Search

Background: Peroxyacetic acid involved chemical pretreatment is effective in lignocellulose deconstruction and oxidation. However, these peroxyacetic acid are usually artificially added. Our previous work has shown that the newly developed PHP pretreatment (phosphoric acid plus hydrogen peroxide) is promising in lignocellulose biomass fractionation through an aggressive oxidation process, while the information about the synergistic effect between H3PO4 and H2O2 is quite lack, especially whether some strong oxidant intermediates is existed. In this work, we reported the PHP pretreatment system could self-generate peroxyacetic acid oxidant, which mediated the overall lignocellulose deconstruction, and hemicellulose/lignin degradation. Results: The PHP pretreatment profile on wheat straw and corn stalk were investigated. The pathways/mechanisms of peroxyacetic acid mediated-PHP pretreatment were elucidated through tracing the structural changes of each component. Results showed that hemicellulose was almost completely solubilized and removed, corresponding to about 87.0% cellulose recovery with high digestibility. Rather high degrees of delignification of 83.5% and 90.0% were achieved for wheat straw and corn stalk, respectively, with the aid of peroxyacetic acid oxidation. A clearly positive correlation was found between the concentration of peroxyacetic acid and the extent of lignocellulose deconstruction. Peroxyacetic acid was mainly self-generated through H2O2 oxidation of acetic acid that was produced from hemicellulose deacetylation and lignin degradation. The self-generated peroxyacetic acid then further contributed to lignocellulose deconstruction and delignification. Conclusions: The synergistic effect of H3PO4 and H2O2 in the PHP solvent system could efficiently deconstruct wheat straw and corn stalk lignocellulose through an oxidation-mediated process. The main function of H3PO4 was to deconstruct biomass recalcitrance and degrade hemicellulose through acid hydrolysis, while the function of H2O2 was to facilitate the formation of peroxyacetic acid. Peroxyacetic acid with stronger oxidation ability was generated through the reaction between H2O2 and acetic acid, which was released from xylan and lignin oxidation/degradation. This work elucidated the generation and function of peroxyacetic acid in the PHP pretreatment system, and also provide useful information to tailor peroxide-involved pretreatment routes, especially at acidic conditions. [ABSTRACT FROM AUTHOR]

To convert lignin into high-valued carbon materials and understand the lignin structure function, oxidized lignin, a by-product from lignocellulose PHP-pretreatment (phosphoric acid plus hydrogen peroxide), was carbonized by one-step KOH-activation; the physico-chemical characteristics and electrochemical performances of the harvested carbons were also investigated. Results indicated the resultant carbons displayed 3-dimensional hierarchical porous morphology with maximum specific surface area of 3094 m2 g−1 and pore volume of 1.72 cm3 g−1 using 3:1 KOH/lignin ratio for carbonization. Three-electrode determination achieved a specific capacitance of 352.9 F g−1 at a current of 0.5 A g−1, suggesting a superior rate performance of this carbon. Two-electrode determination obtained an excellent energy density of 9.5 W h kg−1 at power density of 25.0 W kg−1. Moreover, 5000 cycles of charge/discharge reached 88.46% retention at 5 A g−1, implying an outstanding cycle stability. Basically, low molecular weight and abundant oxygen-containing functional groups of employed lignin mainly related to the excellent porous morphology and the outstanding electrochemical performances, suggesting the oxidized lignin was an ideal precursor to facilely prepare activated carbon for high-performance supercapacitor. Overall, this work provides a new path to valorize lignin by-product derived from oxidative pretreatment techniques, which can further promote the integrality of lignocellulose biorefinery. [Display omitted] • Oxidized lignin was employed to prepare 3-D hierarchical porous carbons. • Oxygen-containing groups facilitated the formation of porous structures of carbon. • The derived carbon was hierarchical porous with large specific surface area. • This carbon electrode displayed good electrochemical performances. • Oxidized lignin is a promising precursor of carbon electrode for supercapacitor. [ABSTRACT FROM AUTHOR]

