Ube Industries, Inc.

Osaka University

Toshihiro Shimakawa

Ryoji Sugise

Shigehiro Nishijima

Koji Kaiso

Fumihito Mishima

Masashi Shirai

Katsumasa Harada

Masayuki Nishio

Sadao Niida

Kouichi Kashiwagi

Toshio Kurafuji

The present invention is a method for applying a gradient magnetic field to a paramagnetic supporting liquid containing a mixture of first particles and second particles to separate the mixture by particle type. A magnetic susceptibility of the first particles is lower than that of the liquid, and a magnetic susceptibility of the second particles is higher than that of the liquid. A gradient magnetic field is applied to the liquid in a separation tank provided with a magnetic filter and the liquid is stirred. The first particles float in the liquid by a magneto-Archimedes effect. A horizontal magnetic force acts on the first particles by the gradient magnetic field, so that the first particles travel to a region lateral to or outward from the magnetic filter and are gathered in the region. The magnetic filter is excited by the gradient magnetic field to catch the second particles.

Method and apparatus for separation of mixture

The present invention provides a method and an apparatus for separating a mixture that are capable of separating a mixture containing a plurality types of particles, using a countercurrent classification technique, even when there is little difference in density and particle diameter depending on the types of particles. In the present invention, a mixture containing first particles and second particles is separated using a separation tubehaving the inverted-conical or pyramidal shape or a substantially inverted-conical or pyramidal shape. The first particles and the second particles are made of substances having different magnetic susceptibilities. A fluid is caused to flow upward through the separation tube, and the flow of the fluid is used to introduce the mixture into the separation tube. The first particles and the second particles are held in the separation tubein a mixed state. A gradient magnetic field is applied to a region inside the separation tubeusing magnetic field generation means, in the state where the first particles and the second particles are held in the separation tube. The magnetic field gradient of the gradient magnetic field has a vertical component.

Provided are a mixture separation method and a separation apparatus in which agglomeration of particles contained in the mixture is suppressed, energy required in distillation treatment of a supporting liquid is small in comparison with conventional methods, and particles that cannot be separated by conventional methods can be separated from a mixture containing the particles. The separation method and separation apparatus of the present invention separate, by type, a plurality of types of particles formed of mutually different materials by applying a magnetic field having a magnetic field gradient to the mixture containing the plurality of types of particles in the supporting liquid. Alternatively, the separation method and separation apparatus of the present invention separate a specific type of particle from such mixture. The supporting liquid is an organic solvent solution obtained by dissolving one or more types of paramagnetic compounds in an organic solvent. The plurality of types of particles includes particles of an inorganic salt, an organic acid salt, an inorganic oxide or a macromolecular compound. The organic solvent may be selected from the group consisting of alcohols, ethers, nitriles, ketones, esters, amides, sulfoxides, halomethanes and hydrocarbon solvents.

A dialkyl carbonate (e.g., dimethyl carbonate) is prepared at a high yield and a high selectivity by decarbonylation of a dialkyl oxalate (e.g., dimethyl oxalate) in a gaseous phase in the presence of an alkali metal compound (e.g., potassium carbonate).

Process for preparing a dialkyl carbonate by gas-phase decarbonylation

Straight-chain acrylonitrile dimers including 1,4-dicyanobutene, 1,4-dicyanobutadiene and adiponitrile are produced at a high selectivity by dimerizing acrylonitrile in the presence of a ruthenium catalyst, and in the presence of a straight-chain dimer selectivity-enhancing agent comprising at least one member selected from

Method of producing straight-chain acrylonitrile dimers

Straight-chain acrylonitrile dimers including 1,4-dicyanobutene, 1,4-dicyanobutadiene and adiponitrile are produced at a high selectivity rate and yield by dimerizing acrylonitrile in the presence of a catalyst comprising at least one ruthenium compound, for example dichloro-tetrakis (dimethylsulfoxide) ruthenium, and in the presence of at least one organic acid, for example, propionic acid, and optionally in the further presence of a basic compound, a reducing compound and/or a sulfoxide compound.

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Yamaguchi, Japan

Toshihiro Shimakawa