Process for Preparing Carbonate and Diol Products

Abstract

A method of forming a cyclic carbonate product is carried out by reacting an alkylene oxide, such as ethylene oxide, with carbon dioxide in the presence of a metal organic framework (MOF) catalyst with less than 0.5 mol % of any potassium or quaternary ammonium salts present based on moles of alkylene oxide feed in a reaction zone under reaction conditions to form a cyclic carbonate product. The cyclic carbonate product may be optionally fed as a crude carbonate product that does not undergo any purification or separation, other than the optional removal of any portion of unreacted alkylene oxide, carbon dioxide, and light hydrocarbon gases, to a second reaction zone containing a transesterification catalyst along with an aliphatic monohydric alcohol. The cyclic carbonate product and monohydric alcohol are allowed to react under reaction conditions to form the dialkyl carbonate and diol products.

We claim: 
     
         1 . A method of forming an alkylene carbonate product comprising:
 reacting an alkylene oxide may have the Formula (1):   
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are independently from one another a —(CH 2 ) m — group, wherein m is an integer of from 1 to 3, with carbon dioxide in the presence of a metal organic framework (MOF) catalyst with less than 0.5 mol % of any potassium or quaternary ammonium salts present based on moles of ethylene oxide feed in a reaction zone under reaction conditions to form the ethylene carbonate product. 
     
     
         2 . The method of  claim 1 , wherein:
 the MOF catalyst is at least one selected from aluminum terephthalate (C 8 H 5 AlO 5 ), copper benzene-1,3,5-tricarboxylate (C 18 ,H 6 Cu 3 O 12 ), and 2-methylimidazole zinc salt (C 8 H 12 N 4 Zn).   
     
     
         3 . The method of  claim 1 , wherein:
 the MOF catalyst is used in an amount to provide a LHSV of from about 0.5 hr −1  to about 10 hr −1 .   
     
     
         4 . The method of  claim 1 , wherein:
 the reacting is conducted without the presence of a homogeneous catalyst.   
     
     
         5 . The method of  claim 1 , wherein:
 the reacting is conducted without the presence of a potassium salt or a quaternary ammonium halide salt.   
     
     
         6 . A method of forming an ethylene carbonate product comprising:
 reacting an ethylene oxide with carbon dioxide in the presence of a metal organic framework (MOF) catalyst with less than 0.5 mol % of any potassium or quaternary ammonium salts present based on moles of ethylene oxide feed in a reaction zone under reaction conditions to form the ethylene carbonate product.   
     
     
         7 . The method of  claim 6 , wherein:
 the MOF catalyst is at least one selected from aluminum terephthalate (C 8 H 5 AlO 5 ), copper benzene-1,3,5-tricarboxylate (C 18 ,H 6 Cu 3 O 12 ), and 2-methylimidazole zinc salt (C 8 H 12 N 4 Zn).   
     
     
         8 . The method of  claim 6 , wherein:
 the MOF catalyst is used in an amount to provide a LHSV of from about 0.5 hr −1  to about 10 hr −1 .   
     
     
         9 . The method of  claim 6 , wherein:
 the reacting is conducted without the presence of a homogeneous catalyst.   
     
     
         10 . The method of  claim 6 , wherein:
 the reacting is conducted without the presence of a potassium salt or a quaternary ammonium halide salt.