Techno-economic analysis of plastic wastes-based polygeneration processes

Abstract

To address the plastic waste reduction and reutilization, three designs of mixed plastic wastes-based polygeneration processes are named Designs 1–3. Designs 1 and 2 produce MeOH and electricity simultaneously by using the cryogenic air separation unit (CASU) and the vacuum pressure swing adsorption unit (VPSA), respectively. To increase the capacity of capturing CO2, the calcium looping process (CaLP) is involved in Design 3 to produce the products of H2 and CO2 and recover waste heat for power generation. The complicated CaLP dramatically increases the total costs of Design 3, although the carbon capture ratio of Design 3 is superior to other designs. If the cumulative carbon revenue is counted into the total annual income according to the emission trading scheme, the economic evaluation shows that Design 3 has a higher net present value (NPV), or a higher internal rate of return (IRR), or a shorter dynamic payback period (DPP) than other designs.