From Principles of Polymer Systems, Sixth Edition by Ferdinand Rodriguez. Problem 5.13.

Propylene is polymerized in a slurry reactor by an equimolar mixture of aluminum triethyl and titanium tetrachloride. The catalyst residue remains with the polymer in a hydrolyzed form. If a customer specifies a maximum ash content of 0.10 weight percent in product, what productivity (moles of monomer converted per mole of catalyst) must be achieved? Assume that the ash is entirely Al2O3 and TiO2.