Abstract
Due to the significant increasing in motorization, the long term sustainable utilization of End-of-Life Vehicles (ELV) wastes is in the focus of the waste management. In the European Union annually 8-9 Mt of ELV waste should be utilized. ELV contains mainly metals but its 15 - 20 % is plastics or rubber. According to the 2000/53/EC directive, from 1 January 2015, 95 % of the waste from vehicles have to be utilized; 85 % of the wastes by mechanical recycling and 10 % of the wastes by chemical recycling. The chemical recycling results valuable products from ELV plastic wastes, such as fuels, oil and hydrocarbon gases, which can be utilized as a feedstock for energy generation, for petrochemical processes or even in oil refinery.
Mixture of real ELV waste plastic was pyrolyzed in a one-stage and a two-stage reactor in the presence of zeolite catalysts at 425 °C in the first reactor. Different modified ZSM-5 catalysts were synthesized by wet impregnation and tested in the first reactor: H/ZSM-5, Fe(III)/ZSM-5, Ni/ZSM-5 and Cu/ZSM-5. In case of two- stage pyrolysis, Ni/Mo-Al2O3 was used in the second reactor. Due to avoid the formation of harmful by- products, the pyrolysis was taken under inert nitrogen atmosphere. The composition of gases was analysed by GC. Higher yield of gaseous products was measured using catalyst in the second reactor; furthermore the hydrogen yield was also higher. Pyrolysis oil was measured by GC, HPLC or even FTIR. Regarding pyrolysis oils, they contain non-branched, branched aliphatic hydrocarbons and aromatics compounds; and significant isomerization was concluded over catalysts.
