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This experiment aimed to find the relation between image texture features of pellets made of various lignocellulosic materials (wood, wheat straw, hay, giant miscanthus, prairie spartina, and giant knotweed) and their physico-mechanical properties (density, compressive energy, maximum compressive strength, modulus of elasticity). Using the Kruskal-Wallis's test, the effect of materials on these properties was examined. Texture features were derived from the grey-level co-occurrence matrix, grey-level run-length matrix, absolute gradient matrix, autoregressive model, and wavelet decomposition, resulting in 86 features, later reduced to 8 factors via explanatory factor analysis. These factors were used as predictors in regression models for physico-mechanical properties. The models for modulus of elasticity achieved R2 adj values of 0.91–0.99 (except for hay and wood), compressive stress models achieved 0.65–0.99 (excluding hay and wood), compressive energy models ranged from 0.60 to 0.97 (excluding hay), and density models ranged from 0.56 to 0.97 (excluding wood). The study confirmed a significant correlation between material type, texture parameters and compression resistance, suggesting this method could monitor pellet quality in production. [ABSTRACT FROM AUTHOR]

[Display omitted] Lignocellulosic materials (LMs) are abundant feedstocks with excellent potential for biofuels and biocommodities production. In particular, nut and coffee wastes are rich in biomolecules, e.g. sugars and polyphenols, the valorisation of which still has to be fully disclosed. This study investigated the effectiveness of ultrasounds coupled with hydrothermal (i.e. ambient temperature vs 80 °C) and methanol (MeOH)-based pretreatments for polyphenols and sugar solubilisation from hazelnut skin (HS), almond shell (AS), and spent coffee grounds (SCG). The liquid fraction obtained from the pretreated HS was the most promising in terms of biomolecules solubilisation. The highest polyphenols, i.e. 123.9 (±2.3) mg/g TS, and sugar, i.e. 146.0 (±3.4) mg/g TS, solubilisation was obtained using the MeOH-based medium. However, the MeOH-based media were not suitable for direct anaerobic digestion (AD) due to the MeOH inhibition during AD. The water-based liquors obtained from pretreated AS and SCG exhibited a higher methane potential, i.e. 434.2 (±25.1) and 685.5 (±39.5) mL CH 4 /g glucose in , respectively, than the HS liquors despite having a lower sugar concentration. The solid residues recovered after ultrasounds pretreatment were used as substrates for AD as well. Regardless the pretreatment condition, the methane potential of the ultrasounds pretreated HS, AS, and SCG was not improved, achieving maximally 255.4 (±7.4), 42.8 (±3.3), and 366.2 (±4.2) mL CH 4 /g VS, respectively. Hence, the solid and liquid fractions obtained from HS, AS, and SCG showed great potential either as substrates for AD or, in perspective, for biomolecules recovery in a biorefinery context. [ABSTRACT FROM AUTHOR]

After acidic and high-temperature pretreatment of lignocellulosic biomass, researchers find that some lignin-like substance appeared on the surface of cellulose, which is called pseudo-lignin. Pseudo-lignin can be formed through carbohydrate degradation or substitution reactions on the aromatic ring of lignin. Pseudo-lignin is identified as Klason lignin in compositional analysis, whereas in Py-GC-MS analysis, it is recognized as material derived from carbohydrates. Pseudo-lignin is an aromatic substance. Similar to lignin, it also affects enzymatic hydrolysis efficiency by blocking the enzymatic reaction sites of cellulose and non-productive adsorption with cellulases. In order to offer theoretical guidance and technical support for the advancement of cost-effective and efficient new pretreatment technology, this review summarizes the latest advancements in research concerning the origins of pseudo-lignin, its effects on enzymatic hydrolysis, and the strategies that inhibit pseudo-lignin formation. • Different pretreatment methods that result in the formation of pseudo-lignin are reviewed. • The specific mechanism of pseudo-lignin formation is clarified. • The deposition of pseudo-lignin inhibits enzymatic hydrolysis. • Measures to hinder the formation of pseudo-lignin are discussed. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass is an important raw material which has been extensively studied for biotechnological applications, but research on its use for the production of γ-polyglutamic acid (γ-PGA) is rarely reported. The present study aimed to improve the release of xylose and glucose from corncob for γ-PGA production using the strain Bacillus subtilis SCP010-1, which could metabolize xylose. The effectiveness of the three chemical reagents NaOH, NH3 and H2O2 pretreatments was investigated by the response surface methodology (RSM). The results showed that maximum glucose and xylose yields of 11.8 ± 0.3 and 17.36 ± 0.6 g/L, respectively, as determined by phloroglucinol-acid and enzymatic methods, were obtained when using 0.986% of NaOH for 2.07 h. Then, the pretreatment solution was subject to further optimize conditions of enzymatic hydrolysis, and the content of glucose and xylose in the corncob hydrolysate reached respectively 15.3 ± 0.3 and 22.34 ± 0.17 g/L under synergism of hemicellulase and cellulase. Finally, the fermentation conditions for γ-PGA production by B. subtilis SCP010-1 were also optimized, and after adding supplemental nutrients to the corncob hydrolysate, a maximum γ-PGA production of 30.035 ± 0.49 g/L was achieved by fed batch fermentation with feeding corncob hydrolysate. Considering the cost of the materials used in this study, nearly 85% of reduction in cost could be achieved, hence indicating that this production plan offers good prospects for industrial production of γ-PGA. More importantly, this process allows the use of environmental-friendly biological resources. [ABSTRACT FROM AUTHOR]

• PNS is a sustainable filler to develop cost-effective PLA biocomposites. • PNS enhanced PLA thermal stability, viscoelastic response, and crystallinity. • High filler loading did not cause significant decay in mechanical properties. • Ball milling of PNS further improved PLA thermal properties and melt fluidity. • Thermal annealing enhanced HDT, stiffness and strength of biocomposites. Biodegradable polymer composites reinforced with agri-food lignocellulosic biowaste represent cost-effective and sustainable materials potentially able to replace traditional composites for structural, household, and packaging applications. Herein, the preparation of polylactic acid (PLA)/pecan (Carya illinoinensis) nutshell (PNS) biocomposites at high filler loading (50 wt%) is reported, alongside the effect of two environmentally friendly physical treatments, namely ball-milling of the filler and thermal annealing on biocomposites. PNS enhanced the thermal stability, the viscoelastic response, and the crystallinity of the polymer. Furthermore, filler ball-milling also increased the melt fluidity of the biocomposites, potentially improving melt processing. Finally, the presence of PNS remarkably enhanced the effect of thermal annealing in the compounds. In particular, heat deflection temperature of the biocomposites dramatically increased, up to 60 °C with respect to the non-annealed samples. Overall, these results emphasize the potential of combining natural fillers and environmentally benign physical treatments to tailor the properties of PLA biocomposites, especially for those applications which require a stiff and lightweight material with low deformability. [ABSTRACT FROM AUTHOR]

