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A set of imidazolium-based ionic liquids: [C4mim][PF6], [C4mim][BF4], [C4mim][Cl], [C4mim][CF3COO], [C4mim][NTf2], [C4mim][OMs], [C4mim][Br], and [C4mim][OAc], was studied by molecular dynamics simulations to elucidate their solvent behavior around a crystallite model of cellulose I β , through atomistic interactions and the degree of departure of its thermodynamic properties from their solvent pure phase. These departure changes were correlated with experimental values of the Kamlet-Taft solvent basicity parameter, and it was found that, even at room temperature, density changes, and vaporization enthalpy changes can be correlated with the capacity of ionic liquids for the preconditioning of the cellulose crystallite. Hydrogen bond occupancies indicate that ionic liquids can disrupt external chains of the cellulose crystallite by replacing and reducing the strong O 6 - H ⋯ O 2 / O 3 hydrogen bonds by weak hydrogen bonds such as O 6 - H ⋯ O 4 along the interchain network. Also, radial distribution functions indicated that structural changes in the cellulose-ionic liquid mixtures did not depart significantly with respect to the pure IL structure. The results of the free energy of solvation calculations for a cellulose chain, presented the following trend: [C4mim][Cl] > [C4mim][OAc] > [C4mim][CF3COO] > [C4mim][Br] > [C4mim][OMs] > [C4mim][BF4] > [C4mim][PF6] > water > [C4mim][NTf2]. It is important to emphasize, that the focus of this work was not the cellulose dissolution, but instead, the solvent behavior and cellulose preconditioning within each IL at room temperature. Our results can provide insights about the preconditioning stage of cellulose at low temperature, useful in the development of lignocellulosic materials and valuable cellulose derivatives by means of low energy requirements. [ABSTRACT FROM AUTHOR]

Mature coconut husk (MCH) and young coconut husk (YCH) are abundantly generated as a by-product from coconut-based industry, which eventually lead to environmental pollution. However, the lignocellulose content in both types of coconut husk has the potential to be exploited as feedstock by way of biochemical processes through the concept of biorefinery. In this study, the MCH and YCH were subjected to alkaline pretreatment by sodium hydroxide (NaOH). Subsequently, enzymatic hydrolysis using Accellerase® 1500 was conducted to convert the lignocellulosic materials into fermentable sugars. The changes in surface morphology of MCH and YCH throughout the process were also observed. Alkaline pretreatment successfully removed 20.15 and 31.17% of lignin content in MCH and YCH, respectively. The increase in cellulose content after alkaline pretreatment was detected around 17% for MCH and 20% for YCH. For optimisation of enzymatic hydrolysis, 10% enzyme loading for 24 h showed significantly higher (p < 0.05) reducing sugar content in MCH and YCH hydrolysates of 19.17 g/L and 24.33 g/L, respectively. The efficiency of the hydrolysis process was proven by high sugar recovery of 71.23% for MCH and 89.49% for YCH. Concurrently, the morphological analysis showed the effect of the treatments on the surface of MCH and YCH, where the structure became swollen and collapsed as the majority of lignocellulosic materials were digested. Therefore, the study pointed out the potential of reutilising MCH and YCH as alternative resources for the future biochemical process feedstock. [ABSTRACT FROM AUTHOR]

A kinetic study based on pinewood (Pinus montezumae) was carried out at heating rates of 5, 10, 15, and 20 °C min−1. The Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Friedman methods were used to analyze the thermal behavior of samples. Thermogravimetry (TG) and derivative thermogravimetry (DTG) curves were obtained at non-isothermal conditions. Ultimate and proximate analyzes from pinewood were obtained and the greater decomposition was in the range of 250 to 380 °C. Mean values of activation energy (Ea) and frequency factor (A) by FWO method were 192.4 kJ mol−1 and 2.73 × 1014 min−1, respectively, whereas the aforementioned values by KAS method were 181.8 kJ mol−1 and 3.32 × 1013 min−1. Lower value of mean activation energy (174.1 kJ mol−1) was obtained with Friedman method. [ABSTRACT FROM AUTHOR]

