POROUS INORGANIC BODY

• US 20130231493A1
• Filed: 02/28/2013
• Published: 09/05/2013
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Shishkov, Igor, Murer, Torsten, Rosendahl, Tobias, Rohde, Wolfgang, Kraus, Martin, Gntherberg, Norbert, Baltes, Christian, Queiroz Da Fonseca, Isa Alexandra, Jochum, Alfons, Bouche, Siegbert
• Granted Patent: US 9,468,906 B2
• Time in Patent Office: Days
• US Class Current: 549/513
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 21/16 Clays or other mineral silicates
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• 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 35/56 Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0201 Impregnation
• CPC Class Codes: B01J 37/08 Heat treatment B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: C04B 2111/00129 Extrudable mixtures
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 38/0064 Multimodal pore size distribution
• CPC Class Codes: C04B 38/067 Macromolecular compounds C04B38/062 takes precedence; polysaccharides C04B38/0645
• CPC Class Codes: C04B 38/068 Carbonaceous materials, e.g. coal, carbon, graphite, hydrocarbons
• CPC Class Codes: C07D 301/00 Preparation of oxiranes
• CPC Class Codes: C07D 301/10 with catalysts containing silver or gold
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts
• CPC Class Codes: Y10T 428/131 Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]

Abstract

The present invention relates to a porous inorganic body comprising pores A having a pore size S_A in the range of from 0.005 to 20 micrometer and a total pore volume V_A, and comprising pores B having a pore size S_B in the range of from more than 20 to 1000 micrometer and a total pore volume V_B, wherein the total pore volume of the pores having a pore size in the range of from 0.005 to 1000 micrometer is V_C and wherein the ratio R_A=V_A/V_C is in the range of from 0.3 to 0.7 as determined via mercury intrusion porosimetry.

Claims

1-24. -24. (canceled)

25. A porous inorganic body comprising pores A having a pore size S_A in the range of from 0.005 to 20 micrometer and a total pore volume V_A, and comprising pores B having a pore size S_B in the range of from more than 20 to 1000 micrometer and a total pore volume V_B, wherein the total pore volume of the pores having a pore size in the range of from 0.005 to 1000 micrometer is V_C and wherein the ratio R_A=V_A/V_C is in the range of from 0.3 to 0.7 as determined via mercury intrusion porosimetry according to DIN 66133.

26. The inorganic body of claim 25, wherein RA is in the range of from 0.35 to 0.65.

27. The inorganic body of claim 25, wherein SA is in the range of from 0.1 to 20 micrometer and SB is in the range of from 100 to 1000 micrometer.

28. The inorganic body of claim 25, wherein SA is in the range of from 0.4 to 20 micrometer.

29. The inorganic body of claim 25, wherein the differential intrusion determined via mercury intrusion porosimetry according to DIN 66133 as a function of the pore size contains at least one peak in the pore size range of from 0.005 to 20 micrometer and at least one peak in the pore size range of from 20 to 1000 micrometer.

30. The inorganic body of claim 25, having a specific surface area (BET) as determined according to DIN ISO 9277 in the range of from 0.5 to 1.5 m²/g.

31. The inorganic body of claim 25, having a specific surface area (BET) as determined according to DIN ISO 9277 in the range of from 0.8 to 1.2 m²/g.

32. The inorganic body of claim 25, having a water absorption in the range of from 0.4 to 1.5 ml/g as determined according to Reference Example 1.

33. The inorganic body of claim 25, at least 95 weight-% thereof being comprised of alumina.

34. The inorganic body of claim 25, at least 99 weight-% thereof being comprised of alpha alumina.

35. The inorganic body of claim 25, comprising at least one element selected from the group consisting of alkali metals, alkaline earth metals, silicon, and iron.

36. The inorganic body of claim 25, comprising of from 200 to 750 weight-ppm of sodium, up to 600 weight-ppm, of silicon, and up to 100 weight-ppm of iron, based on the total weight of the inorganic body, calculated as element and as determined via elemental analysis.

37. The inorganic body of claim 25, having the geometry of a cylinder, having a length in the range of from 3 to 20 mm, an outer diameter in the range of from 2 to 20 mm, and a ratio of outer diameter (in mm) relative to wall thickness (in mm) in the range of from 1 to 15.

38. The inorganic body of claim 25, having the geometry of a cylinder, having a length in the range of from 5 to 10 mm, an outer diameter in the range of from 5 to 10 mm, and a ratio of outer diameter (in mm) relative to wall thickness (in mm) in the range of from 2.5 to 4.5.

39. A catalyst carrier or a catalyst which comprises the inorganic body of claim 25.

51. A method for the preparation of ethylene oxide which comprises utilizing the inorganic body according to claim 25 as a catalyst carrier.

40. A process for the preparation of a porous inorganic body, said process comprising

a) supplying a sinterable inorganic powder, preferably an alumina powder, more preferably an alpha alumina powder, at a first zone of a temperature-controllable zoned extruder comprising a die head and at least 3 zones;

b) supplying an aqueous solution comprising a binder or an aqueous suspension comprising a binder at a second zone of the zoned extruder downstream of the first zone;

c) mixing the sinterable inorganic powder and the aqueous solution or suspension in the extruder to yield a mixture;

d) heating the mixture in the zoned extruder up to a temperature of at most 200°

C. at an essentially constant volume, thereby increasing the pressure and at least partially vaporizing the water comprised in the mixture to yield a pressurized mixture;

e) expanding the pressurized mixture into a volume which is at a pressure lower than that of the pressurized mixture to yield a non-flowable intermediate body after extrusion via the die head;

f) optionally subjecting the intermediate body to a temperature of from 100°

C. to 120°

C. thereby removing remaining water from the intermediate body to yield a green body;

g) calcining the green body or the intermediate body at a temperature of from 300°

C. to 1100°

C.;

h) optionally sintering the calcined green body at a temperature higher than the calcination temperature up to at most 2000°

C. to yield the porous inorganic body;

wherein said process is preferably a continuous process.

41. The process of claim 40, wherein prior to step d), and prior to step c), at least one plasticizing agent is added.

42. The process of claim 40, wherein prior to step d), at least one pore-forming agent and/or at least one pore forming agent precursor is added.

43. The process of claim 40, wherein prior to step d), at least one surface active compound and/or at least one blowing agent precursor is added.

44. The process of claim 40, wherein the mixture heated in step d) comprises from 50 to 90 weight-% of the inorganic powder, relative to the total weight of the mixture.

45. The process of claim 44, wherein the mixture heated in step d) comprises, relative to the inorganic powder, from 2 to 20% weight-% of the at least one binder, from 0.5 to 40 weight-% of the at least one plasticizing agent, optionally from 1 to 50 weight-% of the at least one pore-forming agent, optionally from 0.5 to 10 weight-% of the at least one surface active compound, and optionally from 20 to 90 weight-% of the at least one blowing agent precursor.

46. The process of claim 40, wherein the temperature of the mixtures in the extruder zones prior to step d) is below 100°

C.

47. The process of claim 40, wherein the temperature-controllable zoned extruder is configured as a double-screw extruder.

48. The process of claim 40, wherein the dead volume of the die head of the temperature-controllable zoned extruder is at most 25 ml.

49. The process of claim 40, wherein the die head of the temperature-controllable zoned extruder is equipped with a nozzle having an output side and wherein the nozzle has a wall width at the output side of at most 1 mm.

50. An inorganic body obtained by the process according to claim 40.