The use of biocontrol agents to control soilborne diseases is a promising alternative to chemical pesticides, however, obtaining a homogeneous distribution and incorporation of conidia of fungal biocontrol agents into the soil is often difficult. Several carriers/formulations have been proposed over time, unfortunately without offering an ultimate solution. We propose the use of wood pellets as a carrier of conidia of a saprophytic fungus that has good biodegradation and biocontrol properties (Trichoderma atroviride SC1). The coating process is based on the direct spraying of wood pellets with a conidial suspension at different rates. Beech, fir, and chestnut wood pellets were compared in terms of relevant physicochemical traits and efficacy in supporting the growth of the fungus. Beech wood pellets displayed the best characteristics in terms of water holding capacity, swelling properties, and disintegration time. T. atroviride SC1 grows best on beech and fir wood pellets and reaches a plateau after nine days of incubation, regardless of the initial coating concentrations. The addition of small quantities of a nitrogen source as tryptone or soy flour, soy proteins, and a mixture of animal proteins used as pet food to the conidial suspension can increase the growth by ten-folds on all types of wood pellets. Our results demonstrate that beech and fir wood pellets could be suitable carriers to deliver and sustain the growth of T. atroviride SC1. • New method for coating wood pellets with a conidial suspension of Trichoderma spp. • Beech wood showed the best physicochemical characteristics. • Trichoderma atroviride SC1 can grow on soft wood (fir) as well as hardwood (beech). • Adding tryptone (1 g/L) can enhance the growth of T. atroviride SC1 on wood. • Tryptone can be substituted by soy protein isolates for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful heterologous expression of T. thermophilus CDH in A. nidulans. • CDH demonstrating inter-domain electron transfer in slightly alkaline pH. • CDH oxidize cellooligosaccharides from various degree of polymerization. • Cell-free system for CBA production using hydrolytic and oxidative cocktail. • Sustainable production of CBA from lignocellulosic materials. The fungus Thermothelomyces thermophilus is a thermotolerant microorganism that has been explored as a reservoir for enzymes (hydrolytic enzymes and oxidoreductases). The functional analysis of a recombinant cellobiose dehydrogenase (MtCDHB) from T. thermophilus demonstrated a thermophilic behavior, an optimal pH in alkaline conditions for inter-domain electron transfer, and catalytic activity on cellooligosaccharides with different degree of polymerization. Its applicability was evaluated to the sustainable production of cellobionic acid (CBA), a potential pharmaceutical and cosmetic ingredient rarely commercialized. Dissolving pulp was used as a disaccharide source for MtCDHB. Initially, recombinant exoglucanases (MtCBHI and MtCBHII) from T. thermophilus hydrolyzed the dissolving pulp, resulting in 87% cellobiose yield, which was subsequently converted into CBA by MtCDHB, achieving a 66% CBA yield after 24 h. These findings highlight the potential of MtCDHB as a novel approach to obtaining CBA through the bioconversion of a plant-based source. [ABSTRACT FROM AUTHOR]

As the rapid increasing demand for electrical energy in the world, the research on electrical energy storage becomes urgent and crucial, especially for these ones with the features of cost-effectiveness, high safety and outstanding performance. Aqueous zinc ion batteries (AZIBs) are regarded as environmentally friendly, safe, reliable, and promising devices for electrochemical energy storage systems. However, a variety of challenges such as zinc dendrite formation, corrosion and hydrogen evolution must be addressed for the practical, widespread application of AZIBs. Recently, there has been notable interest in utilizing renewable, biodegradable, and cost-effective lignocellulosic materials to address these challenges, as they have the potential to significantly improve the electrochemical performance of AZIBs. However, there is a lack of comprehensive and systematic summary, as well as a gap in theoretical analysis, on the role of lignocellulosic materials in improving AZIBs performance. The present review covers the development, concept, advantages, and challenges of AZIBs. The most recent advancements and progress on the lignocellulosic materials (including cellulose, lignin, and hemicelluloses) as electrodes, electrolytes and separators for AZIBs applications are summarized. A perspective on existing challenges, potential solutions, and promising prospects of lignocellulosic materials is outlined, aiming to provide the research community with essential technical insights that could drive the commercialization of green and sustainable lignocellulosic materials in high-performance AZIBs. [Display omitted] • The advantages and current challenges of AZIBs have been systematically discussed. • The recent progress of developing lignocellulosic materials for AZIBs has been reviewed. • The strategies for improving the performance of AZIBs via incorporating lignocellulosic materials have been summarized. • The challenges and perspectives in developing lignocellulosic materials for advanced AZIBs have been addressed. [ABSTRACT FROM AUTHOR]

Lignocellulosic materials are mainly composed of cellulose, hemicellulose, and lignin. They have been extensively used in recent years to obtain new value-added products, such as xylitol, vanillin, activated carbon, oligosaccharides, biofuels, among others. Biomass needs a pre-treatment to promote the breaking of the bonds that link the rigid macrostructures. The most common conventional pre-treatments are chemical. However, they cause significant damage to the environment since they either use toxic chemicals or produce waste, causing disposal problem. Non-thermal plasma is considered an environmentally friendly technique and is increasingly explored as a method of treatment and/or pre-treatment of lignocellulosic materials. In this review, we cover the main topics related to the use of non-thermal plasma technology (NTP) as a clean technology for the treatment of different lignocellulosic materials. We also address the main works on the subject and the main effects of this promising technology on different biomass. In addition to the main characterization techniques, we could find that it is possible to use this technique as an effective pre-treatment for future obtaining value-added products from different residues discarded in large quantities. Then, the main contribution of this review is to critically show the efficiency of this technology as an innovative and promising way to the treatment of different lignocellulosic residues. Image 1 • Potential application of non-thermal plasma (NTP) in lignocellulosic materials. • Use of NTP is considered non-toxic, viable and environmentally friendly. • Pre-treatment using NTP causes delignification due to the action of the ozone. • Prospects for the use of non-thermal plasma in lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

The inter-particle interference of lignocellulosic materials describes the order of the macromolecules at a larger size scale, which can give information about the pore structure, and interface of cellulose and lignin. The pore structure and interface influence the rate of enzymatic hydrolysis and thermal decomposition in cellulosic ethanol manufacturing. In this study, the inter-particle interference of cellulose and lignin of three major categories of lignocellulosic materials: wood-based (cedar and oak), energy crop (bamboo), and agricultural or forestry waste (palm) were evaluated. Scanning electron microscopy (SEM) reveals morphological irregularities in the case of bamboo and palm, which may form nucleation sites for faster accessibility to enzyme molecules. Small-angle X-ray scattering (SAXS) shows increased power-law exponent for palm, suggesting a less clustered structure, which was consistent with the rough surface morphology as detected by the SEM. Differential Scanning Calorimetry (DSC) showed a higher temperature maximum for cedar and oak, which is indicative of higher intermolecular forces within their organic compounds, and could result in slower disintegration of the macromolecules during biochemical processing. This study will help to estimate the activity of the macromolecules and absorption capacity of lignocellulosic materials during biochemical processing. • Increased power-law exponent for palm, suggesting a less clustered structure. • SEM revealed nucleation sites for bamboo and palm for faster digestibility. • Higher temperature maximum indicates higher intermolecular forces. • The degradation rate depends on the stability of the macromolecules. • Results can estimate the activity and absorption capacity of cellulosic materials. [ABSTRACT FROM AUTHOR]

• Lignocellulosic materials were compared for suitability in ethanol production. • Results can facilitate cost-effective mixture of cellulosic materials. • Bamboo showed the highest crystallinity (49.5%) and size (4.1 nm) derived from WAXS. • TGA revealed stable structure for cedar and oak, and unstable structure for palm. • Palm with fewer effective materials suggests a cheaper process with a lower yield. The study of lignocellulosic materials calls for understanding the structure, and function of different cellulosic materials from diverse sources to scale-up cellulosic ethanol production. For the first time, a systematic assessment of the molecular and supramolecular structure highlighting the similarities and dissimilarities of three major categories of lignocellulosic materials: wood-based (cedar and oak), energy crop (bamboo), and agricultural or forestry waste (palm) are reported. The cellulose, hemicellulose, and lignin constituents were compared for their suitability in cellulosic ethanol production. FTIR showed structural variations within the functional groups with notable O H group in the palm and C C group in cedar. From the X-ray scattering, bamboo exhibited the highest crystallinity (49.5%), and palm showed the lowest crystallinity (22.6%) and crystallite size (2.6 nm). TGA revealed high cellulose amount and stable structure for cedar and oak, and the most unstable structure in the palm, which indicates a better cellulose/hemicellulose accessibility and biodegradability for enzymatic or chemical action in the palm. This comparative assessment can greatly facilitate material selection and component mixture, for developing an efficient and cost-effective biochemical process in ethanol manufacturing. [ABSTRACT FROM AUTHOR]

