Synthesis of silicoaluminophosphate molecular sieves

Abstract

In a method of synthesizing a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of an AEI framework type material and a CHA framework type material, a first synthesis mixture is prepared comprising water and sources of phosphorus, aluminum and optionally silicon. The first synthesis mixture is then heated under agitation to a first temperature to form an intermediate product mixture containing a silicoaluminophosphate or aluminophosphate precursor material. The intermediate product mixture is then cooled and stored at a second temperature lower than the first temperature, whereafter a second synthesis mixture is prepared comprising at least part of the intermediate product mixture and at least one organic directing agent. The second synthesis mixture is heated to a third temperature higher than the second temperature to convert at least part of the precursor material into the desired molecular sieve and the molecular sieve is recovered.

1 - 43 . (canceled)  
   
   
       44 . A silicoaluminophosphate molecular sieve comprising at least one intergrown phase of an AEI framework type material and a CHA framework type material, produced by: 
 (a) preparing a first synthesis mixture comprising water and sources of phosphorus, aluminum and optionally silicon;    (b) heating said first synthesis mixture under agitation to a first temperature of from about 99° C. to about 150° C. to form an intermediate product mixture containing a silicoaluminophosphate or aluminophosphate precursor material; and    (c) cooling and storing the intermediate product mixture at a second temperature less than 50° C.;    (d) preparing a second synthesis mixture comprising at least part of said intermediate product mixture from (c) and at least one organic directing agent, and, if necessary, a silicon source to provide a SiO 2 :Al 2 O 3  ratio within said second synthesis mixture of from about 0.05 to about 0.3;    (e) heating said second synthesis mixture, under static conditions or with reduced agitation in comparison with that used during heating of said first synthesis mixture, to a third temperature higher than said first temperature and from about 150° C. to about 220° C. to convert at least part of said precursor material into said molecular sieve; and    (f) recovering said molecular sieve.    
   
   
       45 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the first temperature is about 115° C. to about 125° C.  
   
   
       46 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the second temperature is about 0° C. to about 30° C.  
   
   
       47 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the third temperature is about 165° C. to about 190° C.  
   
   
       48 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the pH of the first synthesis mixture is less than 2.  
   
   
       49 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the pH of the first synthesis mixture is between about 1.1 and about 1.5.  
   
   
       50 . The silicoaluminophosphate molecular sieve  claim 44 , wherein the P 2 O 5 :Al 2 O 3  of the first synthesis mixture is between about 0.7 and about 1.0.  
   
   
       51 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the P 2 O 5 :Al 2 O 3  of the first synthesis mixture is between about 0.75 and about 0.9.  
   
   
       52 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the first synthesis mixture comprises said at least one organic directing agent.  
   
   
       53 . The silicoaluminophosphate molecular sieve of  claim 52 , wherein the second synthesis mixture has the same composition as the intermediate product mixture.  
   
   
       54 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the molar ratio of organic directing agent (R) to Al 2 O 3  in the second synthesis mixture is greater than that of the first synthesis mixture.  
   
   
       55 . The silicoaluminophosphate molecular sieve of  claim 54 , wherein the R:Al 2 O 3  molar ratio of the second synthesis mixture is greater than 0.6.  
   
   
       56 . The silicoaluminophosphate molecular sieve of  claim 54 , wherein the R:Al 2 O 3  molar ratio of the second synthesis mixture is about 0.65 to about 1.  
   
   
       57 . The silicoaluminophosphate molecular sieve of  claim 54 , wherein the R:Al 2 O 3  molar ratio of the first synthesis mixture is less than 0.7.  
   
   
       58 . The silicoaluminophosphate molecular sieve of  claim 54 , wherein the R:Al 2 O 3  molar ratio of the first synthesis mixture is about 0.2 to about 0.6.  
   
   
       59 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the H 2 O:Al 2 O 3  molar ratio of the first synthesis mixture is at least 30.  
   
   
       60 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the H 2 O:Al 2 O 3  molar ratio of the first synthesis mixture is about 30 to about 50.  
   
   
       61 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein said precursor material comprises at least one of ALPO-H3, variscite and metavariscite.  
   
   
       62 . The silicoaluminophosphate molecular sieve of  claim 44  and also comprising reducing the water content of the intermediate product mixture prior to storage thereof.  
   
