Dec-2021

The carbon negatives: impact of increasing carbon and coke in spent precious metals catalysts (ERTC)

There is a trend in the petroleum and petrochemical refining industry over the past five years or so as an ever-increasing percentage of carbon is being found within alumina and silica-alumina precious metals (PM) catalysts sent in for reclaim.

Bradford Cook
Sabin Metal Corporation

Article Summary

Some of the material arriving is over 40% carbon, and this has been corroborated by many PM refining companies around the world. This is most likely due to a combination of less and less in-situ pre-reclaim burning, longer process run times and/or more difficult feedstocks. The decision to delay maintenance and turnarounds during the COVID crisis has been quite common, but this high carbon issue pre-dates COVID. The issues of feedstock choice and the analysis of run-time lengths being far more technically motivated decisions, let us focus instead on the bottom line that we must all somehow address…the removal of the carbon.

Not that long ago, it was standard operating procedure for just about every precious metals catalyst user to remove the majority of the carbon, moisture, trace solvents, etc when the change-out was imminent. This was accomplished one of two ways:
a) the user would conduct their own pre-reclaim burn in-situ
b) the spent catalyst would be sent off-site to a vendor specialising in regen and thermal reduction
Unfortunately, it has now become much more common for the user to dump the spent catalyst and send it out to the PM reclaimers dirty. While we do not have detailed data from our competitors, the increase in carbon-loaded lots shipped to Sabin (those that must be kilned) is shown in Figure 1.
Remaining at or around 10% for at least six years prior to 2011, the rise to the present day is dramatic and clear: three times more carbon and coke than just a few years ago.

In-situ pre-burn and the perception of cost savings
Two petroleum customers have provided pre-reclaim burn cost case studies. Both case studies used essentially the same timeline, but for discussion purposes we have rounded the in-situ regen time up to an even 24 hours. Each unit in the study contained 200K lb of catalyst, but different products were being made, so the revenue per day varied, and therefore so did the cost:
$550K revenue per day reactor = in-situ burn at $2.75 per lb
$945K revenue per day reactor = in-situ burn at $4.73 per lb
Average: $3.74 per lb

We could get ourselves into anti-trust thin ice if we start talking about how much all the various precious metals reclaimers charge for kilning, but suffice it to say that it is way less than $3.74 per pound. It would certainly appear from the front-end view that outsourcing the carbon removal is cost-saving, as it allows a faster refinery return to production. This is probably one of the main factors driving catalyst users to choose to forego the in-situ burn, drop the dirty cat and send it off for kilning at a much lower rate. These high levels of coke, carbon, and other contaminants are creating significantly higher operating costs, storage issues, and the “carbon negatives” presented below.

Carbon negatives:
-    Increased wait times for final precious metals return:
    o Catalysts that are received clean, that is, with carbon, benzene, moisture, etc all within acceptable tolerances, proceed directly to sampling. The typical settlement time for relatively clean materials is generally three to four months.
    o The settlement time when kilning is required is at least twice that long. In some extreme cases, heavily coked catalysts (over 40% or so) require second or third runs through the kilns to reduce the carbon sufficiently. This timeframe includes waiting their turn in line for kilning and the kilning time itself.
    o For those leasing platinum or palladium, lease rates remain quite elevated and availability of metal in the market is becoming very tight. With leasing costs exceeding $1000.00 per day, the perceived carbon mitigation “savings” evaporate quickly.

- “Trapped” precious metals
    o The PGM ounces within the backlog at the kilning pinch point have been removed from market circulation for the length of the backlog.
    o Double trouble in the PGM market: the silicon carbide and tungsten added to automotive catalyst recycling has created similar issues: specialised processing is now necessary, there are only a few places that can mitigate the “contaminants”, and an untold number of PGM ounces remain trapped in inventories waiting their turn.

Call to action:
- The PGM reclaimers could continue to add kiln capacity, but that will not achieve full correction and will almost certainly mean higher pricing. If PGM reclaimers raise their kilning prices to near or the same level as the cost of in-situ pre-reclaim burning, the catalyst users will re-evaluate shipping the catalyst dirty.

- Catalyst owners must calculate the overall cost of skipping the in-situ burn and start making this process the norm again. Client companies can only realise savings by looking across a number of functional departments and areas of responsibility, so these types of decisions would have to come from a higher level of management.

- A greater sharing of information between catalyst users and precious metal refiners will help immensely to gain greater understanding of this problem, and industry forums such as the AFPM (American Fuel and Petroleum Manufacturers) and IPMI (International Precious Metals Institute) conferences would seem logical venues to do so. We encourage readers to get involved in this kind of industry stewardship and look forward to working together to achieve the “win-win”.

For more information contact: bcook@sabinmetal.com

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This short article originally appeared in the 2021 ERTC Newspapers, produced by PTQ / DigitalRefining.

You can view the Day 1 Newspaper HERE
You can view the Day 2 Newspaper HERE