Plastic Waste Upcycling for Generation of Power and Methanol: Process Simulation and Energy–Exergy–Economic (3E) Analysis
Qiming Qian, Jingzheng Ren, Chang He
Abstract
To address the global issue of plastic waste, the waste to wealth technique is under investigation. Four processes, known as INP-CC (incineration with carbon capture and power generation), GFP-CC (gasification with carbon capture and power generation), INP-ME (incineration with methanol and power cogeneration), and GFP-ME (gasification with methanol and power cogeneration), which include both traditional and innovative methods, have undergone development, simulation, and comprehensive comparison through techno-economic analysis. GFP-CC and GFP-ME are particularly favored for their energy efficiencies of 43.47 and 34.91%, respectively, in comparison to INP-CC (17.6%) and INP-ME (6.89%). Exergy flow diagrams reveal that the incinerator, gasifier, and combustion chamber account for over 50% of the exergy loss, highlighting their potential for intensification. However, from an economic standpoint, without a larger subsidy fee ($84 per ton) or higher methanol selling price ($550 per ton), processes GFP-ME and INP-ME are not economically attractive due to a negative net present value over 20 years. A sensitivity analysis of key economic parameters demonstrates that the price of methanol and hydrogen has the greatest impact on process economic performance. It appears that process INP-ME is more resilient in terms of economic performance when subjected to the same level of fluctuations in methanol and hydrogen prices, in comparison to GFP-ME.