Gas chromatography-mass spectrometry was used to study the composition of the degradation products of ionic liquids and wood released into the vapor phase during the dissolution of lignocellulosic biomass in 1-butyl-3-methylimidazolium acetate and methyl sulfate and their binary mixtures with dimethyl sulfoxide. It was found that the volatile compounds form at temperatures >100°C, and at 150°C their content can reach 6% of the mass of the initial reaction mixture. They are dominated by methanol and butanol, esters of acetic and benzoic acids, butyl and methyl imidazole, aromatic and aliphatic amines, and toluene. The presence of wood has a significant effect on the thermal decomposition of ionic liquids, including due to the presence of residual moisture. The use of the 1-butyl-3-methylimidazolium methyl sulfate – dimethyl sulfoxide system as a wood solvent leads to the release of many toxic and foul-smelling organosulfur compounds into the vapor phase. [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]

Vegetable fibers are increasingly used in biocomposites, but there is a need for further development in utilizing by-products like cocoa husks. Three-dimensional printing, through Fused Filament Fabrication (FFF), is advancing rapidly and may be of great interest for applying biocomposite materials. This study focuses on developing innovative and fully biodegradable filaments for the FFF process. PLA filaments were prepared using cellulose fibers derived from cocoa husks (5% mass ratio). One set of filaments incorporated fibers from untreated husks (UCFFs), while another set utilized fibers from chemically treated husks (TCFFs). The fabricated materials were analyzed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) techniques, and they were also tested for tensile strength. ANOVA reveals that both UCFFs and TCFFs significantly predict tensile strength, with the UCFFs demonstrating an impressive R 2 value of 0.9981. The optimal tensile strength for the filament test specimens was 16.05 MPa for TCFF8 and 13.58 MPa for UCFF8, utilizing the same printing parameters: 70% infill and a layer thickness of 0.10 mm. Additionally, there was an 18% improvement in the tensile strength of the printed specimens using the filaments filled with chemically treated cocoa husk fibers compared to the filaments with untreated fibers.

Lignocellulosic wastes obtained from vegetal residues in combination with nucleophiles were used as catalysts for carbon dioxide fixation in epoxides to form cyclic carbonates. An adequate combination of the residue and the nucleophile was essential to obtain active catalytic systems. The best binary systems were formed by olive bones, grape waste, date pit and corn leaves husk residues with tetrabutylammonium bromide (TBAB). High conversions in the cycloaddition of CO2 to propylene oxide (76–84%) and 1,2-epoxyhexane (68–79%) were achieved at very low nucleophile loading (0.47 mol % respect to the substrate) under mild conditions (95 °C and 10 atm of CO2). The vegetal wastes were stable under catalytic conditions and could be recycled after adequately supporting the nucleophile TBAB in silica gel. The mechanistic computational study carried out with Density Functional Theory calculations on model catalysts describes the contribution of individual lignin and cellulosic components to the experimental substrate conversion into cyclic carbonate. The energy barriers obtained and the experimental data suggest that the contribution of lignin to the total catalytic activity (barrier energy of 9.9 kcal/mol) may be more important than the contribution of cellulose (energy barrier 11.9 kcal/mol). [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dielectric Barrier Discharge (DBD) can be used to produce a large volume of non-thermal plasma at atmospheric pressure. Such plasmas are sources of highly reactive species (radicals, ozone, atoms, ions and excited molecules). Due to its characteristics, the DBD plasma can be applied for the pretreatment of lignocellulosic materials, in order to extract lignin that prevents the access to remained fermentable sugars in the biomass. In this context, an alternative method for pretreatment of lignocellulosic material in an in-liquid DBD plasma reactor using non-contact electrodes, working with atmospheric air, has been proposed. After the pretreatment, the solids were washed and submitted to enzymatic hydrolysis with a commercial enzyme complex, at 10 FPU/g of pretreated biomass and 50 g/L solids concentration (dry basis), for 72 h. The release of fermentable sugars was measured, comparing the samples obtained with and without plasma treatment. The highest sugar release was achieved using the plasma-in-liquid pretreatment in a single step, with glucose and xylose yields of 51.3 and 38.5%, respectively, after enzymatic hydrolysis. Thus, an effective pretreatment was developed to be applied to biomass such as: corn cob, sugarcane bagasse, bamboo, eucalyptus, etc., in order to reduce the environmental impact and, at the same time, produce biofuels. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dynamics of wheat straw delignification with ozone treatment is studied. The dependence of the residual lignin content on the specific absorption of ozone is determined. It is found that in a prolonged stage of ozonation, ozone is consumed mostly for the reaction with lignin. HPLC is used to record kinetic profiles of water-soluble products of ozonation. The IR spectra of straw samples with various degrees of delignification are analyzed. The results confirm the ozonolytic degradation of lignin and suggest that polysaccharides undergo partial oxidation during prolonged ozonation. A relationship is found between the lignin content and the reactivity of ozone-pretreated straw in enzymatic hydrolysis to sugars. The optimum consumption of ozone is 2 mol-equiv O3 per phenylpropane structural unit (PPU) of the lignin contained in the straw, which corresponds to a residual lignin content of ~10%. [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]