A stable solid acid catalyst, SCPR140‐1, was synthesized from chloromethyl polystyrene resin (CPR) and used for catalytic pretreatment of corncob in aqueous solution. Under the optimized pretreatment condition, 73.07 % of xylose was directly obtained, and the enzymatic digestibility of treated residue reached up to 94.65 %, indicating that the SCPR140‐1 had high selectivity for xylose production and effectively deconstructed the structure of corncob. The −CH2Cl group of CPR was substituted by −SO3H through the sulfonation, and the −SO3H was stably bound on the catalyst during the pretreatment process. Compared with other similar reports, the SCPR140‐1 was not only synthesized through a simpler process but also had a more stable catalytic activity during multiple recycling runs. [ABSTRACT FROM AUTHOR]

Liquid hot water extraction followed by mechanical extrusion is a promising chemical-free pretreatment for cellulosic ethanol production from rigid hardwood. To alleviate the heavy dependence on chemical input of chemical pretreatments and make a better use of current idle thermo-mechanical pretreatment plant for mechanical pulp, a sequential chemical-free pretreatment approach, i.e., liquid hot water extraction followed by mechanical extrusion was investigated in this work. Its ability to fractionate hemicellulose while facilitating cellulose hydrolysis of rigid eucalyptus and aspen hardwood was assessed. The structural changes of lignin during liquid hot water extraction were elucidated using spectrum analysis. Cellulose accessibility to hydrolytic enzymes, cellulose hydrolysis yields and fermentation potential were also assessed. Results showed that the mild liquid hot water extraction recovered 54.0% and 38.1% of xylan hemicellulose from eucalyptus and aspen hardwood respectively, while causing limited lignin condensation reactions. Extending liquid hot water extraction time from 45 to 90 min significantly facilitated the subsequent mechanical deconstruction of both wood substrates without compromising their overall carbohydrate recovery. A maximum cellulose hydrolysis yield of 79.6% and nearly 100% (10 w/v solids loading, enzyme dosage, 20 mg g−1 cellulose) was observed on eucalyptus and aspen substrate respectively, which were feasible for further fermentation process. This work showed liquid hot water extraction followed by mechanical extrusion was a feasible pretreatment strategy for bioethanol production even the starting wood chip substrate was highly rigid. [ABSTRACT FROM AUTHOR]

An effective pretreatment to improve cellulose accessibility and facilitate glucose release is crucial in a cellulosic ethanol biorefinery. This work comparatively assessed four H2O2-involved pretreatments, i.e., concentrated H3PO4 plus H2O2 (PHP), H2O2–CH3COOH (HPAC), alkaline-H2O2 (AHP), and Fenton chemistry (FC), for their pretreatment performances on wheat straw, poplar, and birch biomass. Substrate characteristics before and after pretreatment were assessed using SEM, XRD, and LSCM. The hydrolytic potentials of the pretreated substrates were compared by Simons' stain and cellulose–glucose conversion assessment. The results showed that acidic H2O2-involved pretreatments (PHP and HPAC) were more efficient in biomass delignification compared to AHP and FC. PHP pretreatment is more promising for cellulosic ethanol production due to its corresponding high glucose yield (368.0 mg g−1) after enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

Hydrothermally-pretreated rice straw (HPRS) from various pretreatment temperatures was anaerobically-digested in whole slurry. Results indicated promoting pretreatment temperature significantly deconstructed rice straw, and facilitated the conversion of insoluble fractions to soluble fractions. Although 306.6 mL/g TS biogas was maximally yielded in HPRS-90 and HPRS-180, respectively, via digestion in whole slurry, it was only 3% promotion compared to the unpretreated rice straw. HPRS-210 yielded 208.5 mL/g TS biogas, which was 30% reduction with longer lag period of 19.8 d, suggesting serious inhibitions happened. Through slightly increasing organic loading, more serious acidification and reduction on biogas yield, especially at higher pretreatment temperatures, indicated the soluble fractions controlled digestion performances. Pearson correlation analysis suggested negative relationship existed between methane yield and the soluble fractions including soluble carbohydrates, formic acid and furfural. Hydrothermal pretreatment, especially at higher temperature, did not improve anaerobic digestion, thereby, was not recommended, however, lower temperature can be considered potentially. [ABSTRACT FROM AUTHOR]

