Search

Complete utilization of different agricultural wastes is a great challenge before human society. The present study reports the valorization of rice straw for simultaneous production of reducing sugars and paper. The rice straw was first pre-extracted with water under different reaction conditions sequentially followed by papermaking. A maximum total reducing sugars (TRS) upto 12.38 % was extracted through aqueous pre-treatment. The pulped biomass was assessed for paper properties viz., tensile index, tear index, burst index, Kappa no. and brightness. For untreated rice straw tensile index, tear index and burst index were recorded within a range of 30.9–35.8 N m/g; 2.25–2.62 mN m2/g and 1.91–2.35 kN/g respectively where as it were ranged from 31.1 to 33.7 N m/g, 2.02–2.51 mN m2/g and 1.78–2.08 kN/g respectively for pretreated rice straw. Moreover, for untreated rice straw, kappa number and brightness were recorded in a range from 20.7 to 26.6 and 32.4 to 36.7 % ISO respectively, whereas for pre-treated rice straw it ranged from 19.1 to 26.3 and 31.6 to 35.5 % ISO respectively. High performance liquid chromatography (HPLC) analysis and field emission gun scanning electron microscopy (FESEM) were further employed during the study. In overall, extraction of underutilized sugars prior to pulping may prove as an efficient route for apt utilization of sugars followed by papermaking in near future. [ABSTRACT FROM AUTHOR]

Against the backdrop of a global paper resource shortage, there is a growing need to identify fast-growing tree species capable of producing long-lasting paper. Three plant species namely Broussonetia kazinoki, Broussonetia papyrifera and hybrid paper mulberry, belong to the Broussonetia genus, were collected from China to study their white bark suitability for pulp and papermaking. Their chemical composition revealed that the holocellulose content in Broussonetia kazinoki and Broussonetia papyrifera was more than 80%. The molecular weight distribution of several holocellulose/α-cellulose is observed by GPC, which allows us to better observe the changes of various components on the molecular weight. The yield, lignin, whiteness, and molecular weight of the pulps obtained by NaOH treatment were determined. Optical microscope was used to characterize the fiber length-width ratio and rigidity. Finally, the improvement of the fiber rigidity method based on the Kratky-Porod chain model makes it more theoretical and further reveals the influencing factors of fiber rigidity. This study demonstrates the high potentiality of these three species for papermaking applications. [ABSTRACT FROM AUTHOR]

In pulp mills, lags obscure the effect of upstream operations on downstream measurements. Here, we estimate lags in a Canadian pulp mill using autoregressive exogenous (ARX) models. First, we show that ARX models can approximate lags in a process simulation that resembles the liquor storage tanks in pulp mills, a major source of lag in the kraft recovery cycle. Then, we use ARX models to estimate the lagged effect of a change in species pulped on as-fired liquor heating value, viscosity, and boiling point rise. Additionally, we compare the predictions of the ARX models to autoregressive (AR) models and a persistence model. The estimated lags between a change in species and heating value (49 h) and boiling point rise (41 h) agree with a detailed simulation of the mill and are close to estimated hydraulic residence times, suggesting that the liquor tanks exhibit imperfect mixing. A lagged effect of species change on viscosity could not be identified. ARX and AR models produce similar predictions that are slightly better than those of a persistence model. Finally, we show that process measurements upstream of units characterized by large residence times will likely provide little benefit to prediction accuracy. [ABSTRACT FROM AUTHOR]

Kraft pulping of wood is based on efficient depolymerization and solubilization of lignin, while cellulose is relatively undamaged. Non-cellulose cell wall polysaccharides are however in some cases heavily degraded, especially pectin and to a lesser degree also glucomannan while, xylan is relatively stable. In this mini-review, the most important reactions in lignin and polysaccharide degradation in kraft pulping are described, both the technically favorable and the problematic reactions, and the chemical background to discuss the advantages and drawbacks of the process. An attempt to put the different reactions in the perspective of the goals of the pulping process is made and a special focus is on the development of color in the pulp fiber during the kraft pulping. [ABSTRACT FROM AUTHOR]

