• Unloading contractor encountered fire due to vacuum unloading of HDS reactor. Unloading a fixed bed hydrotreater reactor is classically done under Nitrogen atmosphere in order to avoid any fire due to deposit FeS. And FeS in nearly inavoidable in older units due to corrosion in the upstream equipment. Normally avoiding any fire is ensured by putting the reactor and the unloading nozzles until the drum dedicated to the unloaded catalyst under N2.
    Sometimes it is necessary to unload the reactor from the top by vacuum (e.g. sampling of spent catalyst is needed, or there are baskets on the distributor tray).

    In that case, how the unloading company can avoid that the catalyst comes in contact with air? Can their vacuum facility be operated under N2?