Chevron Phillips Chemical Company LP

Memc Electronic Materials, Inc.

Sunedison, Inc.

Corner Star Limited

Zhihui Gu

Max P McDaniel

Anand Ramanathan

Qing R Yang

Puneet Gupta

Timothy Dinh Truong

Kathy S Clear

Eric D Schwerdtfeger

Carlos A Cruz

Ted H Cymbaluk

Jinping Joe Zhou

Ralph W Romig

James E Hein

Baisheng Zou

David W Dockter

Ryan N Rose

Taryn L Huber

Julian Abrego

Troy Bretz

Gianluca Pazzaglia

Marlon L Jordan

Ravindranath Koyyalagunta

Processes for producing activated chromium catalysts such as titanated chromium/silica catalysts are disclosed, and these processes utilize a multistep process involving exposure to inert and oxidizing atmospheres at specific temperature conditions. The resulting activated chromium catalysts have unexpectedly high melt index potential and can produce ethylene-based polymers with lower gel counts in addition to higher melt indices.

Methods of chromium catalyst activation to reduce gels and improve melt index potential

Processes for producing activated chromium catalysts such as chromium/silica catalysts and titanated chromium/silica catalysts are disclosed, and these processes utilize a multistep process involving exposure to inert and oxidizing atmospheres at specific temperature conditions. The resulting activated chromium catalysts have unexpectedly high melt index potential and can produce ethylene-based polymers with lower gel counts in addition to higher melt indices. Related activation systems are provided in which the fluidizing gas entering the fluidized bed vessel can be adjusted between an inert gas, an oxygen-containing gas, or a mixture of the inert gas and the oxygen-containing gas to minimize or prevent exotherms.

Systems and methods for chromium catalyst activation

Fluorided silica-coated alumina activator-supports have a bulk density from 0.15 to 0.37 g/mL, a total pore volume from 0.85 to 2 mL/g, a BET surface area from 200 to 500 m/g, an average pore diameter from 10 to 25 nm, and from 80 to 99% of pore volume in pores with diameters of greater than 6 nm. Methods of making the fluorided silica-coated alumina activator-supports and using the fluorided silica-coated aluminas in catalyst compositions and olefin polymerization processes also are described. Representative ethylene-based polymers produced using the compositions and processes have a melt index of 0.1 to 10 g/10 min and a density of 0.91 to 0.96 g/cm, and contain from 70 to 270 ppm solid oxide and from 2 to 18 ppm fluorine.

High porosity fluorided silica-coated alumina activator-supports and uses thereof in metallocene-based catalyst systems for olefin polymerization

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900° C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

Methods for chromium catalyst activation using oxygen-enriched fluidization gas

Methods for preparing metallocene-based catalyst compositions include the steps of contacting an alcohol compound and an organoaluminum compound for a first period of time to form a precontacted mixture, and contacting the precontacted mixture with an activator-support and a metallocene compound for a second period of time to form the catalyst composition. Such catalyst compositions can contain an activator-support, a metallocene compound, an organoaluminum compound, and a dialkyl aluminum alkoxide, and these catalyst compositions have increased catalytic activity for the polymerization of olefins.

Processes for preparing metallocene-based catalyst systems with an alcohol compound

Fluorided silica-coated alumina activator-supports have a bulk density from 0.15 to g/mL, a total pore volume from 0.85 to 2 mL/g, a BET surface area from 200 to 500 m/g, an average pore diameter from 10 to 25 nm, and from 80 to 99% of pore volume in pores with diameters of greater than 6 nm. Methods of making the fluorided silica-coated alumina activator-supports and using the fluorided silica-coated aluminas in catalyst compositions and olefin polymerization processes also are described. Representative ethylene-based polymers produced using the compositions and processes have a melt index of 0.1 to 10 g/10 min and a density of 0.91 to 0.96 g/cm, and contain from 70 to 270 ppm solid oxide and from 2 to 18 ppm fluorine.

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900&#xb0; C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

Methods for purifying a halosilane-containing process stream include a process stream purified by removing arsenic and phosphorous impurities by use of distillation.

Methods for purifying halosilane-containing streams

Processes and systems for purifying silane-containing streams and, in particular, for purifying silane-containing streams that also contain ethylene are disclosed. The processes and systems may be arranged such that one or more ethylene reactors are downstream of light-end distillation operations.

Processes and systems for purifying silane

Processes and systems for purifying silane-containing streams are disclosed with relatively less silane being lost in impurity streams by use of distillation and/or condensation operations.

Growing community of inventors

Houston, TX, United States of America

Zhihui Gu