Environmental and Safety Aspects of Spent Hydroprocessing Catalysts - Spent Hydroprocessing Catalysts - page 103

Figure 5.2: Summary of procedure for catalyst passivation and reactor shutdown [From ref. 323 .
Reprinted with permission].
Lassner et al. [325] summarized the actions that should be taken prior to shipment of waste
materials from refinery site. They include a series of tests to determine whether or not the
material is hazardous (e.g., toxic, corrosive, leachable, and flammable). It has been generally
observed that more analytical work was necessary to prove that spent catalyst is non-hazardous
than if it was [326] . The analysis should also indicate the presence of impurities, which could
have an adverse effect during the catalyst handling. The MSDS should be prepared for each
spent catalyst. The MSDS should list necessary precautions and emergency procedures for the
catalyst packaging and shipping.
There may be circumstances in a refinery when the fate of spent catalysts was not yet
determined and a temporary storage was necessary. Also, some refiners may store spent
catalysts on site awaiting when better treatment techniques become available. In this case,
carefully maintained storage using polypropylene super-sacks may be adequate provided that
activities, such as welding, cutting, etc., are not conducted in the proximity. In some cases,
refineries may have an access to a specially engineered landfilling comprising of separate lined
cells capped and isolated from each other and the environment [306] . Another option which
may deserve some attention involves placing metallic drums filled with spent catalyst in the
non-operating mines. But those are still only temporary solutions. Dumping spent catalyst,
although only temporary, near, and/or on the refinery site is perhaps the worst alternative.
Nevertheless, information suggests that there is a 90-day deadline for moving hazardous waste