Thermochemical Conversion of Plastic to Value Added Products
Abstract
In this study, the use of pyrolytic cracking for managing non-recyclable plastic waste by conversion into value-added liquid and gaseous products was investigated. A single-stage reactor and a novel, two-stage reactor set-up were used for experiments involving polyethylene and polypropylene. Parameters including feedstock composition, feed rate, temperature and residence time were studied. The two-stage approach was investigated to overcome existing transportation limitations involved in the typical plastic waste lifecycle. Bulky plastic collected in towns and cities must be transported to industrial facilities typically located elsewhere for reprocessing. Both HDPE and LDPE showed promising results for olefin recovery with ethylene gas yields of 26.6% and 34.1% of the original polymer, respectively. A maximum hydrogen yield over all the experiments of 46.2% which was obtained using LDPE. The economic feasibility of scaling up the processes was analyzed. It was found that the two-stage set up increased the gas yields of both hydrogen and ethylene and rendered the process to be economically viable with a payback period of 3 years.