ABSTRACT

Due to plastics wide range of application, its production, consumption and waste accumulation has been rising rapidly. This study describes the non-catalytic (thermal) and catalytic pyrolysis of waste polypropylene plastic into useful petroleum fractions.

A pilot scale batch pyrolyzer was used to pyrolyse waste polypropylene plastic (WPP) of 500g at thermal and catalytic conditions. The catalyst used was fluid catalytic cracking (FCC) catalyst with the percentage by weight ranging from 10-20%. The minimum and maximum set temperatures were 300⁰C and 400⁰C.Physical and chemical characterization (GC-MS) of the produced oil was also carried out.

Result showed that in the absence of catalyst (thermal condition), the process gave an oil yield of 59.16% at 380⁰C and at catalytic condition of 10wt% and 300⁰C, the oil yield was 79.85%. This shows the effectiveness of fluid catalytic cracking (FCC) catalyst in enhancing oil yield. Results of the physical characterization showed that the pyrolytic oil exhibited features of some conventional fuels: gasoline, diesel, light naphtha, medium naphtha and paraffin oil (kerosene). The chemical analysis reflected the presence of petroleum fractions with carbon numbers ranging from 13 to 20 (C₁₃-C₂₀). It further showed that the pyrolysis of waste polypropylene (WPP) plastic produces a whole spectrum of hydrocarbons including paraffins, olefin, and oxygen containing compounds.