The valorization of cellulose and lignin residues in an integrated biorefinery is of great significance to improve the overall economics but has been challenged by their structural recalcitrance, especially for lignin residue. In this work, a facile chemical conversion route to fabricating functional UV-blocking cellulose/lignin composite films through a facile dissolution–regeneration process using these biomass residues was proposed. Three representative lignin residues, i.e., aspen and poplar wood lignin, and corn stover (CS) lignin were assessed for their feasibility for the film fabrication. The UV-blocking performance of the composite films were comparatively investigated. Results showed that all these three lignin residues could enhance the UV-blocking property of the composite films, corresponding to the reduction in the optical energy band gap from 4.31 to 3.72 eV, while poplar lignin had a considerable content of chromophores and showed the best UV-blocking enhancement among these three assessing lignins. The enhancement of UV-blocking property was achieved without compromising the visible-light transparency, mechanical strength and thermal stability of the composite films even at 4% lignin loading. This work showed the high promise of integrating biomass residue conversion into lignocellulose biorefinery for a multi-production purpose. [ABSTRACT FROM AUTHOR]

The abundantly released tail-gas from lignocellulose pretreatment with phosphoric acid plus hydrogen peroxide (PHP) was found to accelerate the aging of latex/silicone textural accessories of the pretreatment device. Inspired by this, tail-gas was utilized to control organic pollutants. Methylene blue (MB), as a model pollutant, was rapidly decolorized by the tail-gas, and oxidative degradation was substantially proven by full-wavelength scanning with a UV–visible spectrometer. The tail-gas from six typical lignocellulosic feedstocks produced 68.0–98.3% MB degradation, suggesting its wide feedstock compatibility. Three other dyes, including rhodamine B, methyl orange and malachite green, obtained 97.5–99.5% degradation; moreover, tetracycline, resorcinol and hexachlorobenzene achieved 73.8–93.7% degradation, suggesting a superior pollutant compatibility. In a cytotoxicity assessment, the survival rate of the degraded MB was 103.5% compared with 80.4% for the untreated MB, implying almost no cytotoxicity after MB degradation. Mechanism investigations indicated that the self-exothermic reaction in PHP pretreatment drove the self-generated peroxy acids into tail-gas. Moreover, it heated the pollutant solution and thermally activated peroxy acids as free radicals for efficient pollutant degradation. Here, a brand-new technique for degrading organic pollutants with a "Win–Win–Win" concept was purposed for lignocellulose valorization, pollutant control by waste tail-gas, and biofuel production. [Display omitted] • A new way to degrade organic pollutants by tail-gas of lignocellulose pretreatment. • The tail-gas efficiently degraded 7 organic pollutants by 73.8–99.5% within 6–7 min. • The tail-gas from 6 lignocellulose achieved 68.0–98.3% methylene blue degradation. • Self-exothermic process drove volatilization of produced peroxy acids in tail-gas. • Thermally activating peroxy acids into free radicals for the pollutant degradation. [ABSTRACT FROM AUTHOR]

