Lignin valorization: A crucial step towards full utilization of biomass, zero waste and circular bioeconomy

Lignin is an abundant but often overlooked biopolymer. Therefore, its valorization is crucial for achieving the goals of full biomass utilization, zero waste, and a circular bioeconomy. This study proposes a conceptual process framework for effectively valorizing lignocellulose biomass and discusses key steps towards achieving the aforementioned objectives. A holistic green one-pot pretreatment approach to lignocellulose biomass can generate both nutrient-rich hydrolysate (sugar-containing) and lignin-rich solid, which can be further converted into fuels/chemicals and biochar/bio-oil/gas, respectively. This integrated biorefinery approach represents an important strategy for developing a self-sustaining bioprocess industry, consistent with principles of green chemistry and engineering and circular economy concepts. To end with, valorization of lignin not only adds value to biomass, but also has the potential to address waste management and environmental concerns.