The yield of gasoline range hydrocarbons from plastic waste pyrolysis

Abstract

ABSTRACT Plastic waste has become a serious issue that causes environmental contamination because of not degrading naturally and neglecting in the landfills over the years. Therefore, this paper deals with the experimental investigation of thermal and catalytic cracking using various types of plastics including high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) in a stainless-steel semi-batch reactor under nitrogen atmosphere at the temperatures ranging from 350 to 500°C and by varying the residence times (60, 90, and 120 min). In the catalytic cracking, the experiments were run by varying the catalyst to polymer ratios (5, 10, and 15 wt%), as well as a catalyst bed has been designed for catalytic cracking experiments. The produced liquid was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS) which revealed that the liquid produced contained mainly aromatic and paraffinic hydrocarbons that can be used as fuel. According to the experimental results, the highest liquid yield obtained from thermal cracking was 92.4 wt% using PS as feedstock at 500°C and 120 min, while the highest liquid yield obtained from catalytic cracking was 90.45 wt% using LDPE as feedstock and 5 wt% of the Ketjenfine PR.9 catalyst at 500°C and 90 min. Therefore, Ketjenfine PR.9 was found to be appropriate as a catalyst for the degradation of plastics.