To obtain high yield and high concentration glucose from corncob residues (CRs), tetrahydrofuran (THF) + H 2 O co-solvent pretreatment was employed. The pretreatment parameters were firstly optimized by Box-Behnken Design of response surface method, and the maximum glucose yield (498.2 mg/g CRs) was obtained via enzymatic hydrolysis after pretreated under optimized conditions (53.7% THF concentration, 202.3 °C, 1.05 h). Then, the pretreated CRs under optimized conditions (optimized-CRs) were enzymatically hydrolyzed at high solid loading (15%–20%) and low enzyme input (5–8 FPU/g cellulose). The high concentration glucose production (128.6 mg/mL) was obtained from optimized-CRs after enzymatic hydrolysis at 20% solid loading with 10 FPU/g cellulose for 72 h, and then showed potential for reduction of enzyme input. Finally, the interactions between the 9 substrate-related factors and cellulose conversion were analyzed through correlation analysis, and found that Klason lignin remained in the cellulose-rich fractions and pseudo lignin condensed on the surface of the recovered substrate were the predominant inhibitors for enzymatic hydrolysis. • The THF + H 2 O co-solvent pretreatments of CRs were optimized by BBD of RSM. • Maximum glucose yield (498.2 mg/g CRs) obtained under optimized conditions. • 128.6 mg/mL glucose titer was gained at 20% solid loading with 10 FPU/g cellulose. • KL remained in substrate hindered cellulose utilization through steric hindrance. • Pseudo lignin condensed on the surface of substrate decreased enzyme activity. [ABSTRACT FROM AUTHOR]

Highlights • PHP pretreatment integrated CPA, lignin recovery, P-containing wastewater control. • Average 86.0% CPA was recycled for ≥11 runs PHP pretreatment by integrated process. • Average 96.3% enzymatic hydrolysis was achieved after these 11 runs pretreatment. • 1.1 kg CPA can pretreat 1.0 kg wheat straw and yield 155.0 g ethanol and 45.0 g lignin. • 3.5 kg biochar for recovering P from wastewater derived 4.9 kg P-biochar fertilizer. Abstract Pretreating lignocellulosic biomass by phosphoric acid plus hydrogen peroxide (PHP) was integrated with recovering concentrated phosphoric acid (CPA), lignin, and treating phosphorus (P) wastewater. Results indicated no significant effects on cellulose recovery was observed by promoting ethanol addition, but CPA and lignin recovery were improved to 80.0% and 23.3%, respectively. Increasing water addition did not greatly affect CPA recovery (80.0–80.4%), and lignin recovery (22.8–23.6%). Consequently, the ratio of 11:1 (ethanol/PHP solution) and 4:1 (water/de-ethanol liquor) were suggested for solid/liquid separation and lignin precipitation. Average 86.0% CPA was recycled for pretreatment (≥11 runs) with average 96.3% cellulose-glucose conversion. A specially-developed biochar from crab shell was efficient on P removal with maximal adsorption capacity of 261.6 mg/g. Pretreating 1.0 kg wheat straw by 1.1 kg CPA harvested 155.0 g ethanol, 45.0 g high purity lignin and 4.9 kg P-rich biochar fertilizer. Recovering CPA, biochar-fertilizer and lignin, and P wastewater treatment made PHP pretreatment towards more sustainable and cleaner. [ABSTRACT FROM AUTHOR]

Lignin acted as phenolic polymer is a sustainable substitute for phenol to synthesize lignin-phenol-formaldehyde (LPF). Here, PLPF resins were prepared with unmodified PHP-lignin derived from phosphoric acid plus hydrogen peroxide (PHP) pretreatment of biomass waste, the PHP-lignin has plentiful hydroxyl structure and is beneficial to the polymerization with formaldehyde. Meanwhile, ALPF resin synthesized with alkali lignin abundantly produced from pulp and paper industry was also included. The feasibility of lignin as a substitute for phenol, the application of the synthesized PLPF resin in particleboard production and the obstacle on the high-value utilization of waste lignocellulosic biomass due to the existence of the resin adhesive were evaluated. Results indicated that the resins were successfully synthesized when phenol was substituted by 25% lignin. The basic properties, including solid content, free phenol content, free formaldehyde content, viscosity and adhesion performance all met Chinese National Standard (GB/T 14732–2006) of phenol-formaldehyde (PF) resin. The shaped particleboard with PLPF resin usage ranged from 5% to 15% all had good dimensional stability and solvent resistance. Finally, we verified the resin adhesive in the particleboard would greatly influence its enzymatic hydrolysis performance. The cellulose-glucose conversion of hydrothermal pretreated particleboard was merely 18.3%. Detoxification was the first and most important step in the subsequent high-value utilization of waste particleboard, and alkali pretreatment suggested a possible way to eliminate the negative effects, which could improve cellulose-glucose conversion to 57.8%. [Display omitted] • LPF resin was successfully synthesized with unmodified PHP technical lignin. • The properties of LPF resin all met Chinese National Standard of PF resin. • LPF resin had the potential application in practical particleboard production. • Alkali pretreatment promoted high value utilization of waste particleboard with resin. [ABSTRACT FROM AUTHOR]

