CAN PLASTIC WASTE PROCESSING CONTRIBUTE TO CLIMATE CHANGE MITIGATION AND CIRCULAR ECONOMY? TECHNO-ECONOMIC AND ENVIRONMENTAL ASSESSMENT OF SUSTAINABLE POLYPROPYLENE RECYCLING

86 pagesThere were 2.01 billion tons of municipal solid waste (MSW) produced globally in 2019, with numbers for 2050 projected to be 3.4 billion tons. Approximately 5-12% of the MSW currently comprises of plastic wastes, with their share rising rapidly. This increase could cause severe environmental problems if the current disposal practices continue to be adopted. Chemical recycling has the potential to not only reduce these impacts but also to contribute towards a circular economy. This study compares the environmental and economic performance of two such technologies, fast pyrolysis and gasification, with conventional disposal methods for treating polypropylene (PP) waste. High-fidelity process simulations for each technology are conducted to obtain the necessary mass, energy, and economic data for subsequent analyses. Through an extensive life cycle assessment utilizing the IPCC 2013, ReCiPe, and ILCD 2.0 methods, fast pyrolysis and gasification are determined to have lower overall greenhouse gas emissions and better overall environmental performances than the conventional methods of incineration and landfilling. The chemical recycling systems are also found to be considerably profitable with fast pyrolysis and gasification having total NPVs of $149MM and $96MM, respectively. The discount rate, waste PP price, and plant life are the most influential factors for the economic performance of both the systems