1. A method for making a stabilized catalyst support comprising the following steps:
a) forming a mixture of a crystalline hydrous alumina precursor and a first portion of a structural stabilizer, wherein said crystalline hydrous alumina precursor comprises two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm;
b) drying said mixture, wherein drying comprises spray-drying;
c) low-temperature treating the dried mixture from step (b) to form a partially-stabilized support, wherein said low-temperature treating comprises exposing said dried mixture to a temperature of about 350\xb0 C. or less to substantially retain said two or more crystalline boehmites;
d) applying a second portion of said structural stabilizer to said partially-stabilized support to form a support precursor, wherein the step of applying comprises impregnation; and
e) high-temperature treating said support precursor to form a stabilized support, wherein the step of high-temperature treating comprises calcining at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure.
2. The method according to claim 1 wherein said crystalline hydrous alumina precursor comprises a colloidal suspension of said crystalline boehmites, said colloidal suspension being formed by mixing a sol or slurry comprising said two or more crystalline boehmites with an acid.
3. The method according to claim 1 wherein the step (a) of forming said mixture with said first portion of said structural stabilizer comprises mixing said crystalline hydrous alumina precursor with a colloidal suspension of an oxide of said structural stabilizer.
4. The method according to claim 1 wherein the step (d) of applying said second portion of said structural stabilizer comprises impregnating said partially-stabilized support with a colloidal suspension of an oxide of said structural stabilizer.
5. The method according to claim 1 wherein the step (d) of applying said second portion of said structural stabilizer comprises impregnating said partially-stabilized support with a structural stabilizer compound dissolved in an organic solvent.
6. The method according to claim 1 wherein said structural stabilizer comprises silicon.
7. The method according to claim 6 wherein the step (a) of forming said mixture with said first portion of said structural stabilizer comprises mixing said crystalline hydrous alumina precursor with a structural stabilizer compound comprising a tetraalkyl orthosilicate.
8. The method according to claim 6 wherein the step (d) of applying said second portion of said structural stabilizer comprises impregnating said partially-stabilized support with a structural stabilizer compound comprising a tetraalkyl orthosilicate.
9. The method according to claim 6 wherein said steps (a)-(e) are carried out to provide a support which is stabilized with said structural stabilizer comprising silicon, said stabilized support having an average pore size between about 10 nm and about 20 nm; a BET surface area between about 90 m2g support and about 180 m2g support; and a pore volume between about 0.4 ccg support and about 0.55 ccg support.
10. The method according to claim 1 wherein the step (c) of low-temperature treating comprises exposing said dried mixture to a temperature between about 250\xb0 C. and about 350\xb0 C.
11. The method according to claim 1 wherein the step (e) of high-temperature treating comprises calcining said support precursor at a temperature between about 600\xb0 C. and about 850\xb0 C.
12. The method according to claim 1 wherein said crystalline hydrous alumina precursor comprises:
a first crystalline boehmite having a first average crystallite size between about 4 nm and about 15 nm; and
a second crystalline boehmite having a second average crystallite size between about 10 nm and about 40 nm.
13. The method according to claim 1 wherein said crystalline hydrous alumina precursor is free of any aluminum alkoxide.
14. A method for making a stabilized catalyst support comprising the following steps:
incorporating two or more structural stabilizers into a crystalline hydrous alumina precursor to form a support precursor, said crystalline hydrous alumina precursor comprising two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm; and
heat treating said support precursor to form a stabilized support, wherein the step of heat treating comprises calcining at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure;
wherein the incorporating step comprises:
a) mixing said crystalline hydrous alumina precursor with a first structural stabilizer or a compound thereof to form a mixture;
b) drying the mixture from step (a) to form a dried material, wherein said drying comprises at least one spray-drying step; and
c) impregnating said dried material with a second structural stabilizer or a compound thereof to form said support precursor.
15. The method according to claim 14 wherein the step of incorporating further comprises:
low-temperature treating said dried material at a temperature of about 350\xb0 C. or less to substantially retain said two or more crystalline boehmites.
16. The method according to claim 14 wherein said first stabilizer or said second stabilizer comprises silicon, and wherein the compound of said first or second stabilizer which comprises silicon comprises a colloidal suspension of silicon oxide.
