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Item Composition analysis of canola and intermediate wheatgrass biomass and the effects of extraction(BioResources, 2023-01) Johnsrude, Lauren M.; Scheffel, Aidan J.; Allen, Brett L.; Wettstein, Stephanie G.Knowing the composition of biomass is critical for determining accurate yields of renewable chemicals and fuels; however, nonstructural components can affect the results of standard composition procedures, leading to inaccurate reactant amounts. To remove these nonstructural components, solvent extractions can be done, but the impact on composition values has not been well-reported. For this study, compositional analysis was performed on as-received canola (Brassica napus) and intermediate wheatgrass (Thinopyrum intermedium), as well as ethanol, water, and water/ethanol extracted biomasses. Water/ethanol extraction of the intermediate wheatgrass resulted in significantly lower xylose and both acid soluble and insoluble lignin amounts when compared to the as-received analysis. Since sugar was removed during the extractions, it is recommended to use the as-received composition values for glucuronoarabinoxylans; however, the extractives may interfere with the lignin analysis and therefore, the extracted lignin values are likely more reflective of the composition.Item Influence of pretreatment, lignin extraction, and chemical modification on lignin properties and the performance of lignin-formaldehyde resins and lignin-PLA composite materials(Montana State University - Bozeman, College of Engineering, 2022) Saulnier, Brian Keith; Chairperson, Graduate Committee: David Hodge; This is a manuscript style paper that includes co-authored chapters.Bio-ethanol can be produced from lignocellulosic biomass in a biorefinery as part of a three step process, a chemical or mechanical pretreatment, enzymatic hydrolysis of the cell wall, and fermentation of these sugars to ethanol. One of the byproducts of this process is lignin, a complex biopolymer composed of a heterogeneous aromatic structure. Lignin is often burned to provide energy for the biorefinery. Incorporating lignin into higher-value products is crucial to the viability of the biorefinery process and the full utilization of the renewable carbon contained in biomass. Challenges to the inclusion of lignin in value-added products include recalcitrance of the cell wall to deconstruction and lignin extraction, heterogeneity of the lignin chemical structure, polydisperse molecular weight distributions, and low reactivity. In this thesis we address these challenges by using feedstock selection, selection of pretreatment and lignin extraction process conditions, lignin fractional precipitation, and direct chemical modification of lignin. Chapter 1 provides an overall introduction and background of previous work. Chapter 2 uses a diverse panel of corn stover genotypes subjected to dilute acid pretreatment using a variety of process conditions. The response of the biomass to pretreatment was characterized with special attention given to glucose hydrolysis yields and p-coumarate (pCA) content. Chapter 3 uses a single corn stover source pretreated using a variety of dilute acid conditions followed by two different lignin extraction methods. The influence of pretreatment and lignin extraction conditions on lignin properties was characterized with focus on lignin pCA content. This study found that lignin-formaldehyde resins using lignin from optimized process conditions achieved lap shear strengths higher than conventional phenol-formaldehyde resins. Chapter 4 addresses lignin polydispersity and heterogeneity using the fractional precipitation of lignin from formic acid liquors to obtain differing molecular weight lignin fractions while allowing for successful enzymatic hydrolysis of cellulose. Chapter 5 uses fractional precipitation of corn stover alkali liquors along with modification using propylene carbonate to obtain a panel of multi-component biopolymer fractions for manufacture of biopolymer-PLA composite materials. These materials were fully characterized finding materials made with modified biopolymers exhibited better lignin dispersion, and improved thermal and mechanical properties.Item Conversion of biomass sugars to platform chemicals by homogeneous acid catalyst in organic water mixtures(Montana State University - Bozeman, College of Engineering, 2022) Scheffel, Aidan James; Chairperson, Graduate Committee: Stephanie Wettstein; This is a manuscript style paper that includes co-authored chapters.Lignocellulosic biomass could serve as an alternative to petroleum for the production of platform chemicals that can be upgraded to bio-based plastics, chemicals, and fuels. The polysaccharides present in the cellular structure of biomass can be hydrolyzed into common sugars, which can be further reacted into important chemical intermediates such as furfural, 5-hydroxymethylfurfural, and levulinic acid. However, current commercial processes typically result in low yields. This work aimed to study the conversion of model sugars (glucose, xylose, and arabinose) into platform chemicals using a homogeneous acid catalyst in a variety of organic-water mixtures, and compare those findings to reactions carried out using biomass under the same conditions. Reactions were performed in 50-50 solvent-water mixtures using sulfolane, tetrahydrofuran (THF), or gamma-butyrolactone (GBL) as the solvent and using a sulfuric acid catalyst. Intermediate wheatgrass was used in the biomass reactions and its composition was determined using standard NREL methods. Similar trends were observed in both pure sugar and biomass reactions in which the solvent choice had little effect on maximum yield of furfural, HMF, or levulinic acid. However, the THF/water solvent achieved maximum yields at lower severities than the other solvent mixtures indicating that a combination of less time, lower temperature, and/or less acid could be used in the THF reactions compared to the others. Compared to previously published research that found the solvent polarity correlated with product yields of furfural in reactions with no acid present, the effects of solvent properties may be minimized by the presence of the acid catalyst. Higher yields were achieved in biomass reactions than in pure sugar reactions, possibly due to unaccounted for reaction pathways or lowering of degradation reaction rates due to a lower initial reactant weight percent.