Disposal of Spent Catalysts

Disposal of Spent Catalysts

The steam reforming process for ammonia requires that the catalysts be replaced after every 2 to 6 years
in service. Partial oxidation plants use typically 2 to 3 different catalysts.
Spent catalysts, also contain oxides of hexavalent chromium, zinc, iron and nickel. They are returned to
the manufacturer or other metal recovery companies. The carbon dioxide removal stage can use potassium
hydroxide solutions containing activators, aqueous amine solutions or other chemicals.

Most of the catalysts can be recycled to catalyst manufacturers or other metal handling firms for reclamation
of valuable metals. The other catalysts can be used by other companies for various purposes.
The following text is extracted from an article by Parkans International, entitled Recycling in Ammonia
Plants - A Catalyst Perspective, which was published in “Arab Fertilizer”, n° 17, January/March 1998,
Arab Fertilizer Association, Cairo.
Environment
Questions to be asked to help develop a strong, environmentally sensitive program would include:
– Does the ammonia plant management feel comfortable with the environmental impact of their recycling
company and each of the third party sites they utilize? Do they meet your internal standards as an
environmentally friendly operation?
– What types of by-products, if any, are formed from recycling and recovery of the spent catalyst? How
are they handled or disposed? Are there any recycling routes that form no by-products? Is the
recycling operation a potential “sham recycling”?
– If landfills have to be used, are the environmental impacts of the landfilled catalyst well understood?
Does the landfill meet the company’s standards; does the landfill meet “world class” standards for
construction and operation?
– Are there countries with weak environmental standards or existing large pollution problems (especially
in the third world)? Your company may not want to further burden the environmental in these areas,
or to make itself a potential future target for the inevitable search for the parties responsible for
pollution.
Liability and Risk
The following are some questions and ideas that can assist members of the fertilizer industry in developing
their corporate recycling programs to minimize such liabilities and risks:
– Do local landfill sites meet the minimum world wide standards? Are they up to par with what you
know will be required as standards soon? If not, what type of specific problems would you foresee by
continuing shipments to the disposal sites?
– When dealing with a local or foreign recycler, do you know everything about them? Financial strength,
personnel, history, operations? Is all the information before you verifiable?
– Would your company be better served by conducting a thorough audit of the disposal site or the
recycling company before any business takes place?
– Has the recycler explained clearly the procedures to be used in utilizing the spent catalyst? Do you
ask the questions: “Where, who, when, and how?” Where is our material taken; who is the actual
recycler; when will it be used; and how will it be used?
Operations
Several options are available for the plants to consider:
Option I- All inclusive catalyst handling program in which the recycling company handles the entire
catalyst removal and recycling process, beginning with catalyst removal from reactors, to oxidation,
packaging, shipment, and eventual recycling. One problem here is that logistics issues and existing
subcontracting arrangements at the plant might make this approach not feasible.

Option 2-Strictly catalyst recycling program in which the plant contracts, or uses its own personnel or
organization, to perform catalyst changeouts, oxidation, storage, and packaging, and shipment to the
recycler. This process is the standard one across the world.
Option 3-A middle ground between the first two options, in which the plant controls certain aspects of
the turnaround and catalyst handling process, and the recycler provides limited in-plant services such as
labeling, final packaging, and shipment.
Ammonia plants have significant catalyst recycling potential and all ammonia plant spent catalysts
should be recycled. The economics are favorable and all the materials are non-hazardous.
Finally, we recommend to:
– minimize the number of locations handling your spent catalyst;
– use a legitimately audited recycler,
– try to audit your recycler yourself, or be a part of a group that conducts audits on behalf of its
members,– use a recycler that operates its own facilities, has the appropriate local, regional and national permits with an excellent record of compliance, and has knowledgeable and trained personnel, adequate
financial strength and relevant insurance coverages.
– be extra careful with brokers;
– fully oxidize catalysts before shipment;
– properly pack spent catalysts in good quality containers, and ship spent catalysts as soon as reasonably
possible, and, finally;
– avoid landfills to the greatest extent possible.