Midinfrared FT-IR as a Tool for Monitoring Herbaceous Biomass Composition and Its Conversion to Furfural

Abstract

A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donax L.) and switchgrass (Panicum virgatum L.). Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlation area/concentration was achieved for cellulose and lignin, whereas indirect correlations were found for hemicellulose quantification. Good correspondences between the values derived from our model and those reported in the literature or obtained according to the official Van Soest method were ascertained. Average contents of 40-45% of cellulose, 20-25% of hemicellulose, and 20-25% of lignin were obtained for different samples of giant reed species. In the case of switchgrass, a content of 36% of cellulose, 28% of hemicellulose, and 26% of lignin was achieved. This analysis was also carried out on giant reed and switchgrass residues after a mild hydrolysis step carried out with dilute hydrochloric acid for the production of furfural with good yield. Reasonable compositional data were obtained, thus allowing an indirect monitoring which helps the optimization of the hydrothermal pretreatment for furfural production from hemicellulose fractions.

Arundo donax Refining to Second Generation Bioethanol and Furfural

“…A microwave catalyzed process was investigated by Raspolli Galletti et al (2015) for the hydrolysis and dehydration of Arundo donax at 150 • C by using HCl 37% [51]. The authors achieved a yield of 57%, higher than 49 % obtained in the present paper by using an inorganic acid catalyst.…”

Mid-Infrared Spectroscopy Supports Identification of the Origin of Organic Matter in Soils

“…Even if the broadleaf forests under study had mixed species composition, the three classes were clearly differentiated (i.e., beech-, oak-and hornbeam-/maple-/lime-dominated stands (Figure 7). The 1st variate strongly discriminated between oakand hornbeam-dominated forests (with the Mahalanobis distance reaching a value of 24, Table 1), whereas the 2nd variate clearly discriminated samples from beech-dominated forests from the other broadleaf stands (Mahalanobis distances of [12][13][14][15]. Although the majority of buried soils under study did not indicate their adjacency to the forest class, a clear discrimination into classes related to species composition was not possible.…”

“…Land 2021, 10, 215 2 of 11 Furthermore, additional pre-mathematical processing is necessary due to an overlapping or low intensity of peaks from various chemical functional groups [11,12].…”

Hydrothermal Conversion of Giant Reed to Furfural and Levulinic Acid: Optimization of the Process under Microwave Irradiation and Investigation of Distinctive Agronomic Parameters

“…When raw biomass, such as wheat straw, is used as substrate, FA is the major product obtained using HCl in a MW-assisted process [56]. In our recent work [57], the MW-assisted hydrothermal conversion of giant reed and switchgrass into FA was preliminarily investigated, by using quite dilute hydrochloric acid and mild reaction conditions, thus approaching a very good FA yield. Gómez Bernal et al [58] recently investigated the FA synthesis starting from corn stover hemicelluloses, by using a MW-assisted, green and heterogeneously catalyzed two-step cascade process, as follows: first step, hydrothermal fractionation of corn stover hemicelluloses, and second step, hydrolysis/dehydration of soluble hemicellulosic sugars over niobium phosphate to yield FA at moderate temperatures (<200 °C), with both steps being performed in water.…”