SHAPED POROUS BODIES OF ALPHA-ALUMINA AND METHODS FOR THE PREPARATION THEREOF

• US 20100056816A1
• Filed: 07/20/2007
• Published: 03/04/2010
• Est. Priority Date: 11/01/2006
• Status: Abandoned Application

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Wallin, Sten A., Lakso, Steven R., Bhasin, Madan M., Serafin, Juliana G.
• Application Number:
  US12/446,127
• Publication Number:
  US 20100056816A1
• Time in Patent Office: Days
• US Class Current: 549/534
• CPC Class Codes: B01D 2325/10 Catalysts being present on the surface of the membrane or in the pores
• CPC Class Codes: B01D 67/0041 by agglomeration of particles in the dry state
• CPC Class Codes: B01D 67/0083 Thermal after-treatment
• CPC Class Codes: B01D 71/025 Aluminium oxide
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 21/12 Silica and alumina
• CPC Class Codes: B01J 23/66 Silver or gold
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• CPC Class Codes: B01J 27/055 with alkali metals, copper, gold or silver
• CPC Class Codes: B01J 27/125 with scandium, yttrium, aluminium, gallium, indium or thallium
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B01J 35/60 characterised by their surface properties or porosity
• CPC Class Codes: B01J 35/612 less than 10 m2/g
• CPC Class Codes: B01J 35/635 0.5-1.0 ml/g
• CPC Class Codes: B01J 35/653 500-1000 nm
• CPC Class Codes: B01J 35/657 larger than 1000 nm
• CPC Class Codes: B01J 35/66 Pore distribution
• CPC Class Codes: B01J 37/0009 Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: B01J 37/0203 : the impregnation liquid containing organic compounds
• CPC Class Codes: B01J 37/0207 : Pretreatment of the support
• CPC Class Codes: B01J 37/0209 : involving a reaction between the support and a fluid
• CPC Class Codes: B01J 37/26 : Fluorinating
• CPC Class Codes: C01F 7/021 : After-treatment of oxides or hydroxides
• CPC Class Codes: C01F 7/442 : in presence of a calcination additive
• CPC Class Codes: C01P 2004/03 : obtained by SEM
• CPC Class Codes: C01P 2004/20 : extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2006/14 : Pore volume
• CPC Class Codes: C01P 2006/16 : Pore diameter
• CPC Class Codes: C01P 2006/17 : Pore diameter distribution
• CPC Class Codes: C01P 2006/21 : Attrition-index or crushing strength of granulates
• CPC Class Codes: C01P 2006/80 : Compositional purity
• CPC Class Codes: C04B 2111/00793 : as filters or diaphragms
• CPC Class Codes: C04B 2111/0081 : as catalysts or catalyst carriers
• CPC Class Codes: C04B 2235/3201 : Alkali metal oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3206 : Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 : Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3218 : Aluminium (oxy)hydroxides, e.g. boehmite, gibbsite, alumina sol
• CPC Class Codes: C04B 2235/322 : Transition aluminas, e.g. delta or gamma aluminas
• CPC Class Codes: C04B 2235/3232 : Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/3248 : Zirconates or hafnates, e.g. zircon
• CPC Class Codes: C04B 2235/3409 : Boron oxide, borates, boric acids, or oxide forming salts thereof, e.g. borax
• CPC Class Codes: C04B 2235/3418 : Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3445 : Magnesium silicates, e.g. forsterite
• CPC Class Codes: C04B 2235/445 : Fluoride containing anions, e.g. fluosilicate
• CPC Class Codes: C04B 2235/5292 : Flakes, platelets or plates
• CPC Class Codes: C04B 2235/6021 : Extrusion moulding
• CPC Class Codes: C04B 2235/606 : Drying
• CPC Class Codes: C04B 2235/72 : Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/721 : Carbon content
• CPC Class Codes: C04B 2235/94 : Products characterised by their shape
• CPC Class Codes: C04B 35/111 : Fine ceramics
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4515 : application under vacuum or reduced pressure
• CPC Class Codes: C04B 41/4529 : applied from the gas phase
• CPC Class Codes: C04B 41/5011 : containing halogen in the anion
• CPC Class Codes: C04B 41/85 : with inorganic materials
• CPC Class Codes: C07D 301/10 : with catalysts containing silver or gold
• CPC Class Codes: Y02P 20/10 : Process efficiency

