Mechanism of Fouling in Slurry Polymerization Reactors of Olefins

Slurry polymerization processes are used to produce high-density polyethylene of tailor-made properties. The formation of fouling in slurry reactors as well as in its peripheral equipment, such as external heat exchangers, is attributed either to the deposition of oligomers (wax) or to the buildup of electrical charge in small polymer particles. In order to understand the causes of fouling formation, samples were gathered from polymerization processes and they were characterized by microscopy in this research. The results show the existence of an aluminum-based layer as a common element in the samples analyzed. It is supposed that such a layer is formed by the reaction of trialkyl aluminum and water residues during the start-up procedure of the plant.