The purpose of this study was to clarify whether the wood grinding model -- based on an energy balance for the grinding zone -- would improve understanding of wood grinding for pulp. This study relied on previously obtained data by the Finnish Pulp and Paper Research Institute. The frictional coefficient (Pc/Pt) computed and the power-specific groundwood production (Ġw/Pt) were important x- and y- variables, respectively. Fresh spruce wood samples were ground by application of a laboratory grinder, where the stone surface speeds were 30, 15 and 7 m/s, respectively. The power-specific productivities of high- and medium-speed grindings followed one and the same mechanism, since both speeds led to a productivity of 0.99 [(kg/h)/kW]; the low-speed grinding, however, led to a level of 0.66 [(kg/h)/kW] at frictional coefficients closest to 100 mW/kW. The rate of formation of coarse rejects was -- at the same frictional coefficient as before -- 15.0, 4.3 and 2.3 mg/s for high-, medium- and low-speed grindings, respectively. However, the rate of fines formation determined by McNett apparatus was about ten times higher than that of formation of coarse rejects: 123.0, 42.2 and 23.7 mg/s, respectively. The fines-to-shives ratio (determined by a Somerville shive analyser) was assumed to indicate fiberisation for high-, medium- and low-speed grindings, and the true data, most close to 100 mW/kW, were 56.0, 55.9 and 36.1 units of fines-to-shives, respectively. The curves followed the same trend, but on slightly different levels. As for the important sheet properties, the tensile strengths of high-, medium- and low-speed grindings were low, medium and high, respectively: 37.1, 46.9 and 56.2 Nm/g. The light scattering coefficients of high-, medium- and lowspeed grindings were low, medium and high, respectively, or as data being most close to 100 mW/kW: 59.2, 66.0 and 67.5 m2/kg, respectively. Some general conclusions may be drawn from these results. To achieve the best groundwood productivity, the frictional coefficient should be kept on a level close to 100 mW/kW. Generally speaking, it seems that high- and medium-speed grindings appeared to act as following the same mechanism as far as the productivity was concerned, but the rates of shives and fines formation did not follow such a pattern. The groundwood sheets showed lower tensile strength in high-speed grinding than in medium-speed grinding, while the light scattering coefficient was much lower for the high-speed grinding than for the medium-speed grinding. Because of its low productivity, the low-speed grinding does not seem to be useful, although high tensile strength and high light scattering of the sheets would plead for it. [ABSTRACT FROM AUTHOR]

Deep eutectic solvent (DES) provides promising alternatives to conventional pulping and cellulose purification with significantly lower energy consumption and impacts on the environment. In this work, choline chloride – lactic acid (ChCl-LA DES) pulping of eucalyptus wood chips combined with several ECF bleaching sequences was investigated to produce high-grade dissolving pulps. Initially, the dependency of DES pulping yield and delignification efficiency on the moisture content (MC) of used wood chips was evaluated. The results exhibited the crucial influence of the MC of wood chips on the delignification efficiency of DES pulping. DES pulping under optimized conditions resulted in an unbleached pulp with kappa number of 42, relatively high screened yield 48.1% and viscosity 796 cm3/g, as well as very low hemicellulose content, typically less than 3.8%. Further purification of the obtained pulp using D-Ep-D and OO-D-Ep-D bleaching sequences produces several dissolving pulps characterized by a high viscosity 695 cm3/g and brightness 89.5% ISO, indicating low degradation of cellulose during DES pulping. DES pulping exhibited considerable potential to remove the hemicelluloses from wood chips and produce high-quality dissolving pulps. This could be attained through shorter pulping operations conducted at a lower temperature and a higher screened yield compared to current dissolving pulp production operations. Deep eutectic solvent is able to delignify eucalyptus wood chips efficiently at moderate temperature. Moisture content of eucalyptus wood chips has crucial influence on pulping. Pulp contains very low hemicellulose. DES pulps are bleached easily using ECF bleaching sequences. DES pulping of eucalyptus wood chips followed by ECF bleaching produces high quality dissolving pulp with low energy and chemical consumption. [ABSTRACT FROM AUTHOR]

