Consecutive Organosolv and Alkaline Pretreatment: An Efficient Approach toward the Production of Cellulose from Rice Straw

Abstract

The efficient removal of silica from rice straw and separation of its major components is essential for further valorization to produce value-added products. With regard to this, the isolation of cellulose (CEL), hemicellulose (HEM), and lignin (LIG) is imperative but quite challenging. Among several pretreatments of lignocellulosic biomass, the organosolv approach is deemed as one of the promising methods. Here, we present two different two-step approaches for the removal of silica and disintegration of significant components from rice straw, especially CEL; (i) base pretreatment, followed by organosolv treatment in the presence of organic acid, and (ii) organosolv pretreatment in the presence of organic acid, followed by base treatment. After each treatment, the recovered solid components are confirmed by various characterization techniques such as Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, and thermogravimetric analysis. Method 2 demonstrates 82% total removal of HEM and LIG along with 90.4% of silica removal from rice straw to obtain CEL. Furthermore, the obtained crude CEL is found to be with a purity of 78%. Excellent removal of silica (90.4%) reflects that in a test study, the crude CEL obtained from method 2 gives a higher yield of butyl glucosides (59.6%) than rice straw, which affords 45.0% of butyl glucosides.

Rice straw structure changes following green pretreatment with petha wastewater for economically viable bioethanol production

“…Hemicellulose is a susceptible component of RS for acid and alkali pretreatment because it solubilises in alkali. Aggarwal et al 20 recently reported using organosolv and alkaline pretreatment of RS for cellulose production with about 82% total removal of hemicellulose and lignin along with 90.4% of silica removal from RS. It was noted that % lignin removal was higher for A (9.2%) as compared to D (0.54%), % extractives removal was lower for A and no change was reported for D. Quick lime used during preparation of petha sweet, resulted in increase of ash content due to absorption of Ca 2+ ions in A 15 .…”

Organosolv biorefinery: resource-based process optimisation, pilot technology scale-up and economics

“…29,30 However, high-value chemicals and biomaterials can also be obtained. The main studies focus on generating cellulose nanofibrils (CNF), 31 nanocellulose, 32 cellulose nanocrystals (CNCs), 33,34 butyl glucosides, 35 carboxymethylcellulose 36 and dissolving pulp. 37…”

Multiscale investigation of the mechanism of biomass deconstruction in the dimethyl isosorbide/water Co-solvent pretreatment system

“…3 Of these, organosolv pretreatment is an emerging approach to obtain high-quality lignin and high-purity cellulose. 4,5 In the context of promoting an eco-friendly and sustainable bioeconomy and to realize the clean separation and high value-added utilization of lignocellulosic biomass, 6 as alternatives to conventional organic solvents, bio-based green solvents are being investigated, such as γ-valerolactone (GVL), 7 dihydrolevoglucosenone (Cyrene) 8 and dimethyl isosorbide (DMI). 1 Among these, DMI is abio-derived, aprotic, high boiling point, and non-toxic solvent which can be produced from d -glucose.…”