Gyula Deak

Hydrocarbon mixtures from waste polymer degradation

The degradation of waste polymers is one of the possible routes of utilization. Various cracking processes are suggested for different waste polymers, when long alkyl chains are degraded and transformed into lighter hydrocarbons. Yields of the liquid and gas reaction products can be increased and composition thereof can be modified by catalysts. Catalytic cracking of polyolefin waste polymers was studied in a batch reactor without and with Y, FAU (FCC), H-ZSM5 and natural clinoptilolite zeolite catalysts. The additives of the feed polymers did not significantly affect the yields and properties of the products but the type of the catalysts did. Both the gas and liquid yields increased with the catalyst concentration. The activity of the catalysts influenced the yields and the molecular weight of the volatile compounds. In the presence of catalysts both double bond and carbon chain isomerization were observed, but the latter was less significant than the former. The minimum temperature of cracking is lower with catalyst than without catalyst. The grain size of catalyst affects the yields, but less significantly the composition of products.