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This study investigates the production of high-purity cellulose pulp from peach (Prunus persica) fruit wastes generated during the processing of a Greek compote and juice production industry. A three-step chemical process is used, including alkaline treatment with NaOH, organic acid (acetic and formic) treatment, and hydrogen peroxide treatment, with the goal of cellulose extraction and purification. A fractional factorial design optimized reagent levels, revealing the strong influence of NaOH concentration on α-cellulose content and degree of polymerization. The extraction yield ranged between 9.7 and 12.3%, and a yield of 11.6% was achieved under the optimal conditions (NaOH, 3%w/v; acid-to-solid ratio, 6 l/kg; H 2 O 2 , 0.5% v/v) of the factorial experiment. The resulting samples were further characterized by XRD, FTIR, SEM, and TGA techniques. The results of the XRD and FTIR spectra confirmed the presence of cellulose, with a crystallinity index of approximately 57%, balancing strength and reactivity. The SEM analysis demonstrated a strong morphological similarity between the extracted pulp and commercial dissolving-grade pulp (Södra Purple), while images of the raw material confirmed effective purification. Additional evaluations included color, lightness, and lignin content. These findings suggest that cellulose extracted from peach waste is suitable for textile applications, offering a sustainable alternative to conventional cellulose sources and supporting industrial resource efficiency., Competing Interests: Declarations. Ethical approval: Not applicable. Consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).) more...

Driven by concerns over the health and environmental impacts of currently used fire retardants (FRs), recent years have seen strong demand for alternative safer and sustainable bio-based FRs. In this paper, we evaluated the potential of nitrogen-modified biopolyphenols as FRs for cellulosic natural fibres that could be used in low-density cellulose insulations. We describe the preparation and characterisation of nitrogen-modified lignin and tannin containing over 10% nitrogen as well as the treatment of cellulose pulp fibres with combinations of lignin or tannin and adsorption-enhancing retention aids. Combining lignin or tannin with a mixture of commercial bio-based flocculant (cationised tannin) and anionic retention chemical allowed for a nearly fourfold increase in lignin adsorption onto cellulosic pulp. The nitrogen-modified biopolyphenols showed significant improvement in heat release parameters in micro-scale combustion calorimetry (MCC) testing compared with their unmodified counterparts. Moreover, the adsorption of nitrogen-modified lignin or tannin onto cellulose fibres decreased the maximum heat release rate and total heat release compared with cellulose reference by 15-23%. A further positive finding was that the temperature at the peak heat release rate did not change. These results show the potential of nitrogen-modified biopolyphenols to improve fire-retarding properties of cellulosic products. more...

This short communication describes the climate change impacts of using cellulose, and more precisely cellulosic fiber-based materials, in food packaging, representing current and emerging industrial state of the art technology, without specific reference to current scientific advances. First, the different types of cellulosic fiber-based packaging materials, which can be used to replace fossil-based packaging materials, are presented for flexible and rigid applications. The focus is on technological solutions with packaging properties that enable the protection of commonly sold food products. The manufacturing processes associated with these cellulosic fiber-based materials is described and the environmental impact assessment of 4 selected case studies presented: stand-up pouches, flexible flow wraps, frozen or chilled food trays, and molded pulp lids. A simplified eco-design Life Cycle Assessment (LCA) was then performed to compare each solution with its fossil-based counterpart. Differences and similarities between the various cellulosic solutions have been identified. Furthermore, the assessment confirms that cellulosic fiber-based materials have reduced environmental impacts as compared to fossil-based counterparts, if a similar packaging weight is obtained. Indeed, all impacts of plastics are between 3 and 5 kg CO 2 eq/kg, while all impacts of cellulosic fiber-based materials are below 1.5 kg CO 2 eq/kg., (Copyright © 2020 Elsevier Ltd. All rights reserved.) more...

Comparative studies of the effects of two commercial enzyme formulations on fiber refining were conducted. Extensive basic characterisation of the enzymes involved, assessment of their hydrolytic activities on different model substrates as well as on different pulps (softwood sulfate, softwood sulfite, hardwood sulfate) were evaluated. Both enzyme formulations showed endoglucanase as well as some xylanase and β-glucosidase activity. In addition, Enzyme A reached a CMC end viscosity of 19.5 mPa compared to 11.1 mPa for Enzyme B. Reducing sugar release almost doubled from 695 μmol mL -1 for hardwood sulfate pulp to 1300 μmol mL -1 for softwood sulfite pulp with Enzyme B under the same conditions. Enzyme A increased the degree of refining even under non-ideal conditions from 23 °SR to up to 50 °SR. Further characterization of hand sheets, made from enzyme pre-treated and refined cellulose fibers with Enzyme A and B, showed that Enzyme A had the best effects leading to hand sheets with increased tensile strength and low air permeability. In summary, the increase in the degree of refining seen for Enzyme A correlated to higher xylanase and β-glucosidase activity and lower endoglucanase activity., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.) more...

Nanocellulose was successfully isolated from Gelidium elegans red algae marine biomass. The red algae fiber was treated in three stages namely alkalization, bleaching treatment and acid hydrolysis treatment. Morphological analysis was performed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). TEM results revealed that the isolated nanocellulose had the average diameter and length of 21.8±11.1nm and of 547.3±23.7nm, respectively. Fourier transform infrared (FTIR) spectroscopy proved that the non-cellulosic polysaccharides components were progressively removed during the chemically treatment, and the final derived materials composed of cellulose parent molecular structure. X-ray diffraction (XRD) study showed that the crystallinity of yielded product had been improved after each successive treatments subjected to the treated fiber. The prepared nano-dimensional cellulose demonstrated a network-like structure with higher crystallinity (73%) than that of untreated fiber (33%), and possessed of good thermal stability which is suitable for nanocomposite material., (Copyright © 2016 Elsevier Ltd. All rights reserved.) more...

