Abstract: A method for separating aromatic hydrocarbons by an extractive distillation, comprising introducing a hydrocarbon mixture containing aromatic hydrocarbons into the middle of an extractive distillation column (8); introducing an extraction solvent into the upper part of the extractive distillation column; after an extractive distillation, a raffinate containing benzene is discharged from the top of the column, wherein the benzene content is 3-40% by mass, and sent to the lower part of the extraction column (10); the extraction solvent is introduced to the upper part of the extraction column for a liquid-liquid extraction; a raffinate liquid free of aromatic hydrocarbons is discharged from the top of the extraction column; a rich solvent containing benzene is discharged from the bottom of the column and enters the upper-middle part of the extractive distillation column; the rich solvent obtained at the bottom of the extractive distillation column is sent to the solvent recovery column to separate the aromatic h

Abstract: [Problem] To provide a photochromic lens for eye glasses, which has a high refractive index and excellent light-controlling properties and has such a constitution that the weight and thickness of the lens can be reduced. [Solution] Provided is a photochromic lens for eye glasses, which is produced by polymerizing a polymerizable composition prepared by dissolving a photochromic compound into a monomer mixture comprising a first radically polymerizable monomer represented by general formula (I), a second radically polymerizable monomer represented by general formula (II) and divinylbenzene that has a purity of 50% or more and contains a divinylbenzene component and an ethylvinylbenzene component at a total content of 90% or more.

Abstract: A process is presented for the purification of 1,3 butadiene. The process is for treating a butadiene stream from an oxidative dehydrogenation unit, where a butane stream is dehydrogenated, generating a butadiene rich stream. The butadiene rich stream is fractionated and passed through a butadiene recovery unit. Additional C4 compounds recovered from the fractionation bottoms stream are further processed for increasing yields of butadiene.

Abstract: An energy efficient, high throughput process for aromatics recovery can be readily implemented by revamping existing sulfolane solvent extraction facilities, or constructing new ones, so as to incorporate unique process operations involving liquid-liquid extraction and extractive distillation. Current industrial sulfolane solvent based liquid-liquid extraction processes employ a liquid-liquid extraction column, an extractive stripping column, a solvent recovery column, a raffinate wash column, and a solvent regenerator. The improved process for aromatic hydrocarbon recovery from a mixture of aromatic and non-aromatic hydrocarbons requires transformation of the extractive stripping column into a modified extractive distillation column. The revamping incorporates the unique advantages of liquid-liquid extraction and extractive distillation into one process to significantly reduce energy consumption and increase process throughput.

Abstract: A mixture and method of using such mixture is provided for purifying carbon nanotubes. A substituted imidazolium cation is utilized to suspend carbon nanotubes in a nonpolar liquid. A polar solvent immiscible with the nonpolar liquid is mixed in to remove soot from the suspension, allowing recovery of the nanotubes. The relative gentleness of the separation provides nanotubes that are undamaged and unoxidized. The components of the mixture are economically advantageous for this use and the method is simple compared to other nanotube purification methods.

Abstract: The present invention describes a new method for the purification of carbon nanotubes from contaminants deriving from industrial production, constituted by amorphous or carbon crystalline material and metals used for catalysis. The method provides for their organic furretionalization obtaining dirivatized nanotubes, precipitation of functionalized nanotubes and subsequent regeneration of non-functionalized nanotubes by heat treatment.

Abstract: A process for the removal of corrosive compounds from a fluid stream, comprising the steps of: in an extraction column with an outer steel tube and an inner tube of corrosion resistant material having an open inlet end and an open outlet end and being arranged coaxially with and spaced apart within at least top portion of the outer tube, introducing at elevated temperature at the inlet end of the inner tube the fluid stream and an extraction agent and effecting in the mixed stream of the fluid and extraction agent extraction of the corrosive compounds; introducing into an annular space between the walls of the outer and the inner tube a shell stream of a non-corrosive fluid, thereby absorbing in the shell stream amounts of the corrosive compounds diffusing through the wall of the inner tube; passing the shell stream to the bottom portion of the outer tube; cooling the mixed stream at the outlet end of the inner tube by introducing into the stream a cooling stream; passing the cooled stream to the bottom porti

Abstract: A process for the preparation of ajoene using cyclodextrin comprising mixing allicin, where appropriate dissolved in water and/or a water-miscible solvent, with .alpha.-cyclodextrin, .beta.-cyclodextrin, .gamma.-cyclodextrin or any desired mixture of these cyclodextrins; and processing to a water-containing composition; drying this composition; and obtaining the resulting ajoene by decomplexation and extraction from the dried composition.

Abstract: A method for chemically modifying an anionic metal complex, by obtaining from an anionic metal complex insoluble in a non-aqueous solvent and a clathrate compound a clathrate complex thereof with a counter cation of said metal complex, which is soluble in a non-aqueous solvent, and then reacting functional groups of the metal complex, which are not concerned with the coordination of said metal complex, with an organic reagent in the presence of a reaction assistant.The central metal from the chemically modified metal complex may then be removed.

Abstract: Meta- and para-diisopropylbenzenes cannot be easily separated from each other by distillation because of the closeness of their vapor pressures. m-Diisopropylbenzene can be readily removed from p-diispropylbenzene by azeotropic distillation using acetophenone. The acetophenone - m-diisopropylbenzene azeotrope can be separated by solvent extraction with propylene glycol to remove the acetophenone and the propylene glycol - acetophenone mixture is readily separated from each other by rectification.

Abstract: A process for obtaining isobutene from a C.sub.4 -hydrocarbon mixture containing isobutene, by reacting the mixture with a primary alcohol in the presence of an acid condensing agent and decomposing the resulting tertiary ether in the presence of an acid catalyst at an elevated temperature, wherein a primary C.sub.3 - or C.sub.4 -alcohol is used.

Abstract: A method for separating olefins from paraffins in which a mixture of olefin and paraffin is contacted with a dimethyl sulfoxide (DMSO) extractant stream in the liquid phase thereby dissolving olefins in the DMSO and permitting separation of a paraffin stream. The DMSO containing dissolved olefin is then contacted with water and a phase separation is effected between olefin and a mixture of DMSO and water. At least a portion of the DMSO and water mixture can be fractionated to produce a dried DMSO product which can be recycled as a portion of the extractant into contact with the mixture of olefin and paraffin.

Abstract: There is disclosed a process for the separation of ethylene or propylene from a purified, multi-component gas stream produced from the thermal cracking of hydrocarbons and containing ethylene or propylene and other low molecular weight components comprising the steps of: introducing said multi-component gas stream into an aqueous silver salt solution stream to effect the absorption and/or complexing of said contained ethylene or propylene and reaction of trace acetylenes with the silver metal ions of such solution; venting of the silver salt solution stream at reduced pressure to remove the dissolved other low molecular weight components; treating the resulting silver salt solution stream to separate the absorbed and/or complexed ethylene or propylene from the silver salt stream; further treating the resultant silver salt solution stream to release the contained trace acetylenes therefrom and provide an aqueous silver salt stream; and recycling said aqueous silver salt stream to said introducing step.