Life Cycle Assessment of Catechols from Lignin Depolymerization

Abstract

Lignin is the second most abundant natural polymer on Earth. The aromatic structure of lignin makes it a promising platform for biobased chemicals. Catalytic depolymerization of lignin has been demonstrated with high yields and selectivity, resulting in efficient conversion to target products. In this study, we performed a comparative process simulation and life cycle assessment (LCA) of catechol-derived products from lignin contained in candlenut shells with those conventionally derived from petrochemical phenol. The modeled biobased production pathway includes candlenut cultivation, nutshell separation and preparation, lignin extraction and purification, catalytic depolymerization of lignin, and catalyst synthesis. Commercial-scale process modeling was done in ASPEN Plus based on experimental data, while life cycle environmental burdens were modeled using the U.S. EPA’s TRACI 2.1 impact assessment method, covering 10 categories of resource use and impact. Comparison of biobased and fossil-based results ...