Evaluating Lignocellulosic Biomass, Its Derivatives, and Downstream Products with Raman Spectroscopy

Abstract

The creation of fuels, chemicals, and materials from plants can aid in replacing products fabricated from non-renewable energy sources. Before using biomass in downstream applications, it must be characterized to assess chemical traits, such as cellulose, lignin, or lignin monomer content, or the sugars released following an acid or enzymatic hydrolysis. The measurement of these traits allows researchers to gage the recalcitrance of the plants and develop efficient deconstruction strategies to maximize yields. Standard methods for assessing biomass phenotypes often have experimental protocols that limit their use for screening sizeable numbers of plant species. Raman spectroscopy, a non-destructive, non-invasive vibrational spectroscopy technique, is capable of providing qualitative, structural information and quantitative measurements. Applications of Raman spectroscopy have aided in alleviating the constraints of standard methods by coupling spectral data with multivariate analysis to construct models capable of predicting analytes. Hydrolysis and fermentation products, such as glucose and ethanol, can be quantified off-, at-, or on-line. Raman imaging has enabled researchers to develop a visual understanding of reactions, such as different pretreatment strategies, in real-time, while also providing integral chemical information. This review provides an overview of what Raman spectroscopy is, and how it has been applied to the analysis of whole lignocellulosic biomass, its derivatives, and downstream process monitoring.

The Impact of Lignin Structural Diversity on Performance of Cellulose Nanofiber (CNF)-Starch Composite Films

“…To investigate this, we chose tunicate CNF-starch composite film as the blank, and then films containing identical amount of different lignin samples were prepared and characterized. As shown in Figure S8, the introduction of lignin to the CNF-starch composite films is verified by the presence of the peak 1515 cm −1 for all the lignin-containing composite films, which generates from the asymmetric aryl ring stretching in lignin [58]. The interrelation between lignin properties and film performance was further studied.…”

High-Throughput Profiling of the Fiber and Sugar Composition of Sugarcane Biomass

“…These were removed prior to the pretreatment, and only the range of 1100-2300 nm was used for further analysis. NIR spectral data requires different pretreatment in comparison with data obtained from other platforms such as Raman or NMR [44], to remove scatter effects while maintaining a correlation between the signal and analyte concentration. The pretreatment can be first derivative, second derivative, multiplicative scatter correction (MSC), or SNV transforms [16,45].…”

Linking ATR-FTIR and Raman features to phenolic extractability and other attributes in grape skin

“…The band at 1123 cm -1 is due to symmetric stretching of glycosidic C-O-C bonds in cellulose and other polysaccharides [31]. The band at 1342 cm -1 is due to HCC, HCO, HOC bending in cellulose [50] and finally, the band at 1606 cm -1 is due to stretching of aromatic rings of the remaining phenolic compounds [51]. In consequence, these results show and confirm that phenolic extractability is influenced by polysaccharides and that the remaining phenolic compounds can be detected by Raman spectroscopy, mainly in the internal grape skin surface.…”

“…Differences between skin surfaces are not obvious at first sight (data not shown). A tentative assignment is shown in Table 3 [28,30,31,[49][50][51]. Fig.…”