Process for passivating a prophoric catalyst and taking a hydrogenation reactor out of operation

Claim 1

A process for taking passivating a pyrophoric catalyst and out of operation a reactor containing said catalyst which has been used for hydrogenation of a fluid feed, in which hydrogenation the feed is passed over a catalyst consisting essentially of cobalt sulphide and/or nickel sulphide combined with molybdenum sulphide and/or tungsten sulphide or a carrier at least the greater part of which consists of silica and/or alumina in the presence of added hydrogen, said process comprising: a. When the temperature in the reactor is above 300° C reducing the temperature below 300° C; b. maintaining the temperature in said reactor below 300° C for following steps (d)-(h) until the reactor is opened; c. discontinuing the supply of feed and replacing the added hydrogen with an inert purge gas at a time which may be before, after or during said reduction in temperature; d. purging the reactor with purge gas and a hydrocarbon gas oil wherein the amount of hydrocarbon gas oil is from about 5 to about 25% of the design feed rate of the reactor; e. subsequent to step (d) introducing an oxygen-containing gas into the purge gas in a quantity such that the initial oxygen content of the purge gas is at most 1% by volume; f. circulating simultaneously said gas oil and said oxygen containing purge gas through the reactor; g. increasing gradually the oxygen content of the purge gas to the reactor until the oxygen partial pressure of the purge gas is brought to at least 0.2 kg/cm 2 , and continuing the circulation of said gas oil and said oxygen containing purge gas until no further appreciable heat generation in the reactor is found to occur, and then discontinuing said circulation and; h. opening the reactor.