Abstract The demand for high-purity cellulose, optimization of wood utilization, and environmentally friendly processes has increased in dissolving pulp (DP) production. Sago palm fronds (SPF), an abundant agricultural waste in Indonesia, hold great potential as a raw material for cellulose, hemicellulose, and lignin production. This study aimed to explore the production of from SPF by employing a combination of prehydrolysis, soda cooking with 2-methylanthraquinone (MAQ) as a green additive (PHS-MAQ), and totally chlorine-free (TCF) bleaching with peroxymonosulfuric acid (Psa). Furthermore, lignin was recovered from the black liquor of PHS-MAQ. The results showed that prehydrolysis at 150 ºC for 3 h, followed by soda-MAQ cooking at 160 ºC for 1.5 h using 0.03% of MAQ, 23% active alkali (AA), and a five-stage bleaching with oxygen (O), Psa, alkaline extraction with hydrogen peroxide (Ep), Psa, and Ep successfully produced high-purity cellulose as DP, with properties of 94.3% α-cellulose content, 89.9% ISO brightness (SNI ISO 2470–1:2016), 9.1 cP viscosity, and 0.13% ash content. Moreover, the soda-MAQ cooking method exhibited superior delignification compared to prehydrolysis kraft (PHK) and prehydrolysis soda (PHS) processes in a range of kappa numbers of 9.4–22.6 at 17–25% AA. The inclusion of MAQ increased pulp yields by 4.6–4.9% and decreased kappa number by 1.6–3.1 compared to the PHS without additives at similar AA. Lignin was separated from the PHS-MAQ, with yields of 69–77%. This work demonstrated the suitability of SPF processed by PHS-MAQ cooking and Psa bleaching for the preparation of viscose rayon and cellulose derivatives. The lignin recovery could be an attractive biorefinery process in modern pulp mills. more...

1-Alkyl-3-methylimidazolium ionic liquids are common cellulose solvents and biomass pretreatment agents, while beta-irradiation ("e-beaming") is often used to decrease the recalcitrance of biomass towards hydrolysis or saccharification. Aiming at the general goal of elucidating the interaction between lignocellulosics, imidazolium-based ionic liquids, and beta-irradiation, we studied the effect of beta-irradiation on the pure ILs 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium, both as chloride and acetate. Contrary to the expectation of inertness, irradiation caused degradation of the ILs, which was proportional to irradiation dosage, i.e., to irradiation time and intensity. At a dosage of 2400 kGy, 0.2% (2000 ppm) of the IL were chemically altered. The main degradation pathway is the formation of imidazole and N-methylimidazole with concomitant dealkylation. The cleaved-off alkyl groups, apparently in cationic form, react with the anions present, accounting for the formation of alkyl chlorides and alkyl acetates from the chloride ILs and acetate ILs, respectively. A second, minor pathway comprises the degradation of the imidazole ring under conversion of the C2-unit from the former C4-C5 moiety into ethylenediamine and reaction of the C1-unit from the former C2 with the IL anions. Because of the non-neglible byproduct formation, the degradation of the ILs upon beta-irradiation and possible side reactions of the resulting byproducts need to be kept in mind for all setups that involve beta-irradiation and imidazolium ILs simultaneously. [ABSTRACT FROM AUTHOR] more...

Improper disposal of palm biomass wastes resulting from industrial palm oil production may contribute to the environmental issues in Indonesia. However, given their abundance and availability, empty fruit bunches (EFB) can be potentially considered as a raw material for unbleached pulp. In this study, unbleached pulp was produced from oil palm EFB by a pulping process with alkaline pretreatment. FT-IR analysis confirmed the presence of cellulose in the pulp, with absorption peaks at 3332 cm-1 corresponding to the O-H stretching and at 1029 cm-1 assigned to the stretching of the C-O-C bond, respectively. SEM images revealed the aspect of individual fibers, with a rigid appearance, in the pulp obtained from EFB biomass. The major crystalline peak was observed at 2θ of 22.41°, indicating the presence of cellulose. Brown paper was made from the unbleached pulp (A4 size, with a grammage of 134 g/m² and a thickness of 219.3 μm) and proved to have excellent mechanical strength. Therefore, unbleached pulp from oil palm EFB can be recommended to be used in the manufacture of brown paper. [ABSTRACT FROM AUTHOR] more...

This study aimed to investigate the effects of boron compounds on cellulose fibers during recycling. Three recycling stages were conducted, applying boric acid and borax to bleached papers. Physical, mechanical, and optical properties were measured after each process. The highest water absorption (218 g/m2) was observed in test papers from the second recycling stage using 10% borax-treated pulps (10Bx2). Boric acid treatment notably improved burst strength, with the highest value (3.94 kPa m2/g) in the first recycling stage with 5.0% boric acid treatment (5Ba1). The highest tensile strength (49.48 Nm/g) occurred in the first recycling stage with 5.0% boric acid treatment, while the lowest (17.41 Nm/g) was in the second recycling stage (5Bx2) with 5.0% borax treatment. Tear strength exhibited different trends from burst and tensile strength, with notable improvements using 5.0% and 10% boric acid and 10% borax treatments on recovered cellulose fibers. The highest tear strength (9.20 Nm2/g) was achieved with 5.0% boric acid treatment (5Ba2) in the second recycling stage, followed by 8.21 Nm2/g with 10% boric acid treatment (10Ba1) in the first recycling stage. Tear strength trends differed from burst and tensile strength properties, regardless of treatment conditions. [ABSTRACT FROM AUTHOR] more...

Hypochlorous acid bleaching under amine catalysis (Hcat bleaching stage) is an optimized bleaching stage variant that is characterized by working at weakly acidic, near-neutral pH, having high bleaching efficiency, and discharging only very small amounts of chloro-organics. This study addressed the chemical fate of the used 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyst. While literature proposed either homolytic or heterolytic breakage of one ethylene bridge and subsequent release of the resulting fragments as two molecules of formaldehyde, we demonstrated the degradation to proceed by ionic elimination of one ethylene bridge starting from mono-N-chlorinated DABCO. The resulting N-vinyl (enamine) derivative adds water under the release of acetaldehyde and formation of piperazine. The generation of acetaldehyde was experimentally confirmed by 2,4-dinitrophenylhydrazine trapping, directly from the processing liquid. The experimental findings agreed superbly with computations which showed the "acetaldehyde mechanism" to be much favored over the previously proposed pathways under C–C bond cleavage and release of formaldehyde. The results of this study add to a better understanding of the novel Hcat bleaching system. [ABSTRACT FROM AUTHOR] more...

Pretreatment of pulp is a critical step in the fibrillation process to improve the quality and efficiency for cellulose nanofibril (CNF) production. This work employed a straightforward and entirely aqueous methacrylation and subsequent grafting-through polymerization technique to modify bleached softwood kraft pulp (BSKP). Specifically, methacrylate groups, poly(acrylamide) (PAM), and poly(methyl methacrylate) (PMMA) were chemically affixed to the surface of BSKP fibers, which was confirmed using FTIR spectroscopy. Bench-scale experiments were scaled up to pilot scale to prepare the modified BSKP samples, these were subjected to fibrillation using a Supermasscolloider (SMC), and the net cumulative energy (NCE) expended was monitored during the fibrillation process. Notably, the modified BSKP samples exhibited a substantial reduction in NCE, with the methacrylate modified BSKP sample achieving a 68% reduction in NCE expenditure to attain 90% fines as compared to the fibrillation of unmodified BSKP and producing methacrylate modified cellulose nanofibrils (Met-CNFs). Furthermore, we delved into the impact of polymeric surface modifications, both pre-and post-fibrillation, on fiber and fibril behavior, including the water retention value (WRV), hard-to-remove water (HR-Water), and rheological behavior. The attached polymer's hydrophilicity and hydrophobicity influenced the physical properties of the CNFs. Additionally, we executed a post-grafting polymerization process on the produced Met-CNFs. This additional step allowed us to modify nanofibril surfaces, yielding increased surface functionalization and producing modified CNFs that could be used for composite applications. [ABSTRACT FROM AUTHOR] more...

