Integration of Methane Reforming and Chemical Looping Technologies for Power Generation from Waste Plastic: Technical and Economic Assessment

An imperative environmental concern is escalating due to the widespread disposal of plastic waste in oceans and landfills, adversely impacting ecosystems and marine life. In this context, sustainable methods for plastic waste utilisation were evaluated, particularly for power generation. Two case studies were developed to assess the potential utilisation of waste plastic, specifically polyethylene and polypropylene, by integrating gasification with steam methane reforming (SMR) alongside two oxygen-supplying techniques for combustion including cryogenic air separation (ASU) and chemical looping combustion (CLC) for case 1 and case 2, respectively. For this, thorough process simulations of both case studies were performed to obtain detailed material and energy balances. The techno-economic analysis was performed to assess the economic performance of the processes by estimating levelized cost of electricity (LCOE). The results indicated that case 2 is more efficient (5.4%) due to the lower utility requirement of the CLC process as compared to ASU. Consequently, case 2 generated a LCOE of USD 137/MW. It was also seen from the results that the power output is directly proportional to the methane input while the increase in gasifier temperature enhances the H₂ and CO content in syngas.