[Display omitted] The presence of ions in a solution is anticipated to induce distinct effects on macromolecules. Consequently, the tuning of adsorption and mass transfer of lignin molecules can be achieved by incorporating ions with chaotropic or kosmotropic characteristics. This study examines the adsorption and mass transfer behavior of lignin molecules across model cellulose membranes in presence of ions from the Hofmeister series. Experimental investigations encompassed the use of diffusion cells to quantify lignin's mass transfer through the membranes, and quartz crystal microbalance with dissipation (QCM-D) monitoring was used for adsorption studies. Notably, at high ion concentrations, the mass transport rate of lignin was observed to be lower in the presence of highly hydrated (kosmotropic) sulfate ions, conforming to the Hofmeister series. Intriguingly, this relationship was not apparent at lower ion concentrations. Furthermore, QCM-D experiments indicated that lignin displayed higher adsorption onto the cellulose surface when exposed to less hydrated (chaotropic) nitrate anions. This behavior can be rationalized by considering the system's increased entropy gain, facilitated by the release of adsorbed ions and water molecules from the cellulose surface upon lignin adsorption. This study highlights the complexity of ion-specific effects on mass transfer and adsorption processes and their dependency on ion concentrations. [ABSTRACT FROM AUTHOR]

European paper mills are currently facing the question of whether recovered paper, their main raw material, will be available in sufficient quantities and an acceptable quality in the future. An alternative to recovered paper or wood fiber is the use of agricultural residues such as wheat straw. Sodium carbonate-based straw pulping processes have the advantage of not requiring recausticizing for chemical recovery, which reduces investment and operating costs. With the addition of oxygen, delignification can be significantly improved to provide pulps suitable for bleaching. This study compares the pulping of wheat straw using sodium carbonate, sodium carbonate + oxygen, and sodium carbonate + sodium hydroxide + oxygen. Pulping parameters such as temperature, retention time, and chemical charge were varied, and their influence on pulp properties was studied. The use of sodium carbonate alone produced pulps with high yields of up to 72% and comparably high burst and compressive strength. The addition of oxygen and small amounts of sodium hydroxide produced pulps with a high initial brightness of 42 %ISO and a low kappa number (18), still at high pulp yields of 62%. These pulps were two-stage bleached to achieve brightness levels of up to 73 %ISO. [ABSTRACT FROM AUTHOR]

Low-cost production of nanocellulose from diverse lignocellulosic feedstocks has become an important topic for developing sustainable nanomaterials. The available feedstocks include both woody and nonwoody plants, where the latter are relatively underutilized. Interestingly, the porous structure and low lignin content in most non-woody plants, such as agricultural residues and natural fibers, also makes them ideal sources for lower energy nanocellulose production using simpler methods than those required to process woody plants. To enhance the goal of circularity, this review first provides an overview of the nanocellulose conversion from cellulose and then comprehensively discusses the use of non-woody feedstocks for nanocellulose production. Specifically, the availability of suitable non-woody feedstocks and the use of low-cost processes for pulping and cellulose oxidation treatments, including alkaline, solvent pulping, and nitrogen-oxidation treatments, are discussed. The information in this review can lead to new opportunities to achieve greater sustainability in biobased economies. Additionally, demonstrations of nanocellulose-based water purification technologies using agricultural residues derived remediation materials are highlighted at the end of this review. [ABSTRACT FROM AUTHOR]

Monosaccharides such as L-arabinose (Ara) and D-tagatose (derived from D-galactose, Gal) are low-calorie sweeteners associated with improved glycaemic and insulin control compared to disaccharides such as sucrose. However, alternative sources and better sugar-sugar separation methods are needed to improve the sustainability and economics of their production. Here, these sugars were obtained from purified and ultrafiltered compression screw pressate (CSP) of thermo-mechanical pulping of softwood (Pinus radiata) and orange peels (OPs). Basubstituted zeolite X (BaX) molecular sieves showed superior separation performance of Ara from other sugars compared to conventional Ca-form ion exchange resin. To facilitate subsequent separation of sugars, OP hydrolysates were fermented to leave just Ara and Gal, while OP pectin was hydrolysed to generate a Gal-rich mixture. Overall, BaX has good potential for separating Ara from Ara-rich hydrolysates containing several different sugars. It is also suited for separating Ara and another monosaccharide such as Gal or Xyl in the absence of other sugars. [ABSTRACT FROM AUTHOR]

