Silicate Materials, Method For Their Manufacture, And Method For Using Such Silicate Materials For Adsorptive Fluid Separations

Abstract

Embodiments of crystalline, titanium silicate molecular sieves are described having a formula representing mole ratios of oxides of n M 1 O:TiO 2 :y SiO 2 :zH 2 O:wX where Mi refers to a metal cation or mixture of metal cations; n is from about 1 to about 2; y is from about 1 to about 10; z is from 0 to about 100; X is a halide anion other than fluorine, or combination of halide anions that excludes fluorine; and w is greater than 0. The pore size of the sieves can be adjusted by ion exchanging Mi cations with a suitable amount of another species. Embodiments of the invention are useful for various adsorptive fluid separation processes, including pressure swing adsorption processes. For example, disclosed embodiments are useful for separating methane from air.

1 . A crystalline titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX   
       wherein M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X is a halide anion other than fluorine, or a combination of anions excluding fluorine, and w is greater than 0. 
     
     
         2 . The titanium silicate molecular sieve according to  claim 1  wherein w is less than 1. 
     
     
         3 . The titanium silicate molecular sieve according to  claim 1  wherein w is greater than about 0.01. 
     
     
         4 . The titanium silicate molecular sieve according to  claim 1  wherein X is Cl. 
     
     
         5 . The titanium silicate molecular sieve according to  claim 1  wherein z is from about 5 to about 40. 
     
     
         6 . The titanium silicate molecular sieve according to  claim 1  wherein y is at least 2 and up to about 5. 
     
     
         7 . The titanium silicate molecular sieve according to  claim 1  wherein M 1  consists of metal cations. 
     
     
         8 . The titanium silicate molecular sieve according to  claim 7  wherein M 1  is selected from IUPAC classification Groups 1-3 metals, Group 8-12 metals, alkaline earth metals, rare earth metals, and all combinations thereof. 
     
     
         9 . The titanium silicate molecular sieve according to  claim 8  wherein M 1  comprises barium. 
     
     
         10 . The titanium silicate molecular sieve according to  claim 9  wherein M 1  additionally comprises sodium and potassium. 
     
     
         11 . The titanium silicate molecular sieve according to  claim 1  wherein the molecular sieve has a crystal structure having substantially similar lattice spacings as zorite. 
     
     
         12 . The crystalline titanium silicate molecular sieve according to  claim 11  wherein at least one peak of its XRD pattern has an intensity greater than an intensity of a peak at a d-spacing of 6.96 Å. 
     
     
         13 . The titanium silicate molecular sieve according to  claim 1  having a pore size that ranges from greater than about 2 Å to about 5 Å. 
     
     
         14 . A process for preparing the titanium silicate molecular sieve according to  claim 1 , comprising:
 providing a source of silicon, a source of titanium, a source of alkalinity, a metal salt, and a halide anion source other than fluorine, to form a composition where the mole ratio of SiO 2 /Ti is greater than about 1, H 2 O/SiO 2  is greater than about 2 and M 1 /SiO 2  is from about 0.1 to about 10; and   processing the composition at a temperature and for a period of time effective to produce the molecular sieve.   
     
     
         15 . The process according to  claim 14  further comprising performing ion exchange on the titanium silicate molecular sieve to produce an ion-exchanged titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 2 O:TiO 2 :y SiO 2 :zH 2 O:wX   
       wherein M 2  is at least one metal cation and n is from about 1 to about 2. 
     
     
         16 . The process according to  claim 15  wherein barium is exchanged for cations M 1  in the titanium silicate molecular sieve. 
     
     
         17 . The process according to  claim 16  wherein M 1  in the titanium silicate molecular sieve comprises sodium, potassium or combinations thereof. 
     
     
         18 . The process according to  claim 17  wherein M 2  in the ion-exchanged titanium silicate molecular sieve comprises barium, sodium, and/or potassium. 
     
     
         19 . The process according to  claim 15  where the source of silicon is silica, silica hydrosol, silica gel, silicic acid, alkoxides of silicon, alkali metal silicates, and mixtures thereof. 
     
     
         20 . The process according to  claim 14  wherein the metal salt is the halide anion source. 
     
     
         21 . The process according to  claim 20  where the metal salt is a Group 1 metal halide. 
     
     
         22 . The process according to  claim 21  where the Group 1 metal halide is sodium or potassium chloride, iodide, or mixtures thereof. 
     
     
         23 . The process according to  claim 22  where the Group 1 metal halide is potassium chloride, potassium iodide, or mixtures thereof. 
     
     
         24 . The process according to  claim 14  where the source of alkalinity is an alkali metal hydroxide. 
     
     
         25 . The process according to  claim 24  where the alkali metal hydroxide is a Group 1 metal hydroxide. 
     
     
         26 . The process according to  claim 25  where the alkali metal hydroxide is sodium hydroxide or potassium hydroxide. 
     
     
         27 . The process according to  claim 14  wherein the source of titanium is a titanium halide. 
     
     
         28 . The process according to  claim 27  wherein the source of titanium is TiCl 3 . 
     
     
         29 . The process according to  claim 14  where processing comprises heating within a range of from about 100° C. to about 300° C. 
     
     
         30 . The process according to  claim 29  comprising heating for a period of time ranging from about 8 hours to 40 days. 
     
