Methods of preparation of an olefin oligomerization catalyst

Abstract

A method of making an olefin oligomerization catalyst, comprising contacting a chromium-containing compound, a heteroatomic ligand, and a metal alkyl, wherein the chromium-containing compound comprises less than about 5 weight percent chromium oligomers. A method of making an olefin oligomerization catalyst comprising a chromium-containing compound, a nitrogen-containing compound, and a metal alkyl, the method comprising adding a composition comprising the chromium-containing compound to a composition comprising the metal alkyl. A method of making an olefin oligomerization catalyst comprising a chromium-containing compound, a nitrogen-containing compound, and a metal alkyl, the method comprising abating all or a portion of water, acidic protons, or both from a composition comprising the chromium-containing compound, a composition comprising the nitrogen-containing compound, or combinations thereof prior to or during the preparation of the catalyst. Methods of oligomerizing olefins by contacting such catalysts with an alpha olefin.

1 . A method of making an olefin oligomerization catalyst, comprising contacting a chromium-containing compound, a heteroatomic ligand, and a metal alkyl, wherein the chromium-containing compound comprises less than about 5 weight percent chromium oligomers.  
   
   
       2 . The method of  claim 1  wherein the olefin oligomerization catalyst further comprises a halide containing compound.  
   
   
       3 . The method of  claim 1  wherein the chromium-containing compound comprises less than about 5 weight percent hydrated chromium species.  
   
   
       4 . The method of  claim 1  wherein the chromium-containing compound comprises less than about 50 weight percent free acid.  
   
   
       5 . The method of  1  wherein the chromium-containing compound comprises a chromium carboxylate.  
   
   
       6 . The method of  claim 5  wherein the chromium carboxylate comprises chromium(III) 2-ethylhexanoate.  
   
   
       7 . The method of  claim 1  wherein the heteroatomic ligand comprises a nitrogen-containing compound.  
   
   
       8 . The method of  claim 1  wherein the heteroatomic ligand comprises a pyrrole-containing compound.  
   
   
       9 . The method of  claim 1  wherein a composition comprising the chromium-containing compound is added to a composition comprising the metal alkyl.  
   
   
       10 . The method of  claim 1  further comprising abating all or a portion of water, acidic protons, or both from a composition comprising the chromium-containing compound, a composition comprising the heteroatomic ligand, or combinations thereof.  
   
   
       11 . The method of  claim 10  wherein the olefin oligomerization catalyst further comprises a non metal halide containing compound and the method further comprises abating all or a portion of water, acidic protons, or both from the non metal halide containing compound.  
   
   
       12 . A method of oligomerizing olefins comprising contacting the catalyst of claim 1 with an alpha olefin.  
   
   
       13 . The method of  claim 12  wherein the method of oligomerizing olefins comprises trimerizing or tetramerizing ethylene.  
   
   
       14 . A method of making an olefin oligomerization catalyst comprising a chromium-containing compound, a nitrogen-containing compound, and a metal alkyl, the method comprising adding a composition comprising the chromium-containing compound to a composition comprising the metal alkyl.  
   
   
       15 . The method of  claim 14  wherein the chromium-containing compound comprises less than about 5 weight percent chromium oligomers.  
   
   
       16 . A method of making an olefin oligomerization catalyst comprising a chromium-containing compound, a nitrogen-containing compound, and a metal alkyl, the method comprising abating all or a portion of water, acidic protons, or both from a composition comprising the chromium-containing compound, a composition comprising the nitrogen-containing compound, or combinations thereof prior to or during the preparation of the catalyst.  
   
   
       17 . The method of  claim 16  wherein the olefin oligomerization catalyst further comprises a non metal halide containing compound and the method further comprises abating all or a portion of water, acidic protons, or both from the non metal halide containing compound prior to or during the preparation of the catalyst.  
   
   
       18 . The method of  claim 16  wherein the chromium-containing compound comprises less than about 5 weight percent chromium oligomers.  
   
   
       19 . A method of making an olefin oligomerization catalyst comprising a chromium-containing compound, a heteroatomic ligand, a metal alkyl, the method comprising abating all or a portion of water, acidic protons, or both from a composition comprising the chromium-containing compound, a composition comprising the heteroatomic ligand, or combinations thereof, and wherein the heteroatomic ligand is described by the general formula (R) n A—B—C(R) m  wherein A and C are independently selected from a group consisting of phosphorus arsenic, antimony, oxygen, bismuth, sulfur, selenium, and nitrogen; B is a linking group between A and C; each R is independently selected from any homo or hetero hydrocarbyl group; and n and m are determined by the respective valence and oxidation state of A and C.  
   
   
       20 . The method of  claim 19  wherein the olefin oligomerization catalyst further comprises a non metal halide containing compound and the method further comprises abating all or a portion of water, acidic protons, or both from the non metal halide containing compound prior to or during the preparation of the catalyst.  
   
   
       21 . The method of  claim 19  wherein the chromium-containing compound comprises less than about 5 weight percent chromium oligomers.