The pretreatment of pulp with enzymes has been extensively studied in the laboratory. However, due to cost constraints, the application of enzymes in the pulp and paper industry is very limited. In this paper, an environment-friendly and efficient pulping method is proposed as an alternative to traditional pulping and papermaking methods. This new method overcomes the low efficiency and extreme pollution problems associated with traditional pulping methods. In addition, fitting equations for the new pulping method are constructed using data on enzyme treatments, which reflect the effect of enzymes and enable the realization of real-time control of the pulping process. The experimental results show that the efficiency of the pulping and papermaking process can be improved using biological enzymes, and the separation of cellulose can be facilitated using mixed enzymes, which have a better effect than single enzymes. [ABSTRACT FROM AUTHOR]

Background and Objectives: While the primary objective of cultivating of seed flax (Linum usititassimum L.) is to produce seeds and extract oil, the plant's significant quantities of long bast fibers also make it a favorable source for papermaking industries. The aims of this study were to assess the quantitative and qualitative characteristics of seed flax and analyze its pulping properties, while exploring the impact of planting distance on these identified characteristics. Materials and Methods: This study was conducted at the UPark farm of the University of Maine, USA, spanning from May to August 2015. The experiments followed a split-plot design within a randomized complete block layout. The primary factors consisted of four planting distances (9.0, 5.1, 2.2, and 4.4 cm), while the secondary factors included three harvest times (50, 75, and 100 days after planting). The distance between the planting rows was set at 4.25 cm, and each plot was comprised of five rows, each measuring 2 m in length. For each plot, the diameter and length of stems were measured for 30 samples extracted from the three middle rows at 50, 75, and 100 days after planting. Following the sample harvest, various plant components (core, stem bast, leaves, roots, and fruit capsules) were measured, and their respective weights and weight percentages per hectare were calculated in the laboratory. Additionally, fiber biometrics analyses were conducted on the stem bast and core. Pulping experiments were performed using the bast and the whole stem using two methods: SO2-ethanol-water (SEW) and soda. All statistical analyses were carried out utilizing the SPSS software, and the means were compared using the Duncan test at significance levels of 1% and 5%. Results: The results of the ANOVA indicated that the individual effects of different factors on the length and diameter of seed flax stems were significant at the 1% level, while their interaction was not significant. Increasing the planting distance led to higher yields of stem, root, leaf, and fruit capsules. Despite a decrease in the percentage of seed flax stem bast from 33% to 25.4% when the planting distance increased from 0.9 cm to 4.4 cm, the overall stem yield showed a significant increase. Notably, the longest bast and core fibers (4700 µm and 608 µm, respectively) were observed at a planting distance of 0.9 cm, while the shortest fibers (4080 µm and 510 µm, respectively) were at 4.4 cm. The pulping experiments conducted using the whole stem with soda and SEW methods demonstrated that the highest and lowest yields were 62.9% and 48.57%, respectively, achieved at cooking times of 30 and 90 minutes in the SEW process. The ANOVA results indicated that the independent effects of planting distance and stem components on the Kappa number of the resulting SEW pulps were significant at the 5% and 1% levels, respectively. The highest Kappa number (62.12) was associated with the pulp obtained from the core of seed flax planted at a distance of 4.4 cm, while the lowest (14.88) was associated with the bast of seed flax planted at a distance of 0.9 cm. The Duncan test revealed no significant difference in the Kappa values of the pulp obtained from the core of seed flax planted at distances of 0.9 and 4.4 cm. Conclusion: Increasing the planting distance of seed flax positively influences the yield of both bast and core of the stem. However, qualitatively, the length of bast and core fibers decreases, with the length of bast fibers consistently being approximately 8 times longer than that of core fibers. In terms of pulping, both the Kappa value and the yield of SEW pulp obtained from the bast and the core of the stem increases. [ABSTRACT FROM AUTHOR]

