Corn stover is the non-food biomass residue from corn harvesting, approximately 80-100 million dry tons/yr produced, mainly consisting of stalks, leaves, shells, cobs, and corn. Around 70% of this residue is composed of lignocellulosic materials, namely cellulose, hemicellulose, and lignin. This underutilized material presents then significant potential as a renewable platform for the synthesis of bio-based chemicals and polymers such as polylactic acid (PLA). However, the recalcitrance of corn stover has limited its utilization for biorefinery, therefore, research on fractionation technology for lignocellulose valorization is essential for its efficient utilization. It is also important to consider current limitations of conventional procedures for lignin fractionation, such as low yields, high energy demands, inhibitory byproduct formation, and post-treatment for the neutralization of extractives.
This project aims to explore the potential of corn stover as a sustainable feedstock for fermentative processes aimed at polylactic acid (PLA) synthesis, with emphasis on pretreatment strategies to improve biomass accessibility and fermentation efficiency. It is intended to evaluate different emerging, non-conventional technologies, to selectively disrupt the lignin network while preserving carbohydrate-rich fractions, improving fermentable sugar extraction, and reducing inhibitory compounds generation.
Preliminary work has demonstrated the feasibility of fermenting hydrolysates derived from traditionally pretreated lignocellulosic materials (LM). It has also been demonstrated by leveraging technologies such as microwave radiation, minimizing the inhibitory compound formation, lignocellulosic hydrolysates can be used as carbon source (⁓25g/L glucose from LM) for lactic acid synthesis (⁓9.6g/L), considering a conversion of approximately 38% glucose to lactic acid. These results have motivated the exploration of more sustainable and efficient routes to access fermentable sugars. The present study aims to build a comparative framework for evaluating yield, energy efficiency, and process scalability across these advanced pretreatment strategies.
Although the experimental phase is currently under development, the project represents a promising platform for the integrated conversion of agro-industrial waste into lactic acid and other value-added biochemicals. By minimizing environmental impact and addressing the limitations of conventional hydrolysis methods, this work contributes to the advancement of next-generation biorefineries and the broader application of bio-based products in materials science, packaging, and biomedical sectors.