🏭 The Column: October 31, 2025

Good morning, and Happy Halloween! Today’s edition is all about a weird line of business called catalyst “rejuvenation” (not to be confused with regeneration). It’s tied to some interesting history and I think it’s pretty cool. Let me know if you agree!

Bringing catalysts back to life

So the news here is that Axens is buying Ketjen out of their joint venture, Eurecat. That’s notable for two reasons: (a) Eurecat is one of only two companies in the world (Evonik is the other) that can rejuvenate spent hydrotreating catalysts, and (b) Ketjen (formerly Albemarle’s catalysts business) is the company that pioneered this rejuvenation technology in the first place. But the real reason I’m writing about it is because there’s some fun history behind this whole “rejuvenation” thing and I wasn’t sure if this topic would ever come up.

If you studied ChemE in undergrad, you probably learned that catalysts work by lowering the activation energy of the reaction, and that this magic occurs at actual physical sites on the surface of the catalyst—but that’s about it. It turns out that in the world of supported heterogeneous catalysis, optimizing the morphology of these surface sites is the name of the game.

For context: throughout the 20th century, hydrotreating catalysts were the workhorse for cleaning up fuels, particularly removing sulfur from diesel. They worked well enough, and could reliably get sulfur levels down to ~500 ppm. But in the early 2000s, governments introduced new regulations that mandated sulfur levels in diesel to be <10 ppm. To hit that number with the existing catalyst (referred to as “Type I”), refiners were going to need roughly 3x as much—which implies bigger reactors (CapEx!).

But fortunately some clever folks at Albemarle figured out a way for refiners to defer that CapEx and absorb the cost in OpEx instead. The key was changing the mechanism by which the metals (nickel and molybdenum) were deposited onto the support surface (alumina). Historically, metals were deposited onto the catalyst support as dissolved salts. Albemarle switched to chelated metal precursors, which allowed the metal to form longer, more active structures on the surface. That shift unlocked a step-change in activity, which meant that refiners could use their same reactors as long as they started using Albemarle’s new “Type II” catalyst.

Catalysts still age, though. Active metal sites agglomerate, migrate, and lose dispersion. So a few years after they were brought to the market, refiners started seeing activation fall, and they looked to a traditional technique for extending spent catalyst lifetime: thermal regeneration. But this basically brought the catalyst back to Type I activity, not Type II. The only way back go Type II activity was if you redispersed those metals with a chelant solution again—and thus “rejuvenation” was born, and rejuvenating catalyst became Eurecat’s core business.

Now, as to why Ketjen wants out of this business and why Axens wants more of it, I have no idea. If you have a clue, let me know. [LINK]

Other Things Happened:

Aclara Resources is separating heavy rare earth metals in Louisiana. BASF built an ammonium hydroxide plant in Germany. Celanese is divesting its electronic inks and pastes business for $500m. Elkem is curtailing its ferrosilicon production in Norway and Iceland. ExxonMobil secured permits from the EPA to sequester CO2 with injection wells near Beaumont, Texas. Sumitomo is acquiring Tanaka Chemical, a cathode material producer. Kraton will no longer make hydrogenated styrenic block copolymers at its site in Berre, France. Braskem’s board approved an ethylene and polyethylene expansion. Evonik is starting up a new fumed alumina plant in Yokkaichi, Japan. Saint-Gobain opened a new gypsum mine in British Columbia and expanded its existing mine in Florida. Venator is selling its titanium oxide site in Greatham, England. Malaysia’s first melamine plant is about to start up. BASF is starting up their new neopentyl glycol plant in Zhanjiang, China.