Supported metal oxide double active center polyethylene catalyst, process for preparing the same and use thereof

Patent metadata

Field	Value
Publication number	US-9725530-B2
Application number	US-201314395487-A
Country	US
Kind code	B2
Filing date	Apr 19, 2013
Priority date	Apr 20, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The present invention relates to a supported hybrid vanadium-chromium-based catalyst, characterized in the catalyst is supported on a porous inorganic carrier and a V active site and a inorganic Cr active site are present on the porous inorganic carrier at the same time. The present invention further relates to a process for producing a supported hybrid vanadium-chromium-based catalyst. The invention also provides the preparation method of the catalyst, titanium or fluorine compounds, vanadium salt and chromium salt according to the proportion, different methods of sequence and load on the inorganic carrier, after high temperature roasting, still can further add organic metal catalyst promoter prereduction activation treatment on it. The catalyst of the present invention can be used for producing ethylene homopolymers and ethylene/α-olefin copolymers. The hybrid vanadium-chromium-based catalyst can have high activity and produce polyethylene polymers having the properties of broad molecular weight distribution (Part of the products are bimodal distribution) and excellent α-olefin copolymerization characteristic.

First claim

The invention claimed is:

1. A supported hybrid vanadium-chromium-based catalyst, characterized in that the catalyst is supported on a porous inorganic carrier and wherein an inorganic chromium active site and vanadium active site are present on the porous inorganic carrier;
the chromium precursor and vanadium precursor are presented on the porous inorganic carrier as supported Cr/V metal oxide double active centers by one of the following processes of chemisorption or physical adsorption followed by drying and calcination at high temperature:
i) impregnating the porous inorganic carrier into a solution of the vanadium precursor, drying and calcining at 300˜900° C., and
ii) impregnating the product obtained in step i) into a solution of the chromium precursor, drying and calcining at 300˜900° C.;
or
i) impregnating the porous inorganic carrier into a solution of the chromium precursor, drying and calcining at 300˜900° C., and
ii) impregnating the product obtained in step i) into a solution of the vanadium precursor, drying and calcining at 300˜900° C.;
or
impregnating the porous inorganic carrier into a solution of the chromium and vanadium precursor, drying and calcining at 300˜900° C.

2. The catalyst according to claim 1 , wherein said porous inorganic carrier is modified with titanium and fluorine.

3. The catalyst according to claim 1 , wherein the porous inorganic carrier is selected from the group consisting of silica, alumina, titania, zirconia, magnesia, calcium oxide and inorganic clays, and combinations thereof.

4. The catalyst according to claim 1 , wherein the porous inorganic carrier has a surface area from 50 to 500 m 2 /g.

5. The catalyst according to claim 1 , wherein the porous inorganic carrier has a pore volume from 0.1 to 5.0 cm 3 /g, and an average pore diameter of 1 to 50 nm.

6. The catalyst according to claim 1 , wherein the chromium loading on the porous inorganic carrier is, based on the weight of chromium, from 0.01 to 10 wt. % of the total weight of the catalyst.

7. The catalyst according to claim 1 , wherein the ratio of the vanadium loading to the chromium loading on the carrier is 0.1 to 5 based on the weight of chromium and vanadium.

8. The catalyst according to claim 1 , wherein the vanadium loading on the porous inorganic carrier is, based on the weight of vanadium, from 0.01 to 10 wt. % of the total weight of the catalyst.

9. The catalyst according to claim 1 , wherein the chromium precursor of the chromium active site is selected from chromium trioxide, nitric acid chromium, acetic acid chromium, chromium chloride, chromium acid ammonium sulfate, ammonium dichromate and alkali type chromium acetate and combinations thereof.

10. The catalyst according to claim 1 , wherein the vanadium precursor of the V active site is selected from vanadic nitrate, vanadic phosphate, vanadic sulfate, vanadic acetate, ammonium hexafluorovanadate, vanadic acetate, vanadic nitrate, vanadyl oxalate, ammonium metavanadate, vanadyl sulfate, vanadium sulfate oxide hydrate, vanadic sulfate, vanadyl trichloride, sodium orthovanadate, sodium metavanadate, vanadyl bis (acetylacetone), vanadic triisopropoxide oxide, vanadic oxytripropoxide, vanadic acetylacetone, vanadic oxytriethoxide, vanadyl chloride, vanadic silicide, and combinations thereof.

11. The catalyst according to claim 2 , wherein the titanium loading on the porous inorganic carrier is, based on the weight of chromium, from 0.01 to 30 wt. % of the total weight of the catalyst.

12. The catalyst according to claim 2 , wherein the fluorine loading on the porous inorganic carrier is, based on the weight of fluorine, from 0.01 to 10 wt. % of the total weight of the catalyst.

13. The catalyst according to claim 2 , wherein the titanium is selected from acetylacetone titanium oxide, titanium trichloride, titanium tetrachloride, tertiary butanol titanium, tetra-n-butyl titanate, titanium oxide sulfate, titanium sulfate, ammonium hexafluorotitanate, titanium isopropoxide, tetraethyl titanate, and soluble titanium salt combinations thereof.

14. The catalyst according to claim 2 , wherein the fluorine is selected from hydrogen fluoride and fluorine gas, ammonium fluoride, ammonium fluoride, ammonium fluoride boric acid, or fluoboric acid copper, silver fluoboric acid, or fluoboric acid gold, fluosilicic acid copper, fluosilicic acid copper, silver fluosilicate, ammonium fluosilicate gold, fluoboric acid, or hexafluoride ammonium vanadate, six ammonium fluosilicate, fluoboric acid zinc, magnesium silicate fluoride, zinc fluoride silicate, sodium fluoboric acid, soluble fluoride salt or combinations thereof.

15. The catalyst according to claim 2 , wherein the porous inorganic carrier is prepared by one process selected from the following four processes:
(1) an immersion method in which a titanium compound is dissolved in solvent and reacted with and inorganic carrier, dried, then under a temperature of 300 to 900° C. undergoes calcination activation, to obtain a titanium dioxide modified inorganic carrier;
(2) a coprecipitation method in which a titanium compound and a silicate compound are reacted, dried, then under a temperature of 300 to 900° C. undergoes calcination activation, to obtain a titanium dioxide modified inorganic carrier;
(3) a sol-gel application method in which a titanium compound is mixed with water and anhydrous ethanol to undergo a hydrolysis reaction, then is further reacted with an inorganic acid and an inorganic carrier, dried, then under a temperature of 300 to 900° C. undergoes calcination activation, to obtain a titanium dioxide modified inorganic carrier; and
(4) a sol-gel application method in which a titanium compound is stirred in organic solvents, then is reacted with an inorganic acid in an acid reflux reaction, then is further reacted with an inorganic carrier, dried, then under a temperature of 300 to 900° C. undergoes calcination activation, to obtain a titanium dioxide modified inorganic carrier.

16. The catalyst according to claim 15 , wherein the silicate compound is selected from aluminum silicate, sodium silicate, ethyl silicate, magnesium silicate and calcium silicate, soluble silica salt and combinations thereof.

Assignees

• Univ East China Science & Tech

Inventors

• Cheng Ruihua
• Liu Boping
• Xue Xin
• He Yun
• Dong Xuan
• He Xuelian
• Liu Zhen
• Liu Weiwei
• Wang Lisong
• Sun Qiaoqiao

Classifications

• C08F10/02 Primary

  Ethene · CPC title

• C08F4/69

  Chromium, molybdenum, tungsten or compounds thereof · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• C08F4/22 Primary

  of chromium, molybdenum or tungsten · CPC title

• C08F4/025

  Metal oxides · CPC title