Development of novel synthetic routes and intensified processes for biomass-derived chemicals
Date
2025
Authors
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Publisher
University of Delaware
Abstract
The valorization of biomass into high-value specialty chemicals offers a promising alternative to petrochemicals but remains limited by challenges in selectivity, process efficiency, and end-product performance. This thesis addresses these limitations through catalyst development, process intensification, and product-by-design strategies. The work focuses on three core thrusts: (1) selective synthesis of oleo-furan surfactants from biomass, including a novel route that integrates plastic waste valorization; (2) development of flow-based processes for long-chain ketone production as lubricant precursors; and (3) discovery and ecological evaluation of biobased insecticides. Together, these contributions offer scalable and environmentally conscious alternatives to petroleum-based specialty chemicals. ☐ Chapter 2 focuses on replacing petroleum-derived linear alkylbenzene sulfonates (LAS) with biomass-derived analogues via cross-ketonization. A range of alkaline earth and mixed metal oxides were tested, with magnesium oxide (MgO) achieving ~90% yield by minimizing decarboxylation side reactions. Mechanistic studies reveal the role of surface complexation in directing product selectivity, and catalyst recyclability is demonstrated over multiple runs. ☐ Chapter 3 details reactor buildup targeted at debottlenecking the self ketonization of fatty acids for lubricant production, We demonstrate a solvent-free, continuous flow process for producing 12-tricosanone via self-ketonization of lauric acid. A trickle-bed reactor designed to handle high-viscosity feeds achieved 90% selectivity at industrially relevant conditions, enabling monthly production of 25 kg.Catalyst deactivation from carbonate formation was reversed by calcination, and performance was improved with mixed metal oxides. A techno-economic analysis revealed a 29% reduction in minimum selling price compared to commercial polyalphaolefins (PAOs), and life cycle assessment showed an 8.9% reduction in global warming potential under carbon-neutral assumptions. ☐ Chapter 4 explores the aldol condensation of furfural with acetone using amine-functionalized UiO-66-NH₂ metal–organic frameworks (MOFs). A C₂₁ oxygenate was synthesized in a single step, eliminating the need for fatty acid intermediates. Structural tuning of the MOF—including ligand substitution, modulator choice, and defectiveness—was systematically performed to optimize yield and product distribution, contributing to a fully cellulosic route to long-chain oxygenates. ☐ Chapters 5 through 7 outline a comprehensive platform for developing safer, scalable biobased insecticides. Chapter 5 introduces a two-step synthesis of carbamate insecticides from furfural and vanillin via Rh/Al₂O₃-catalyzed reductive amination and La(OTf)₃-catalyzed carbonylation. The furfural-based carbamate matched the potency of carbofuran (LC₅₀ = 251.25 μg/cm²), with predicted minimal ecotoxicity and bioaccumulation. Six additional aldehyde substrates were used to expand the chemical library. A techno-economic analysis revealed an MSP of $11.10/kg, half the cost of commercial equivalents. ☐ Chapter 6 implements a structure-directed molecular design strategy to accelerate bioinsecticide discovery. Using SMARTS-based molecular enumeration and pre-synthesis ecological screening (QSAR predictions for aquatic toxicity, biodegradation, and persistence), 72 candidate molecules were narrowed to 10 leads. Each molecule was synthesized in high purity from biobased sources. Experimental testing against Alphitobius diaperinus showed that ring saturation and substituent effects significantly influenced toxicity and degradability. THMFC_OMe emerged as the most potent (LC₅₀ = 0.20 mg/cm²) with a low predicted environmental footprint. ☐ Chapter 7 extends this platform to diamide and benzoylurea analogues by replacing aromatic and fluorinated cores with renewable furan motifs. These structures retained mode-of-action specificity while improving ecological safety, expanding the bioinsecticide portfolio to include modern crop protection compounds. ☐ Chapter 8 introduces a novel dual-waste valorization strategy that merges biomass and plastic waste streams. Oxygenates obtained from plasma-oxidized alkanes (derived via hydrogenolysis of low-density polyethylene) were reduced to alcohols and esterified with 2-furoic acid. Reaction conditions were optimized to suppress side reactions and maximize compatibility with real plastic waste streams. This chapter offers a new synthetic route for high-performance surfactants, reducing dependence on biobased fatty acids.
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Keywords
Biomass, Catalysis, Process intensification, Reaction engineering, Synthesis