Linking process-level biorefinery innovations to systems-scale sustainability

Biological conversions and catalytic upgrading offer promising pathways to sustainably manufacture biofuels and bioproducts from renewable feedstocks. Among emerging bioproducts, 3-hydroxypropionic acid (3HP), triacetic acid lactone (TAL), and succinic acid are of particular interest as platform chemicals to produce commercially important chemicals including acrylic acid, sorbic acid, and highly recyclable plastics. Despite the potential of these bioproducts to advance sustainable biomanufacturing, there has been a disconnect between fundamental advancements—e.g., in synthetic biology, strain engineering, and process scale-up—and systems-level assessments of financial viability and environmental impacts, leading to isolated studies focused on discrete sets of assumptions that offer limited insight to guide research, development, and deployment (RD&D). The goal of this dissertation was to prioritize RD&D needs for biorefinery technologies at laboratory and pilot scales by elucidating key drivers of system cost and environmental impacts under uncertainty and across technological landscapes. First, we designed, simulated, and evaluated (by techno-economic analysis, TEA, and life cycle assessment, LCA) under uncertainty biorefineries producing acrylic acid via fermentation of sugars to 3HP. By evaluating across the theoretical fermentation space (all potential combinations of fermentation titer, rate, and yield), we showed advancements in fermentation yield, titer, and saccharification solids loading could enable financially viable and environmentally beneficial acrylic acid production, and we provided a quantitative roadmap for the continued development of fermentative 3HP production. Working closely with implementation partners, we iteratively prioritized fermentation and separation RD&D needs at laboratory and pilot scales through agile system design and TEA-LCA under uncertainty. We showed our developed 3HP production pipeline was financially viable at industrial scale, with the potential for reduced life cycle carbon intensity and fossil energy consumption relative to fossil-derived acrylic acid. Next, we worked to advance bio-based TAL production from sugarcane. We experimentally characterized TAL solubility, calibrated solubility models, and designed a TAL separation process. We showed the current state-of-technology under uncertainty for biological TAL production could enable sustainable production of sorbic acid and polydiketoenamine plastics, and through this work we proposed new strategies for biorefinery separations and quantitative insights to prioritize RD&D. Leveraging this body of work, we integrated our portfolio of biorefinery models to design, simulate, and evaluate 32 biorefineries (accepting glucose, corn, sugarcane, and corn stover to produce acrylic acid, TAL, potassium sorbate, and succinic acid) across theoretical fermentation spaces under uncertainty. Through this analysis, we developed a generally applicable mathematical expression that robustly captured how fermentation performance influenced system cost. We leveraged the proposed mathematical expression to elucidate key drivers that influence the relationship between fermentation and the rest of the biorefinery’s design and performance, generating widely applicable insights. Overall, the conclusions from this dissertation illustrate how agile and robust system analyses can help screen promising biorefinery designs, elucidate salient trends, navigate sustainability tradeoffs, prioritize RD&D needs, and chart quantitative roadmaps to advance biofuels and bioproducts.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Environ Engr in Civil Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Bhagwat, Sarang Sunil

Contributors dc:contributor

• Guest, Jeremy S
• Cusick, Roland D
• Rao, Christopher V
• Huber, George W

• sustainable design
• techno-economic analysis (TEA)
• life cycle assessment (LCA)
• fermentation titer-rate-yield opportunity space
• BioSTEAM
• uncertainty analysis
• sensitivity analysis

Statement dc:rights

• Copyright 2025 Sarang Sunil Bhagwat.

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129663

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129663