Navigating Tradeoffs Among Pretreatment Methods for Lignocellulosic Biomass of Varying Composition

With sources including grass, wood, energy crops (e.g., Miscanthus), and various agrowastes (e.g., corn stover), lignocellulosic biomass is arguably the most abundant terrestrial biomass and has attracted significant attention as a promising feedstock for the emerging bioeconomy. It is primarily composed of lignin, hemicellulose, and cellulose, which are strongly interlinked thus highly resistant to (bio)chemical conversion, requiring effective pretreatment methods to break down the recalcitrant structure and liberate individual components prior to further processing. Although a wide range of physical, chemical, physiochemical, and biological pretreatment methods have been investigated in the past decades, interactions between composition of lignocellulosic biomass and efficiency of pretreatment methods have not been examined in a quantitative and dynamic manner. In particular, several studies have recognized impacts of lignin content on pretreatment efficiency, yet no study has examined these impacts in a systematic way. This research quantitatively evaluated the impacts of lignin content on pretreatment efficiencies and categorizes prevailing pretreatment methods based on these impacts and mechanisms of the pretreatment methods. Connections between lignin content and pretreatment efficiency are incorporated into a biorefinery modeling platform where techno-economic analysis (TEA) is conducted to evaluate tradeoffs between efficiency and cost of pretreatment methods for lignocellulosic biomass of varying composition. Leveraging these results, the full spectrum of biomass composition is divided into individual zones based on the optimal pretreatment method and cost drivers for each pretreatment method are identified to prioritize future research.