SRU (Claus) catalyst destruction

[Ulther]

Does anybody experienced severe claus catalyst damage. I am not writing about any deactivation mechanism (e.g. sulfation, sulfur condensation, coke formation, loss of specific area due to hydrothermal conditions)wchich are pretty well described in literature. I am interested in a situation where part of catalyst beads lose their physical integrity and break into pieces. In consequecne large quantity of dust is formed, which cause plugging of pipelines and condensers. Situation leads to pressure drop build up and ultimately to SRU shut down.
What could be a reason for such catalyst destruction (except for high temperature due to sulfur burning during improper unit shut down? Maybe it is worth to mention that this did not happen immediately after catalyst replacement but after a few years of operation.
I would be really grateful for sharing your knowledge. Maybe you had similar problem in your SRU's?

 

[Jason5000]

I guess fines generation through attrition could cause this, but it seems unusual. Perhaps wetting the catalyst then heating up too fast could popcorn it, if a shutdown cycle was involved.

A colleague of mine once shared a story about an SRU so heavily sooted from burning hydrocarbon that it was impossible to even blow air through it with the blower.

 

[blacksmith37]

Not my area, but friability/strength were a factor in testing all types of catalyst base materials for reformers,desulfurizers, hydrocrackers, etc.

 

[Jason5000]

Crush strength and abrasion loss are typically reported by vendors for SRU catalysts as well.

Another thought, how are the rundown legs attached to the condensers in your SRU? The units I've worked with where the seal legs come directly out of the condenser cover plates operate fairly trouble free. However, I've been on units where the rundown legs come out of a small sump in the back end of the condenser. The condensers with the little sump were far worse about plugging up the seal legs and requiring an occasional rodding out.