17. The method according to claim 14 wherein said first stabilizer or said second stabilizer comprises silicon, and wherein the compound of said first or second stabilizer which comprises silicon comprises a tetraalkyl orthosilicate.
18. A method for making a stabilized catalyst support comprising the following steps:
a) shaping by spray-drying a crystalline hydrous alumina precursor with a binder comprising silica, wherein said crystalline hydrous alumina precursor comprises two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm;
b) preheating the shaped crystalline hydrous alumina precursor from step (a) at a temperature of 350\xb0 C. or less to substantially retain said two or more crystalline boehmites and to form a preheated support material;
c) impregnating said preheated support material from step (b) with a structural stabilizer or compound thereof, wherein said structural stabilizer comprises silicon; and
d) calcining the impregnated material from step (c) to form a stabilized support, wherein said calcining is carried out at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure.
19. The method according to claim 18 wherein silica in said binder used in step (a) is in the form of a dried silica gel or a gelatinous silica precipitate.
20. The method according to claim 18 wherein the step (b) of preheating comprises exposing said shaped crystalline hydrous alumina precursor to a temperature between about 250\xb0 C. and about 350\xb0 C.
21. The method according to claim 18 wherein step (c) comprises impregnating the preheated support material from step (b) with a structural stabilizer compound dissolved in an organic solvent.
22. The method according to claim 18 wherein step (c) comprises impregnating the preheated support material from step (b) with a structural stabilizer compound comprising at least one of ammonium silicate, calcium silicate, tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetrahexyl orthosilicate, tetraallyl orthosilicate, silicon tetraboride, silicon tetraacetate, zirconium silicate, silicic acid, or a silica-alumina gel.
23. The method according to claim 18 wherein step (c) comprises impregnating the preheated support material from step (b) with a structural stabilizer compound comprising a tetraalkyl orthosilicate.
24. The method according to claim 18 wherein step (d) comprises calcining the impregnated material from step (c) at a temperature between about 600\xb0 C. and about 850\xb0 C.
25. The method according to claim 18 wherein the crystalline hydrous alumina precursor comprises:
a first crystalline boehmite having a first average crystallite size between about 4 nm and about 15 nm; and
a second crystalline boehmite having a second average crystallite size between about 10 nm and about 40 nm.
26. A process for producing hydrocarbons employing a catalyst supported on a stabilized support with an enhanced hydrothermal stability, comprising:
reacting a feed gas comprising carbon monoxide and hydrogen under conversion promoting conditions in the presence said catalyst supported on said stabilized support to produce hydrocarbons with 5 or more carbon atoms; wherein said stabilized support is prepared by a method comprising the following steps:
a) forming a mixture of a crystalline hydrous alumina precursor and a first portion of a structural stabilizer, wherein said crystalline hydrous alumina precursor comprises two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm;
b) drying said mixture, wherein drying comprises spray-drying;
c) low-temperature treating the dried mixture from step (b) to form a partially-stabilized support, wherein said low-temperature treating comprises exposing said dried mixture to a temperature of about 350\xb0 C. or less to substantially retain said two or more crystalline boehmites;
d) applying a second portion of said structural stabilizer to said partially-stabilized support to form a support precursor, wherein the step of applying comprises impregnation; and
e) high-temperature treating said support precursor to form a stabilized support, wherein the step of high-temperature treating comprises calcining at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure.
27. A process for producing hydrocarbons employing a catalyst supported on a stabilized support with an enhanced hydrothermal stability, comprising:
reacting a feed gas comprising carbon monoxide and hydrogen under conversion promoting conditions in the presence of said catalyst supported on said stabilized support to produce hydrocarbons with 5 or more carbon atoms; wherein said stabilized support is prepared by a method comprising the following steps:
incorporating two or more structural stabilizers into a crystalline hydrous alumina precursor to form a support precursor, said crystalline hydrous alumina precursor comprising two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm; and
heat treating said support precursor to form said stabilized support, wherein said heat treating comprises calcining at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure;
wherein the incorporating step comprises:
a) mixing a first structural stabilizer or compound thereof with said crystalline hydrous alumina precursor comprising said crystalline boehmites to form a mixture;
b) drying the mixture from step (a) to form a dried material, wherein said drying comprises at least one spray-drying step; and
c) impregnating the dried material from step (b) with a second structural stabilizer or compound thereof to form said support precursor.
