Process for preparing molecular sieve bodies
AssigneeUop LLC
InventorsWilliam H. Flank, Walter P. Fethke, Jr., Julio Marte
Life of this patent
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Abstract
A method is disclosed for preparing molecular sieves of the zeolite type, particularly A, X and Y, in massive bodies that exhibit higher crush strengths than observed for prior art massive bodies. Sized unreactive kaolin-type clay, a pore generating material, and preferably a set strength enhancing agent are mixed with water to a consistency that can be shaped into preformed bodies. In the cases of zeolites X and Y silica may be included in the mixture. These bodies are calcined, optionally aged, and digested to convert them to massive bodies containing the desired zeolite.
Claims67
A method of preparing molecular sieves of the zerolite type in massive bodies which comprises digesting in the presence of alkali metal oxide massive preformed or shaped bodies, which contain reactive clay and which are prepared from particles of non-reactive clay, in which at least fifty weight percent (50%) of the particles range in size from about 1.5 to about 15 microns, until said reactive clay is substantially converted to crystalline zeolite.
A method of preparing molecular sieves of the zeolite type in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay in which at least fifty weight percent (50%) of the particles range in size from about 1.5 to about 15 microns;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies after thermal treatment;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to:
- i. convert said non-reactive clay to a reactive form;
- and
- ii. generate substantial porosity in said shaped bodies by destroying substantially all of said pore generating material;
- and
- c. digesting in the presence of aqueous alkali metal oxide said thermally treated shaped bodies until said reaction form of clay is substantially converted to pure crystalline zeolite.
A method of preparing molecular sieves of zeolite A in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay in which at least fifty weight percent (50%) of the particles range in size from about 1.5 to about 15 microns;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies after thermal treatment;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to:
- i. convert said non-reactive clay to a reactive form;
- and
- ii. generate substantial porosity in said shaped bodies by destroying substantially all of said pore generating material;
- and
- c. digesting said thermally treated shaped bodies in an aqueous alkaline reaction medium whose overall composition, including both solid and liquid phases, may be approximately expressed in terms of mole ratio of oxides as:
- M.sub.2 O/SiO.sub.2 =0.5-1.5
- SiO.sub.2 /Al.sub.2 O.sub.3 1.6-2.2
- H.sub.2 O/M.sub.2 O=10-100
- until said reactive form of clay is substantially converted to crystalline zeolite A.
A method of preparing molecular sieves of zeolite X in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay in which at least fifty weight percent (50%) of the particles range in size from about 1.5 to about 15 microns;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies after thermal treatment;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to:
- i. convert said non-reactive clay to a reactive form;
- and
- ii. generate substantial porosity in said shaped bodies by destroying substantially all of said pore generating material;
- and
- c. digesting said thermally treated shaped bodies in an aqueous alkaline reaction medium whose overall composition, including liquid and solid phases, may be approximately expressed, in terms of mole ratio of oxides as:
- M.sub.2 O/SiO.sub.2 =0.8-1.5
- SiO.sub.2 /Al.sub.2 O.sub.3 =2.5 -5
- H.sub.2 O/M.sub.2 O=25-60
- until said reactive form of clay is substantially converted to crystalline zeolite X.
A method of preparing molecular sieves of zeolite Y in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay in which at least fifty weight percent (50%) of the particles range in size from about 1.5 to about 15 microns;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies after thermal treatment;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to:
- i. convert said non-reactive clay to a reactive form;
- and
- ii. generate substantial porosity in said shaped bodies by destroying substantially all of said pore generating material;
- and
- c. digesting said thermally treated shaped bodies in an aqueous alkaline reaction medium whose overall composition, including liquid and solid phases, may be approximately expressed, in terms of mole ratio of oxides, as:
- M.sub.2 O/SiO.sub.2 =0.3-0.6
- SiO.sub.2 /Al.sub.2 O.sub.3 =6-9
- H.sub.2 O/M.sub.2 O=35-50
- until said reactive form of clay is substantially converted to crystalline zeolite Y.
A method of preparing molecular sieves of the zeolite type in massive bodies, which method comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies during digestion, wherein said material is water soluble after the thermal treatment in step b below;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to convert said clay to a reactive form;
- and
- c. digesting said thermally treated shaped bodies in an aqueous alkaline medium under conditions of time, temperature and concentration sufficient to convert substantially all of said reactive form of clay into crystalline zeolite.
A method of preparing molecular sieves of the zeolites A, X, and Y in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay in which at least fifty weight percent (50%) of the particles range in size from about 1.5 microns to about 15 microns;
- ii. pore generating material in sufficient quantity to provide substantial porosity in said shaped bodies during digestion;
- and
- iii. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to convert said clay to a reactive form;
- and
- c. digesting said thermally treated shaped bodies in an aqueous alkaline medium whose overall composition, including both solid and liquid phases, may be approximately expressed in terms of moles of oxide by the values given in Table 1 at a temperature and for a time sufficient to convert substantially all of said reactive form of clay to crystalline zeolite.
A method of preparing molecular sieves of the zeolite type in massive bodies which comprises:
- a. forming into massive preformed or shaped bodies a mixture comprising:
- i. non-reactive clay having the general formula Al.sub.2 O.sub.3.SiO.sub.2.2-4H.sub.2 O in which at least fifty weight percent (50%) of the particles range in size from about 2 to about 10 microns;
- ii. a wet strength enhancing agent comprising an attapulgite clay whose particles are small than about one micron in size;
- iii. pore generating materials in sufficient quantity to provide substantial porosity in said shaped bodies after thermal treatment;
- and
- iv. water in sufficient quantity to provide plasticity;
- b. thermally treating said shaped bodies at a temperature and for a time sufficient to:
- i. convert said non-reactive clay to an amorphous reactive form which can be converted to crystalline aluminosilicates of the zeolite type;
- and
- ii. generate substantial porosity in said shaped bodies by destroying substantially all of said pore generating material;
- and
- c. digesting in the presence of aqueous alkali metal oxide said thermally treated shaped bodies until said reactive form of clay is substantially converted to pure crystalline zeolite.
A method according to claim 67 wherein said mixture of a. further comprises pore generating material which is water soluble after said thermal treatment and thus provides additional porosity in said shaped bodies during the digestion of c.
Dependencies are inferred from the claim text.