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[Display omitted] • The p-TsOH/2-MeTHF/H 2 O system was desirable for high selectivity fractionation. • 95.69% cellulose was retained as high removal of hemicellulose and lignin. • The hydrolysate was dehydrated into 80.07% furfural in the biphasic system. • The digestibility of residue was achieved at 95.82%. • 33.83% precipitated lignin could be obtained based on raw material. Developing an environmentally friendly and efficient pretreatment to utilize wheat straw is essential to a sustainable future. An acid biphasic system with 2-methyltetrahydrofuran (2-MeTHF) organic solvent and dilute p-toluenesulfonic acid (p-TsOH) were employed for the simultaneous fractionation of three components. Results showed that the biphasic system had excellent cellulose protection and high removal of hemicellulose and lignin. In detail, Under the optimal conditions (0.1 M p-TsOH, 2-MeTHF: H 2 O = 1:1 (v:v), 140 °C, 3 h), mostly cellulose retained in the residues (95.69%), 57.18% of lignin was removed and high yield of hemicellulose-based C5 sugars was achieved (77.49%). In the further process of dehydration of pre-hydrolysate dichloromethane (DCM) as an organic phase, the yield of furfural was 80.07% (170 °C–80 min). The saccharification of residue reached 95.82%. p-TsOH/2-MeTHF/H 2 O pretreatment was desirable for high selectivity fractionation. Important chemicals for bioenergy including furfural, monosaccharides and lignin are obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using SPR to elucidate how pseudo-lignin inhibits enzymatic hydrolysis. • The adsorption–desorption process of pseudo-lignin and cellulase was explored. • Key factors of pseudo-lignin affecting the enzymatic digestibility of cellulose. To explore the interaction mechanism of pseudo-lignin (PL) with cellulase and its influence on cellulose hydrolysis, different PLs were extracted from pretreated bamboo holocellulose (HC) using different organic solvents. Meanwhile, the real-time interaction of PL and cellulase was analyzed using surface plasmon resonance (SPR). The results showed that the extraction effect of the tetrahydrofuran and 1, 4-dioxane/water solution on PL was more effective than the ethanol/water solution. The inhibition of PL fraction obtained from HC by acid pretreatment with higher temperature showed less effect on Avicel's enzymatic hydrolysis. SPR analysis revealed that PL formed at higher pretreatment temperature had a lower dissociation rate after adsorption with cellulase. Besides, the binding affinity of PL (160 °C) to cellulase was much greater than that of PL obtained from 180 °C, indicating PL extracted at higher temperature treated biomass is more easily dissociated from cellulase after binding. [ABSTRACT FROM AUTHOR]

[Display omitted] • Poplar was pretreated by reusable organic solvent under mild temperature (≤100 °C). • Almost all hemicelluloses and part of lignin was extracted with cellulose retained. • Sulfonic acid groups were introduced into lignin structure remained in substrates. • 89% improved glucose conversion compared with that of non-sulfonated substance. • New strategy is exploited to realize sulfonation and promote biomass bioconversion. Biomass pretreatment is an essential strategy to overcome biomass recalcitrance and promote lignocellulosic bioconversion. Here, a reusable organic solvent system (formic acid-methanesulfonic acid) was explored to pretreat poplar under a mild temperature (below 100 °C). The results showed that the co-solvent system could extract basically complete hemicelluloses and part of lignin with original cellulose retained in the pretreated substrates. Meanwhile, sulfonic acid groups were introduced into lignin structure remained in the substrates. The glucose conversion yield of the substrates with a higher concentration of sulfonic acid groups (13.2 mmol/kg) reached 45.9 % by reducing the hydrophobic interaction between lignin and cellulase, showing 89.3 % improvement compared with that of the substrates treated with single formic acid. This progressive study aimed to develop a new strategy to realize sulfonation and promote enzymatic hydrolysis of substrates by using mild organic solvent pretreatment. [ABSTRACT FROM AUTHOR]

A novel and efficient organic amine and organosolv synergetic pretreatment method was developed to overcome the recalcitrance of lignocellulose to produce fermentable sugars and high-quality salt-free lignin. After optimization of the process parameters, a delignification of 81.7% and total sugar yield of 83.2% (87.1% glucose, 75.4% xylose) could be obtained using n -propylamine (10 mmol/g, biomass) as a catalyst and aqueous ethanol (60%, v/v) as a solvent. The susceptibility of the substrates to enzymatic digestibility was explained by their physical and chemical characteristics. The physical structure of extracted lignin showed higher β -aryl ether bonds content and functionalities, offering the potential for further downstream upgrading. The role of organic amine catalyst and a synergistic mechanism is proposed for the present system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Removal of silica and lignin from rice straw under mild conditions is investigated. • High silica (92%) removal from rice straw in the presence of aqueous NH 3 is achieved. • High removal of lignin (60%) with NH 3 in water-THF solvent is obtained. • Parent rice straw affords 8- and 4-fold lower yields of furfural and levulinic acid. • Removal of silica/lignin improves the productive rate of target products. The intricate nature and rigidity of rice straw, particularly the presence of lignin and silica, hinders the catalytic valorization, consequently decreasing the yield of target products. This study reports the concurrent removal of lignin and silica from rice straw to obtain enriched holocellulose, then transforming it to furfural (FUR) and levulinic acid (LA). Interestingly, rice straw in the form of powder displays an improved removal of lignin (51.0%) and silica (92.0%) during ammonia treatment. Encouragingly, adding organic solvents, such as THF, to the aqueous system during the pretreatment of rice straw improves the lignin removal to 60.0%. Upon improving lignin removal to 60%, the obtained holocellulose enriched solid residue yields 71.0% FUR along with 52.0% LA, which is 8 and 4-fold higher than what is obtained with parent rice straw, signifying the importance and the prerequisite of lignin and silica removal from rice straw. [ABSTRACT FROM AUTHOR]

