Nonwoven composites and related products and processes

• US 20050042151A1
• Filed: 04/28/2004
• Published: 02/24/2005
• Est. Priority Date: 10/28/2002
• Status: Active Grant

• Current Assignee: Geo2 Technologies, Inc.
• Original Assignee: Geo2 Technologies, Inc.
• Inventors: DiChiara, Robert A. Jr., Alward, Gordon S.
• Granted Patent: US 7,550,117 B2
• Time in Patent Office: Days
• US Class Current: 422/177
• CPC Class Codes: B01D 39/2082 the material being filamentary or fibrous
• CPC Class Codes: B01D 39/2086 sintered or bonded by inorganic agents
• CPC Class Codes: B01D 46/521 using folded, pleated material
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01J 35/04 Foraminous structures, sieves, grids, honeycombs
• CPC Class Codes: B01J 35/06 Fabrics or filaments
• 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 35/58 Fabrics or filaments
• CPC Class Codes: C03C 13/00 Fibre or filament compositions manufacture of fibres or filaments C03B37/00
• CPC Class Codes: C04B 2235/5224 Alumina or aluminates
• CPC Class Codes: C04B 2235/5228 Silica and alumina, including aluminosilicates, e.g. mullite
• CPC Class Codes: C04B 2235/5232 Silica or silicates other than aluminosilicates, e.g. quartz
• CPC Class Codes: C04B 2235/5236 Zirconia
• CPC Class Codes: C04B 35/624 Sol-gel processing
• CPC Class Codes: C04B 35/6303 Inorganic additives
• CPC Class Codes: C04B 35/6316 Binders based on silicon compounds
• CPC Class Codes: D04H 1/4209 Inorganic fibres
• CPC Class Codes: F01N 2330/10 Fibrous material, e.g. mineral or metallic wool
• CPC Class Codes: F01N 2370/22 used in non-catalytic purification apparatus
• CPC Class Codes: F01N 3/0211 : Arrangements for mounting filtering elements in housing, e.g. with means for compensating thermal expansion or vibration
• CPC Class Codes: F01N 3/0226 : the structure being fibrous
• CPC Class Codes: F01N 3/027 : using electric or magnetic heating means
• CPC Class Codes: F01N 3/2013 : using electric or magnetic heating means
• CPC Class Codes: F01N 3/2835 : fibrous
• CPC Class Codes: F01N 3/2853 : using mats or gaskets between catalyst body and housing
• CPC Class Codes: F01N 3/30 : Arrangements for supply of additional air control, e.g. using by-passes or variable air pump drives, F01N3/22
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y10S 264/48 : Processes of making filters
• CPC Class Codes: Y10S 55/30 : Exhaust treatment
• CPC Class Codes: Y10T 29/49345 : Catalytic device making

Abstract

The present invention in certain embodiments is directed to a catalytic substrate suitable for use in a number of applications, including as a substrate in a catalytic converter or a particulate filter. Another aspect of the present invention is a filtering substrate suitable for use in a number of applications, including as a substrate in a particulate filter, such as a diesel particulate filter (DPF), or diesel particulate trap (DPT). The invention also provides an improved substrate for removing and/or eliminating pollutants from the exhaust of combustion engines. The catalytic substrate and filtering substrate provide, in certain embodiments, improvements in removing pollutants from an exhaust gas. The improvements include one or more of the following: faster light-off period, depth filtration of PM, less backpressure, lower probability of clogging, ability to be placed in multiple locations in the exhaust system including the manifold or the head itself, high probability of catalytic reaction, high conversion ratios of NOx, HC, and CO, a faster burnoff of PM, minimization of catalyst material use, and the like.

Claims

1-47. -47. (Cancelled).

48. A substrate for hosting a chemical reaction, said substrate comprising a nonwoven sintered refractory ceramic composite.

49. The substrate according to claim 48, wherein said composite comprises aluminaboriasilica fibers, silica fibers, and alumina fibers.

50. The substrate according to claim 48, wherein said composite comprises an alumina enhanced thermal barrier ceramic.

51. The substrate according to claim 48, wherein said composite comprises an OCTB ceramic.

52. The substrate according to claim 48, wherein said composite comprises a FRCI ceramic.

53. The substrate according to claim 48, wherein said composite comprises from about 5% to about 50% of alumina fiber.

54. The substrate according to claim 48, wherein said composite comprises from about 50% to about 90% of silica fiber.

55. The substrate according to claim 48, wherein said composite comprises from about 10% to about 25% aluminaboriasilica fibers.