Microcrystalline cellulose (MCC) was successfully synthesized from sugarcane bagasse using a rapid, low-temperature hydrochloric acid (HCl) gas treatment. The primary aim was to develop an energy-efficient "green" cellulose extraction process. Response surface methodology optimized the liquid-phase hydrolysis conditions to 3.3 % HCl at 117 °C for 127 min to obtain MCC with 350 degree of polymerization. An alternative gas-phase approach utilizing gaseous HCl diluted in hot 40 °C air was proposed to accelerate MCC production. The cellulose pulp was moistened to 15–18 % moisture content and then exposed to HCl gas, which was absorbed by the moisture in the cellulose fibers to generate a highly concentrated acidic solution that hydrolyzed the cellulose. The cellulose pulp was isolated from depithed bagasse through soda pulping, multistage bleaching and cold alkali purification. Hydrolysis was conducted by saturating the moist cellulose fibers with gaseous HCl mixed with hot air. Extensive analytical characterization using FT-IR, XRD, SEM, TGA, DSC, particle size, and porosity analyses verified comparable physicochemical attributes between MCC samples prepared via liquid and gas phase methods. The gas-produced MCC revealed 85% crystallinity, 71 Å crystallite dimensions, and thermally stable rod-shaped morphology with an average diameter below 200 μm. The similar material properties validate the proposed gas-based technique as an equally effective yet more energy-efficient alternative to conventional aqueous acid hydrolysis for fabricating highly pure MCC powders from lignocellulose. This sustainable approach enables the value-addition of sugarcane bagasse agro-industrial residue into cellulosic nanomaterials for wide-ranging industrial applications. In summary, the key achievements of this work are rapid MCC production under mild temperatures using HCl gas, optimization of liquid phase hydrolysis, successful demonstration of gas phase method, and extensive characterization verifying equivalence between both protocols. The gas methodology offers a greener cellulose extraction process from biomass. [ABSTRACT FROM AUTHOR]

Cellulose is an organic compound belonging to polysaccharides. This biopolymer is made of glucose subunits. This compound plays an essential role in the structure and strength of plants. This polymer has biodegradable, biocompatible, and renewable properties. Agricultural wastes are excellent sources for cellulose extraction. Agricultural wastes are lignocellulosic materials, and cellulose and lignin are the main components of these wastes. Millions of tons of agricultural waste are thrown away and burned yearly. This large amount of waste leads to environmental pollution and waste of renewable energy resources. Upgrading such waste by developing innovative products such as cellulose nanomaterials and nanocomposites can have high environmental and economic benefits. The intelligent use of agricultural waste as a rich source of cellulose can be primarily responsible for the increase in population and industrialization of countries. Optimal cellulose extraction from agricultural waste can be widely used in various fields of agriculture, industry, medicine, and energy. Different chemical, physical, physicochemical, and biological methods have been presented to extract cellulose and its derivatives from agricultural waste. In this review, we will discuss the position and importance of cellulose, the importance of agricultural waste in the extraction of cellulose, and the use of extracted cellulose from agrarian wastes in various sources. • Agricultural wastes as an excellent source for cellulose extraction. • The use of agricultural waste intelligently to extract cellulose and use it in various industries. • Cellulose extracted from agricultural waste as a natural biocompatible and degradable polymer can greatly interest agriculture. [ABSTRACT FROM AUTHOR]

In this work, a dual-chamber microbial electrolysis cell (MEC) with concentric cylinders was fabricated to investigate hydrogen production of three different lignocellulosic materials via simultaneous saccharification and fermentation (SSF). The maximal hydrogen production rate (HPR) was 2.46 mmol/L/D with an energy recovery efficiency of 215.33 % and a total energy conversion efficiency of 11.29 %, and the maximal hydrogen volumetric yield was 28.67 L/kg from the mixed substrate. The concentrations of reducing sugar and organic acids, the pH, and the current in the MEC system during hydrogen production were monitored. The concentrations of reducing sugar, butyrate, lactate, formate, and acetate initially increased during SSF and then decreased due to hydrogen production. Moreover, the highest current was obtained from the mixed substrate, which means that the mixed substrates are beneficial to microbial growth and metabolism. These results suggest that lignocellulosic materials can be used as substrate in a low-energy-input dual-chamber MEC system for hydrogen production. • Lignocellulosic materials were used for H 2 production through SSF in a MEC system. • The maximal H 2 yield was 2.56 mmol with an energy recovery efficiency of 215.33%. • The reducing sugar, butyrate, lactate, formate, and acetate were key intermediates. • Butyrate and lactate significantly influenced H 2 production. • The maximal current was obtained from the mixed substrate during SSF in the MEC. [ABSTRACT FROM AUTHOR]

Abstract Safflower straw, an abundant, inexpensive, and renewable lignocellulosic waste, was used as a substrate of anaerobic digestion to produce biogas. Hydrothermal pretreatment was carried out on the straw at 120, 150, and 180 °C for 1, 2, and 5 h to increase the biogas yield. The pretreatment resulted in a solid (mainly cellulose) and a liquid (mainly hemicellulosic monomers). The highest biomethane yield from solid fraction (191.4 NmL/g VS) was obtained at the least severe pretreatment conditions (120 °C for 1 h), which showed 98.3% improvement in comparison to the untreated straw. The maximum methane yield of 406.9 NmL/g VS was attained from the liquid fraction of pretreatment at 180 °C for 1 h. Overall, at the optimum pretreatment conditions (120 °C for 1 h), 148.4 m3 methane was produced from each ton of pretreated safflower straw, whereas the methane production from the untreated straw was 86.9 m3 methane. Furthermore, enzymatic hydrolysis was carried out on solid fractions. The results revealed that the most severe pretreatment conditions (180 °C for 5 h) led to the highest released sugar concentration of 25.1 g/L using the enzyme loading of 10 FPU/g substrate, while it was only 4.5 g/L for the untreated one. Graphical abstract Image 109 Highlights • Hydrothermal pretreatment of safflower straw was studied for biogas production. • The pretreatment solid and liquid fractions were subjected to anaerobic digestion. • Hydrothermal pretreatment of safflower straw significantly improved biogas yield. • Maximum biogas yield was obtained at low severity pretreatment conditions. [ABSTRACT FROM AUTHOR]