On account of the irreversible environmental damage caused by the utilization of non-renewable raw materials in industrial production, since the end of the twentieth century, the interest in replacing the traditionally applied petroleum-based starting compounds in the polyurethane production by more sustainable feedstocks has grown enormously. Such pursuit of Green Chemistry has been fostered by the implementation of a set of national and international initiatives and stricter regulations, especially in the field of adhesives. In this respect, the latest advances in the production of bio-based polyurethanes are collected in this review. Thus, after a brief introduction to this subject and main tendencies towards the production of more sustainable polyurethanes, the first section reviews the feasibility of manufacturing polyurethanes from a range of natural platforms, including lignocellulosic biomass and vegetable oils, whether modified or in their original form, along with some industrial wastes. Afterwards, the hitherto considered synthetic routes for the preparation of greener polyurethanes are assessed, encompassing waterborne, radiation-curable and non-isocyanate polyurethane techniques. Finally, the last section focuses on the research advancement on the synthesis, properties and different uses of bio-based polyurethanes specifically implemented in the field of adhesives. [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]

Four lignocellulosic materials (walnut shell, chestnut shell, pine wood and burnt pine wood) were analyzed as biosorbents to remove nickel ions in aqueous solution. The optimal pH condition was determined. Due to this, a range of different pHs (3.0 to 7.5) was tested. The adsorption isotherms and kinetics were established. To plot Langmuir and Freundlich isotherms, batch adsorption tests were made with variable nickel concentrations (5 to 200 mg L−1). The pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models were used to describe the kinetics, batch adsorption tests were carried out with 25 mg L−1 of nickel solution and agitation time varied from 10 to 1440 min. The specific surface area of the different materials was between 3.97 and 4.85 m2g−1 with the exception for wood with 1.74 m2g−1. The pore size was 26.54 nm for wood and varied between 5.40 and 7.33 nm for the remaining materials. The diffractograms analysis showed that all the lignocellulosic materials presented some crystalline domains with the exception of burnt pine wood which was completely amorphous. The best pH was found to be around 5.0. At this pH the adsorption was higher for chestnut shells, walnut shells, burnt pine wood and wood, respectively. All samples fitted the Langmuir model well, with R2 of 0.994 to 0.998. The sorption kinetics was well described by the pseudo-second order equation with R2 between 0.996 and 1.00. No significative differences on the surface of the materials before and after adsorption could be observed by SEM. Finally, all materials tested were able to remove nickel ions in aqueous solution.

A poly(urethane-acrylate) polymer (PUA) was synthesized, and a sufficiently high molecular weight starting from urethane-acrylate oligomer (UAO) was obtained. PUA was then loaded with two types of powdered ligno-cellulosic waste, namely from licorice root and palm leaf, in amounts of 1, 5 and 10%, and the obtained composites were chemically and mechanically characterized. FTIR analysis of final PUA synthesized used for the composite production confirmed the new bonds formed during the polymerization process. The degradation temperatures of the two types of waste used were in line with what observed in most common natural fibers with an onset at 270 °C for licorice waste, and at 290 °C for palm leaf one. The former was more abundant in cellulose (44% vs. 12% lignin), whilst the latter was richer in lignin (30% vs. 26% cellulose). In the composites, only a limited reduction of degradation temperature was observed for palm leaf waste addition and some dispersion issues are observed for licorice root, leading to fluctuating results. Tensile performance of the composites indicates some reduction with respect to the pure polymer in terms of tensile strength, though stabilizing between data with 5 and 10% filler. In contrast, Shore A hardness of both composites slightly increases with higher filler content, while in stiffness-driven applications licorice-based composites showed potential due to an increase up to 50% compared to neat PUA. In general terms, the fracture surfaces tend to become rougher with filler introduction, which indicates the need for optimizing interfacial adhesion.

