Sustainable strategy for converting plastic waste into energy over pyrolysis: A comparative study of fluidized-bed and fixed-bed reactors

Abstract

This paper proposed a sustainable strategy for converting plastic waste into energy over pyrolysis to address the dual crises of environment and energy. A fluidized-bed reactor was designed for processing three different plastic waste (PP, LDPE and ABS). A product yield and properties from a fluidized bed system were comprehensively analyzed and compared with those from a fixed-bed system. The fluidized-bed reactor well converted ABS and PP wastes into pyrolysis fuel, exhibiting higher medium and low fraction (C5 ∼ C22 of 89.17 % for ABS) as compared to the amount from a fixed bed reactor (84.7 %) whereas LDPE and PP resulted in the similar product yields in the range of C5 ∼ C22 from both reactors. In case of LDPE, the given pyrolysis temperature (520 °C) was not feasible to properly process them into fuels so that dominant heavy oil (∼67.4 %) were produced regardless of the reactor type. GCMS analysis indicated that ABS pyrolysis oil is mainly composed of aromatics, aromatic-N and olefins whereas PP pyrolysis oil mainly includes olefins, paraffins and oxygenated compounds. From the current study, a potential use of a fluidized-bed reactor for pyrolysis was evaluated to overcome the major limitations of conventional pyrolysis process.