A comprehensive framework for evaluating lignin hydrothermal carbonization: Rigorous process design, life cycle assessment, and techno-economic analysis
Journal
Process Safety and Environmental Protection
Journal Volume
208
Start Page
108442
ISSN
09575820
Date Issued
2026-03-01
Author(s)
Abstract
Hydrothermal carbonization (HTC) is a promising technology for converting lignin into biochar. However, significant research gaps remain in modeling this process due to the complex reaction mechanisms, lack of reliable macroscopic kinetic models, and challenges in product identification. For the first time, this study develops a comprehensive framework to evaluate lignin HTC through rigorous modeling, covering model compound selection, reaction pathway development, thermodynamic modeling, process design and optimization, and integrated life cycle assessment (LCA) and techno-economic analysis (TEA). The LCA study underscores the critical role of impact allocation in the pretreatment of lignin. Two allocation scenarios show negative global warming potential (GWP): Scenario 1, employing mass allocation, exhibited a GWP of −2.05 kg-CO2eq/kg-biochar, while Scenario 2, utilizing benefit allocation, showed a GWP of −2.49 kg-CO2eq/kg-biochar. In contrast, Scenario 3, based on main product allocation, resulted in a net positive emission of + 1.87 kg-CO2eq/kg-biochar. In contrast, TEA determines the minimum selling price (MSP) at 1.42 USD/kg-biochar. Integrated LCA and TEA suggest that under high carbon pricing, MSP for carbon-negative scenarios could approach zero. It indicates that producing biochar for CO2 removal is likely to be profitable. Overall, this study presents an effective framework that enables comprehensive and rigorous evaluation of the HTC process of lignin.
Subjects
Biochar
Hydrothermal carbonization
Life cycle assessment
Lignin
Process design
Techno-economic analysis
Publisher
Institution of Chemical Engineers
Type
journal article