Large amounts of lignin residue is expected in the future when biorefineries for producing biofuels and bio-products will increase in numbers. It is, therefore, valuable to find solutions for using this resource for the sustained production of useful bioenergy or bio-products. Anaerobic digestion could potentially be an option for converting the biorefinery lignin into a valuable energy product. However, lignin is recalcitrant to biodegradation under anaerobic conditions unless the structure is modified. Wet oxidation followed by steam explosion (wet explosion) was previously found to make significant changes to the lignin structure allowing for biodegradation under anaerobic conditions. In this study, we examine the effect of wet explosion pretreatment for anaerobic digestion of wheat straw lignin under mesophilic (37 °C) conditions. Besides the biorefinery lignin produced from wheat straw, untreated lignin was further tested as feed material for anaerobic digestion. Our results showed that wet exploded lignin pretreated with 2% NaOH showed the highest lignin degradation (41.8%) as well as the highest methane potential of 157.3 ± 9.9 mL/g VS. The untreated lignin with no pretreatment showed the lowest methane yield of 65.8 ± 4.8 and only 3.5% of the lignin was degraded. Overall, increased severity of the pretreatment was found to enhance anaerobic degradation of lignin.

Agave bagasse is a residual biomass in the production of the alcoholic beverage tequila, and therefore, it is a promising raw material in the development of biorefineries using hot compressed water pretreatment (hydrothermal processing). Surfactants application has been frequently reported as an alternative to enhance monomeric sugars production efficiency and as a possibility to reduce the enzyme loading required. Nevertheless, the surfactant’s action mechanisms in the enzymatic hydrolysis is still not elucidated. In this work, hot compressed water pretreatment was applied on agave bagasse for biomass fractionation at 194 °C in isothermal regime for 30 min, and the effect of non-ionic surfactants (Tween 20, Tween 80, Span 80, and Polyethylene glycol (PEG 400)) was studied as a potential enhancer of enzymatic saccharification of hydrothermally pretreated solids of agave bagasse (AGB). It was found that non-ionic surfactants show an improvement in the conversion yield of cellulose to glucose (100%) and production of glucose (79.76 g/L) at 15 FPU/g glucan, the highest enhancement obtained being 7% regarding the control (no surfactant addition), using PEG 400 as an additive. The use of surfactants allows improving the production of fermentable sugars for the development of second-generation biorefineries.

Abstract Background Algal biofilm technology is recently supposed to be a promising method to produce algal biomass as the feedstock for the production of biofuels. However, the carrier materials currently used to form algal biofilm are either difficult to be obtained at a low price or undurable. Commercialization of the biofilm technology for algal biomass production extremely requires new and inexpensive materials as biofilm carriers with high biomass production performances. Results Four types of lignocellulosic materials were investigated to evaluate their performance of acting as carriers for algal cells attachment and the relevant effects on the algal biomass production in this study. The cultivation of algal biofilm was processed in a self-designed flat plate photo-bioreactor. The biofilm production and chemical composition of the harvested biomass were determined. The surface physics properties of the materials were examined through a confocal laser-scanning microscopy. Algal biomass production varied significantly with the variation of the carriers (P

Due to the high dimensional variation of bamboo, the manufacturing of materials such as plywood and laminated bamboo produces a high amount of residues. The production of particleboards could be used to overcome this problem and become a viable solution to reuse the generated waste as a raw material to high value-added products. This study aimed to present an overview of the bamboo particleboard production, as well as the mechanical and physical properties of this material, followed by a review of the advances in its research and development. In general, independently of the resin or bamboo species utilization, several bamboo particleboards meet the mechanical properties requirements of international standards for wood-based medium-density particleboards. The main focus of this study is to provide a review, in order to support research groups interested in using new bamboo-based materials for the development of manufactured durable products.