In this work, Lewis acids (FeCl 3 , AlCl 3) and bases (Na 2 CO 3 , Na 2 SO 3) were incorporated into a neutral deep eutectic solvent (DES, choline chloride/glycerin) to intensify the lignocellulose fractionation. The efficiency of fractionation in terms of the maximum delignification rate (89.7 %) and well-pleasing cellulose saccharification (100 %) could be achieved by the Lewis acid-mediated DES. An in-depth insight of the evolution of lignin structure revealed that Lewis acid-mediated DES could cleave the β -O-4 linkages efficiently to achieve a high yield lignin fragments. Meanwhile, the lignin fragments with the enhanced amphiphilic properties facilitate the preparation of lignin nanospheres (LNSs) via the self-assembly process. The resultant LNSs extracted by Lewis acid-mediated DES exhibited an excellent thermal stability, and enhanced antibacterial capacity, which were associated with the phenolic OH content. However, the extracted lignin by Lewis base-mediated DES was mainly attributed to the cleavage of lignin-carbohydrate complexes bond, especially the lignin-carbohydrate ester bond, which retained more ether bonds and a relatively complete structure. This study illuminated the different mechanisms of lignin extraction and the structural evolution of lignin from Lewis acid/base-mediated DES, and provided guidance to select suitable fractionation techniques for upgrading the downstream products. [Display omitted] • Lewis acid/base mediated-DESs were designed for lignocellulose fractionation. • The maximum delignification rate of 89.7 % was achieved in AlCl 3 -ChCl/Gly. • In-depth insights into different mechanisms of lignin extraction were conducted. • The effect of lignin structure on the LNSs functional properties was evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • The swelling induced choline alkali-urea process realized complete rice straw fractionation. • 23.7 g lignin-carbohydrate complex was co-produced from 100 g rice straw. • The spent choline alkali-urea was regenerated into choline chloride-urea after XOSs recovery. • The choline alkali-urea exhibited high ability of hydrogen bonding network disruption. Upgrading lignocellulosic biomass into value-added product forms has been attractive but challenged by its structural recalcitrance and heterogeneity. Prevalent fractionation techniques employ aggressive chemical solvents or catalysts to cleave lignin-carbohydrates bonds with the purpose of dissolution ability enhancement. This work tailored the swelling induced choline alkali-urea (SICAU) process to fractionate rice straw with the powerful choline alkali-urea (ChOH-Ur) deep eutectic solvents (DES) with the preservation of lignin-carbohydrates bonds, thus the super high yield of high-value lignin-carbohydrates complexes (LCCs) was co-produced together with highly hydrolysable cellulose and ethanol-insoluble xylooligosaccharides (XOSs) fractions. Results showed that rather high cellulose recovery (87.3 %-100 %) was obtained with nearly 100 % cellulose to glucose conversion. Optimized LCCs yield of 34.3 % was achieved with 50 % choline alkali-urea concentration and 4 h cooking time, along with the corresponding yield of 10.2 % XOSs during the DES conversion process. The LCCs linkages were 0.06–0.16/100 Ar depending on cooking conditions. The proposed integrated SICAU process realized the complete upgrading of rice straw into three value-added products, which showed a very different working profile with prevalent systems that usually fractionated lignocellulose into cellulose, lignin, and hemicellulose. Therefore, the SICAU process could extract higher value from lignocellulose towards a more sustainable lignocellulose biorefinery. [ABSTRACT FROM AUTHOR]