Kraft pulp is the most common and economically advantageous raw material for making cellulose nanofibers (CNFs). However, it is revealed that high temperatures and pressures during kraft cooking cause the aggregation of cellulose microfibrils, which reduces the nanofibrillation capability of kraft pulp. Herein, we studied the optimum kraft cooking conditions required to obtain uniform CNFs by preventing aggregation. The fibrillation ability was compared with that of undried pulp treated with purification method only. Suspensions of undried pulps were mechanically fibrillated for various durations. The degree of fibrillation was evaluated by sedimentation, morphology, and water retention values. Kraft pulp cooking at a H-factor of approximately 650 for 140 °C, 160 °C and 170 °C resulted in less fibrillation than in the Wise-based pulp, even at low temperatures such as 140 °C. In contrast to expectations, high matrix substances with lignin contents of 30% did not prevent aggregation of the cellulose microfibrils. The production of CNFs requires a pulping technique for extracting cellulose without aggregation. [ABSTRACT FROM AUTHOR] more...

The use of products with high biomass yield per unit area as a renewable energy source, which are not consumed primarily for food purposes or can be used for multi-purposes, is of great importance in terms of food safety. For this purpose, sweet sorghum plant, which can grow in salty-alkaline soils, tolerant to drought and short-term floods, and has wide adaptability, has gained importance as a lignocellulosic bioethanol raw material in recent years. The aim of this study is to theoretically determine the lignocellulosic bioethanol yield of 21 different sweet sorghum (Sorghum bicolor var. saccharatum (L.) Mohlenbr.) genotypes grown under second crop conditions in the ecology of Şanlıurfa province, obtained from domestic and foreign sources. In the study, sweet sorghum pulp from plant sap was used as lignocellulosic bioethanol raw material. The cellulose and hemicellulose contents of the pulp were determined and the amount of lignocellulosic bioethanol that could be obtained per decare was calculated by using the bioethanol conversion rates. According to the data obtained, the highest yield was obtained from UNLHybrid- 3 (805.5 L/da), Theis (766.5 L/da), Smith (698.1 L/da) genotypes. In order to solve problems such as increasing the octane of gasoline, reducing greenhouse gas emissions and gasoline imports, it is recommended that these three genotypes be cultivated and disseminated for lignocellulosic bioethanol production in Şanlıurfa ecological conditions. [ABSTRACT FROM AUTHOR] more...

In recent years, the search for alternatives to petroleum derived products, such as plastic films, has become a priority due to the growing depletion of fossil reserves and the pollution of water resources by microplastics, microscopically small plastic particles which are harmful to ocean and aquatic life. Cellulose-based films, e.g., cellophane and cuprophane, have been on the market for almost a century. Despite being a more ecological option compared to plastic films, the manufacture of these cellulose films involves high production costs and the use of harmful chemicals. As an alternative, a sustainable and eco-friendly process based on the Lyocell-type Ioncell® technology is presented to produce cellulose films. Regenerated cellulose films are created by continuous extrusion via dry-jet wet spinning of an ionic liquid–cellulose solutions. The influence of the polymer concentration (8–13 wt%) and processing temperature (50–100 °C) on the properties of the films were studied by the determination of the thickness, mechanical properties, physical appearance, morphology, chemical composition, and hydrophobicity. The obtained films are thin (12–21 μm), transparent (transmittance = 91%) and of homogeneous structure. Moreover, they exhibit excellent mechanical properties: stress values up to 210 MPa and elongations up to 19% in machine (longitudinal) direction. These values clearly outperform commercial cellophane, which presents stress values of 125 MPa and elongations of 22%. The films presented herein hold great potential to become an eco-friendly and sustainable option to commercial films. [ABSTRACT FROM AUTHOR] more...

In the context of the so-called lignocellulose bio-refinery, the coconut shell (S) and pulp (P) of Acrocomia aculeata (Arecaceae) are interesting agro-industrial wastes that can be used as feedstock for the production of high value-added products. The aim of this work was to evaluate these lignocellulosic residues S and P, to obtain the microcrystal (MCC) and microfiber (MFC) of cellulose, and to characterize them to propose possible applications. First, cellulose content in the raw materials was determined, being 39.69% and 45.42% for both (S and P)) respectively, respectively. Then, the purification of residues was carried out via alkaline and bleaching treatments. Next, in order to obtain MCC and MFC from the purified cellulose, a chemical treatment with HCl (for MCC) and a mechanical treatment with a blender (for MFC) were performed. The size and morphology were observed via MEB, and properties were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential thermogravimetric analysis (DTG). [ABSTRACT FROM AUTHOR] more...

β-Irradiation ("e-beaming") as well as swelling in ionic liquids, each process by itself, are common pretreatments in biorefinery scenarios. A combination of both, such as occurs with β-irradiation of biomass that was insufficiently washed and still contains traces of ionic liquids, causes covalent derivatization of the contained cellulose and incorporation of nitrogen. The nitrogen uptake occurred only in the presence of the ionic liquid and correlated linearly with both the irradiation dose and the concentration of the contained ionic liquid. The presence of other wood constituents during β-irradiation decreased nitrogen uptake, but did not prevent it. The derivatization of cellulose did not depend on the degree of crystallinity, but appeared to depend on the content of oxidized groups (carbonyl functionalities), also with a linear correlation. Future work must now clarify the mechanism of this reaction and the influence of other wood constituents, and address the possible potential of e-beaming in the presence of imidazolium ionic liquids for cellulose chemistry. [ABSTRACT FROM AUTHOR] more...

Cellulose nanofibrils (CNFs) from hardwood bleached kraft pulp (HwBKP) are produced via enzymatic, chemical, and mechanical treatment. A nanoporous structured CNF-based separator is produced, and the electrochemical performance, morphology, and thermal stability analyses are performed in comparison to the commercial polyethylene separator. The results obtained show that the electrolyte-philic CNF separator has capacity retention of 88.6% over 200 cycles and very good ionic conductivity and wettability results due to its high hydrophilic nature. At 140°C, the CNF separator was resilient to heat and remained intact. The CNF separator reflects high thermal resistance and good electrolyte uptake properties that are among the mandatory requirements of a separator hence, a promising contender for use in lithium-ion batteries. [ABSTRACT FROM AUTHOR] more...