This work physically, mechanically, and chemically characterized the composites produced from Portland CP II-E32 cement and fresh Indian cedar wood particles previously treated by immersion in hot and cold water. Density values for wood particulate composites were around 50% lower compared with the wood-free control treatment, from 0.88 to 1.78 g/cm³. A larger swelling was observed for the composite material. The results of compressive strength and stiffness indicated that there is no need for particle treatment for composite production. Hot and cold water immersion treatments reduced the total Indian cedar wood extractives by 33% and 42%, respectively. Optical microscopy analysis was used to identify adhesion failures between the cement/wood interface of the composite produced with fresh particles, which presented a higher percentage of extractives. This result indicated that the greater concentration of total extractives partially inhibits the matrix-matrix interaction reinforcement. Despite the reduction in total extractives caused by the treatments, this process is not necessary for the composite production because there is no statistical difference between the treatments. The values obtained for the composite indicate the possibility of application in sealing blocks in light construction systems. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Forestry Research is the property of Indonesian Journal of Forestry Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The implementation of biorefineries based on lignocellulosic materials as an alternative to fossil-based refineries calls for efficient methods for fractionation and recovery of the products. The focus for the biorefinery concept for utilisation of biomass has shifted, from design of more or less energy-driven biorefineries, to much more versatile facilities where chemicals and energy carriers can be produced. The sugar-based biorefinery platform requires pretreatment of lignocellulosic materials, which can be very recalcitrant, to improve further processing through enzymatic hydrolysis, and for other downstream unit operations. This review summarises the development in the field of pretreatment (and to some extent, of fractionation) of various lignocellulosic materials. The number of publications indicates that biomass pretreatment plays a very important role for the biorefinery concept to be realised in full scale. The traditional pretreatment methods, for example, steam pretreatment (explosion), organosolv and hydrothermal treatment are covered in the review. In addition, the rapidly increasing interest for chemical treatment employing ionic liquids and deep-eutectic solvents are discussed and reviewed. It can be concluded that the huge variation of lignocellulosic materials makes it difficult to find a general process design for a biorefinery. Therefore, it is difficult to define "the best pretreatment" method. In the end, this depends on the proposed application, and any recommendation of a suitable pretreatment method must be based on a thorough techno-economic evaluation. [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]

Microbial xylanases have gathered great attention due to their biotechnological potential at industrial scale for many processes. A variety of lignocellulosic materials, such as sugarcane bagasse, rice straw, rice bran, wheat straw, wheat bran, corn cob, and ragi bran, are used for xylanase production which also solved the great issue of solid waste management. Both solid-state and submerged fermentation have been used for xylanase production controlled by various physical and nutritional parameters. Majority of xylanases have optimum pH in the range of 4.0–9.0 with optimum temperature at 30–60 °C. For biochemical, molecular studies and also for successful application in industries, purification and characterization of xylanase have been carried out using various appropriate techniques. Cloning and genetic engineering are used for commercial-level production of xylanase, to meet specific economic viability and industrial needs. Microbial xylanases are used in various biotechnological applications like biofuel production, pulp and paper industry, baking and brewing industry, food and feed industry, and deinking of waste paper. This review describes production, characteristics, and biotechnological applications of microbial xylanases. [ABSTRACT FROM AUTHOR]

This study evaluated the gases CO, CO2, NO and SO2 emitted from five in natura Brazilian biomasses: pine sawdust, sugarcane bagasse, coffee and rice husks, tucumã seed and the residues generated when these biomasses were applied to combustion atmospheres (N2/O2: 80/20%) and oxy-fuel combustion (CO2/O2: 80/20%) in a Drop Tube Furnace. The in natura samples and residues were evaluated by TG/DTG (thermogravimetry/derivative thermogravimetry), SEM images (scanning electron microscopy) and EDS analysis (energy-dispersive spectroscopy). The SEM images revealed some of the main morphological differences in the in natura materials. However, for the residues under both atmospheres, a large part of the lignocellulosic matrix was degraded, indicating the good efficiency of the thermal process. The TG/DTG curves for the in natura samples and residues for both thermal processes enabled the quantification of the contents of remaining moisture, total organic materials consumed and ashes produced. The emissions for both atmospheres ranged between 90 and 6200 mg Nm−3 g−1 for CO, 5 and 210 mg Nm−3 g−1 for CO2, 10 and 170 mg Nm−3 g−1 for NO and 25 and 870 mg Nm−3 g−1 for SO2 and are directly related to the chemical composition of the lignocellulosic materials, oxidizing atmospheres and furnace conditions. The O2 consumption (6–77 mg Nm−3 g−1) inside the furnace for the oxidizing atmospheres and different biomasses exhibited an 80% CO2 > 80% N2 trend. The chemical composition (EDS) for the in natura samples and residues under both atmospheres revealed different proportions of organic, inorganic and metallic elements in the samples and that the individual behavior of the biomass is a consequence of the diversity of its properties. [ABSTRACT FROM AUTHOR]