Highlights • Ultrasound-assisted acid hydrolysis (UAAH) of lignocellulosic biomass conversion into furfural. • Reaction time, ultrasound amplitude, and feedstock amount were evaluated using a cup horn system. • UAAH is performed at atmospheric pressure and under milder reaction conditions in contrast to conventional process. • Lignin removal is not required in the present UAAH procedure. • About 7.2% of grass (whole mass) was converted to furfural, using. • 4 mol L−1 HNO 3 , at 30 °C, 50% of amplitude and 60 min of sonication. Abstract Furanic platforms (e.g. furfural, furfuryl alcohol and hydroxymethylfurfural) can be obtained from biomass, being considered as a green alternative to petrochemical products such as fuels, and solvents. In this work, the use of ultrasound energy was investigated for the conversion of several lignocellulosic materials into furfural. The following parameters were evaluated: reaction time (30 to 120 min), ultrasound amplitude (20 to 70%) and feedstock amount (100 to 500 mg). The ultrasound-assisted acid hydrolysis (UAAH) process was applied to several lignocellulosic materials (sugar cane straw, rice husk, yerba-mate waste, grass and wood waste) aiming an investigation about the effects when working with real and complex feedstock. Better furfural yields (72.4 ± 4.3 mg g−1) were obtained from 0.1 g of grass, employing an ultrasound cup horn system operating at 20 kHz, 20 mL of 4 mol L−1 HNO 3 , at 30 °C, 50% amplitude, and 60 min of sonication. Under the same reaction conditions, the results were compared with those obtained at silent condition (mechanical stirring, 100 to 500 rpm), which demonstrate the ultrasound effects for furfural synthesis. Therefore, the proposed UAAH process can be considered as a suitable alternative for biomass conversion to furfural, because it does not need previous step of lignin removal and might be performed in a single step. [ABSTRACT FROM AUTHOR]

Abstract Working at high values of lignocellulosic Dry Matter (DM), as wheat straw, increases the reaction medium viscosity, making the mixing inefficient with the traditional agitators. Batch and fed-batch tests were conducted using different impellers: i) inclined blades, ii) marine impeller, iii) anchor, iv) paravisc and v) double helical impeller. Inclined blades appeared an inadequate device for batch and fed-batch tests. On contrary, double helical impellers and anchor gave optimal performances. An alternative to improve the reactor's rheology is the modification of the feeding strategy. A particular fed-batch strategy allowed keeping low the reaction medium viscosity by a gradual increasing of the DM content in the reactor. In this way, three main benefits were achieved: i) a very good performances in terms of glucose concentration (85 g/L), ii) a strong reduction of the energetic consumption compared to batch test and iii) the adoption of a simple mixing devise. Graphical abstract Image Highlights • Enzymatic hydrolysis from wheat straw causes bad mixing at high DM content. • Different impellers have been tested in batch and fed-batch mode. • Small impellers were inefficacy, double helical impeller had high performances. • A fed-batch strategy (FBGA) has been implemented to use small impellers. • FBGA allowed to minimize energy consumption and to increase the glucose yield. [ABSTRACT FROM AUTHOR]

The present work provides a comprehensive study on the utilization of rapeseed stalks, an agricultural waste, as a raw material for the production of resin-free fiberboards and particleboards, using LCNFs as binder. The rapeseed stalks underwent appropriate crushing and fibrillation and were combined with a novel class of lignocellulosic nanofibers (LCNFs) derived from date palm waste, another agricultural residue. The incorporation of LCNFs in both fiberboards and particleboards resulted in increased density and enhanced mechanical properties, dimensional stability, and fire resistance. These positive effects can be attributed to several factors. Firstly, the incorporation of LCNFs led to a reduction in porosity, positively impacting the modulus of rupture, modulus of elasticity, and internal bonding of the produced fiberboards and particleboards. Notably, fiberboards containing 15 wt% LCNF exhibited superior specific properties compared to our commercial reference. Additionally, this densification effect mitigated moisture absorption and thickness swelling, as even a 2 wt% incorporation of LCNF in fiberboards showed reduced values for both properties. Secondly, the high lignin content of the LCNFs contributed to decreased hydrophilicity in the fiberboards and particleboards, leading to significant improvements in water contact angle, water absorption, and thickness swelling. Lastly, the increased density of the fiberboards and particleboards resulted in improved fire resistance, with flame propagation time being higher for all boards containing LCNFs, even at low content (2 wt%), compared to the commercial fiberboard. Notably, fiberboards demonstrated superior performance compared to particleboards, attributed to factors such as low cohesion, particle heterogeneity, and excessive porosity. Overall, this study demonstrates the feasibility of utilizing agricultural waste as a raw material for board production, eliminating the need for urea-formaldehyde resins and paraffin waxes commonly found in commercial fiberboards. [Display omitted] • Fiber- and particleboards from rapeseed stalks and date palm wastes were produced. • LCNFs provided improved mechanical performance and dimensional stability. • Fire retardancy of fiberboards was better than the commercial reference. • Density plays a key role in the main properties of particleboards and fiberboards. • Lignin from LCNFs were determinant in the hydrophobization and fire retardancy. [ABSTRACT FROM AUTHOR]

Abstract Activated carbons have been prepared by phosphoric acid activation of lignocellulosic precursors, an industrial method, followed by heat treatment in ammonia. Thus, a cost-effective, scalable and metal-free electrocatalyst was developed for use in oxygen reduction reaction (ORR) at fuel cell cathodes. The physicochemical properties of the activated carbons have been analyzed by elemental analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen adsorption. The ORR electrocatalytic performances of the activated carbons have been investigated by cyclic voltammetry and linear sweep voltammetry in an alkaline electrolyte. The results showed that phosphorus-containing groups are key to endowing phosphoric-acid-activated carbons with comparable electrocatalytic activity to that of commercial Pt/C. This was because these phosphorus-containing groups facilitated the formation of both nitrogen-containing groups and defects in the microstructure. Besides, heat treatment of phosphoric-acid-activated carbons in ammonia produced a highly developed mesopore structure and thus kinetically facilitated the ORR. Graphical abstract Image 1 Highlights • Electrocatalysts were prepared by H 3 PO 4 activation of lignocellulosic materials. • The phosphorus-containing groups favor the formation of nitrogen-containing groups. • Phosphoric-acid-activated carbons modified by ammonia possess developed mesopore. • Phosphoric-acid-activated carbons modified by ammonia show excellent ORR activity. [ABSTRACT FROM AUTHOR]

A novel anion exchanger was prepared by modifying poplar sawdust (PSD) with 3-chloro propyl trimethoxysilane and (1,4-diazabicyclo[2.2.2]octane). After characterizing the physicochemical properties of PSD and modified PSD (MPSD), the effects of various operational conditions on nitrate adsorption by MPSD were examined. The results indicated that the MPSD removed over 98% of nitrate from water at optimum operation conditions, i.e. Ci = 20 mg L−1; pHi = 7; T = 25 ± 1°C; adsorbent dosage = 2 g L−1; and contact time = 30 min. Kinetic studies showed that the adsorption process followed the pseudo-second- order model and was a three-step process. Among the equilibrium isotherms, Freundlich model provided the best fit to the experimental data, which demonstrated multilayer adsorption of nitrate on heterogeneous surfaces. According to thermodynamic studies, the nitrate adsorption by MPSD was exothermic (ΔH° < 0) and spontaneous (ΔG° < 0) in nature. Among the studied competing anions, sulfate had the maximum inhibition effect on the nitrate adsorption by MPSD, while phosphate had the minimum effect. In a nutshell, it can be concluded from the experimental results that the MPSD was an efficient and economical adsorbent for nitrate removal from water. [ABSTRACT FROM AUTHOR]

The higher heating values (HHVs) of 11 non-wood lignocellulosic materials from Turkey were measured experimentally and calculated incorporating various theoretical models with the values of both lignin and extractive contents. Multiple linear regression (MLR) and real valued genetic algorithm (RVGA) were used to derive the theoretical models. A non-linear RVGA6 model was determined as the best non-linear model considering the experimental results with a regression coefficient of 92% coefficient of determination ( R 2 ), 0.301 sum of squared errors ( SSE ), 0.301 mean squared errors ( MSE ), 0.548 root mean squared errors ( RMSE ) and 0.0187 mean absolute percentage error ( MAPE ) and is proposed as a better alternative for theoretical HHV calculations to the multiple linear modellings such as MLR and RVGA1. [ABSTRACT FROM AUTHOR]