A reinforced eco-friendly cushioning material (ECM) comprising starch and cellulose material was developed. The ECM was prepared based on the starch type and cellulose material content; it was compared with commercial CMs. Different sizes of refined pulp (RP) and microfibrillated cellulose (MFC) were manufactured from hardwood bleached kraft pulp via beating and grinding, respectively. Thereafter, amylose-containing corn starch (CS) or amylopectin-only-containing glutinous rice starch (GS) was mixed with the manufactured cellulose materials. A slurry comprising starch and cellulose materials was homogenized for 2 min and lyophilized to prepare the ECM, after which the structure and strength characteristics of the prepared ECM were evaluated. The GS-prepared ECM produced a plate-like internal structure because of its amylopectin content, and amylose-containing CS exhibited a net-like shape. The cellulose materials offered support between starches with plate-like or net structure ECMs, and the pore shape was formed by adding MFC. As the cellulose material content increased, the strength of the ECM increased compared with that of the commercial CMs. Thus, ECMs with higher strength than their commercial counterparts could be manufactured with GS and cellulose materials. [ABSTRACT FROM AUTHOR] more...

Copyright of Listy Cukrovarnicke a Reparske is the property of VUC Praha a.s. 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.) more...

Copyright of Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara Ion Ionescu de la Brad Iasi, Seria Horticultura is the property of University of Agricultural Sciences and Veterinary Medicine (Editura Ion Ionescu de la Brad) 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.) more...

The fast-growing Zara plant (a putative hybrid of Pennisetum purpureum Schumach.) is usually planted for cattle fodder. For the first time, Zara plant was evaluated for its pulping potential based on anatomical, chemical, and morphological characteristics. This plant was characterized by an acceptable amount of α-cellulose (40.32%) and lignin (18.4%), with medium fiber length (1.09 mm). Soda-anthraquinone (AQ) pulping of Zara plant was investigated. Anatomically, stems of Zara plant had porous structure, mainly composed of vascular bundles surrounded by parenchyma tissue. Consequently, they were easier to delignify and defibrate, and a pulp yield of 46.54% was obtained, with kappa number 15.45 under the conditions of 14% alkali charge for 120 min of cooking at 150 ℃. Good papermaking properties were observed, the tensile index was 78.9 N.m/g at 43 °SR. The resulting pulps showed good bleachability in elemental chlorine-free (ECF) bleaching sequences (D0(EP)D1). Pulp brightness of 81.5%, with the viscosity of 16.0 mPaS, was obtained, with the consumption of 25 kg ClO2/ton of pulp. [ABSTRACT FROM AUTHOR] more...

In this work, we produced composites of mesoporous silica synthesized in-situ on never-dried bleached eucalyptus kraft pulp fibers with the aim of providing cost-effective depth filters, having high flux, and adsorptivity. The mesoporous silica loading for the produced samples was in the range of 12–35 wt%. The performance of double-layer membranes was studied for the adsorption of charged molecules. The best nanofibrillated cellulose-pulp-mesoporous silica membrane adsorbed 1160 mg/m2 of methylene blue and had a flux of 10 L m−2 h−1 bar−1. The nanofibrillated cellulose layer supported the pulp-mesoporous silica layer and improved the adsorptivity of the pulp-mesoporous silica depth filter layer by controlling flux. The membranes showed non-linear-pseudo-first-order adsorption kinetics and non-linear Freundlich isotherm for methylene blue adsorption. The nanofibrillated cellulose-pulp-mesoporous silica membrane was modified for metanil yellow adsorption by adding polyamide amine-epichlorohydrin resin. The best metanil yellow saturated adsorption capacity was 9400 mg/m2. The nanofibrillated cellulose-pulp-mesoporous silica depth filter without modification with a polyelectrolyte also had 92% and 94% heavy metal removal of 20 mg of Cu2+ and Pb2+ ions, respectively. The novel pulp-mesoporous silica composite membrane, with high adsorption capacity and manufactured by lower embodied energy of cellulose fiber, can significantly lower large-scale depth filter production costs due to the elimination of cellulose pre-treatment for the depth filter layer. The reusability performance in the fifth cycle, after four cycles of metanil yellow adsorption and desorption, was 5.2 mg/g, which was stabilized from the 3rd to 5th cycles. This suggests the suitability of these membranes for industrial applications. [ABSTRACT FROM AUTHOR] more...

Objective: To obtain cellulose from oil palm agroindustrial waste that meets standard physicochemical characteristics to produce value-added products. Design/methodology/approach: Bagasse fibers from the palm agroindustry were used to obtain cellulose, by means of the acid – alkaline hydrolysis methodology. The samples obtained in each stage and the cellulose obtained were characterized by the Fourier Transform Infrared Spectroscopy (FTIR) technique and thermogravimetric analysis (TGA). Results: The final characterized product presented a band corresponding to 1370 cm-1 which is a characteristic value of cellulose. The peak at 1731 cm-1 is related to C=O bonds of unconjugated ketones present in hemicellulose. A major thermal event for treated fiber near 355 °C and the high residual mass indicate a good chemical treatment for hemicellulose and lignin elimination. Study limitations/implications: A fiber yield of 39.3% cellulose was obtained during the process from oil palm bagasse. Findings/conclusions: Obtaining cellulose from a highly polluting residue such as palm bagasse and with high production figures in our state, makes it a potential for use to generate biopolymers in combination with natural polysaccharides, providing sustainable benefits and economic impact and promoting sustainable development by replacing conventional fossil plastics, in addition to obtaining value-added products for the same agribusiness and in sectors such as the food industry. [ABSTRACT FROM AUTHOR] more...

A physical coagulator of fines was employed to separate suspensions comprising refined sulphate cellulose and waste paper, where no reagents were required. The physical coagulator was a porous cylinder with a rotating disk placed in its cavity. Using the MorFi Neo fibre analyser and the Hitachi SU 3500 digital microscope, a dispersed size distribution of well-developed fines in a suspension derived from softwood and hardwood pulp was obtained. The kinetics of fine sedimentation in the suspension was studied. The sedimentation rate of both individual agglomerates and a mass of them, as well as the magnitude of mass concentration in a cleared liquid, was determined. A relationship between the concentration of fines in the suspension and the structure of the pulp during their sedimentation was established. To intensify the fines sedimentation process, it was proposed to return a part of the sediment to the suspension passing into the physical coagulator. Process parameters for the sedimentation process and the construction of the sedimentation tank were obtained. The unit designed for collecting fines from the suspension is shown schematically. Use of this unit reduced the fibre sedimentation time, decreased the loads in wastewaters, and retained the consumer value of the pulp fibres. [ABSTRACT FROM AUTHOR] more...