Corn cob is one of lignocellulosic material used for bioethanol production due to its high content of cellulose which can be converted into glucose through enzymatic hydrolysis. Unfortunately, the hydrolysis process is time consuming and the yield is relatively low. It is necessary to develop a more efficient process by applying optimum conditions. The objective of this research is to study the effect of the substrate concentration and the stirring rate on the amount of the glucose produced, to optimize these parameters and to derive a kinetic model of the enzymatic hydrolysis process studied. Pre-treated corn cobs and multiple enzymes (Cellic® C-Tec2 and Cellic® H-Tec2 from Novozymes) are used. The results show that the higher substrate concentration and the higher stirring rate lead to a higher amount of glucose. However, if the stirring rate is greater than 150 rpm, the enzymes activity decreases as they are sensitive to a mechanical stress. The optimum values of the substrate concentration and the stirring rate in case of corn cobs enzymatic hydrolysis are equal to 15 % (w/v) and 150 rpm, respectively. The kinetics of the process studied is well described by the model of Yi Zhouliang and E. Barson leading to values of Vmax and KM of 0.0043 mg/ml h and 2.856 mg/ml, correspondingly. [ABSTRACT FROM AUTHOR]

In this work, a mathematical model is proposed to predict the kinetic behaviour of the enzymatic conversion of various types of lignocellulosic biomass into fermentable sugars. Digestion of the cellulosic polymers is carried out using enzymatic hydrolysis under different conditions. Unlike other kinetic models, published previously for this process, this one considers the heterogeneous nature of the process by which a solid, in the form of small particles, is decomposed to monosaccharides by the action of a diverse set of enzymes in solution. The effect of the particle size on the hydrolysis rate has also been taken into consideration. To assess the model's goodness of fit to any general situation, the experimental data obtained in the hydrolysis of three different lignocellulosic residues have been analysed. Thus, the hydrolysis data of wheat straw, rice husks and exhausted sugar beet pellets have been compared with the theoretical values calculated by the model. The results obtained show that this model predicts the enzyme's hydrolysis of lignocellulosic substrates under different conditions very accurately and it could therefore be used efficiently in the optimization of the hydrolysis processes implemented in the bio‐refinery industry. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

As an important sustainable source of biomass, lignocellulosic materials are highly recalcitrant to biotransformation, which limits their use and prevents economically viable conversion into value-added products. Ionic liquids (ILs) have emerged as attractive solvents for lignocellulosic biomass pretreatment in the production of biochemical feedstocks. In this work, a mixture of wood powder and waste paper was dissolved in the ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). Composite films were made from the regenerated lignocellulosic materials in [AMIM]Cl by adjusting the ratio of the raw materials. The physical and mechanical properties of biomass composite films were determined by optical microscopy (OM), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), and tensile strength tests. The results indicated that lignocellulosic materials were dissolved in [AMIM]Cl by destroying interand intramolecular hydrogen bonds between lignocelluloses. With increasing waste paper cellulose content, the dissolution of the fir powder in [AMIM]Cl was accelerated, and the tensile strength and elongation at break of the composite films increased. The rate of dissolution initially rose rapidly with increasing content of waste paper cellulose content, but the rate leveled off when the content was above 40%. This research highlights new opportunities for biodegradable composite films made from waste biomass. [ABSTRACT FROM AUTHOR]