56. The substrate according to claim 48, wherein said composite comprises fibers comprising Al₂O₃, SiO₂, and B₂O₃, said fibers having a melting point of from about 1600°

C. to about 2000°

C. and a refractive index of from about 1.5 to about 1.8.

57. The substrate according to claim 48, wherein said composite comprises aluminosilicate fibers and silica fibers in a ratio of about 19:

1 to about 1;

19; and

boron oxide.

58. The substrate according to claim 48, wherein said composite is prepared from amorphous silica fibers, amorphous alumina fibers, and about 2% to about 12% boron oxide.

59. The substrate according to claim 48, wherein said substrate comprises a plurality of channels.

60. The substrate according to claim 59, wherein the cell density of said channels is from about 50 to about 1000 channels per square inch.

61. The substrate according to claim 59, wherein the cell density of said channels is about 200 channels per square inch.

62. The catalytic substrate of claim 60, wherein said channels have a shape selected from the group consisting of square, triangular, and hexagonal.

63. The substrate according to claim 59, having a flow through configuration.

64. The substrate according to claim 59, having a wall-flow configuration.

65. The substrate according to claim 59, wherein the thickness of the walls of said channels is from about 2 to about 20 mils.

66. The substrate according to claim 59, wherein the density of said composite is from about 8 to about 16 pounds per cubic foot.

67. The substrate according to claim 59, further comprising one or more catalysts.

68. The substrate according to claim 67, wherein said catalyst is applied in an amount of about 5 to about 150 g/ft³.

69. The substrate according to claim 67, wherein said one or more catalysts are selected from the group consisting of an oxidation catalyst, a reduction catalyst, a two-way catalyst, a three-way catalyst, a four-way catalyst, a NOx adsorber, and mixtures thereof.

70. The substrate according to claim 67, wherein at least one catalyst is suitable for catalyzing an oxidation reaction of a hydrocarbon.

71. The substrate according to claim 67, wherein at least one catalyst is suitable for catalyzing a reduction reaction of NOx.

72. The substrate according to claim 67, wherein said one or more catalysts are selected from the group consisting of a platinum catalyst, a palladium catalyst, a rhodium catalyst, derivatives thereof, and combinations thereof.

73. The substrate according to claim 67, wherein said catalyst is selected from the group consisting of a chromium catalysts, a nickel catalyst, a rhenium catalyst, a ruthenium catalyst, a silver catalyst, an osmium catalyst, an iridium catalyst, a platinum catalyst, a magnesium catalyst, a gold catalyst, a base metal catalyst, a rare earth metal catalyst, derivatives thereof, and combinations thereof.

74. The substrate according to claim 67, wherein said substrate further comprises a coating applied to the surface of said substrate.

75. The substrate according to claim 74, wherein said coating is applied to the internal surface of said substrate.

76. The substrate according to claim 74, wherein said coating is applied to the external surface of said substrate.

77. The substrate according to claim 76, wherein said coating comprises a toughening coating.

78. The substrate according to claim 76, wherein said coating is a toughened unipiece fibrous insulation (TUFI) coating or a reaction cured glass (RCG) coating.

79. The substrate according to claim 74, wherein said coating comprises a washcoat.

80. The substrate according to claim 74, wherein said coating comprises a toughening coating and a washcoat.

81. The substrate according to claim 59, wherein said composite has a porosity of about 90% to about 99%.

82. The substrate according to claim 59, wherein said composite has a porosity of about 80% to about 90%.

83. The substrate according to claim 59, wherein said composite is selected from an alumina enhanced thermal barrier ceramic and an OCTB ceramic;

said ceramic having a density of from about 8 to about 16 pounds per cubic foot, a porosity of about 80% to about 99%, and wherein the density of said plurality of channels is from about 50 to about 1000 channels per square inch, and the thickness of the walls of said channels is from about 1 to about 20 mils.

84. The substrate according to claim 83, further comprising a catalyst.

85. The substrate according to claim 83, further comprising a coating.

86. An improved diesel particulate filter for a vehicle, wherein the improvement comprises a substrate according to claim 48.

87. The diesel particulate filter according to claim 86, wherein said vehicle is selected from the group consisting of heavy duty truck, medium duty truck, and light duty truck.

88. The diesel particulate filter according to claim 86, wherein said vehicle is a passenger automobile.

89. The diesel particulate filter according to claim 86, wherein said vehicle is selected from the group consisting of an agricultural vehicle and a construction vehicle.