Lignin-carbohydrate complexes (LCC) that exhibit both structural advantages of lignin and carbohydrates are promising amphiphilic biopolymers, but the extraction is challenged by its liable chemical bond cleavage between lignin and carbohydrates. This work proposed a facile chemical route to integrating the production of water-insoluble (WIS LCC) and water-soluble LCC (WS LCC) into the emerging deep eutectic solvent (DES) biorefinery at mild conditions. The tailored mechanochemical fractionation process of ball milling assisted aqueous alkaline DES could extract 24.2 % LCC in total, with the co-production of a highly hydrolysable cellulose fraction (98.7 % glucose conversion). The resulting LCC exhibited considerably high contents of β-O-4, phenyl glycoside, and ferulic acid linkage bonds. When 100 g starting straw was subjected to this technique route, 9.1 g WIS LCC, 15.1 g WS LCC and 45.5 g glucose were cascaded produced. It was proposed that the selective disruption of hydrogen bonding entangled network and the quasi-state dissolution of the whole biomass allowed the subsequent cascade fractionation of WIS LCC, WS LCC and highly hydrolysable cellulose through solution property adjustment. This work showed a promising approach for LCC production with high yield without compromising cellulose conversion potential, which has been challenging in the current lignocellulose biorefinery. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The acid-catalyzed hydrothermal achieved complete hemicellulose removal. • The coupling effect between deep eutectic solvent and hydrothermal was investigated. • The deprotonation ability of alkaline DES promotes lignin extraction. • Alkaline DES cellulose exhibited higher purity and degree of polymerization. Mild hydrothermal pretreatment (HP) integrating with solvent extraction is a promising two-step technique to enhance the overall lignin and carbohydrate output for lignocellulose fractionation. This work comparatively assessed the coupling effect between mild HP (the first step) and the emerging acidic choline chloride-natural acid or alkaline choline hydroxide based deep eutectic solvents (DES, the second step) for wheat straw fractionation. It was shown HP with 0.3% p -toluenesulfonic acid (p -TsOH) catalyst achieved a good compromise between complete hemicellulose removal (nearly 100%) and high cellulose recovery (99.2%). While choline hydroxide based DES showed better coupling effect with HP than choline chloride-natural acid DES, corresponding to 75.6 and 31.2% lignin removal respectively. It was proposed that the alkaline DES enhanced lignocellulose swelling the lignin phenolic hydroxyl groups deprotonation and thus facilitating lignin solubilization despite of its condensation at HP. Therefore, the alkaline DES resulting cellulose-rich fraction exhibited higher potential for further processing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal coupled with deep eutectic solvent pretreatment was proposed. • Combinational pretreatment was designed to selectively fractionate lignocellulose. • In-depth insight into structural transition facilitated products upgrading. • Lignocellulose was completely upgraded into three multi-functional products. • Molecule-level transformation of lignocellulose promoted biorefinery integration. To achieve the maximum value from lignocellulosic biomass, an integrated biorefinery based on molecule-level design is required. In this study, a combination of hydrothermal pretreatment (HTP) coupling deep eutectic solvent (DES) pretreatment was proposed to produce three upgraded products, namely hemicellulose-derived activated nanocarbon (ANC), lignin nanosphere (LNS), and lignin-containing cellulose nanofiber (LCNF) pesticide nanocarrier, from rice straw. The hydrothermal filtrate, which consists of 100% hemicellulose, was converted into value-added nanocarbon by in-situ carbon sequestration. The upgraded nanocarbon exhibited an excellent specific surface area (2692.3 m2 g−1) and a high degree of graphitization, which value-added attributes could increase revenue to integrated biorefinery. The subsequent DES extraction increased the phenolic –OH content and further aggregated the lignin condensed structure, which facilitated lignin nanosphere preparation by the self-assembly process. Meanwhile, the DES swelling of cellulose facilitated the nanofibrillation of LCNF, which was used as a pesticide carrier to improve pesticide utilization efficiency by simple cationic modification. The residual lignin with functional groups facilitated the crosslinking between the lignin fragments and cellulose fibers by hydrogen bonding interactions, which endowed LNCF highly entangled network and unique lignin properties. The functionalized LCNF exhibited enhanced adhesion and unique anti-UV ability for pesticide deposition and retention. This work realized the all-components upgrading of lignocellulose and inspired the development of sustainable and viable biorefineries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Key SSF variables were optimized for PHP-pretreated PM wood at two thermal levels. • SSF process at 35 °C is preferable compared to a higher trade-off level of 38 °C. • With optimal SSF at 35 °C, high ethanol titer (77 g/L) and yield (84%) were gained. • Optimal SSF at 35 °C can reduce energy demand while increasing ethanol production. The optimization of key simultaneous saccharification and fermentation (SSF) parameters for bioethanol production from phosphoric acid plus hydrogen peroxide pretreated paper mulberry wood was carried out under two isothermal scenarios; the yeast optimum and trade-off temperatures of 35 and 38 °C, respectively. The optimal conditions established for SSF at 35 °C (solid loading: 16%; enzyme dosage: 9.8 mg protein/g glucan; and yeast concentration: 6.5 g/L) achieved high ethanol titer and yield of 77.34 g/L and 84.60% (0.432 g/g), respectively. These corresponded to 1.2 and 1.3-folds increases, compared to the results of the optimal SSF at a relatively higher temperature of 38 °C. The information from this study would prove beneficial in reducing process energy demands to some extent, while also helping to achieve high levels of both ethanol concentration and yield that are desired in cellulosic ethanol production. [ABSTRACT FROM AUTHOR]