To further our understanding of the change in association between lignin and carbohydrates after kraft pulping, isotope-labeled kraft pulp (KP) was prepared using 13C and D double-isotope-labeled wheat straw, and it was subjected to enzymatic hydrolysis and ionic liquid treatment to explore the linkages between lignin and carbohydrate complexes in wheat straw. Isotope abundance determination showed that 13C and D abundances in the experimental groups were substantially higher than those in the control group, indicating that the injected exogenous coniferin-[α-13C], coniferin-[γ-13C], and d-glucose-[6-D2] were effectively absorbed and metabolized during wheat internode growth. Solid-state CP/MAS 13C-NMR spectroscopy showed that lignin was mainly linked to polysaccharides via acetal, benzyl ether, and benzyl ester bonds. Kraft pulp (KP) from the labeled wheat straw was degraded by cellulase. The obtained residue was fractionated using the ionic liquid DMSO/TBAH to separate the cellulose–lignin complex (KP-CLC) and xylan–lignin complex (KP-XLC). X-ray diffractometer determination showed that the KP-CLC regenerated cellulose type II from type I after the ionic liquid conversion. The 13C-NMR spectrum of Ac-En-KP-CLC showed that the cellulose–lignin complex structure was chemically bonded between the lignin and cellulose through acetal and benzyl ether bonds. The 13C-NMR spectrum of En-KP-XLC showed a lignin–hemicellulose complex structure, wherein lignin and xylan were chemically bonded by benzyl ether and acetal bonds. These results indicate that the cross-linking between lignin and carbohydrates exists in lignocellulosic fibers even after kraft pulping. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine the effect of sodium methyl mercaptide (SMM) on the yield of the packaging-grade kraft pulp. Based on our experience with bleachable grade kraft pulping using SMM, only a co-addition of 4.38% SMM with white liquor was studied. The cooking temperature and H-factor were adjusted to reach the target kappa number. The experimental results showed about a 2.7% (on O.D. (oven dry) wood basis) increase in the pulp yield after the co-addition of 4.38% SMM (on O.D. wood basis). The use of 4.38% SMM allowed lowering of the severity of the following process variables: the white liquor effective alkali charge (EA, on O.D. wood basis) by 2.4%, the cooking temperature from 165 °C to 157 0C, and the H-factor from 535 to 295. For 98 kappa pulp, the increase in pulp yield was mostly due to the increased retention of xylan (1.63%, on wood basis) and lignin (1.71%). The retention of galactoglucomannan was negligible (0.26%). There was a minor loss of cellulose (0.70%). The increase in the pulp yield in the presence of SMM can be explained by two non-exclusive mechanisms: stabilization of carbohydrate-reducing end groups during impregnation, and faster delignification during the bulk cooking phase. Based on the experimental data, we presently do not know which of the two mechanisms for increasing the pulp yield is dominating. [ABSTRACT FROM AUTHOR]