Protection of environment is of immediate concern and this can only be achieved by avoiding the use of chemicals for fuel production. Lignocellulosic waste is becoming popular as a feedstock for biofuel production. The can be converted into usable form for biofuel production by using a suitable pretreatment method. Different pretreatment methods have been used by researchers which are physical, chemical, physico-chemical, biological and combined pretreatments. Evidently chemical pretreatment is found to be more expensive as a large amount of chemicals are used for pretreating the lignocellulosic substrate. It has been shown that combined pretreatments are more effective as compared to single pretreatment and there is an extensive scope of combinations which can also be applied in future. Recent review critically discusses and compares different pretreatment methods, biomass resources, chemical composition of different agricultural biomass and the use of this biomass for bioenergy generation. Various pretreatment processes used for bio-hydrogen, bio-methane, bio-ethanol, bio-methanol bio-butanol and bio-diesel production are also discussed. [ABSTRACT FROM AUTHOR]

The goal of this study was to sequential fermentation of hydrogen and methane from sugarcane bagasse (SCB). Steam explosion conditions for pretreating SCB were optimum at 195 °C and 1.5 min, which yielded 36.35 g/L of total sugar and 2.35 g/L of total inhibitors. Under these conditions (all in g/L): glucose, 11.33; xylose, 24.41; arabinose, 0.61; acetic acid, 2.33; and furfural, 0.02 were obtained. The resulting hydrolysate was used to produce hydrogen by anaerobic mixed cultures. A maximum hydrogen production rate of 396.50 mL H 2 /L day was achieved at an initial pH of 6 and an initial total sugar concentration of 10 g/L. The effluent from the hydrogen fermentation process was further used to produce methane. Response surface methodology with central composite design was used to obtain the suitable conditions for maximizing methane production rate (MPR). An MPR of 185.73 mL/L day was achieved at initial pH, Ni and Fe concentrations of 7.59, 3.61 mg/L and 8.44 mg/L, respectively. Total energy of 304.11 kJ/L-substrate was obtained from a sequential fermentation of hydrogen and methane. This approach will not only add value to SCB, in the form of safe and clean energy, but also provide a solution for making use of this abundant waste. [ABSTRACT FROM AUTHOR]

Bio-based natural macromolecules are primarily composed of complex polysaccharides that strengthen microbial growth for the production of industrially relevant enzymes. In this study, an initial range of natural materials was used as fungal growth and solid substrates for the support of enzyme production. After the stipulated fermentation time (72 h), a large quantity of pectinolytic cocktail complex, composed of polygalacturonase (PG), pectin lyase (PL), and pectin methylesterase (PME), was obtained. Following the initial solid substrate screening, the effects of the different parameters were optimized through response surface methodology (RSM) by adopting a central composite design (CCD) using the best-yielded material. The crude pectinolytic cocktail complex showed commendable results in the de-bittering of the investigated fruit juices. A considerable color and turbidity reduction from 100% to 45.0% and 32.5%, respectively, was recorded for apple juice. For orange juice, the color and turbidity significantly decreased by up to 38.2% and 31.6%, respectively. In conclusion, the maximum production of the pectinolytic cocktail complex in the presence of a cheaper substrate at a low concentration makes the enzyme useful for industrial sectors, especially in the juice industry. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the capacity a cellulolytic complex produced by Rhizopus oryzae has to provide functional compounds from lignocellulosic material. Its characterization upon soybean meal (SBM) and corn husk (CH) was carried out. The effect was estimated in terms of cellulose reduction and protein and starch digestibility, besides the content of phenolic compounds (PC) and their profiles. Enzymatic hydrolysis caused 34% cellulose reduction in SBM whereas, in CH, it was 55%. In CH, the reduction promoted PC release (21%). The greatest change in the antioxidant activity after hydrolysis was found in phenolic compounds soluble in methanol (PCSM), a fact that could be attributed to concomitant reduction in ferulic acid and increase in hydroxybenzoic acid. In SBM, the activity of the cellulolytic complex caused increases in protein (74%) and starch (95%) digestibility. Therefore, available protein in SBM can be used as food supplement and thickener whereas PC derived from CH may be applied as food additive. [ABSTRACT FROM AUTHOR]

The present work investigates the impact of the physical properties and loading strategies of wheat straw and miscanthus on enzymatic hydrolysis at high DM concentration. Three parameters have been chosen to evaluate the enzymatic hydrolysis performance: (i) the mixing time, (ii) the energetic mixing consumption and (iii) the glucose concentration. It was demonstrated that the hydrolysis of miscanthus is easy to perform and has low viscosity. On the contrary, the higher porosity grade of wheat straw than miscanthus (73% against 52%) contributed to have a very high viscosity at 20% w/w DM. The development of a fed-batch strategy allowed the reduction of viscosity inducing the energetic consumption lowering from 30 kJ to 10 kJ. It has been also proven that the miscanthus addition in wheat straw achieved to decrease mixing energy consumption at 5–8 kJ, when it represented more than 30% of the total mass of the reaction medium. [ABSTRACT FROM AUTHOR]

The issue of mercury pollution in environmental remediation has garnered significant attention due to its severe health hazards to humans. Various strategies have been devised to mitigate the impact of toxic mercury ions, including coagulation, ion exchange, adsorption, membrane technology, and electrochemical treatment. Among these approaches, adsorption has emerged as an efficient and widely employed method for the uptake of low concentrations of mercury ions. It offers convenient operation, high removal efficiency, and facile regeneration of the adsorbent. Wood, being the most abundant renewable and sustainable bioresource, has garnered attention as a promising material for treating heavy metal wastewater. This is attributed to its unique physical and chemical characteristics, encompassing hierarchical pores, aligned channels, active functional groups, biodegradability, and cost-effectiveness. However, a comprehensive examination of the cutting-edge applications of wood and wood-derived biopolymers in the detection and removal of mercury ions from wastewater has yet to be undertaken. Consequently, this article presents a chronological overview of recent advancements in materials and structures derived from bulk wood and its constituents, including cellulose, lignin, hemicellulose, and tannin, with a specific focus on their utility in detecting and eliminating mercury from water sources. Subsequently, the most promising techniques and strategies involving wood and wood-derived biopolymers in addressing the predicament of mercury pollution are explored. Furthermore, this piece offers insights into the existing challenges and future prospects concerning environmentally friendly materials derived from wood, aiming to foster the development of cost-effective mercury adsorbents and detection devices. [Display omitted] • Mercury pollution is a serious threat to ecology and human health. • The inherent components and structures of wood are discussed. • Wood-derived materials used to tackle mercury pollution problems are summarized. • Current problems and future perspectives are proposed. [ABSTRACT FROM AUTHOR]

The cleaning of water polluted by toxic geogenic compounds is challenging and demands novel, sustainable and low-cost adsorbents. To address this environmental problem, agricultural wastes functionalized with lanthanum have been studied for the depollution of arsenate and fluoride in aqueous solution. A simple and straightforward approach was utilized to anchor lanthanum on the surface of avocado seed, cauliflower stem, and macadamia nut shell wastes with the aim of effectively removing these toxic water pollutants and avoiding the microorganism growth on the biomass and its degradation during prolonged equipment operation. The adsorption mechanism using these modified biomass samples was endothermic and multi-ionic, involving up to two arsenate and three fluoride ions that can interact with the biomass surface functionalities. The simultaneous adsorption of these pollutants was antagonistic, and the co-anion concentration inhibited the adsorption of target geogenic pollutants. Overall, the fluoride adsorption properties of these modified lignocellulosic wastes were better than those for arsenate. The antibacterial activity of the lanthanum-modified biomass samples may enable for their use in packed-bed columns for long-term water treatment processes. The adsorption and antimicrobial properties of these functionalized biomass residues are promising for the implementation of efficient and economic processes for purifying water contaminated by arsenate and fluoride. [Display omitted] • Lanthanum-functionalized biomass wastes removed arsenate and fluoride from water. • Simultaneous fluoride and arsenate adsorption was antagonistic. • Cauliflower stems functionalized with lanthanum was the best adsorbent. • Lanthanum-functionalized biomass wastes showed antibacterial properties. [ABSTRACT FROM AUTHOR]