Abstract

This invention relates to shaped porous bodies of alpha-alumina platelets which are useful as catalyst carriers, filters, membrane reactors, and preformed bodies for composites. This invention also relates to processes of making such shaped bodies and processes for modifying the surface composition of alpha-alumina.

Claims

1. A method for making a shaped porous body comprising interlocking alpha-alumina platelets, the method comprising:

a. providing a vessel in which a total pressure can be varied and controlled;

b. introducing into the vessel a shaped precursor body which comprises at least one alpha-alumina precursor;

c. introducing into the vessel, as a fluorine-containing gas at the conditions of introduction, a fluorine-containing compound;

d. establishing a total pressure within the vessel of between about 1 torr and 100,000 torr; and

e. contacting the introduced fluorine-containing compound with at least a portion of the shaped precursor body, at one or more temperatures, for one or more pressures, for one or more time periods, sufficient to convert at least 50% of the alpha-alumina precursor to alpha-alumina platelets.

5. A method for modifying the surface composition of a shaped porous body comprising alpha-alumina platelets comprising:

a. providing a vessel;

b. providing the product of one or more of step e of claim 1 and/or 2, and/or step d of claim 3 in the vessel;

c. introducing into the vessel, as a fluorine-containing gas at the conditions of introduction, a fluorine-containing compound; and

d. contacting the introduced fluorine-containing compound with at least a portion of the surface of the alpha-alumina for one or more periods of time, and at one or more temperatures sufficient to modify the surface composition of the alpha-alumina.

14. The method of claim 1 wherein:

a. the temperature at which the fluorine-containing compound is introduced to the vessel containing the shaped precursor body is insufficient to convert the alpha-alumina precursor to alpha-alumina platelets;

b. the fluorine-containing compound-contacted, heated shaped precursor body is then heated to a second temperature for a time sufficient for the introduced fluorine-containing compound to convert at least 50% of the alpha-alumina precursor to alpha-alumina platelets.

15. The method of claim 1, further comprising removing at least a portion of the remaining fluorine-containing compound;

and

heating the product of step e under vacuum to a second temperature in the range of about 1050°

C. to about 1600°

C. for between about 1 hour and about 48 hours.

17. The method of claim 1 further comprising removing at least a portion of the remaining fluorine-containing compound;

and

introducing into the vessel, as a fluorine-containing compound at the conditions of introduction, a second fluorine-containing compound.

45. A method of increasing the crush strength of a shaped porous body comprising alpha-alumina platelets comprising the method of any one of claims 1 through 3, further comprising treating the shaped porous body comprising alpha-alumina with heat at a temperature of greater than 1000°

C. in an air atmosphere.

48. A catalyst for the production of an olefin comprising silver and one or more promoters deposited on the shaped porous bodies of claim 1, the modified alpha-alumina of claims 4 or 5, the carrier of claims 8 or 9, or the heat treated shaped porous body of claim 45.

49. A method for the production of alkylene oxide comprising contacting in a vapor phase an alkene with oxygen or an oxygen-containing gas in the presence of the catalyst of claim 48, the contacting being conducted under process conditions sufficient to produce an alkylene oxide.

50. A method for producing an ethylene glycol, an ethanol amine, or an ethylene glycol ether comprising converting the ethylene oxide produced by the process of claim 49.

2. A method for making a shaped porous body comprising interlocking alpha-alumina platelets, the method comprising:

a. providing a vessel;

b. introducing into the vessel a shaped precursor body which comprises at least one alpha-alumina precursor;

c. heating the vessel to a temperature above 700°

C.;

d. introducing into the heated vessel, as a fluorine-containing gas at the conditions of introduction, a fluorine-containing compound; and

e. contacting the introduced fluorine-containing compound with at least a portion of the shaped precursor body, at least one temperature above 700°

C., for one or more time periods, sufficient to convert at least 50% of the alpha-alumina precursor to alpha-alumina platelets.

