Simultaneous isolation of cellulose and lignin from wheat straw and catalytic conversion to valuable chemical products

Abstract

Convertible cellulose and lignin were simultaneously isolated from wheat straw using a two-stage process via simply varying temperature and H2SO4 concentration. At the first-stage, cellulose was obtained by pretreating wheat straw at lower temperature and acid concentration using an organosolv process. The purity, yield and recovery rate of cellulose reached 86.8 wt%, 55.2 and 92.8% at 150 °C with 1 wt% H2SO4. At the second stage, the residual liquid was further treated at higher temperature and acid concentration, giving 17.4% lignin yield with 86.6% recovery rate and 93.2 wt% purity at 180 °C with 1.5 wt% H2SO4. The conversion of the as-isolated cellulose and lignin into chemicals was further investigated. The total yield of 5-hydroxymethylfurfural and glucose derived from wheat straw cellulose reached 82.5%, and 18.3% yield of monophenolic compounds from lignin were obtained, respectively. These results indicated that the two-stage process was effective for obtaining high-quality cellulose and lignin from wheat straw. Both of them displayed excellent convertible property.

Extraction of natural fibers of Catole coconut (Syagrus Cearensis): Application as reinforcing filler in polypropylene‐based composites

“…2,38 The weak shoulder bands at 1732 and 1519 cm À1 correspond to aliphatic esters (C=O) of hemicellulose and C=C of lignin, respectively. 39 The band at 1619 cm À1 often indicates the bending vibration of -OH related to adsorbed water. 2,40,41 Bands at 1150 and 894 cm À1 are characteristic of C-O-C stretching and C-H bending vibrations of glycosidic bands of cellulose.…”

“…2,40,41 Bands at 1150 and 894 cm À1 are characteristic of C-O-C stretching and C-H bending vibrations of glycosidic bands of cellulose. 39 Furthermore, even though the fibers were not subjected to any chemical or thermal treatment, a small band at 809 cm À1 indicated humins 39 formation, which might have been thermally promoted during fiber drying at 60 C. Humins are very attractive in the development of natural fiber composites. 37…”

Cellulose Nanocrystals (CNCs) and Cellulose Nanofibers (CNFs) as Adsorbents of Heavy Metal Ions

“…Te missing peak at wavenumber 1734 cm −1 indicates that lignin and hemicellulose have completely disappeared from the CNFs [163]. Several missing peaks indicate the cellulose content in the sample has increased [10,66,165].…”

“…Te result of this synthesis is usually referred to as TOCNF [92]. Te TEMPO oxidation method has several advantages, including its efciency, selectivity, and convenience [165,180]. Te TEMPO radicals are used to convert monosaccharide primary alcohol groups to carboxyl groups.…”

Directional synthesis of furfural compounds from holocellulose catalyzed by sulfamic acid

“…The conversion of hemicellulose from Aleurites fordii HemsL to FUR in γ-valerolactone (γ-GVL) was catalyzed by sulfamic acid, giving yield of 70.9% (Zhang et al 2019). It is unavoidable to successively separate the components such as cellulose and hemicellulose to prepare furfural compounds from them, thus leading to tedious pretreatment process (Yu et al 2021). It is no doubt that the combined conversion of cellulose and hemicellulose for coproduction of 5-HMF and FUR simultaneously is more advantageous.…”