Correctness and reliability of molar mass data by viscometry in organometallic solvents (cuen, cuoxam, cadoxen) are compromised by the alkalinity of these solvents which causes immediate depolymerization especially in the case of pulps with higher carbonyl content (oxidative damage). The viscosity values thus correspond to the molar mass after the beta-elimination reactions that underly these degradative processes, which is sometimes significantly smaller than the molar mass determined by gel permeation chromatography (GPC) in the non-degrading solvent system DMAc/LiCl. Despite this well-known drawback, viscosity measurements have become a standard approach for molar mass measurements due to their ease and fastness, especially in the pulp and paper industries. A potential way to reduce the inherent error of these molar mass determinations via viscosity measurements is a reductive treatment prior to dissolution of the pulp in the organometallic solvents, which converts the labile, alkali-sensitive carbonyl structures back to the respective alcohols. Using sodium borohydride (NaBH4) on different types of cellulosic pulps, we demonstrate the beneficial effects of such a reduction step on the determined degree of polymerization (DP) for all three common solvents: cuen, cuoxam and cadoxen. Molar mass distributions and profiles of carbonyl groups were determined by GPC and by carbonyl selective fluorescence labeling ("CCOA method"). Such a reductive treatment was especially valuable for hemicellulose-containing pulps. While the decreased measurement error according to the new protocol is beyond doubt, an immediate acceptance in the pulp and paper industries is at least questionable, because the new, more correct data would not agree with the old – wrong, but consistent – numbers accumulated over years and decades. In the long run, however, the new, improved protocol will prevail here as well due to its lower error rate. [ABSTRACT FROM AUTHOR] more...

The dry pulp direct kneading method is an industrially viable, low-energy process for manufacturing cellulose nanofiber (CNF)-reinforced polymer composites, where the chemically modified pulps are nanofibrillated and uniformly dispersed in the polymer matrix during melt compounding. In the present study, cellulose fibers of various sizes ranging from surface-fibrillated pulps (20 μm in width) to fine CNFs (20 nm in width) were prepared from softwood bleached kraft pulps using a refiner and a high-pressure homogenizer. These cellulose fibers were modified with alkenyl succinic anhydride and dried. The dried fibers were used as a feed material for melt compounding in the dry pulp direct kneading method to fabricate CNF-reinforced high-density polyethylene (HDPE). When surface-fibrillated pulps were employed as a feed material, the pulps were nanofibrillated and dispersed uniformly in the HDPE matrix during melt compounding. The resulting composites had much better properties—i.e., much higher tensile modulus and strength values, and much lower coefficient of thermal expansion values—than the composites produced using pulps without pre-fibrillation. However, when CNFs were used as a feed material, they were shortened and agglomerated during melt compounding, and the properties of the composites consequently deteriorated. The study concludes that surface-fibrillated pulp, which can be produced cost-effectively using a refiner on an industrial scale, is more suitable as a feed material than CNFs for melt compounding in the dry pulp direct kneading method. This finding enables the elimination of a preliminary step in the preparation of CNFs from pulps, which is a time-consuming and energy-intensive process. [ABSTRACT FROM AUTHOR] more...

Macaranga hypoleuca, a lesser-known and rarely used wood species, is a pioneer species in the secondary succession that is classified as a fastgrowing plant with long fibers. M. hypoleuca was composed of holocellulose, lignin, and extractives, at contents of 68.1 ± 0.5%, 25.5 ± 0.6%, and 4.7 ± 0.1%, respectively. In this study, refined M. hypoleuca pulp was treated by alkali treatment, delignification, and maleic acid hydrolysis. The pre-treated pulp was further disintegrated by mechanical treatment, which produced nanofibrillated cellulose (NFC) with a yield of 53.5 ± 2.7%. The average diameter of the NFC was 43.0 ± 4.9 nm. The use of maleic acid (C4H4O4) hydrolysis also reduced the hydrophilicity of the NFC, as confirmed by the Fourier-transform infrared (FTIR) spectra. It was determined that the Macaranga tree is a suitable lignocellulose source to produce NFC, which can be used in transparent flexible substrates, coating, and composite applications. [ABSTRACT FROM AUTHOR] more...

Fluorescence labeling with N -(1-naphthyl)ethylenediamine is highly effective for quantifying oxidized reducing end groups (REGs) in cellulosic materials. When combined with size exclusion chromatography in DMAc/LiCl, along with fluorescence / multiple-angle laser light scattering / refractive index detection, a detailed profile of C1-oxidized REGs relative to the molecular weight distribution of the cellulosic material can be obtained. In this work, the derivatization process was extensively optimized, to be carried out heterogeneously in the solvent N -methyl-2-pyrrolidone. Furthermore, we show that to achieve high selectivity for carboxyl groups at the C1 position, keto and aldehyde groups need to be selectively reduced (e.g., by NaBH 4), and carboxyl groups other than at C1 need to be blocked (e.g., by methylation with (trimethylsilyl)diazomethane) prior to fluorescence labeling of carboxyl groups at C1 position. Finally, we demonstrate the practical value of the analytical method by measuring the content of the C1-oxidized REGs in cellulose samples after chemical (by Pinnick oxidation) or enzymatic (by treatment with C1-oxidizing LPMO enzymes) oxidation of various pulp samples. [Display omitted] [ABSTRACT FROM AUTHOR] more...

Different types of rotor-stator and jet-impingement refining equipment are used depending on the methods of production of fibre semi-finished products and on the initial state of raw materials. This article examines various refining modes for jet-impingement devices and their influence on the physical and mechanical properties of the processed material. Main design parameters that affect the refining process in this type of plant were determined. It was shown that the time required to refine a fibre mass using this plant depends on the jet flow rate (from the nozzle to the barrier), i.e. as the jet flow rate increases, the time required to refine the fibre mass decreases. A dimensionless machine parameter was obtained that characterises the effectiveness of the refining process and the design of jet-impingement refining plants. Using the dimensional method, a functional dependence was observed of breaking length, bursting strength, folding strength, and tearing strength on the machine complex parameter. The numerical value of the machine complex parameter was determined, depending on refining duration. [ABSTRACT FROM AUTHOR] more...