The object of research is the black liquor of the alkaline pulping sample Paulownia Clone in Vitro 112® with active alkali consumption of 14, 18 and 22 % in Na2O units from the mass of completely dry raw materials. The problem solved in the work is related to the formation of waste in the form of black liquor during pulp production. It is noted that as a result of the production of 1 ton of cellulose, up to 7 tons of black liquor is formed. In the course of the work, an analysis of the total titrated and active alkalinity in the white and black liquor after cooking paulownia wood was carried out, and the pH value was determined. The dependence of the content of dry substances in black liquor on the consumption of active alkali, the duration of cooking, the presence of a catalyst, and the final temperature of the delignification process is given. The amount of organic and mineral components of dry substances of black liquor per 1 ton of air-dry fibrous semi-finished products was calculated. It was established that with an increase in temperature by 20 °C (from 150 to 170 °C) and a duration of approximately 1.5 times (from 60 to 90 min and from 90 to 150 min), with the same consumption of active alkali and the use of a catalyst in the conditions after sodium pulping, the content of dry substances in the black liquor increases by 1.5–3 %. This regularity is explained by the transition into the solution of a greater number of dissolution products of lignin, hemicelluloses, and mineral substances. Estimated values for the content of mineral and organic substances in black liquor after cooking paulownia wood for a duration of 150 min and a final temperature of 170 °C at different consumptions of active alkali and the use of catalysts in the form of anthraquinone and ethyl alcohol are within the range of 1024–1518 kg per 1 ton dry pulps of normal yield and can be used in practice. The obtained results can be used to form an assessment of the black liquor as an additional resource potential for the economy of production. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNC) were prepared from delignified kenaf bast fiber by using alkaline pulping, based on soda anthraquinone, hydrogen peroxide bleaching, and acid hydrolysis treatment with H2SO4. The size and morphology of the fibers were characterized by scanning electron microscopy (SEM), and the isolated fiber from unbleached and bleached pulp had a diameter between 9 to 30 µm. Fourier transform infrared (FTIR) spectroscopy exhibited that the content of lignin decreased in the pulping process, and the lignin was almost completely removed during hydrogen peroxide bleaching. Moreover, fibers were characterized for crystallinity using X-ray diffraction (XRD). The fiber crystallinity gradually increased at each stage of the process (raw kenaf bast, unbleached pulp, bleached pulp, and acid hydrolysis). The fiber was characterized by atomic force microscopy (AFM), which showed that the isolated pulp nanofibers had diameters of approximately 30 nm. [ABSTRACT FROM AUTHOR]

Wood is an abundant and renewable feedstock for pulping and biorefining, but the aromatic polymer lignin greatly limits its efficient use. Sulis et al. recently reported a multiplex CRISPR editing strategy targeting multiple lignin biosynthetic genes to achieve combined lignin modifications, improve wood properties, and make pulping more sustainable. [ABSTRACT FROM AUTHOR]

Grasses are potential candidate to replace wood as a raw material for pulping and paper making, and several processes have been developed to produce grass pulp. In this study, wheat straw was used as raw material, and the possibility of sequential treatment with a mechanical method and deep eutectic solvent (DES) to prepare high-quality dissolving pulp was explored. Firstly, the wheat straw was mechanically treated, and then the wheat straw was delignified using a choline chloride–lactic acid deep eutectic solvent. The results showed that the optimal treatment conditions of deep eutectic solvent were 110 °C, 6 h, and a solid–liquid ratio (ratio of pulp to DES) of 1:40. The removal rate of lignin was 82.92%, the glucose content of pulp was increased by 11.42%. The DES recovery rate was further calculated, and the results showed that the DES recovery rate was more than 50% with rotary evaporation. The pulp viscosity after bleaching was 472 mL/g, and the α-cellulose accounted for 81.79%. This treatment has advantages in biomass refining, and the total utilization rate of wheat straw reaches 72%. This study confirmed that combined mechanical and deep eutectic solvent treatment can effectively remove lignin from wheat straw to produce high-quality wheat straw dissolving pulp. [ABSTRACT FROM AUTHOR]

β-sitosterol (BS) is a phytosterol with wide potential in cosmeceutical, biomedical and food applications. In acid sulphite pulp cooking, BS and its derivatives are considered an underutilized natural source of bioactive compounds, which are adsorbed on the resulting pulp or dispersed in the spent liquor. In this work, a new method for the isolation of BS from alkaline extract (AE) of unbleached sulphite pulp purification stage is proposed. BS was recovered by two-step acidification of AE up to pH 3 under pre-selected conditions, followed by fractionation of the formed precipitate with water-miscible organic solvents, having obtained best results (>90% of BS purity; yield of 70-210 mg/dm3 of AE) with mefthanol fractionation followed by BS crystallization induced via addition of water (ca. 10% vol.). When ethanol was used instead, BS was detected in low amounts in the isolate, being fatty acid sterol esters and fatty acid glycerides the major components, as revealed from analyses by wet chemistry coupled with gas chromatography-mass spectrometry and thin layer chromatography (TLC). The method is adaptable for large-scale industrial production of BS and may represent an important source of sterol-based products. [ABSTRACT FROM AUTHOR]

