(287g) Plastic Wastes Gasification: Versatile Metal Oxide Redox Gasification Pathways for Conversion of Post-Consumer Waste Plastics into Energy Carriers

Plastics are essential in everyday life due to their flexible properties such as strength-to-weight ratio, corrosion resistance, thermal and electrically insulating, etc. Their role is vital and irreplaceable in the food industry, aerospace, and packaging. With the increasing demand and production of plastics, the strain on the limited fossil resources is increasing, necessitating an efficient, economical, and environmentally attractive waste conversion process. The Plastic-to-Syngas (PTS) chemical looping process is a novel approach to converting post-consumer waste plastics into a value-added component. A co-current moving bed reducer reactor is implemented to partially oxidize the plastic feed, producing syngas suitable for H₂ generation and requiring no net heat input to the process. Large operating ranges allow for the co-injection of additional waste plastic species, such that they are non-chlorinated and non-fluorinated, without performance losses in the system. The iron-titanium composite metal oxide (ITCMO) oxygen carrier developed at The Ohio State University can crack the higher hydrocarbon tars in the plastic volatiles, reducing operational problems present in the traditional approach using steam gasification of plastic. Experimental results of the reducer reactor match the thermodynamic simulation, and an integrated system for the production of H₂ is presented compared to a steam gasification process. The process integration simulations show that the PTS CL system has a higher cold gas efficiency (CGE), effective thermal efficiency (ETE), and H₂ yield when compared to the steam gasification system, i.e., CGE, ETE, and H₂ yield of 67%, 93%, and 0.213kg/kg feed the CL system, compared to those of 63%, 89%, and 0.203 kg/kg feed for the steam gasification system, respectively. CO₂ is reduced by nearly 30% in the PTS CL system over that in the steam gasification system due to the CL system's ability for autothermal operation of the process, unlike the highly exothermic steam gasification process.