It was proposed that pre-hydrolysing tule (Typha domingensis Pers) would make it possible to produce handsheets with strength-related properties similar to those of conventional commercial paper, in addition to valorizable hemicelluloses. The hypothesis was tested with a biorefining scheme involving autohydrolysis. Conditions were optimized to maximize the extraction of hemicelluloses while preserving glucan integrity. The autohydrolysis at a liquid to solid ratio of 13 at 141 °C for 45 min (optimized conditions) provided a commercially useful liquor containing primarily tule hemicelluloses. The autohydrolysis of tule before alkaline extraction made it possible to obtain a valuable liquid phase comprising between 23.3% and 71.6% of all hemicelluloses in the raw material. The gross heating value for the hydrolyzed tule was increased (1.6% to 7.9 %) with respect the raw material. The solid phase was subjected to soda-anthraquinone pulping. The yield, ethanol extractives, kappa number, viscosity, glucan, xylan, Klason lignin, soluble lignins, as well as the tensile index were evaluated. Tule was found to be amenable to industrial processing for the production of quality cellulose derivatives. Autohydrolysis provided valorizable liquor in addition to solid that yielded soda-anthraquinone pulp having properties similar to those obtained in its absence, but using milder operating conditions. [ABSTRACT FROM AUTHOR] more...

TEMPO-oxidised cellulose fibres are often explored as nano-reinforcement for polymers. However, it is unclear whether micrometre-sized TEMPO-oxidised cellulose fibres also possess similar reinforcing potential. In this work, we report the mechanical response of polypropylene (PP) composites reinforced with TEMPO-oxidised cellulose (TOC) of different fibre widths. Micrometre-sized TOC fibres (TOCF) containing sodium carboxylate (TOCF-Na) and free hydroxyl (TOCF-H) groups, as well as nano-sized TOC nanofibrils (TOCN) were produced from dissolving pulp and incorporated into PP matrix via melt-extrusion. It was found that model PP composites containing micrometre-sized TOCF-Na and TOCF-H possessed the highest tensile modulus of up to 2.5 GPa; 40% improvement over neat PP and 30% increase over PP/TOCN composite. No significant differences in the tensile strength of PP/TOCF-Na and PP/TOCF-H composites were observed when compared to neat PP. The incorporation of nano-sized TOCN into PP however, led to a 6% decrease in tensile strength. Single-edge notched beam fracture toughness test further showed that PP/TOCN composite possessed the lowest fracture toughness of 2.52 MPa m1/2; a decrease of 18% over PP reinforced with micrometre-sized TOCF-Na and TOCF-H. Our study shows that micrometre-sized TOCFs serve as better reinforcement for polymers compared to nano-sized TOCN. This is attributed to the better dispersion of TOCF in the PP matrix. Furthermore, the presence of surface microfibrillation on TOCFs also enhanced the quality of the TOCF-PP interface through mechanical interlocking and local stiffening of the PP matrix. [ABSTRACT FROM AUTHOR] more...

Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which are important to understand in order to optimize their applications. In this investigation, the structures of CNCs produced upon 48–64% H2SO4 hydrolysis of hydrothermally-treated poplar, bleached kraft pulp, cotton microcrystalline cellulose, bacterial cellulose, tunicin, and cladophora cellulose were comparatively analyzed. TEM provided information on the morphological aspects. Raman, MAS-NMR, and XRD provided information on one aspect of the supramolecular organization, namely, crystallinity (CrI). Other characteristics of supramolecular structure were analyzed by various Raman methods, namely, accessibility to water, exocyclic CH2OH conformation ratio, and chain conformation disorder (CCONDIS)—the last method was developed in the present study. In general, CNCs retained the crystallinity of the starting material irrespective of the measurement method of CrI. Additionally, it was found that crystallite size and supramolecular organization influenced CrI as well. These analyses further indicated that poplar- and pulp-CNCs had significantly higher water accessibility as compared with CNCs from cladophora, bacterial, tunicin, and cotton MCC CNCs, implying higher molecular disorder, which was also reflected in measurements of CH2OH conformation ratio and CCONDIS. The findings indicate that significant differences among the CNCs seem to arise largely from differences between the starting materials. Additionally, considering that CNCs can have very different morphologies and structural properties depending upon how they are produced, the analyses carried out here can characterize such CNCs and estimate their applications. [ABSTRACT FROM AUTHOR] more...

In this work we studied the influence on the mechanical and physical properties of paper made from short-fiber pulp by adding different percentages of nanofibrillated cellulose. Bleached Eucalyptus sp. Kraft pulp was submitted to three different grinding regimes to obtain the nanofibrillated cellulose of 2, 10 and 20 passes through the grinder. Paper was produced by incorporating nanofibrillated cellulose in the proportions of 3, 6 and 9 wt%. The results showed that the addition of nanofibrillated cellulose increased the following mechanical properties: tensile index, tear index, and burst index. The porosity and the apparent density decreased. The addition of 9% of nanofibrillated cellulose obtained from 2 grinding passes provided the best results with improvements in tensile, burst and tear resistance of 111, 114 and 70%, respectively, in comparison to normal paper. The improvement in the mechanical properties of paper is related to the very dense network of hydrogen bonds, resulting in greater surface area obtained after defibrillation. Nanofibrillated cellulose can be applied to improve paper quality and for reinforcing composites. [ABSTRACT FROM AUTHOR] more...

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The influence of the composition of the working mixed acid, mass ratio, and nitration temperature and time on the properties and yield of cellulose nitrates from an unconventional feedstock such as the large-tonnage grain-processing residue, oat hulls, was studied. Experimental statistical models were constructed on the basis of a series of experiments. They enable the properties of cellulose nitrates to be predicted as a function of the mixed acid composition and conditions of the nitration process. The mixed acid composition and the mass ratio of mixed acid to cellulose were found to have the primary effect on the properties of cellulose nitrates, while the nitration temperature and time had no noticeable effect on the final result. Under the optimum synthetic conditions, pilot batches of cellulose nitrates were produced, which corresponded to Colloxiline-N in the main properties: mass fraction of nitrogen was 12.08–12.18%, viscosity was 12–15 mPa s, and the solubility in an alcohol—ether mixture was 98%. The correspondence of the synthesized samples to Colloxiline-N was confirmed by FTIR spectroscopy. The cellulose nitrates derived from the unconventional feedstock may find practical use in manufacturing ballistic powder and composite explosives. [ABSTRACT FROM AUTHOR] more...

Argan pulp is an abundant byproduct from the argan oil process. It was investigated to study the feasibility of second-generation bioethanol production using, for the first time, enzymatic hydrolysis pretreatment. Argan pulp was subjected to an industrial grinding process before enzymatic hydrolysis using Viscozyme L and Celluclast 1.5 L, followed by fermentation of the resulting sugar solution by Saccharomyces cerevisiae. The argan pulp, as a biomass rich on carbohydrates, presented high saccharification yields (up to 91% and 88%) and an optimal ethanol bioconversion of 44.82% and 47.16% using 30 FBGU/g and 30 U/g of Viscozyme L and Celluclast 1.5 L, respectively, at 10%w/v of argan biomass. more...

