COMPARISON OF IN-SITU TO EX-SITU ACTIVITIES OF BITUMEN-DEACTIVATED CATALYSTS

Catalyst deactivation runs were carried out in a flow reactor using bi tumen and its maltene fraction as feeds in heptane solvent. Catalytic activity tests, using a mixture of model compounds, were performed to evaluate hydrogenation and C-N hydrogenolysis activities both directly after the aging run and again after the same aged catalyst had been p osttreated by extraction with chloroform and resulfided. Two types of carbonaceous deposits were identified on the aged catalysts. One type, deposits left on the catalyst directly after the aging run, contained relatively large amounts of polymer-like material and caused signific ant losses in catalyst surface area. Catalytic activity was best relat ed to residual, unblocked surface area and some poisoned sites. The se cond type, deposits remaining after extraction of the aged catalyst, w as typical of conventional coke and did not block any pores. Subsequen t activity tests showed activities were related to catalyst coke conte nt.