Catalytical and thermal pyrolysis of polyolefins

Polyolefins have a high potential for alternative oil production since they contain only carbon and hydrogen atoms. By pyrolysis of these materials up to 95% can be obtained as oil and gas. Upgrading the products by catalytic cracking of polyolefins is a subject of growing interest in the last years as less energy is needed for the pyrolysis and more valuable products are formed. Numerous studies have been reported in which a variety of catalysts such as zeolites, silica-alumina, mesoporous MCM-41, solid acids and reaction conditions have been investigated. In our studies we used Lewis acids and mixtures of Ziegler–Natta catalyst such as TiCl4, AlCl3 to pyrolyse polypropylene. Experiments were carried out in a batch reactor as well as in a fluidized bed process. The pyrolysis temperature can be decreased by 100 °C compared to runs without catalysts. A drastic increase in the amount of low boiling compounds (C4 hydrocarbons) can be observed by the use of the catalysts instead of longer chained hydrocarbons.