Highlights: [•] This provides basic information ascertaining promising solvents for the recovery. [•] Some organic solvents are effective to recovery ionic liquid and obtain lignin. [•] The effective order is isopropanol>ethanol>acetonitrile>ally alcohol>methanol. [Copyright &y& Elsevier]

Abstract: The solubility of lignin from hydrolyzed almond (Prunus amygdalus) shells in different acetone, ethanol and dioxane–water mixtures and conditions (extraction time and temperature) was studied. The concept of the solubility parameter (δ-value) was applied to explain the effect of organic solvent concentration on lignin solubility. The organic solvent–water mixture that led to the highest lignin extraction was composed of a 75% vol. of organic solvent for all the solvent series investigated (acetone, ethanol and dioxane). Moreover, the best lignin extraction conditions were a temperature of 210°C and an extraction time of 40min for the acetone and ethanol series, and 25min for the dioxane series. The δ-value of the hydrolyzed almond shell lignin [14.60 (cal/cm3)1/2] and that of the organic solvent–water mixtures was calculated. The experimental delignification capacity of the aqueous organic solvents clearly reflected the proximity of their δ-value to that of lignin. The hydrogen-bonding capacity of the solvent–water mixtures was also taken into account. [Copyright &y& Elsevier]

• Lignin extracted from sawdust biomass by alkali fractionation method. • Structure, total phenol content and antioxidant characteristics of lignin were analyzed. • Industrial level model was developed for the simulation of lignin fractionation process. • Economic and sensitivity of lignin fractionation process were analyzed. The present work was focused on the investigation of lignin isolation from saw industry biomass (sawdust (SD)) using alkali solution, and to perform economic analysis for 2000 kg/batch hypothetical plant using techno-economic analysis. The isolated lignin was fractionated using organic solvent to obtain purified lignin. FTIR and 1H NMR analysis were performed to examine the structural characteristics of lignin. Lignin nanoparticles (LN) showed higher total phenolic content (TPC) (244.1 ± 2 µg of GAE per mg) and antioxidant activity (63.2 ± 1.7%) compared with crude lignin (CL), ethanol fractionated lignin (EL), and acetone fractionated lignin (AL). SuperPro designer was exposed to design and simulated 2000 kg/batch of sawdust fractionation process. The techno-economic analysis estimated that the lignin production cost is about $ 487,000 per year, and the annual revenue could be $ 1,850,000 per year. The techno-economic analysis and sensitivity analysis could be useful for the industrial level sawdust fractionation process. [ABSTRACT FROM AUTHOR]

Abstract: A functional lignin-based material, lignocresol, was synthesized from eucalyptus wood meal by using phase separation treatment with p-cresol and 72% sulfuric acid. Lignocresol physically adsorbs Trichoderma reesei cellulase and functions as an immobilized cellulase. Lignocresol-immobilized cellulase was treated with acetone or ethanol to separate the enzyme and its support. Most lignocresol was dissolved in organic solvents and then precipitated in diethyl ether. The recovery yield of lignocresol using acetone was 85% and that using ethanol was 72%, with very low or negligible residual cellulase. Lignocresol is an innovative recyclable enzyme support that can be easily separated using only organic solvents after deactivation of the immobilized enzyme. [Copyright &y& Elsevier]

• Kraft lignin was fractionated by 5 organic solvents. • Higher heating value is inversely proportional to the molar mass. • GPC molar mass distribution increased from fraction 1 (F1) to fraction 5 (F5) • Thermal degradation of lignin in the 300–400 ℃ range was verified. The new concept of integrated biorefineries has significantly changed pulp and paper industries. Lignin, which until then was only burned to generate energy, is now an important raw material for new products production. Kraft lignin (KL) fractions obtained by sequential fractionation with five organic solvents. This sequence allows to extract fractions from lower molar mass to higher molar one, resulting in more homogeneous samples. Lignin's fractions were characterized by FTIR, GPC, TGA and Higher Heating Value (HHV). HHV for KL was 24966, the lowest being 17,891 (F5) and the highest being 27051 J/g (F1), inversely proportional to the molar masses of fractions. This is a very important result indicating that the lower HHV fractions can be used for certain applications, such as antioxidants, additives, polymers, among others, adding value to kraft lignin. Fractions with higher HHV could be used for energy generation in the cellulose paper industry. [ABSTRACT FROM AUTHOR]

• Multi-grade lignin can be obtained by solvent fractionation. • Different organic solvents have different proportions of dissolved lignin. • Lignin fractions have different physicochemical properties and hydroxyl content. • Microsphere with different surface morphologies was prepared from lignin fractions. Here we report a centrifugation-based fractionation methodology that was integrated with three types of organic solvents to fractionate industrial alkali lignin toward the fabrication of lignin microsphere. The Fourier-transform infrared spectroscopy (FT-IR) result showed that the chemical structure of lignin was not changed by solvent fractionation. Soluble lignin in each solvent had lower molecular weight, improved polydispersity index (PDI) and less impurities (S, N), while insoluble lignin had a high bio-char yield and can be utilized as potential carbon source for porous carbon nanosphere materials. In addition, well-shaped lignin microsphere with smooth or anisotropic surface can be prepared by selecting proper lignin fraction without any chemical modification. This work thus provides a new strategy for the derivation of lignin as raw materials for value-added products, which paved a new way to develop a green and sustainable bio-refining industry. [ABSTRACT FROM AUTHOR]