(576d) Integrated Life Cycle and Techno-Economic Analysis Framework for Hydrothermal Liquefaction of Municipal Waste

We developed an integrated life cycle assessment (LCA) and techno-economic analysis (TEA) framework to elucidate the sustainability implications of hydrothermal liquefaction (HTL) as a valorization technology for municipal solid waste. Component additivity models were integrated with LCA and TEA modeling to provide mechanistic links among unit operations and to perform dynamic cost and life cycle environmental impact assessments of processing various feedstock compositions at different HTL temperatures. Displacement credits were applied for co-produced biochar, terephthalic acid, and bisphenol-A. Uncertainties were characterized through Monte Carlo simulation, and global sensitivity analyses were conducted using both Spearman correlation and Morris method to identify the key drivers for economics and environmental impacts. Our results showed that the simulated municipal waste in the New York metropolitan area can be processed via HTL (at 425 °C) with global warming potential of – 0.60 ± 0.35 kg CO₂ eq. per kg feedstock processed using displacement allocation and produce gasoline – diesel blend with minimum fuel selling price of 1.48 ± 0.51 $/gallon. We also compared the HTL system with conventional waste processing scenarios to identify the suitability of feedstocks for HTL. The results indicate HTL having a potential GHG saving of 0.33 kg CO₂ per kg MSW processed when compared to the current practice.