Agriculture and forestry yield enormous lignocellulosic biomass resources to produce bioenergy and bioproducts. To fully convert lignocellulosic biomass into high-value chemical components and manufactured products, phosphoric acid plus hydrogen peroxide (PHP) pretreatment was selected to fractionate them into cellulose-rich, water-soluble polysaccharides, and lignin fractions, and further upgraded into biofuel and biomaterials correspondingly. Results showed that the recalcitrant structure of the employed lignocellulose can be well disrupted the PHP, by which almost 100 % hemicellulose and 50.5–83.6 % lignin in these lignocellulosic biomasses can be removed. Correspondingly, the accessibility of cellulose hydrolytic enzymes was enhanced and achieved 100 % cellulose-glucose conversion, thus maximumly producing 18.4 g of bioethanol from 100 g of poplar hardwood. The acid hydrolysis ability of PHP facilitated the production of water-soluble polysaccharides with a high carbohydrate purity (98.3 %). The oxidation ability of PHP introduced additional carboxylic groups and aliphatic chains in lignin, which enhanced the amphiphilic properties of lignin to form uniform and stable lignin nanoparticles. The tailored PHP multiple product platform is thus applicable to achieve full conversion of agriculture and forestry residues into bioproducts as a sustainable biorefinery. [Display omitted] • Maximum converted lignocellulose waste into three high value-added bioproducts. • Multifunctional PHP technology allowed the facile upgradation of lignocellulose. • The maximum ethanol yield achieved at 18.4 g from 100 g lignocellulose by SSF. • The resulting high-value water soluble-polysaccharides exhibited high purity. • Mixed aromatic-aliphatic structure enhanced the amphiphilicity of lignin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mushrooms converted from lignocellulose were employed for biochar preparation. • Homogenization of precursors can be achieved by the mushroom cultivation. • Homogeneity of biochar properties can be improved via the homogenized precursors. • Homogenization of biochar properties can stabilize the application performances. To reduce the feedstock-sourced heterogeneity of biochar, mushrooms, cultivated from lignocellulosic feedstocks (LFs), were used as precursors for biochar preparation. The coefficient of variation (CV) was adopted to show the homogeneity changes. In contrast to LFs, mushrooms produced relatively lower CVs in terms of elemental and proximate analysis. Furthermore, the CV of H/C (9.20%) and O/C (13.32%) of mushroom-based biochars (MRBCs) was lower than that of LF-based biochars (LFBCs), suggesting more homogeneous aromaticity and hydrophilicity. The relatively lower CV of the volatile matter (0.87%), fixed carbon (0.45%), and ash (2.44%) of MRBCs suggested an improvement in the homogeneity of chemical components. The homogenized physical structure was reflected in the lack of a difference in pore characteristics of MRBCs. The lower CVs (1.89–14.82%) for the pollutant adsorption of MRBCs, implied more stable performance. In conclusion, converting LFs to mushrooms reduced the precursor's heterogeneity, consequently homogenizing the biochar's properties and performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Clean and facile fractionation of lignocellulose was achieved. • Lignocellulose was completely converted into three high-value nanomaterials. • Enhanced amphiphilicity of lignin fragments facilitated their self-assembly. • Cellulose swelling eased its mechanical nanofibrillation. An integrated technique of hydrothermal pretreatment coupling with deep eutectic solvent (DES) extraction was tailed to cleanly fractionate lignocellulose into three usable forms, i.e., water-soluble hemicellulose, cellulose-rich and lignin fractions, which were further upgraded to three nanomaterials, i.e., activated nanocarbons (ANCs), lignin-containing cellulose nanofibers (LCNFs), lignin nanospheres (LNSs) respectively. Almost 100% hemicellulose was solubilized in the hydrothermal pretreatment, which was used as carbon source to produce ANCs with rather high specific surface area (about 2680 m2 g−1) through in situ carbonation followed by activation. Cellulose-rich fraction was used to produce LCNFs with high aspect ratio (about 150) using facile mechanical refining. While the clean lignin fraction with enhanced amphiphilic properties was used to produce LNSs (223 nm diameter) using self-assembly method. The related mechanism was that condensed lignin could still be extracted by DES due to its excellent lignin solubility. The resulting lignin amphiphilicity provided a powerful driving force to enhance the self-assembly process thus compact LNSs was obtained. Meanwhile, the DES-swelled cellulose structure significantly facilitated the subsequent mechanical disintegration for LCNFs production. In this work, the proposed integrated technique platform realized the complete utilization concept of lignocellulosic biomass, and also provided three high-value nanomaterials product streams for downstream application towards an industrial relevant process. [ABSTRACT FROM AUTHOR]