90. The diesel particulate filter according to claim 86, further comprising a diesel oxidation catalyst, a NOx adsorber, or a combination thereof.

91. The diesel particulate filter according to claim 86, wherein said substrate is a wall-flow substrate comprising an alumina enhanced thermal barrier ceramic having a density of from about 8 to about 16 pounds per cubic foot, a porosity of about 80% to about 99%, and wherein the density of said plurality of channels is from about 50 to about 1000 channels per square inch.

92. A catalytic converter for use in an automobile, comprising a canister;

a matting; and

a substrate according to claim 67.

93. The catalytic converter according to claim 92, wherein said substrate further comprises a coating.

94. The catalytic converter according to claim 92, wherein said catalytic converter is a precat or a backcat.

95. A catalytic converter for use in a motorcycle, said catalytic converter comprising a canister;

a matting; and

a substrate according to claim 67.

96. The catalytic converter according to claim 95, wherein said substrate further comprises a coating.

97. An improved exhaust system for a small engine, wherein the improvement comprises a catalytic converter comprising a substrate according to claim 67.

98. The exhaust system according to claim 95, wherein said small engine is selected from the group consisting of a leaf blower engine, a trimmer engine, a brush cutter engine, a chainsaw engine, a lawn mower engine, a riding mower engine, a wood splitter engine, a snowblower engine, and a chipper engine.

105. A method of catalyzing a reaction comprising exposing a plurality of molecules to a substrate according to claim 67 in an environment suitable to catalyze said reaction.

106. The method according to claim 105, wherein said molecules are from an exhaust of an internal combustion engine.

107. The method according to claim 106, wherein said reaction comprises an oxidation reaction, a reduction reaction, or a combination thereof.

108. The method according to claim 105, wherein said substrate further comprises a coating.

109. The method according to claim 105, wherein said substrate comprises an alumina enhanced thermal barrier ceramic.

112. The method according to claim 108, wherein said substrate further comprises a plurality of channels and wherein the cell density of said channels is from about 50 to about 1000 channels per square inch.

113. The method according to claim 112, wherein the pore spaces of said substrate are heated.

114. The method according to claim 112, wherein the efficiency of said burn off is from about 70% to about 99.9%.

115. The method according to claim 114, wherein said particulate matter comprises PM-10 particulate matter, PM-2.5 particulate matter, and mixtures thereof.

116. The method according to claim 114, wherein said particulate matter is from the exhaust of an internal combustion engine.

117. The method according to claim 116, wherein said engine is a diesel engine.

118. The method according to claim 116, wherein said composite comprises an alumina enhanced thermal barrier ceramic having a density of from about 8 to about 16 pounds per cubic foot, a porosity of about 80% to about 99%, and wherein the density of said plurality of channels is from about 50 to about 1000 channels per square inch, and the thickness of the walls of said channels is from about 1 to about 20 mils.

99. A filtering substrate for filtering an exhaust of an internal combustion engine, said filtering substrate comprising a nonwoven sintered refractory ceramic composite.

100. The filtering substrate according to claim 99, wherein said composite comprises aluminaboriasilica fibers, silica fibers, and alumina fibers, wherein said filtering substrate is capable of reducing PM-10 emission from an exhaust gas by at least about 50%.

101. The filtering substrate according to claim 99, wherein said composite comprises aluminaboriasilica fibers, silica fibers, and alumina fibers, wherein said filtering substrate is capable of reducing PM-10 emission from an exhaust gas by at least about 80%.

102. The filtering substrate according to claim 99, wherein said composite comprises an alumina enhanced thermal barrier ceramic.

103. A catalytic converter substrate comprising a nonwoven sintered refractory ceramic composite, and a catalyst;

wherein said substrate has a plurality of channels, and a shape suitable for use in a catalytic converter used with an internal combustion engine.

104. The catalytic converter substrate according to claim 103, wherein said substrate comprises an alumina enhanced thermal barrier ceramic or an OCTB ceramic.

110. A method of effecting burn off of particulate matter, comprising contacting said particulate matter with a substrate for hosting a chemical reaction, said substrate comprising a nonwoven sintered refractory ceramic composite;

and exposing said substrate and said particulate matter to heat sufficient to effect said burn off of said particulate matter.

111. The method according to claim 110, wherein said heat is transferred through said composite primarily by hot gas convection.