The termite gut contains different kinds of lignin and lignocellulose degrading microbes. This study was conducted to isolate and identify termite gut symbiotic bacteria with lignocellulose-degrading potential, and evaluate their effects on the chemical composition and in vitro digestibility of wheat straw and date leaves. Termite gut contents were extracted and cultured in 9 different culture media containing lignin and lignocellulosic materials that had been prepared from water-extracted sawdust and wheat straw. Three superior bacteria capable of growing on all media, and with higher lignin peroxidase activity, were selected and subjected to molecular identification. Following this, wheat straw and date leaves were incubated with the isolated bacteria in liquid medium for 6 weeks. 16S rRNA sequence analysis showed that these isolates possessed 97, 99 and 97% similarity with Bacillus licheniformis , Ochrobactrum intermedium and Microbacterium paludicola , respectively. The highest (P < 0.05) dry matter (DM) loss in wheat straw and date leaves was observed following treatment with B. licheniformis . In the case of wheat straw, the organic matter (OM) and neutral detergent fiber (NDF), and for date leaves OM, NDF and acid detergent lignin (ADL) contents were not influenced by the treatments (P > 0.05). The greatest and lowest (P < 0.05) ADF content of wheat straw was observed as a result of treatment with B. licheniformis and O. intermedium , respectively. However, bacterial treatments decreased (P < 0.05) ADF content of date leaves when compared to the control. Acid detergent lignin content of wheat straw was decreased (P < 0.05) by bacterial treatments in comparisons to the control. For wheat straw, the highest and lowest (P < 0.05) value of crude protein (CP) was observed in the case of M. paludicola and O. intermedium treatments, respectively. For date leaves, the CP content of the control treatment was highest (P < 0.05) among treatments. For wheat straw, bacterial treatments enhanced (P < 0.05) DM, OM and ADF digestibility when compared to the control. However, highest and lowest (P < 0.05) CP digestibility was observed using O. intermedium and M. paludicola , respectively. For date leaves, treatment with B. licheniformis significantly increased (P < 0.05) digestibility of DM, OM and NDF when compared to the others. However, CP and ADF digestibility was not different (P > 0.05) between experimental groups. Overall, the results of this study showed that the isolated bacteria partially changed the chemical composition of wheat straw and date leaves while, they improved digestibility of nutrients. These bacteria are suitable candidates for increasing nutritive value of by-products for ruminants. [ABSTRACT FROM AUTHOR]

The utilization of white rot fungi (WRF) as degrader agents in extreme environments is still limited by their specific growth requirements. This study examined the ability of Bjerkandera adusta SM46 (GenBank accession number: KU055648 ), a recently isolated WRF from Saragamine mountain, Japan, to treat sea sand and sea water contaminated with polycyclic aromatic hydrocarbons (PAHs) for potential applications in the bioremediation processes. Several PAHs (2–5 rings) were used as pollutants under saline-alkaline stress conditions. Among four lignocellulosic materials, i.e., wood meal, kapok fibre, rice straw, and pulp waste, rice straw was a lignocellulosic material selected as the most suitable support based on the fungal growth, ligninolytic enzymes production, and degradation rates of PAHs after inoculation with B. adusta SM46. Rice straw-immobilized B. adusta (RSIB) showed faster growth and colonization, and increased laccase (Lac), manganese peroxidase (MnP), and lignin peroxidase (LiP) activity. The optimum granule size of rice straw as an immobilizing agent for B. adusta was 840 µm. Lac, MnP, and LiP activities were monitored for 15 and 30 d. Low-molecular-weight PAHs (LMW-PAHs, 2–3 rings) were the most extensively degraded by RSIB. When grown on high-molecular-weight PAHs (HMW-PAHS, 4–5 rings), degradation rates varied between 16% and 63% on contaminated sea sand and between 22% and 61% on contaminated sea water. RSIB may also be used as an alternative method to more effectively and efficiently produce ligninolytic enzymes than the submerged culture method. [ABSTRACT FROM AUTHOR]

Agricultural feedstocks (brewers’ spent grain – BSG, corncob – CC, corn husk – CH, wheat straw – WS and Luffa sponge – LS) were pretreated by liquid hot water (LHW) in order to increase cellulose recovery and enzymatic saccharification. LHW-pretreatment resulted in hemicellulose solubilization, and solids enriched in cellulose. Chemical analysis showed different susceptibilities of the feedstocks to LHW-pretreatment and enzymatic hydrolysis. Pretreated feedstocks presented higher crystallinity (determined through X-ray diffraction) and thermal stability (determined through thermogravimetric analysis) than untreated feedstocks. SEM images confirmed the effect of LHW-pretreatment on structural changes. Moreover, enzymatic hydrolysis and cellulose conversion to glucose (CCG) were improved for pretreated feedstocks, with exception of LS. CCG (in relation to glucose potential on solids) followed the order: BSG > CH > WS > CC > LS. LHW-pretreatment showed to be a good technology to pretreat multi feedstocks and for improving the enzymatic hydrolysis of recalcitrant agricultural feedstocks to sugars, which can be further converted to ethanol-fuel and other value-added chemicals. [ABSTRACT FROM AUTHOR]

The modification of lignin is recognized as an important aspect of the successful refining of lignocellulosic biomass. Schizophyllum commune , a white rot basidiomycete was studied for ligninolytic enzymes (manganese peroxidase, lignin peroxidase and laccase) production in solid-state fermentation (SSF) of rice straw. Various physiological factors such as incubation time, culture pH, incubation temperature, C:N ratio and addition of mediators were optimized to enhance enzymes productivity. Maximum enzyme recoveries were obtained at pH, 5.0; temperature, 35 °C; C:N ratio, 20:1; mediator, MnSO 4 ; inoculum size, 4 mL after incubation time of 144 h. The crude ligninolytic extract thus produced was used for delignification of various agro-industrial residues. The enzyme extract caused 61.7%, 47.5%, 72.3% and 67.2% lignin removal from banana stalk, corn cobs, sugarcane bagasse, and wheat straw, respectively. The optimally delignified substrate was enzymatically digested by crude cellulase extract from Trichoderma harzaianum that resulted 47.3% and 69.4% cellulose hydrolysis from the native and pre-treated bagasse, respectively. The results suggested that lignocellulosic waste could be utilized as low-cost substrate for the production of enzymes which play significant role in many industrial and biotechnological sectors. [ABSTRACT FROM AUTHOR]

This study attempted to enhance anaerobic conversion of lignocellulosic materials in excess sludge by bioaugmentation and pretreatment. The results reveal that highly active lignocellulolytic microorganisms ( Clostridium stercorarium and Bacteroides cellulosolvens ) could be enriched from anaerobic sludge in ordinarily operated anaerobic digester (AD). Inoculating these microorganisms into AD could substantially enhance the degradation of cellulose and hemicellulose. However, this effect of bioaugmentation was shielded for raw excess sludge due to lignin incrustation in native biosolids. For this problem, pretreatments including acid, alkali, thermal and ultrasonic methods were effectively used to deconstruct the lignin incrustation, in which thermal pretreatment was demonstrated to be the most effective one. Then, pretreatment associated with bioaugmentation was successfully used to enhance the energy conversion of lignocellulosic materials, which resulted in the degradation of cellulose, hemicellulose and lignin to 68.8–78.2%, 77.4–89% and 15.4–33.7% respectively and thus increased the CH 4 production by 210–246%, compared with ordinary AD. [ABSTRACT FROM AUTHOR]