A newly developed PHP (phosphoric acid plus hydrogen peroxide) pretreatment for lignocellulose is integrated to be a multi-product platform for bioethanol, lignin, and ultra-high surface area carbon; the performances of this multi-product strategy are investigated in this work. Based on PHP pretreatment platform, 100.0 g wheat straw yield 16.0 g ethanol from the cellulose fraction, and 7.2 g high purity lignin can be recovered from the derived liquid fraction in pretreatment. Activated carbon (PHPK-800) with ultra-high surface area of 3291 m2 g−1 can be produced from the water-soluble fractions derived from pretreatment. As electrode material for supercapacitor, PHPK-800 displays an excellent specific capacitance of 303.5 F g−1 at 0.5 A g−1, and retains 87.0% of initial specific capacitance with more than 95.0% coulomb efficiency after 5000 cycles. The fabricated symmetric supercapacitor harvests an excellent energy density of 13.2 Wh kg−1 with 199.9 W kg−1 power density. Besides, a superior CO 2 adsorption capability of 4.61 mmol g−1 is achieved by activated carbon of PHPK-700. According to these performances, PHP pretreatment platform is promising for converting lignocellulose into bioethanol, lignin and carbons by the biomass full utilization to achieve a more sustainable lignocellulosic refinery. • Efficient lignocellulose pretreatment with yielding ultra-high surface area carbon. • 100.0 g wheat straw yielded considerable ethanol of 16.0 g after pretreatment of PHP. • 7.2 g high pure lignin with low molecular weight was yielded from 100 g wheat straw. • High specific surface area carbons were featured with a large number of micropores. • Resultant carbons displayed an excellent specific capacitance and CO 2 adsorption. [ABSTRACT FROM AUTHOR]