CYCLODIMERIZATION OF BUTADIENE IN THE PRESENCE OF COPPER-CONTAINING ZEOLITE CATALYSTS

A study has been made of the cyclodimerization of butadiene (85-190 de grees C, pressure 0.1 MPa, amount of catalyst 17 cm(3), time of reacti on cycle 4.5-7.5 hr, butadiene feed rate 15-17 hr(-1)) in a flow-type reactor with a stationary catalyst bed in the presence of copper-conta ining bead catalyst Cu-TSEOKAR-10 and original ultrastable zeolite cat alysts. It has been shown that, under certain conditions in the presen ce of Cu-TSEOKAR-10, within 30-32 hr of its operation, including the s tages of activation (200 degrees C, N-2, time 2-3 hr) and reaction (14 0 degrees C, butadiene feed rate 17 hr(-1), duration of one stage 4.5- 7.5 hr), selective conversion of butadiene to target reaction products (4-vinylcyclohexene-1-ethylbenzene) can take place with a selectivity of 70-75 wt.% and a butadiene conversion of 10-12 wt.%. It was establ ished that the dealuminizing of an ultrastable Y zeolite promotes an i ncrease in the Si/Al modulus and in the activity of the catalyst. It i s shown that, at 190 degrees C with a pressure of 0.1 MPa and a butadi ene feed rate of 17 hr(-1), within 4-6 hr the selectivity with respect to the main reaction products amounts to 77-89 wt.%, with a butadiene conversion of 60-90 wt.%. A suggestion is made concerning the cause o f the change in the ratio of target products during the reaction and t he main factors affecting the activity of the catalysts studied and th e selectivity of their action. (C) 1997 Elsevier Science Ltd. All righ ts reserved.