Abstract: A lower olefin producing catalyst which has high olefin production efficiency and maintains its activity for a long period of time when lower olefins are produced from an oxygen-containing compound, which is a solid catalyst used in producing lower olefins from an oxygen-containing compound, includes a solid-state catalyst component containing an MFI-type zeolite, in which, at a position where the shortest distance to the outer surface is maximum among all positions inside a structure of the solid catalyst, the thickness defined as a distance twice the shortest distance from the point to the outer surface is in a range of from 0.1 to 2.0 mm, and a method for producing lower olefins.

Abstract: There are provided a catalyst for manufacturing propylene, which can keep stable activity for a prolonged period of time in manufacturing propylene by bringing an oxygen-containing compound into contact with the catalyst in the presence of an olefin having 4 or more carbon atoms, and a method for manufacturing propylene using this catalyst for manufacturing propylene.

Abstract: A lower olefin producing catalyst which has high olefin production efficiency and maintains its activity for a long period of time when lower olefins are produced from an oxygen-containing compound, which is a solid catalyst used in producing lower olefins from an oxygen-containing compound, includes a solid-state catalyst component containing an MFI-type zeolite, in which, at a position where the shortest distance to the outer surface is maximum among all positions inside a structure of the solid catalyst, the thickness defined as a distance twice the shortest distance from the point to the outer surface is in a range of from 0.1 to 2.0 mm, and a method for producing lower olefins.

Abstract: The disclosure described a process for producing an .alpha.-olefin oligomer, which comprises carrying out oligomerization of an .alpha.-olefin in a solvent in the presence of a catalytically effective amount of a chromium-based catalyst system composed of a combination of at least (a) a chromium compound, (b) a nitrogen-containing compound of at least one selected from the group consisting of an amine, an amide and an imide, (c) an alkylaluminum compound and (d) a halogen-containing compound,wherein each of the .alpha.-olefin, the chromium compound (a), the nitrogen-containing compound (b) of at least one selected from the group consisting of an amine, an amide and an imide, the alkylaluminum compound (c) and the halogen-containing compound (d) is supplied to a reaction system in a mode that the chromium compound (a) and the alkylaluminum compound (c) do not contact each other before each of said compounds (a) to (d) and the .alpha.-olefin coexists in the reaction solvent and the oligomerization of an .alpha.

Abstract: The disclosure describes a process for preparing .alpha.-olefin oligomers, which comprises carrying out oligomerization of an .alpha.-olefin in a solvent by reacting said .alpha.-olefin in a chromium-based catalyst system composed of a combination of at least a chromium compound, an amine or metal amide, and an alkylaluminum compound, in a contacting mode that the chromium compound and the alkylaluminum compound are not previously contacted with each other.

Abstract: An oligomerization of .alpha.-olefins is carried out in a solvent using a chromium-based catalyst system comprising at least (a) a chromium compound, (b) at least one nitrogen-containing compound selected from amines, amides and imides, and (c) an alkylaluminum compound, and the catalyst components and by-product polymers are recovered simultaneously from the reaction solution. Such process is an industrially advantageous process for producing .alpha.-olefin oligomers by using a chromium-based catalyst, and is simple and capable of efficiently recovering the by-product polymers and the catalyst components simultaneously.