Functionalizing biosourced materials is a major topic in the field of materials science. In particular, grafting polymerization techniques have been employed to change the surface properties of various substrates. Here, we report on the grafting of amphiphilic block copolymers in lignocellulosic materials using surface‐initiated activators generated by electron transfer atomic transfer radical polymerization (SI‐AGET‐ATRP). With this modification, it is possible to combine the interesting properties (anisotropy and high mechanical stability) of lightweight lignocellulosic materials, such as wood, with the special properties of the grafted block copolymers. Hydroxyl groups on wood cell wall biopolymers were used for the chemical bonding of an alkyl bromide as the initiator for AGET‐SI‐ATRP of a highly hydrophilic monomer ([2‐(methacryloyloxy)ethyl]trimethylammonium chloride) and a highly hydrophobic fluorinated monomer (2,2,3,3,4,4,5,5‐octafluoropentyl methacrylate). The successful grafting of homopolymers and block copolymers onto the wood structure was confirmed through Fourier transform infrared and Raman spectroscopy. The functionalization with the two homopolymers yielded lignocellulosic materials with opposite wettabilities, whereas by the adjustment of the ratio between the two copolymer blocks, it was possible to tune the wettability between these two extremes. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 885–897 Amphiphilic block copolymers were synthesized on a bio‐based bulk material (wood) containing a superhydrophilic monomer ([2‐(methacryloyloxy)ethyl]trimethylammonium chloride) and a highly hydrophobic fluorinated monomer (2,2,3,3,4,4,5,5‐octafluoropentyl methacrylate). The feasibility of growing the combination of these two monomers onto a solid scaffold is characterized. The different wettability properties obtained by the introduction of these monomers onto the wood scaffold, by themselves and in combination, are shown. [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]

The cost of bioethanol production from lignocellulosic materials is relatively high because the additional processes of delignification and saccharification are required. Consolidated bioprocessing (CBP) simultaneously uses the multiple processes of delignification, saccharification, and fermentation in a single reactor and has the potential to solve the problem of cost. Some wood-degrading basidiomycetes have lignin- and cellulose-degrading abilities as well as ethanol fermentation ability. The white rot fungus Schizophyllum commune NBRC 4928 was selected as a strong fermenter from a previous study. The lignin-degrading fungus Bjerkandera adusta and polysaccharide-degrading fungus Fomitopsis palustris were respectively added to S. commune ethanol fermentations to help degrade lignocellulosic materials. Bjerkandera adusta produced more ligninase under aerobic conditions, so a switching aeration condition was adopted. The mixed culture of S. commune and B. adusta promoted direct ethanol production from cedar wood. Fomitopsis palustris produced enzymes that released glucose from both carboxymethylcellulose and microcrystalline cellulose. The mixed culture of S. commune and F. palustris did not enhance ethanol production from cedar. The combination of S. commune and cellulase significantly increased the rate of ethanol production. The results suggest that CBP for ethanol production from cellulosic material can be achieved by using multiple fungi in one reactor. [ABSTRACT FROM AUTHOR]

Sunflower stalks could be an alternative raw material for use in the particleboard industry since the requirements of P1 general purpose boards for use in dry conditions and P2 boards for interior fitment for use in dry conditions are easily satisfied. Acetylation of sunflower stalks is found to greatly improve the thickness swelling (TS) value, with acetylated boards showing 19.7% weight gain, meeting the TS requirements of P3 Non-Load-Bearing—Humid and P4 Load Bearing—Dry criteria; however, acetylation adversely affects the internal bond strength (IBS). It is suggested that combinations of industrial wood chips with sunflower raw material may be used for the overall improvement performance of the particleboards. [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]

Pathogenic microbes are a major source of health and environmental problems, mostly due to their easy proliferation on most surfaces. Currently, new classes of antimicrobial agents are under development to prevent microbial adhesion and biofilm formation. However, they are mostly from synthetic origin and present several disadvantages. The use of natural biopolymers such as cellulose, hemicellulose, and lignin, derived from lignocellulosic materials as antimicrobial agents has a promising potential. Lignocellulosic materials are one of the most abundant natural materials from renewable sources, and they present attractive characteristics, such as low density and biodegradability, are low-cost, high availability, and environmentally friendly. This review aims to provide new insights into the current usage and potential of lignocellulosic materials (biopolymer and fibers) as antimicrobial materials, highlighting their future application as a novel drug-free antimicrobial polymer.

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]

Lignocellulosic biomass resources are renewable materials that can be converted to fermentable sugars and subsequently into ethanol. Water hyacinth (Eichhornia crassipes) is a cellulosic aquatic plant that has high carbohydrates, low lignin content, and notable reducing sugars content in its structure. Based on the literature review in the case of water hyacinth, the most frequently used pretreatment methods were acid and alkali, while ionic liquid and microwave-assisted methods were used rarely. The dominant sugars were glucose, xylose, galactose, arabinose, and mannose. Based on the findings, cellulase and S. cerevisiae were mostly used for enzymatic hydrolysis and fermentation of water hyacinth to ethanol, respectively. This review presents the recent studies in pretreatment, hydrolysis, and fermentation of water hyacinth biomass into ethanol.