A Superstructure-Based Lignin Valorization Process Optimization Model for Lignocellulosic Biorefineries through Biological Upgrading

This study presents an optimization framework to identify economically viable pathways for lignin valorization in biorefineries that employ biological upgrading. The economic potential for converting lignin from softwood, hardwood, and herbaceous plants into valuable bioproducts is evaluated. The research indicates that the production of 2-pyrone-4,6-dicarboxylic acid (PDC) from softwood is the most economically promising, with an estimated net present value (NPV) of $1,259 million and an internal rate of return (IRR) of 25.63%. Capital costs represent a significant portion of the total expenses across all scenarios. Revenue from woody feedstocks is largely derived from lignin-based products, while for herbaceous plants, co-products such as sugars are the main revenue contributors. The financial viability is influenced by factors such as the price and yield of the final products, the cost of feedstocks, and the capital expenses. The analysis provides strategic insights for the development of lignin valorization biorefineries and guides the chemical industry toward a more sustainable use of renewable carbon sources.