1-HEXENE OLIGOMERIZATION IN LIQUID, VAPOR, AND SUPERCRITICAL PHASES OVER BEIDELLITE AND ULTRASTABLE Y-ZEOLITE CATALYSTS

1-Hexene was oligomerized at 200 degrees C and a pressure of 5 MPa in a down-flow fixed-bed tubular reactor filled with beidellite or ultras table Y zeolite catalysts. Vapor, liquid, and supercritical states of the reacting hydrocarbons in the reactor tube were established by usin g propane, pentane, octane, and dodecane as solvents. The initial acti vity, stability with operation time, and selectivity are very dependen t on the physical state of the hydrocarbons. Highest activity and stab ility are reached in the liquid phase using octane and dodecane solven t. The chain length of the solvent has a strong influence on the deact ivation of the catalyst, on the oligomerization selectivity and on the formation of Ca saturates and cracked products. (C) 1998 Academic Pre ss.