(99g) Agile Systems Analysis Framework to Assess the Sustainability Implications of Cellulosic Biorefineries Using Consolidated Bioprocessing

The current aviation industry contributes substantially to transportation-related emissions, making it a critical target for decarbonization efforts. Sustainable Aviation Fuel (SAF) is a renewable drop-in biofuel with the potential to significantly reduce the carbon footprint compared to conventional jet fuel. SAF can be produced through several ASTM-approved pathways, each with defined blending limits. Among these pathways, the alcohol-to-jet (ATJ) route offers distinct advantages, utilizing cellulosic ethanol to produce SAF blendstock, with renewable naphtha as a co-product. Previous studies found sustainable supply of ethanol is the key the feasibility of SAF. However, cellulosic ethanol biorefineries have historically experienced mixed economic outcomes, often resulting in plant closures.

A new approach has been developed by Center for Bioenergy Innovation (CBI) researchers, where cellulose biomass is configured to be directly fermented into either ethanol or isobutanol using a consolidated bioprocessing (CBP) approach. Following this approach, cellulose biomass is directly fermented into either ethanol or isobutanol using a consolidated bioprocessing (CBP) method. Clostridium thermocellum, a thermotolerant cellulolytic bacterium, is utilized to simultaneously produce enzymes, break down cellulose, and carry out fermentation within a single vessel. This integration simplifies the process while still allowing for separate processing of other biomass streams.

Past studies have assessed the economic performance of biorefineries and employed global sensitivity analysis to identify key cost drivers. Yet, there has been limited exploration of SAF-focused designs that account for strain design changes under uncertainty across all system parameters. This presentation provides an overview of the latest advancements in agile techno-economic analysis (TEA) and life cycle assessment (LCA) for CBP to produce cellulosic ethanol biorefineries. It features a case study using an agile TEA/LCA framework to simulate a consolidated bioprocessing system, with integrated global sensitivity analysis. Key factors such as inflation, commodity prices, reactant conversions, and production capacity are evaluated in TEA in relation to past biorefinery performance, underscoring the need for further model refinement in this field.