The present invention relates to a gas/liquid oligomerization reactor with successive zones of variable diameter. The invention also relates to a process for the oligomerization of ethylene using a gas/liquid oligomerization reactor with successive zones of variable diameter.

The present invention relates to a gas/liquid oligomerization reactor with successive zones of variable diameter. The invention also relates to a process for the oligomerization of ethylene using a gas/liquid oligomerization reactor with successive zones of variable diameter.

Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

Techniques are provided for catalyst preparation. A method includes heating a mixture of one or more transition metal compounds and an oxide support or a chromium containing oxide support to a temperature or a set of temperatures that enables the a transition metal compound of the one or more transition metal compounds to sublime, melt, or thermally decompose, such that a transition metal of the one or more transition metal compounds reacts with and is deposited onto a surface of the oxide support or the chromium containing oxide support to form a catalyst, and activating the catalyst. The catalyst is configured to facilitate a reaction that produces a target inorganic material.

Techniques are provided for catalyst preparation. A method includes heating a mixture of one or more transition metal compounds and an oxide support or a chromium containing oxide support to a temperature or a set of temperatures that enables the a transition metal compound of the one or more transition metal compounds to sublime, melt, or thermally decompose, such that a transition metal of the one or more transition metal compounds reacts with and is deposited onto a surface of the oxide support or the chromium containing oxide support to form a catalyst, and activating the catalyst. The catalyst is configured to facilitate a reaction that produces a target inorganic material.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

A hydrogel comprising water, and a plurality of titanium-silica nanoparticle agglomerates, wherein each titanium-silica nanoparticle agglomerate is an agglomeration of titanium-silica nanoparticles, the agglomerates having an average titanium loading designated x with a coefficient of variation for the average titanium loading of less than about 1.0, wherein a silica content of the hydrogel is of from about 10 wt. % to about 35 wt. % based on a total weight of the hydrogel.