by the sulfides, delivering the scavenger to a contacting vessel, contacting the sulfides in the gas stream with the scavenger to reduce the sulfide concentration below a given level, separating the gas stream from the spent scavenger and removing the spent scavenger from the vessel.

Abstract: There is disclosed a process for cleaning a harmful gas which comprises bringing a gas containing a basic gas as a harmful component such as ammonia and amines into contact with a cleaning agent comprising a cupric salt supported on an inorganic carrier composed of an metallic oxide such as silica and alumina or a metallic oxide mixture of cupric oxide and manganese dioxide to remove the harmful component from the gas containing a basic gas.According to the above process, it is made possible to effectively remove a basic gas such as ammonia and trimethylamine contained in the exhaust gas from semiconductor production process; and a harmful basic gas contained in dilution gas such as air or nitrogen which dilutes the harmful gas suddenly leaked in emergency from a gas bomb filled inside with the harmful gas. Moreover, the process enables to prevent the occurrence of fire even in the coexistence of other gas such as silane, while maintaining excellent effect on the removal of the harmful gas.

Abstract: A low-cost and facile method of purifying fullerenes to obtain a preparation enriched in a fullerene of selected molecular weight using activated carbon involves adding a fullarena mixture to the top end of a column comprising activated carbon, passing a solvent in which the selected molecular weight fullerene is soluble through the column, and recovering a fraction enriched in the selected molecular weight fullerene from the bottom end of the column. In addition to activated carbon, the column may further comprise silica gel, diatomaceous earth, or other materials which aid in column packing and eluent flow. The invention also provides for preparation of gram quantities of pure C.sub.60 and C.sub.70 fullerenes after a single column pass.

Abstract: The invention relates to a process for the removal of HCN from gas mixtures that contain at least HCN and sulfur compounds, especially from gas mixtures that are obtained by partial oxidation of hydrocarbons, by catalytic decomposition of HCN, as well as a catalyst for the decomposition of HCN. According to the invention, the gas mixture is brought into contact with a catalyst which decomposes the HCN by hydrogenation and/or by hydrolysis and COS that is contained in the gas mixture is decomposed at least partially in this catalyst by hydrolysis. Advantageously, a catalyst that is based on titanium oxide and/or zirconium oxide as a vehicle and that contains chromium oxide as an active component is used. Advantageously, the catalyst is reduced during catalyst production or before use with H.sub.2 and/or a reducing gas at temperatures above the operating temperature of catalytic decomposition.

Abstract: A fullerene composite comprises a matrix formed of ultrafine fullerene such as, for example, C.sub.60 crystallite having diameters in the range of from 5 to 50 nm and a reinforcing member formed of a mixture consisting of carbon nanotubes, carbon nanocapsules, and inevitable indeterminate carbonaceous impurities and incorporated in the matrix. The amount of the reinforcing member incorporated in the matrix is in the range of from 15 to 45% by weight based on the amount of the matrix. Owing to the use of the reinforcing member which contains carbon nanotubes and carbon nanocapsules, the produced fullerene composite is enabled to acquire improved mechanical strength and resistance to deformation, and the wide applicabilities are endowed with fullerene composites.

Abstract: The method of cleaning an exhaust gas containing nitrogen oxides including disposing an exhaust gas cleaner comprising a heat-resistant, porous body, which may support a catalyst consisting essentially of (a) at least one of alkali metal elements; (b) at least one of elements selected from the group consisting of Cu, Co, Mn and V, (c) at least one of rare earth elements, in a flow path of the exhaust gas, spraying a liquid hydrocarbon into a stream of the exhaust gas on the upstream side of the exhaust gas cleaner, thereby causing atomized and gasified hydrocarbon to function as a reducing agent for reducing the nitrogen oxides in the exhaust gas.

Abstract: A mixture of carbon nanotubes and impurity carbon materials, which include carbon nanoparticles and may possibly include amorphous carbon, is purified into carbon nanotubes of high purity by utilizing a significant difference in oxidizability between the nanotubes and the nanoparticles. The mixture is pulverized and heated in the presence of an oxidizing agent at a temperature in the range from 600.degree. to 1000.degree. C. until the impurity carbon materials are oxidized and dissipated into gas phase. The nanotubes remain almost unoxidized except for loss of some lengths from the tube tips. It is suitable to perform the heating in air or oxygen.

Abstract: Dry milling an alpha alumina precursor produces direct conversion to alpha alumina at room temperature.

Abstract: Solid residues formed as byproducts during the refining of sugars (e.g., beet sugar or cane sugar) are employed to sorb acidic gases such as oxides of sulfur or nitrogen. Calcines of the solid residues can also be used. Sorption of acidic gases from gaseous mixtures containing acidic gases is thus accomplished.