     
         31 . The process according to  claim 14  further comprising processing while controlling pH values within the range of from about 10.45 to about 11.0±0.1. 
     
     
         32 . A process for adjusting the pore size of the titanium silicate molecular sieve according to  claim 1  comprising performing ion exchange on the titanium silicate molecular sieve to produce an ion-exchanged titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 2 O:TiO 2 :ySiO 2 :zH 2 O:wX   
       wherein M 2  is at least one metal cation. 
     
     
         33 . The process according to  claim 32  wherein w is greater than about 0.01. 
     
     
         34 . The process according to  claim 32  wherein X comprises Cl. 
     
     
         35 . The process according to  claim 32  wherein barium is exchanged for cations M 1  in the titanium silicate molecular sieve. 
     
     
         36 . The process according to  claim 32  wherein M 1  in the titanium silicate molecular sieve comprises sodium, potassium or combinations thereof. 
     
     
         37 . The process according to  claim 36  wherein M 2  in the ion-exchanged titanium silicate molecular sieve comprises barium, sodium, and potassium. 
     
     
         38 . A crystalline titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX   
       wherein M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X consists of halide anions other than fluorine, and w is greater than 0, and wherein the titanium silicate molecular sieve is produced by the process according to  claim 14 . 
     
     
         39 . A composition, comprising:
 a crystalline titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX 
   
       wherein M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X is a halide anion other than fluorine, or a combination of anions excluding fluorine, and w is greater than 0; and
 from greater than zero weight percent to less than one hundred percent of at least one additional material. 
 
     
     
         40 . The composition according to  claim 39  wherein the at least one additional material is an inert material, an active material, or combinations thereof. 
     
     
         41 . The composition according to  claim 39  wherein the at least one additional material is a synthetic zeolite, a naturally occurring zeolite, a desiccant, a catalyst, a clay, silica, a metal oxide, or combinations thereof. 
     
     
         42 . The composition according to  claim 39  wherein the at least one additional material is a zeolite. 
     
     
         43 . The composition according to  claim 50  wherein the at least one additional material is a catalyst. 
     
     
         44 . The composition according to  claim 41  wherein the clay is a montmorillonite or a kaolin clay. 
     
     
         45 . The composition according to  claim 41  where the clay is a sub-bentonites or kaolin commonly known as Dixie, McNamee, Georgia and Florida, or others in which the main constituent is halloysite, kaolinite, dickite, nacrite or anauxite. 
     
     
         46 . The composition according to  claim 39  wherein the at least one additional material is a porous matrix material. 
     
     
         47 . The composition according to  claim 46  wherein the porous matrix material is silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-berylia, silica-titania, as well as ternary compositions, such as silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. 
     
     
         48 . The composition according to  claim 39  comprising from greater than 1 percent to at least 90 percent titanium silicate molecular sieve by weight of the composition. 
     
     
         49 . The composition according to  claim 48  comprising from about 2 to about 50 percent titanium silicate molecular sieve by weight of the composition. 
     
     
         50 . An adsorber for use in an adsorption separation process, comprising an adsorbent comprising a titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :y SiO 2 :zH 2 O:wX   
       where M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X is a halide anion other than fluorine, or a combination of anions excluding fluorine, and w is greater than 0. 
     
     
         51 . An adsorptive fluid separation process, comprising:
 providing a titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX 
   
       where M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X is a halide anion other than fluorine, or a combination of anions excluding fluorine, and w is greater than 0; and
 contacting the titanium silicate molecular sieve with a feed fluid mixture comprising at least a first component and a second component to produce at least one product fluid enriched in the first component relative to the second component using an adsorption process. 
 
     
     
         52 . The process according to  claim 51  comprising a pressure swing separation process. 
     
     
         53 . The process according to  claim 52  comprising a rapid cycle pressure swing separation process. 
     
     
         54 . The process according to  claim 51  where the feed fluid mixture comprises nitrogen and methane, and the product fluid is enriched in methane. 
     
     
         55 . An adsorptive fluid separation process, comprising:
 providing a titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX 
   
       where M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10 1  z is from 0 to about 100, X is a halide anion other than fluorine, or a combination of anions excluding fluorine, and w is greater than 0; and
 contacting the titanium silicate molecular sieve with a feed fluid mixture comprising methane to produce at least one product fluid enriched in methane using an adsorption process. 
 
     
     
         56 . The process according to  claim 55  comprising a pressure swing separation process. 
     
     
         57 . The process according to  claim 56  comprising a rapid cycle pressure swing separation process. 
     
     
         58 . A crystalline titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX   
       wherein M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X consists of halide anions other than fluorine, and w is greater than 0, and wherein the titanium silicate molecular sieve is produced by the process according to  claim 15 . 
     
     
         59 . A crystalline titanium silicate molecular sieve having a formula representing mole ratios of oxides of
   nM 1 O:TiO 2 :ySiO 2 :zH 2 O:wX   
       wherein M 1  is at least one metal cation, n is from about 1 to about 2, y is from about 1 to about 10, z is from 0 to about 100, X consists of halide anions other than fluorine, and w is greater than 0, and wherein the titanium silicate molecular sieve is produced by the process according to  claim 32 .