A cobalt-based Fischer-Tropsch catalyst, after 125 days of continuous
synthesis, was found to have retained excessive amounts of synthesis p
roducts and was not pyroforic in air. Upon resuming synthesis, unusual
reactions were observed for about 20 h. Carbon monoxide conversion wa
s quantitative. The major product was methane, with a fairly flat dist
ribution of paraffins and isoparaffins. Excessive end gas volumes and
the presence of isoparaffins suggest that hydrocracking of the waxes d
eposited in the catalyst pores may have been the major reaction. Later
, ''normal'' synthesis occurred. Catalyst activity measurements indica
ted a successful regeneration by the events.