28. A process for producing hydrocarbons employing a catalyst supported on a stabilized support with an enhanced hydrothermal stability, comprising:
reacting a feed gas comprising carbon monoxide and hydrogen under conversion promoting conditions in the presence of said catalyst supported on said stabilized support to produce hydrocarbons with 5 or more carbon atoms; wherein said stabilized support is prepared by a method comprising the following steps:
a) shaping by spray-drying a crystalline hydrous alumina precursor with a binder comprising silica, wherein said crystalline hydrous alumina precursor comprises two or more crystalline boehmites having different average crystallite sizes differing by at least 1 nm;
b) preheating the shaped crystalline hydrous alumina precursor from step (a) at a temperature of 350\xb0 C. or less to substantially retain said two or more crystalline boehmites and to form a preheated support material;
c) impregnating said preheated support material from step (b) with a structural stabilizer or compound thereof, wherein said structural stabilizer comprises silicon; and
d) calcining the impregnated material from step (c) to form said stabilized support, wherein said calcining is carried out at a temperature between about 450\xb0 C. and about 900\xb0 C. to effect the conversion of said two or more crystalline boehmites to a stabilized aluminum oxide structure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A toaster comprising:
a housing;
a heating chamber positioned in said housing and having a bread product receiving section;
a first movable heating element assembly on a first side of said bread product receiving section and a second movable heating element assembly on a second side of said bread product receiving section;
a carriage assembly in operable connection with said first and second movable heating element assemblies, said carriage being movable between a raised position and a lowered position, the carriage assembly further comprising:
a lever arm pivotally attached near a rear portion of said heating chamber;
a carriage plate operably attached to said lever arm adjacent a front wall of said heating chamber; and
a carriage lever operably attached to said lever arm for said movement of said carriage assembly
means for moving said first heating element assembly and said second heating element assembly in connection with a movement of said carriage assembly, each said means for moving said heating element assembly comprising a first linkage leader on a first end of said heating element assembly and a second linkage leader on a second end of said heating element assembly, said first and second linkage leaders being supported for combined movement by a linkage trailer, said carriage assembly being in operable engagement with at least one of said linkage leader and said linkage trailer for movement of at least one of said first and second heating element assemblies; and
a control interface system for controlling a function of said toaster.
2. A toaster comprising:
a housing;
a control interface system for controlling a function of the toaster;
a heating chamber positioned in said housing and having a bread product receiving section;
a first movable heating element assembly on a first side of said bread product receiving section and a second movable heating element assembly on a second side of said bread product receiving section;
a carriage assembly in operable connection with said first and second movable heating element assemblies, said carriage being movable between a raised position and a lowered position; and
means for moving said first heating element assembly and said second heating element assembly in connection with a movement of said carriage assembly, each said means for moving said heating element assembly comprising a first linkage leader on a first end of said heating element assembly and a second linkage leader on a second end of said heating element assembly, said first and second linkage leaders being supported for combined movement by a linkage trailer, said carriage assembly being in operable engagement with at least one of said linkage leader and said linkage trailer for movement of at least one of said first and second heating element assemblies, the means for moving said first heating element assembly and said second heating element assembly comprises:
a spring return operably attached to said first heating element assembly near a linkage leader and to said second heating element assembly near a linkage leader, said spring return biasing the movement of said heating element assemblies toward each other; and
wherein said carriage assembly is operably engaged with at least one of said linkage leaders and said linkage trailers for assisting in the movement of said heating element assemblies by said at least one spring return.
