Linear alpha olefins (LAOS) may be formed by oligomerization of ethylene in the presence of a Ziegler-type catalyst. The presence of trace water during oligomerization can result in unwanted formation of insoluble higher oligomers or polymer. Methods for limiting the presence of water during ethylene oligomerization reactions may include separating residual ethylene and 1-butene from an LAO product stream to form a higher LAO-enriched stream comprising C.sub.6+ LAOs, separating 1-hexene as an overhead stream from the higher-LAO enriched stream using a first distillation column, obtaining separated solvent as a side stream from the first distillation column or as a side stream from a first of one or more downstream distillation columns, and returning the separated solvent to a reactor in a recycled solvent stream. The recycled solvent stream passes through one or more driers before returning to the reactor.

Linear alpha olefins (LAOS) may be formed by oligomerization of ethylene in the presence of a Ziegler-type catalyst. The presence of trace water during oligomerization can result in unwanted formation of insoluble higher oligomers or polymer. Methods for limiting the presence of water during ethylene oligomerization reactions may include separating residual ethylene and 1-butene from an LAO product stream to form a higher LAO-enriched stream comprising C.sub.6+ LAOs, separating 1-hexene as an overhead stream from the higher-LAO enriched stream using a first distillation column, obtaining separated solvent as a side stream from the first distillation column or as a side stream from a first of one or more downstream distillation columns, and returning the separated solvent to a reactor in a recycled solvent stream. The recycled solvent stream passes through one or more driers before returning to the reactor.

Process for producing alpha olefins comprising contacting ethylene, a zirconium based catalyst system comprising, a hydrocarbylmetal compound, a chain transfer agent, and optionally an organic reaction medium. Chain transfer agents which can be utilized include a) hydrogen, b) a compound comprising a hydrogen silicon bond, a compound having a hydrogen sulfur bond, a compound having a hydrogen phosphorus bond, or c) a transition metal compound chain transfer agent.

Process for producing alpha olefins comprising contacting ethylene, a zirconium based catalyst system comprising, a hydrocarbylmetal compound, a chain transfer agent, and optionally an organic reaction medium. Chain transfer agents which can be utilized include a) hydrogen, b) a compound comprising a hydrogen silicon bond, a compound having a hydrogen sulfur bond, a compound having a hydrogen phosphorus bond, or c) a transition metal compound chain transfer agent.

Methods for making alpha olefin oligomers and polyalphaolefins include a step of contacting a C.sub.4 to C.sub.20 alpha olefin monomer and a catalyst system containing a metallocene, a first activator comprising a solid oxide chemically-treated with an electron withdrawing anion, and a second activator comprising an organoaluminum compound. The alpha olefin oligomers and polyalphaolefins prepared with these catalyst systems can have a high viscosity index combined with a low pour point, making them particularly useful in lubricant compositions and as viscosity modifiers.

Methods for making alpha olefin oligomers and polyalphaolefins include a step of contacting a C.sub.4 to C.sub.20 alpha olefin monomer and a catalyst system containing a metallocene, a first activator comprising a solid oxide chemically-treated with an electron withdrawing anion, and a second activator comprising an organoaluminum compound. The alpha olefin oligomers and polyalphaolefins prepared with these catalyst systems can have a high viscosity index combined with a low pour point, making them particularly useful in lubricant compositions and as viscosity modifiers.

A modified solid polyalkylaluminoxane is provided, which is capable of providing α-olefin suppressing adhesion of any polymer produced as a by-product onto the reactor wall and the stirrer, and which is capable of providing a highly active olefin oligomerization reaction catalyst. An olefin oligomerization reaction catalyst containing the modified solid polyalkylaluminoxane is also provided. The modified solid polyalkylaluminoxane for olefin oligomerization reactions contains structural units represented by general formula (a) and structural units represented by general formula (b), whose median diameter is equal to or larger than 0.1 μm and equal to or smaller than 50 μm,

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in which R′ in the general formula (a) represents an alkyl group having 1 to 20 carbon atoms, and R″ in the general formula (b) represents a halogenated alkoxy group having 1 to 20 carbon atoms or a halogenated aryloxy group having 6 to 20 carbon atoms.

Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization or for normal alpha olefins. The process comprises selecting waste plastics containing polyethylene and/or polypropylene and then passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a naphtha/diesel fraction, a heavy fraction, and char. The naphtha/diesel fraction is passed to a crude unit in a refinery from which is recovered a straight run naphtha fraction (C.sub.5-C.sub.8) or a propane/butane (C.sub.3-C.sub.4) fraction. The straight run naphtha fraction, or propane and butane (C.sub.3-C.sub.4) fraction, is passed to a steam cracker for ethylene production. The ethylene is converted to normal alpha olefin and/or polyethylene. Also, a heavy fraction from the pyrolysis reactor can be combined with a heavy fraction of normal alpha olefin stream recovered from the steam cracker. The combined heavy fraction and heavy fraction of normal alpha olefin stream can be passed to a wax hydrogenation zone to produce wax.

Provided is a continuous process for converting waste plastic into recycle for polyethylene polymerization or for normal alpha olefins. The process comprises selecting waste plastics containing polyethylene and/or polypropylene and then passing the waste plastics through a pyrolysis reactor to thermally crack at least a portion of the polyolefin waste and produce a pyrolyzed effluent. The pyrolyzed effluent is separated into offgas, a naphtha/diesel fraction, a heavy fraction, and char. The naphtha/diesel fraction is passed to a crude unit in a refinery from which is recovered a straight run naphtha fraction (C.sub.5-C.sub.8) or a propane/butane (C.sub.3-C.sub.4) fraction. The straight run naphtha fraction, or propane and butane (C.sub.3-C.sub.4) fraction, is passed to a steam cracker for ethylene production. The ethylene is converted to normal alpha olefin and/or polyethylene. Also, a heavy fraction from the pyrolysis reactor can be combined with a heavy fraction of normal alpha olefin stream recovered from the steam cracker. The combined heavy fraction and heavy fraction of normal alpha olefin stream can be passed to a wax hydrogenation zone to produce wax.

Provided is a method for preparing a linear alpha olefin using a chromium-based catalyst, including the steps of: removing oxygen impurities by contacting an olefin with an oxygen adsorbent; injecting the olefin from which the oxygen impurities are removed; a chromium-based catalyst into a reactor; and oligomerizing the olefin in the reactor.