Abstract: In a process for the oligomerization of alpha olefins using a boron trifluoride/alcohol catalyst complex a method for recovering the boron trifluoride from the product stream which comprises lowering the pressure of the product stream to flash off excess boron trifluoride, mixing the boron trifluoride with fresh alcohol to form fresh boron trifluoride/alcohol catalyst complex, and introducing the fresh catalyst back into the oligomerization reactor.

Abstract: A dimer composition has an improved low temperature viscosity if it has less than a certain amount of normal paraffin. A 1-octene dimer should have less than 0.50 wt. % normal hexadecane, a 1-decene dimer should have less than 0.05 wt. % normal eicosane, a 1-dodecene dimer should have less than 0.60 wt. % normal tetracosane, and a 1-tetradecene dimer should have less than 0.10 wt. % normal octacosane.

Abstract: An oligomer is made by contacting an olefinic monomer with a catalyst comprising boron trifluoride, an alcohol alkoxylate, and a ketone. In one embodiment, the olefinic monomer is a straight-chain, .alpha.-olefinic monomer containing from 8 to 12 carbon atoms, the alcohol alkoxylate is 2-ethoxyethanol, the ketone is methyl ethyl ketone, and the oligomer product has a kinematic viscosity at 100.degree. C. of less than 1.7 cSt. Before removal of unreacted monomer, the oligomer product is at least 50 wt. % dimer, at least 80 wt. % dimer plus trimer, and less than 3.25 wt. % tetramer and greater.

Abstract: An oligomer is made by contacting a straight-chain, .alpha.-olefinic monomer with boron trifluoride and a hydroxy carbonyl promoter. The hydroxy carbonyl is preferably a .beta.-hydroxy-ketone, such as 4-hydroxy-4-methyl-2-pentanone. A second promoter can be used in conjunction with the boron trifluoride and the hydroxy carbonyl promoter. Possible secondary promoters include aldehydes, alcohols, alcohol alkoxylates, carboxylic acids, ethers, ketones, and their mixtures. Preferably the oligomer product has a kinematic viscosity at 100.degree. C. of less than 1.7 cSt; has a dimer to trimer and higher oligomer ratio of at least 1:1; and is at least 90 wt. % dimer and trimer of the monomer.

Abstract: Apparatus is provided to size finely divided catalyst particles so that all of the catalyst particles passing through the apparatus are sized so as to have a maximum particle diameter. The apparatus includes:(a) A sealed cylindrical housing having an arcuate opening cut into its lower surface,(b) A fine mesh screen which overlaps the arcuate opening cut into the cylindrical housing,(c) A hemicylindrical housing attached to the lower surface of the cylindrical housing and defining a cavity in communication with the cylindrical housing,(d) An inlet port in the top center surface of the cylindrical housing,(e) An outlet port in the bottom center surface of the hemicylindrical housing,(f) A shaft rotating axially within the cylindrical housing and having brushes attached thereto which force catalyst particles from the cylindrical housing through the screen and break down catalyst agglomerates introduced into the cylindrical housing.