Furfural, a platform chemical with a bright future, is commercially obtained by acidic processing of xylan-containing biomass in aqueous media. Ionic liquids (ILs) can be employed in processed for furfural manufacture as additives, as catalysts and/or as reaction media. Depending on the IL utilized, externally added catalysts (usually, Lewis acids, Brönsted acids and/or solid acid catalysts) can be necessary to achieve high reaction yields. Oppositely, acidic ionic liquids (AILs) can perform as both solvents and catalysts, enabling the direct conversion of suitable substrates (pentoses, pentosans or xylan-containing biomass) into furfural. Operating in IL-containing media, the furfural yields can be improved when the product is continuously removed along the reaction (for example, by stripping or extraction), to avoid unwanted side-reactions leading to furfural consumption. These topics are reviewed, as well as the major challenges involved in the large scale utilization of ILs for furfural production. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of microwave (MW) and microwave–chemical (MWC) pretreatment on barley straw and to identify the acidic, basic, or oxidative chemicals that provide the highest sugar conversion for subsequent enzymatic hydrolysis. The MW and MWC processes were applied as a pretreatment step before fermentation. MW radiation at 200 and 300 W and MW radiation plus a chemical (H2SO4or NaOH or H2O2) as catalyst were applied, and total sugar, total phenol, and Klason and acid-soluble lignin were measured. Although the MWC pretreatment produced a higher total sugar concentration than the MW pretreatment, the addition of an NaOH solution produced the best results in terms of all parameters. Fourier transform infrared analysis was also performed to observe the deterioration of molecular structures after the application of MW and MWC. [ABSTRACT FROM PUBLISHER]

This review provides an overview and discusses analytical strategies for the preconcentration of trace elements using lignocellulosic sorbents for solid-phase extraction. This procedure is widely used for the determination of metals and metalloids in different types of samples due to its simplicity, rapidity, minimal waste generation, reduction of sample matrix effects as well as sorption of the target species on the solid surface. For this purpose, some inorganic, organic, and several natural adsorbents are used. New approaches to obtaining adsorbent materials from natural sources such as agro-industrial residues and composting materials have received attention. The most used lignocellulosic materials as sorbents for solid-phase extraction are bagasse sugarcane, cotton, sisal, palm fiber, coconut, corn cob, soybean straw, jute, and rice. The lignocellulosic materials have been investigated because the presence of functional groups in their structures is made up of lignin and cellulose. These materials have been used in the development of analytical methods with the varied proposal, such as preconcentration or speciation of analytes. • Preconcentration of trace elements using lignocellulosic sorbents. • Development of sustainable and environmentally friendly analytical methods. • Lignocellulosic biosorbents in solid phase extraction coupled with elemental detection techniques. • Advantages and disadvantages of lignocellulosic materials in the development of preconcentration methods. [ABSTRACT FROM AUTHOR]

Environmentally friendly flexible materials with functionalities such as reversibly tunable wettability have become much sought after because of their great potential for biological, chemical and electronic applications. We prepared a flexible superhydrophobic material by coating the hydrophobic nano-TiO 2 particles on lignocellulosic paper. The coated paper surfaces exhibited a reversible switching between superhydrophobicity and superhydrophilicity through UV irradiation and heating, respectively. After the UV irradiation treatment for about 100 min, the wettability of the coated paper is switched from superhydrophobicity to superhydrophilicity. After the coated paper with superhydrophilicity is heated for 25 h, the water contact angle (WCA) recovers to the original superhydrophobic state. Compared to the literatures, the switching time between two kinds of superwettability is significantly reduced. SEM images and XPS spectra indicate that the change in chemical composition of the coated paper surface is responsible for the reversible switching of wettability. The coated paper developed in this study is an attractive smart material with reversibly switchable wettability which has significant potential application in many fields which require tunable wettability. • A simple and practical approach to prepare superhydrophobic paper by roll coating with modified nano-TiO 2. • The coated paper surfaces exhibited a reversible switching between superhydrophobicity and superhydrophilicity through UV irradiation and heating, respectively. • After the UV irradiation treatment for about 100 min, the wettability of the coated paper is switched from superhydrophobicity to superhydrophilicity. • After the coated paper with superhydrophilicity is heated for 25 h, the water contact angle (WCA) recovers to the original superhydrophobic state. [ABSTRACT FROM AUTHOR]

Lignocellulosic materials are potential renewable substrates for fermentative H 2 production; however, most of the methods available to hydrolyze these materials produce fermentation inhibitors. This study assessed the effect of three different groups of inhibitors on fermentative H 2 production by a mixed culture: (1) acetic acid; (2) furan derivatives, such as furfural and 5-hydroxymethylfurfural (HMF); and (3) phenolic monomers, such as vanillin, syringaldehyde, and 4-hydroxybenzoic acid (HBA). Conduction of batch assays in the presence of glucose and different concentrations of inhibitors helped to assess how the inhibitors affected the kinetic parameters of the modified Gompertz model ( R m , H max , and λ ). The concentrations of inhibitors that reduced 50% of the maximum H 2 production rate (IC50) were estimated. In terms of IC50, HBA provided the largest inhibition, 0.38 g L −1 , which is a novel result in the literature. HBA was followed by HMF and furfural, 0.48 and 0.62 g L −1 , respectively. Vanillin, syringaldehyde, and acetic acid at 0.71; 1.05; and 5.14 g L −1 provided the same inhibition level, respectively. Knowledge about the degree of inhibition of these compounds shall contribute to sustainable H 2 production from lignocellulosic substrates. [ABSTRACT FROM AUTHOR]

This work proposes the biorefining of eucalyptus residues (ER), wheat straw (WS) and olive tree pruning (OP) combining hydrothermal pretreatment (autohydrolysis) with acid post-hydrolysis of the liquid fraction and enzymatic hydrolysis of the solid fraction towards maximal recovery of monosaccharides from those lignocellulose materials. Autohydrolysis of ER, WS and OP was performed under non-isothermal conditions (195–230 °C) and the non-cellulosic saccharides were recovered in the liquid fraction while cellulose and lignin remained in the solid fraction. The acid post-hydrolysis of the soluble oligosaccharides was studied by optimizing sulfuric acid concentration (1–4% w/w) and reaction time (10–60 min), employing a factorial (2 2 ) experimental design. The solids resulting from pretreatment were submitted to enzymatic hydrolysis by applying commercial cellulolytic enzymes Celluclast® 1.5 L and Novozyme® 188 (0.225 and 0.025 g/g solid, respectively). This strategy provides high total monosaccharide recovery or high glucose recovery from lignocellulosic materials, depending on the autohydrolysis conditions applied. [ABSTRACT FROM AUTHOR]