Abstract: A cleaning method for an exhaust gas containing ammonia, silanes, and organometallic compounds exhausted from a nitride film production step, etc., for producing compound semiconductors.After removing the silanes and the organometallic compounds from the exhaust gas by contacting the exhaust gas with a cleaning agent comprising soda lime having provided thereon a copper(II) salt, the exhaust gas is contacted with an ammonia decomposition catalyst to decompose ammonia into hydrogen and nitrogen, and undecomposed ammonia in the remaining exhaust gas is then removed by a cleaning agent comprising an inorganic carrier having provided thereon a copper(II) salt, or an active carbon having provided thereon copper sulfate.

Abstract: There is disclosed an organic amine scrubbing process for acid gas abatement of gas streams. The process comprises Donnan dialysis of an absorbent solution to separate and convert organic amine heat stable salts back to free amine absorbent using an anion exchange or neutral membrane. The organic amine absorbent may be an alkanolamine, a substituted or unsubstituted 5-7 member heterocyclic amine or any organic amine suitable for acid gas scrubbing. There is also disclosed a dialysis cell comprising a two compartment cell separated by a membrane. The cell includes a charge of an organic amine high in the organic amine heat stable salt concentration in one compartment and a charge of a base solution in the other compartment. Also disclosed is a process for abating acid gases wherein the organic amine absorbent is regenerated by Donnan dialysis, and an apparatus for effecting the regeneration.

Abstract: A method and apparatus for minimizing the environmental release of acids and toxic organic compounds from a waste incinerator-air pollution control train. The apparatus comprises an incinerator, a gas cooling means such as a waste heat boiler or quench chamber, a means for the partial removal of acid gases and dioxins by contact with either finely-divided alkaline solids or alternatively, by an alkaline solution in a spray drier-absorber, a dry solids collection means such as a fabric filter or electrostatic precipitator, a wet scrubber means for residual metal, dioxin/acid gas removal and an induced draft fan. In the method of this invention, the final wet scrubber stage operates without alkaline neutralization, but under scrubber acid concentrations and operating conditions that provide an exhaust gas within compliance limits of emission regulations. The contaminated liquor blowdown from the wet scrubber, which contains toxic organics and acids, is recycled back into the incinerator.

Abstract: HF can be recovered from aqueous streams, particularly those which are dilute and have a concentration of HF lower than the azeotrope between HF and water. Such aqueous streams are contacted with carbon molecular sieves, preferably those having an average pore size of about 3.5 Angstroms, which adsorb both HF and water. When regenerated by heating, more dilute aqueous streams are desorbed at lower temperatures, followed by desorption of HF which is free of water, making possible a separation of HF and water and avoiding formation of the azeotrope.

Abstract: There is disclosed a process for cleaning a harmful gas which comprises bringing a harmful gaseous halogenide such as chlorine, hydrogen chloride, dichlorosilane, silicon tetrachloride, phosphorus trichloride, chlorine trifluoride, boron trichloride, boron trifluoride, tungsten hexafluoride, silicon tetrafluoride, fluorine, hydrogen fluoride and hydrogen bromide into contact with a cleaning agent comprising zinc oxide, aluminum oxide and an alkali compound to remove the above halogenide. The above process is extremely effective for promptly and efficiently removing the above gaseous halogenide that is contained in the gas discharged from semiconductor manufacturing process.

Abstract: Disclosed herein is a crystallization apparatus for use in the crystallization of L-.alpha.-aspartyl-L-phenylalanine methyl ester. The stirring blade of the crystallization apparatus is composed of a band plate member for sweeping the bottom of a vessel and rod- or band plate-members arranged thereon and extending substantially vertically and horizontally.

Abstract: Absorption solvents for removing mercaptans from gas streams are disclosed. The absorption solvents comprise an alkylether of a polyalkylene glycol, e.g., methoxytriglycol, and a secondary monoalkanolamine, e.g., N-methylethanolamine, as well as optionally other amines, e.g., methyldiethanolamine and diethanolamine. The absorption solvents do not require the presence of iodine for removal of mercaptans. Absorption processes utilizing the solvents are also disclosed.

Abstract: The invention discloses a method of reducing the concentration of NO.sub.x in the exhaust streams of internal combustion ignitions wherein a selected producing agent is introduced into the combustion chamber of such an engine via the fuel and/or air feed stream introduced into the combustion chamber. Also disclosed is an apparatus for reducing the concentration of NO.sub.x in the exhaust streams of internal combustion engines having a piston-cylinder assembly having an air fuel mixture contained therein, a means for storing a selective reducing agent selected from the group consisting of ammonia, hydrazine and cyanuric acid and a means for introducing the reducing agent into the lean air/fuel mixture before combustion occurs such that upon combustion of the air/fuel mixture, the reducing agent decomposes to react with one or more products of combustion to produce an engine exhaust stream having a reduced concentration of NO.sub.x.