This study examines the effect of pulp type on the formability and elongation of paperboard, which are of key importance when producing 3D packages. Material performance was studied with a press-forming machine using laboratory handsheets as substrates. The handsheets were prepared from bleached softwood and hardwood kraft pulps, chemi-thermomechanical pulp, recycled newsprint, and mixtures of birch kraft and other pulps. The effect of microfibrillated cellulose (MFC) on substrate properties and material formability was also investigated. The 3D elongation of MFC-free handsheets varied between 1.2 and 5.5%. Depending on the pulp type and sheet composition, three essential sheet properties were recognized. These properties were bulk, elastic modulus and bending stiffness, the first two of which affect material bending stiffness. Sheets made from softwood fibers were superior to other samples, but their low bending stiffness resulted in distortion of formed trays. A partial replacement of birch kraft with recycled newsprint did not lead to a loss of sheet extensibility, which suggests that the interactions between the converting tools and the substrate have a great effect on material convertibility. Scanning electron micrographs showed that the pulp type affects the mechanism behind fracture initiation. The ability of MFC to increase extensibility was limited to mechanical pulps, indicating the important role of the main pulp component in defining tensile properties. [ABSTRACT FROM AUTHOR] more...

Abstract: The chemistry of cellulosic key chromophores is challenging because of the usually very low concentration of the colored compounds in real-world cellulosic matrices. It offers many surprises and positive outcomes; unfortunately there are also pitfalls and disappointments. This report discusses eight examples or surprising chemistry out of the realm of cellulosic key chromophores. The reactions have either taken unforeseen paths or provided unexpected products. The reaction mechanisms of the "strange" processes are described and the products are comprehensively analytically characterized. Given that the seemingly obvious approaches have failed, alternatives for obtaining the desired products are provided, wherever possible. Graphical abstract: [ABSTRACT FROM AUTHOR] more...

Abstract: Dynamic vapor sorption (DVS) coupled with deuterium exchange was applied in determining the amount of hydroxyl (OH) groups accessible for deuteration in pulps and pure cellulose quantitatively. The samples studied with the method were different types of chemical pulps as well as microcrystalline and amorphous cellulose powders. The measurement sequence consisted of drying the samples first until the change in sample mass was less than 0.0005% min−1 followed by rewetting the sample with deuterium oxide (D2O) vapor at set relative humidity (RH) of 95% for 600 min and then drying the sample again the same way as the initial drying was done. The method allows determination of the absolute amount of OH groups accessible to deuterium exchange in the samples fully automatically within 1 day. In addition, the equilibrium moisture contents (EMC) of the samples were measured at RH 95% without prior drying enabling the assessment of the EMC of the samples in as-received state without the need to assess the effect of drying. The accessibilities of chemical pulps were found to vary between 54 and 61% of the theoretical maximum, whereas the accessibilities of microcrystalline cellulose and amorphous cellulose were 51 and 63%, respectively. Interestingly, it was found that the accessible OH group content and the EMC of the samples in mol kg−1 correlated with each other and that, in fact, their ratio was close to one.Graphical abstract: [ABSTRACT FROM AUTHOR] more...

The feasibility of using near infrared spectroscopy (NIR) to rapidly determine the cellulose content in pulp was investigated in this study. Partial least square regression analyses were performed to describe the relationships between the data sets of wet chemistry analysis and the NIR spectra. The selection of relevant wavenumbers combined with the appropriate data pre-processing methods produced satisfactory prediction models. The test statistics (R2, RMSECV, and RPD) improved compared with the models over the wavenumber range 10000 cm-1 to 4000 cm-1. The predicted cellulose content models, using the cross validation in the appropriate wavenumber ranges coupled with the spectral data preprocessing methods of multiplicative scattering correction (MSC), standard normal variate (SNV), and first derivative (FD) normalization, were established. The highest R2 value was found to be 0.92 with the lowest RMSECV values 0.60 using FD 19 normalization at the wavenumber range from 7250 to 6500 and 5500 to 4000 cm-1. The highest RPD value was 2.45. NIR spectroscopy, combined with multivariate statistical analysis, could predict cellulose content in the pulp with efficient accuracy. [ABSTRACT FROM AUTHOR] more...

As worldwide agricultural production rises, agro-industrial biomass becomes an abundant raw source for uses in energy and materials production. In Colombia fique plants ( Furcraea spp.) are traditionally used to extract hard cellulosic fibers using mechanical decortication. Juice, pulp and tow, the by-products of this process, represent almost 95% of the fique leaf weight and are produced in large quantities. Data on these materials is scarce and greatly needed to guide and fuel fique agro-industrial development in Colombia. In this contribution we study the physicochemical properties of fique fibers and by-products (tow and pulp), before and after alkaline hydrogen peroxide treatment (AHP), using spectroscopic and microscopic techniques. Raw/clean fique tow is similar in structure and composition to fique fibers with average cellulose, hemicellulose and lignin contents of 52.3, 23.8 and 23.9%; in this by-product cellulose exists as a highly ordered structure with crystallinity index of 57%. Raw/clean fique pulp, composed of cellulose filaments from secondary cell walls and leaf epidermis, has average cellulose, hemicellulose and lignin contents of 30.5, 29.7 and 9.6%, with cellulose exhibiting an amorphous structure with a crystallinity index of 35%. The AHP treatment of these by-products effectively removed non-cellulosic compounds such as hemicellulose and lignin. After AHP lignin content in fique tow decreases to 2.8% while cellulose crystallinity increases up to 73%, Likewise, fique pulp shows a reduction in lignin to 2.1% and an increase in cellulose crystallinity up to 47%. IR spectroscopic analysis, after AHP, show a decrease of signals attributed to hemicellulose and lignin and FESEM images show a disruption of the lamellar structure in the macro fiber by the removal of hemicellulose, lignin and ground tissue, leaving cellulose fibrils exposed. As the first in-depth report on fique by-products characterization, our results indicate that pulp and tow are interesting lignocellulosic materials due to their significant content of crystalline and amorphous cellulose. [ABSTRACT FROM AUTHOR] more...