   
       63 . The silicoaluminophosphate molecular sieve of  claim 62 , wherein preparing the second synthesis mixture in (d) also comprises adding water to said intermediate product mixture from (c).  
   
   
       64 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the H 2 O:Al 2 O 3  molar ratio of the second synthesis mixture is the same as that of the first synthesis mixture.  
   
   
       65 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the heating in (b) is conducted so as to raise the temperature of said first synthesis mixture at a rate of at least 8° C./hour.  
   
   
       66 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the heating in (b) is conducted so as to raise the temperature of said first synthesis mixture at a rate of from about 10° C./hour to about 40° C./hour.  
   
   
       67 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the heating (e) is conducted without agitation.  
   
   
       68 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the heating in (e) is conducted so as to raise the temperature of said first synthesis mixture at a rate of at least 8° C./hour.  
   
   
       69 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein the heating in (e) is conducted so as to raise the temperature of said first synthesis mixture at a rate of from about 10° C./hour to about 40° C./hour.  
   
   
       70 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein (c) comprises storing said cooled intermediate product mixture for at least 2 hours before the heating (e).  
   
   
       71 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein (c) comprises storing said cooled intermediate product mixture for about 30 hours to about 30 days before the heating (e).  
   
   
       72 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein said at least one intergrown phase has an AEI/CHA ratio of from about 5/95 to about 40/60 as determined by DIFFaX analysis.  
   
   
       73 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein said at least one intergrown phase has an AEI/CHA ratio of from about 10/90 to about 30/70 as determined by DIFFaX.  
   
   
       74 . The silicoaluminophosphate molecular sieve of  claim 44 , wherein said at least one intergrown phase has an AEI/CHA ratio of from about 15/95 to about 20/80 as determined by DIFFaX.  
   
   
       75 . The silicoaluminophosphate molecular sieve of  claim 72 , wherein said silicoaluminophosphate molecular sieve has an X-ray diffraction pattern comprising at least one reflection peak in each of the following ranges in the 5 to 25 (2θ) range:  
     
       
         
               
             
                   
               
                   
               
                 2θ (CuKα) 
               
                   
               
                 9.3-9.6 
               
                 12.7-13.0 
               
                 13.8-14.0 
               
                 15.9-16.1 
               
                 17.7-18.1 
               
                 18.9-19.1 
               
                 20.5-20.7 
               
                  23.7-24.0. 
               
                   
               
                   
               
           
              
              
              
              
             
             
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       76 . The silicoaluininophosphate molecular sieve of  claim 44 , wherein said silicoaluminophosphate molecular sieve comprises first and second intergrown phases each of an AEI framework type material and a CHA framework type material.  
   
   
       77 . The silicoaluminophosphate molecular sieve of  claim 76 , wherein said first intergrown phase has an AEI/CHA ratio of from about 5/95 to about 40/60 as determined by DIFFaX analysis and said second intergrown phase has a different AEI/CHA ratio from said first intergrown form.  
   
   
       78 . The silicoaluminophosphate molecular sieve of  claim 77 , wherein said second intergrown phase has an AEI/CHA ratio of about 30/70 to about 55/45 as determined by DIFFaX analysis.  
   
   
       79 . The silicoaluminophosphate molecular sieve of  claim 77 , wherein said second intergrown phase has an AEI/CHA ratio of about 50/50 as determined by DIFFaX analysis.  
   
   
       80 . A silicoaluminophosphate molecular sieve produced by the method of  claim 44 .  
   
   
       81 . A process for making an olefin product from an oxygenate feedstock comprising contacting said oxygenate feedstock with a catalyst comprising the silicoaluminophosphate molecular sieve of  claim 80 .  
   
   
       82 . The process of  claim 81 , wherein the oxygenate-containing feedstock comprises methanol, dimethyl ether, or mixtures thereof and the olefin product comprises ethylene and propylene.  
   
   
       83 . The process of  claim 81  and further comprising converting the olefin product to polymer.  
   
   
       84 . A process for making an olefin product from an oxygenate feedstock comprising contacting said oxygenate feedstock with a catalyst comprising the silicoaluminophosphate molecular sieve of  claim 44 .  
   
   
       85 . The process of  claim 84 , wherein the oxygenate-containing feedstock comprises methanol, dimethyl ether, or mixtures thereof and the olefin product comprises ethylene and propylene.  
   
   
       86 . The process of  claim 84  and further comprising converting the olefin product to polymer.