Various pretreatment techniques can change the physical and chemical structure of lignocellulosic biomass and improve the hydrolysis rates. High-intensity ultrasound could be a promising technique in the biomass pretreatment process. The objective of this work was to study the effect of biomass concentration, pH, ultrasonic power level and sonication time on the production yield in total sugars (S T ) and reducing sugars (S R ) during the pretreatment of banana flower-stalk biomass. A qualitative evaluation was carried out by scanning electron microscopy, showing a disruptive effect on the biomass structure at high ultrasonic power levels and low biomass concentrations. An experimental design with three-levels for the four-variables was used in order to set the conditions for the pretreatments. Stepwise regression (SRG) and an artificial neural network (ANN) were applied in order to establish mathematical models that could represent and be used to study the dependence of the factors on both the S T and S R yields. The statistical results indicated that the ANN approach provided a more accurate estimation than SRG. [ABSTRACT FROM AUTHOR]

During the pretreatment of lignocellulosic biomass for second generation bioethanol production, fermentation inhibitors are released. To overcome this, the use of a robust industrial strain together with agro-industrial by-products as nutritional supplementation was proposed to increase ethanol productivity and yields. Two factorial experimental designs were carried out to optimize fermentation of hydrolysate from autohydrolysis of Eucalyptus globulus . The most influential variables on ethanol production were cheese whey and K 2 O 5 S 2 (potassium metabisulfite) supplementation. Nutrient addition effect was demonstrated using the whole slurry from autohydrolysis in two process configurations (separate hydrolysis and fermentation, SHF and simultaneous saccharification and fermentation, SSF). Comparing the supplemented SHF and SSF assays with non-supplemented, 2.3 and 7.4 fold higher ethanol concentrations were obtained, respectively. In the case of SSF, 50.4 g L −1 of ethanol concentration and 92.2% of ethanol conversion were attained, demonstrating an improved fermentation performance in industrial lignocellulose fermentations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Anaerobic digestion (AD) of hazelnut skin (HS) was investigated in fed-batch mode. • Higher CH 4 production was obtained at lower solid retention time and higher HS load. • Maceration and organosolv pretreatment removed 82 and 97% of the HS polyphenols. • Methanol-organosolv pretreatment increased the CH 4 potential of HS by 21%. • Reactor configuration enabled enriching microorganisms capable of HS degradation. This study provided important insights on the anaerobic digestion (AD) of hazelnut skin (HS) by operating a fed-batch AD reactor over 240 days and focusing on several factors impacting the process in the long term. An efficient reactor configuration was proposed to increase the substrate load while reducing the solid retention time during the fed-batch AD of HS. Raw HS produced maximally 19.29 mL CH 4 /g VS add /d. Polyphenols accumulated in the reactor and the use of NaOH to adjust the pH likely inhibited AD. Maceration and methanol-organosolv pretreatments were, thus, used to remove polyphenols from HS (i.e. 82 and 97%, respectively) and improve HS biodegradation. Additionally, organosolv pretreatment removed 9% of the lignin. The organosolv-pretreated HS showed an increment in methane potential of 21%, while macerated HS produced less methane than the raw substrate, probably due to the loss of non-structural sugars during maceration. [ABSTRACT FROM AUTHOR]

Co-production of high-value biobased products in biorefineries is a promising option for optimized utilization of biomass. Lignocellulosic materials such as agricultural and forest residues have been identified as attractive alternative feedstocks because of their high availability and low resource demand. This study assessed the greenhouse gas (GHG) performance and energy balance of ethanol co-production with biogas and electricity in biorefineries using straw and forest residues. Two calculation methods were used: Method I (ISO), which applied the international standard for life cycle assessment, and Method II, which applied the EU Renewable Energy Directive (RED) methodology. These methods differed in allocation procedure, functional unit and system boundaries. Analysis of the importance of significant methodological choices and critical parameters showed that the results varied depending on calculation method, with co-product handling and the inclusion of upstream impacts from residue harvesting explaining most of the differences. Important life cycle steps were process inputs in terms of enzymes and changes in soil organic carbon content due to removal of residues. Ethanol produced from forest residues generally gave lower GHG emissions than straw-based ethanol. The GHG savings for both feedstocks were 51–84% relative to fossil fuel. Omission of upstream impacts from residue recovery in agriculture and forestry in the RED method means that it risks overlooking important environmental effects of residue reuse. Furthermore, the default allocation procedure used in the RED method (energy allocation) may need revision for biorefineries where multiple products with different characteristics are co-produced. [ABSTRACT FROM AUTHOR]

Four types of purified xylooligosaccharides (XOS) from several lignocellulosic materials, showing different structural features (including chain length, branching, and linkage types), obtained from different feedstocks ( Eucalyptus globulus wood, rice husks, wheat bran or barley wastes), were assessed (using fructooligosaccharides as reference substrate) for their effects on the growth of six different probiotic Lactobacillus strains in basal MRS media and survival in different simulated gastrointestinal tract (GIT) conditions. The hydrophobicity of bacterial cells, which measures their potential for epithelial adhesion, was also evaluated. Improved growth of Lactobacillus strains was observed for media containing XOS as the single source of carbohydrate, confirming their role as prebiotics. These oligosaccharides also led to improvement in the resistance of the target Lactobacillus to the simulated GIT environment. The enhancement of the survival rates depended on the type of oligosaccharide. This is the first comparative study of the effects in lactobacilli involving four types of XOS obtained from different lignocellulosic materials. The obtained results show that these oligosaccharides manufactured from alternative sources could be interesting prebiotic substrates with different structures in comparison with the available commercially and with interesting potential towards the development of synbiotic products. [ABSTRACT FROM AUTHOR]

The paper mainly aims to study the effect of the incorporation of barley straws and wood shavings on the physico-mechanical properties of sand concrete intended for the construction in arid zones. Basing on the study at fresh state, the experimental work has been firstly devoted to searching for optimal compositions of the composite. Then, a second study has focused on the physico-mechanical characterization of sand concrete without lignocellulosic materials. Finally, a special experimental program has been devoted to the study of sand concrete with lignocellulosic materials. The obtained results show that it is quite possible to develop a lightweight sand concrete by the incorporating, separately and in combination, of barley straws and wood shavings. Moreover, it has been noted that the combined addition of barley straws and wood shavings gives the best physico-mechanical results which were strongly confirmed by a microstructure study. With combined addition, the problem of shrinkage was relatively solved: decreases of about 11.76% and 39.02% were recorded in comparison with the cases where barley straws and wood shavings are taken separately. In addition, the thermal diffusivity has been reduced of about 35.47% with respect to the basic composition. Due to its higher deformability, the barley straw improves the toughness and ductility of sand concrete and reduces its dimensional variations. Indeed, the studied composites, offer to the local constructions important technical and economic interests: good thermal insulation and efficient energy saving and low cost of materials. [ABSTRACT FROM AUTHOR]

Abstract: Natural lignocellulosic materials have an outstanding potential as thermoplastic reinforcement. Polypropylene composites were prepared using different types of lignocellulosic materials by melt blending of 70 wt% polypropylene (PP) and 30 wt% biomasses. The specimens were firstly evaluated for structural and morphological properties by infrared spectroscopy, X-ray diffraction, scanning electron and polarized optical microscopy. Depending on the biomass type, there were evidenced some particular shifts of the infrared bands and also crystallinity changes. An increase in crystallinity is explained by nucleating agent role of biomass. The morphological changes are directly related to variation in mechanical and rheological properties, an increase in Young modulus, melt viscosity and storage and loss moduli being recorded. [Copyright &y& Elsevier]

Highlights: [•] Dilute-acid pretreatment of Jatropha curcas shells for enzymatic hydrolysis was assessed. [•] Cellulose conversions above 80% were achieved in the enzymatic hydrolysis. [•] Optimal conversion was predicted for pretreatment at 136°C, 30min and 1.5% H2SO4. [•] Water extraction prior to pretreatment was found to further improve the enzymatic conversion. [ABSTRACT FROM AUTHOR]