3. A method for making a shaped porous body comprising interlocking alpha-alumina platelets, the method comprising:

a. providing a vessel;

b. introducing into the vessel a shaped precursor body which comprises at least one alpha-alumina precursor;

c. introducing into the vessel, as a fluorine-containing gas at the conditions of introduction, a fluorine-containing compound not consisting essentially of hydrogen fluoride, selected from the group consisting of (1) fluororocarbons, SiF₄, BF₃, NF₃, F₂, XeF₂, SF₆, PF₅, CF₄, CHF₃, C₂H₂F₄, and AlF₃, (2) mixtures of two or more of these gases, and (3) mixtures of HF and one or more of fluororocarbons, SiF₄, BF₃, NF₃, F₂, XeF₂, SF₆, PF₅, CF₄, CHF₃, C₂H₂F₄, and AlF₃; and

d. contacting the introduced fluorine-containing compound with at least a portion of the shaped precursor body, at one or more temperatures, and for one or more time periods, sufficient to convert at least 50% of the alpha-alumina precursor to alpha-alumina platelets.

16. The method of claim 3, further comprising removing at least a portion of the remaining fluorine-containing compound;

and

heating the product of step d under vacuum to a second temperature in the range of about 1050°

C. to about 1600°

C. for between about 1 hour and about 48 hours.

4. A method for modifying the surface composition of alpha-alumina comprising:

a. providing a vessel;

b. introducing into the vessel alpha-alumina having a surface composition;

c. introducing into the vessel, as a fluorine-containing gas at the conditions of introduction, a fluorine-containing compound; and

d. contacting the introduced fluorine-containing compound with at least a portion of the alpha-alumina for one or more periods of time, and at one or more temperatures sufficient to modify the surface composition of the alpha-alumina.

43. The method of claim 4, wherein the alpha-alumina is in the form of a shaped body.

44. The method of claim 4, wherein the alpha-alumina comprises platelets.

6. A carrier for a catalyst for the epoxidation of an olefin wherein the carrier:

(a) comprises at least 80 percent by weight alumina, and of that alumina, at least 90 percent is alpha-alumina, exclusive of modifier;

(b) has a surface area of at least 1.0 m²/g;

(c) has a porosity of at least 75 percent; and

an average flat plate crush strength of at least 1 lb/mm (0.45 kg/mm), measured as a hollow cylinder having an axial cylindrical opening the length of the cylinder, an O.D. of 0.26 inches (6.60 mm) and an I.D. of the opening of 0.1 inches (2.54 mm) and a length of 0.25 inches (6.35 mm).

7. A carrier for a catalyst for the epoxidation of an olefin wherein the carrier:

(a) comprises at least 80 percent by weight alumina, and of that alumina, at least 90 percent is alpha-alumina, exclusive of modifier;

(b) has a surface area of at least 1.0 m²/g;

(c) has a porosity of at least 70 percent and an average flat plate crush strength of at least 3.5 lb/mm (1.6 kg/mm), measured as a hollow cylinder having an axial cylindrical opening the length of the cylinder, an O.D. of 0.26 inches and an I.D. of the opening of 0.1 inches and a length of 0.25 inches.

8. Interlocking alpha-alumina platelets comprising a surface composition comprising silicon-containing species with a concentration of about 1 to about 20 atom percent silicon as measured by x-ray photo-electron spectroscopy.

9. Interlocking alpha-alumina platelets comprising a surface composition comprising boron-containing species with a concentration of about 1 to about 20 atom percent boron as measured by x-ray photo-electron spectroscopy.

10-13. -13. (canceled)

18-42. -42. (canceled)

46-47. -47. (canceled)

51-52. -52. (canceled)