3. A toaster comprising:
a housing;
a heating chamber in said housing, said heating chamber having a bread product receiving section;
a first heating element assembly in said heating chamber, said first heating element assembly comprising a first heating element and a first grill;
a second heating element assembly in said heating chamber, said second heating element assembly comprising a second heating element and a second grill;
means for moving said first and second heating element assemblies laterally in said bread product receiving section, each said means for moving said heating element assembly comprising a first linkage leader on a first end of said heating element assembly and a second linkage leader on a second end of said heating element assembly, said first and second linkage leaders being supported for combined movement by a linkage trailer;
at least two spring returns operably attached to said first heating element assembly and said second heat element assembly to bias the movement of said linkage leaders and to bias the movement of the associated heating element assemblies toward a center of said bread product receiving section.
4. A toaster comprising:
a housing;
a heating chamber in said housing, said heating chamber having a bread product receiving section;
a first heating element assembly in said heating chamber, said first heating element assembly comprising a first heating element and a first grill;
a second heating element assembly in said heating chamber, said second heating element assembly comprising a second heating element and a second grill;
means for moving said first and second heating element assemblies laterally in said bread product receiving section, each said means for moving said heating element assembly comprising a first linkage leader on a first end of said heating element assembly and a second linkage leader on a second end of said heating element assembly, said first and second linkage leaders being supported for combined movement by a linkage trailer; and
a carriage assembly movable between a raised position and a lowered position, said carriage in operable engagement with at least one of said means for moving said first and second heating element assemblies, the carriage assembly comprising:
a lever arm pivotally attached near a rear portion of said heating chamber;
a carriage plate operably attached to said lever arm adjacent a front wall of said heating chamber; and
a carriage lever operably attached to said lever arm for said movement of said carriage assembly.
5. The toaster of claim 4, wherein said carriage plate further comprises a guide surface for matingly engaging a surface of said linkage leader, wherein a movement of said guide surface across said linkage leader in connection with said movement of said carriage-assembly causes a movement of said linkage leader.
6. A toaster having a moveable heating element assembly, said movable heating element assembly comprising:
a first heating element assembly having a first linkage leader on a first end of said first heating element assembly, a second linkage leader on a second end of said first heating element assembly, and supported for combined movement by a first linkage trailer;
a second heating element assembly having a first linkage leader on a first end of said second heating element assembly, a second linkage leader on a second end of said second heating element assembly, and supported for combined movement by a second linkage trailer;
a spring return operably attached to said first heating element assembly near a linkage leader and to said second heating element assembly near a linkage leader, said spring return biasing a movement of said heating element assemblies toward each other; and
a carriage assembly moveable between a raised position and a lowered position and operably engaged with at least one of said linkage leaders and said linkage trailers for assisting in the movement of said heating element assemblies by said spring return.
7. A toaster comprising:
a housing having a top face with at least one opening and a glass base, said base being interchangeable with said housing;
at least one heating chamber positioned in said housing at an angle from a horizontal surface, said at least one heating chamber being accessible through said opening and having a bread product receiving section;
a base chamber positioned between said heating chamber and said horizontal surface for supporting said heating chamber at said angle;
a heat shield at least partially covering said heating chamber, said heat shield having a top with integrally connected front and rear walls, said top having at least one opening corresponding to said opening in said housing top;
a first heating element assembly in said heating chamber, said first heating element assembly comprising a heating element and a grill;
a second heating element assembly in said heating chamber, said second heating element assembly comprising a heating element and a grill;
a first pair of linkage leaders attached to said first heating element assembly and supported for combined movement by a first linkage trailer;
a second pair of linkage leaders attached to said second heating element assembly and supported for combined movement by a second linkage trailer;
a spring return operably attached to said first heating element assembly near a linkage leader from said first pair and operably attached to said second heating element assembly near a linkage leader from said second pair, said spring return biasing the movement of said heating element assemblies toward each other;
a carriage assembly movable between a raised position and a lowered position, said carriage assembly comprising a bread rack positioned in said bread product receiving section for holding a food item thereon and comprising a slidable connection with a guide rod and a damper for absorbing at least one of noise and vibration associated with a sliding movement of said carriage along said guide rod, said carriage assembly further comprising an operable engagement with at least one of said linkage leaders and said linkage trailers for assisting in the movement of said heating element assemblies by said spring return; and
a toaster control interface on said top face of said housing, said toaster control interface comprising a concentric rotary control for shade selection surrounding a central control means for controlling a supply of power to said heating elements.