Oat hulls are a promising feedstock annually renewable at an industrial scale for the production of second generation ethanol. Chemical pretreatment of oat hulls with a 4% (w/w) nitric acid solution at atmospheric pressure was performed in pilot production to give a pulp in which hydrolyzables account for 79.9%. Acid-insoluble lignin totaling 12.5% in the pulp does not deteriorate the efficiency of enzymatic hydrolysis using an enzyme cocktail of commercial BrewZyme BGX and CelloLux-A. At an initial solid loading of 33.3 g/L, a hydrolyzate was obtained with a reducing sugar yield of 93.0% of the overall hydrolyzables. The high yield is assured only by removal of residual, water-soluble, nitrated lignin by water washing. Alcoholic fermentation was run using Saccharomyces сerevisiae Y-1693. Simultaneous saccharification and fermentation with delayed inoculation (dSSF) at an initial pulp loading of 90 g/L was found to improve the ethanol yield by 1.2 times compared to separate hydrolysis and fermentation (SHF), i.e. 0.428 versus 0.343 g/g cellulose, respectively. The ethanol samples obtained from oat hulls contain low percentages of esters and methanol. [ABSTRACT FROM AUTHOR] more...

The potential health and environmental impacts associated with the improper management of chemically treated wood waste demands the adoption of recycling, and disposal practices. Chemically treated wood waste has several physical and chemical properties which makes it usable for the manufacture of another product to multiple use, among which the production of paper and fuel. This paper presents the initial life cycle assessment (LCA) study on wood waste used for paper production. The study boundary is limited with raw materials (raw wood or waste wood) processing and paper production itself, thus corresponds to “gate-to-gate” life cycle with a special focus on life cycle inventory data on waste wood treatment via hydrolysis process. The results of the analysis demonstrate competitiveness of the waste wood use for paper production vs. raw wood in such environmental categories as human health and ecosystem quality. [ABSTRACT FROM AUTHOR] more...

Hexeneuronic acid (HexA) is formed under pulping conditions from 4- O-methyl-glucuronic acid residues in xylans by methanol elimination. It is usually removed by an acidic washing treatment (A-stage) within the pulp bleaching sequence. Hexeneuronic acid has long been recognized as a source of color generation in pulps, but the chemical structure of the actual chromophoric compounds remained elusive. We report the synthesis of isotopically (C) labeled HexA model units carrying a label at any of the six carbon atoms. Confirming pertinent literature accounts, it is shown that HexA forms three primary degradation intermediates, 2-furancarboxylic acid, 5-formyl-2-furancarboxylic acid, and formic acid, under mildly acidic conditions, and their formation mechanism is discussed. 2-Furancarboxylic acid is demonstrated to be deformylation product of 5-formyl-2-furancarboxylic acid. The three primary intermediates are colorless and do not represent chromophores themselves. Their mixture, upon thermal or acidic treatment, gives rise to the same chromophores that are also directly formed from HexA. [ABSTRACT FROM AUTHOR] more...

Hexeneuronic acids (HexA) have long been known as triggers for discoloration processes in glucuronoxylan-containing cellulosic pulps. They are formed under the conditions of pulping from 4- O-methylglucuronic acid residues, and are removed in an 'A stage' along the bleaching sequences, which mainly comprises acidic washing treatments. The chemical structures of HexA-derived chromophoric compounds 4- 8, which make up 90% of the HexA-derived chromophores, are reported here for the first time. The compounds are ladder-type, mixed quinoid-aromatic oligomers of the bis(furano)-[1,4]benzoquinone and bis(benzofurano)-[1,4]benzoquinone type. The same chromophoric compounds are generated independently of the starting material, which can be either a) HexA in pulp, b) the HexA model compound methyl 1-C-4-deoxy-β-L- threo-hex-4-enopyranosiduronic acid ( 1) or c) a mixture of the primary degradation intermediates of 1, namely 5-formyl-furancarboxylic acid ( 2) and 2-furancarboxylic acid ( 3). Isotopic labeling (C) in combination with NMR spectroscopy and mass spectrometry served for structure elucidation, and final confirmation was provided by X-ray structure analysis. C-Isotopic labeling was also used to establish the formation mechanisms, showing all the compounds to be composed of condensed, but otherwise largely intact, 2-carbonylfuran and 2-carbonylfuran-5-carboxylic acid moieties. These results disprove the frequent assumption that HexA-derived or furfural-derived chromophores are linear furanoid polymers, and might have a direct bearing on structure elucidation studies of 'humins', which are formed as dark-colored byproducts in depolymerization of pentosans and hexosans in different biorefinery scenarios. [ABSTRACT FROM AUTHOR] more...

Hexeneuronic acids (HexA) are a major cause of discoloration (yellowing/brightness reversion) in pulps from xylan-containing wood, being generated from the xylan's 4- O-methylglucuronic acid residues. The HexA-derived chromophores, whose identification and structure confirmation have been described in the previous part of this series (Rosenau et al. in Cellulose, 2017), were subject to conditions of peroxide bleaching, i.e. treatment with hydrogen peroxide in alkaline medium. These chromophores, ladder-type oligomers of mixed aromatic-quinoid and mixed furanoid-benzoid character, are degraded relatively quickly to one major product, 2,5-dihydroxy-[1,4]-benzoquinone (DHBQ), and a minor component, 2,5-dihydroxyacetophenone (DHA). These two compounds, which have already been identified as two of the three key chromophores (besides 5,8-dihydroxy-[1,4]-naphthoquinone, DHNQ) in aged cellulosics, are potent chromophores themselves and are subsequently more slowly degraded to non-colored degradation products, according to pathways already described in previous parts of this series. The occurrence of DHBQ and DHA in the bleaching treatment of the HexA-derived chromophores establishes the link between HexA chemistry and the key chromophore classes of residual chromophores found in aged cellulosic materials. [ABSTRACT FROM AUTHOR] more...

Application of Soybean including its bean virgin oil and residual straw in a whole-crop biorefinery was highlighted. Compared to other conventional raw materials, soybean contains all the necessary block raw materials to constitute a biorefinery unit. Virgin oil extract of soybean can be used to produce biodiesel through transesterification reaction. Soybean residual straw contains a sufficient amount of cellulose, hemicelluloses and lignin for producing a variety of biomaterials, biofuels and biochemicals. Pulp mills which produce cellulosic fibers look like a “biorefinery” plant: nearly pure separated cellulose are used today mostly as paper; through the process after separation and solubilization, lignin and hemicelluloses are remained as “black liquor” and incinerated in recovery boiler. The main demands of power for running pulp mill comes from this recovered heat. The heat thus produced covers largely the energy needs of the pulp mill, which may then become a net producer of electricity. This review gathers the different technologies of soybean processing in a third generation of biorefinery, so called whole crop biorefinery. Biochemical transformation of soybean oil to biodiesel was explained following the processing of straw. Then, extraction of biopolymers rom soybean straw with different procedures was described. Finally, integration of the whole crop in a biorefinery system was proposed to produce different value added biofuels, biomaterials and biochemicals. [ABSTRACT FROM AUTHOR] more...