A new method of recycling cooking with pulping wastewater was developed to save energy and reduce carbon dioxide emissions in a pulp mill, which used bio-fuel of eucalyptus instead of coal and oil, and reduced the steps of black liquor combustion and lime regeneration in the traditional pulp mill to reduce carbon dioxide emission. As results, the bio-fuel consumption and CO 2 emission are 2.04 × 104 MJ (1.2 tons of eucalyptus) and 2.2 tons for per ton of pulp. It reduces 28.23% of fuel energy consumption and 14.06% of CO 2 emission comparison with that by the traditional pulp mill. In addition, while using the generated lignin as part of bio-fuel, the product value-added is 765.88 RMB for per ton of pulp, being 23.72% lower than that of 1004.08 RMB by the traditional pulp mill. Therefore, this study demonstrates the advance and feasibility of using only bio-fuel for a new pulp mill with a new method of recycling cooking, and will promote the technological revolution of cleaner production in the pulp and paper industry. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the effect of active alkali charge, in kraft cooking of Eucalyptus globulus wood, on the properties of the laboratory-produced tissue paper. Eucalyptus wood chips were cooked under similar conditions at four different active alkali (AA) levels of 16, 19, 21, and 23 % and DEDED sequence was used for subsequent ECF bleaching. Pulps were analyzed for their intrinsic viscosity, chemical composition, and fiber morphology, while the corresponding papers (20 g/m2) were examined for their strength properties, absorptivity, and softness. It was demonstrated that changes in the AA upon cooking, not only affected the chemical composition of the obtained pulps and their intrinsic viscosity, but also the fiber's shape (e.g., curl and kink). These changes caused variations in the properties of laboratory-produced tissue papers. Thus, the increase in AA led to paper with lower tensile strength, but with better softness. Even though the increase of AA in cooking led to bulkier papers, their absorptivity was not significantly enhanced. This was explained, at least in part, by the lower water retention of the pulps obtained from cooking with higher AA. [ABSTRACT FROM AUTHOR]

Sugarcane straw fiber (SSF) samples were prepared by chemical pulping (CP) and steam explosion (STE). CP (5, 10, 15% NaOH + 0.2% w/w anthraquinone at 121 °C for 1 h) and STE pressure (1.77, 1.96, and 2.16 MPa at 220 °C for 4 min) SSF trays were molded with a hydraulic hot-press machine at 120 °C, 7 min, and 1.72 MPa. The yield (%) of SSF from STE (54–60% dry basis (db.)) was higher than CP (32–48% db.). STE trays had greater tensile strength than CP. However, STE's elongation and compression strength was lower than CP tray samples. The trays made from SSF using STE had less swelling in thickness, longer water wetting time, and a higher water contact angle than those made from CP. The micrographs displayed a smaller size of SSF obtained in STE than the CP. The appearance and area of peaks in ATR-FTIR spectra and XRD diffractograms, respectively, revealed that the STE trays had a larger residual lignin content from the lignin study and a lower crystallinity index than the CP trays. Moreover, the lightness values of the STE trays were lower than those of the CP trays due to lignin retention. The study results indicate that CP is the preferred method for producing SSF packaging material with high flexibility and fiber purity. However, when considering the specific SF of 4.28, the STE treatment showed superior physical and mechanical properties compared to CP. This suggests that STE could be an excellent alternative green pulping technique for producing durable biobased trays. Overall, the findings highlight the potential of STE as a viable option for obtaining trays with desirable characteristics, providing a sustainable and efficient approach to tray production. [ABSTRACT FROM AUTHOR]

Lignin structure is an important factor affecting the cooking part of the pulping process. In this study, the effect of lignin side chain spatial configuration on cooking performance was analyzed, and the structural characteristics of eucalyptus and acacia during cooking were compared and studied by combining ozonation, GC-MS, NBO, and 2D NMR (1H-13C HSQC). In addition, the changes in the lignin content of four different raw materials during the cooking process were studied via ball milling and UV spectrum analysis. The results showed that the content of lignin in the raw material decreased continuously during the cooking process. Only in the late cooking stage, when the lignin removal reached its limit, did the lignin content tend to be stable due to the polycondensation reaction of lignin. At the same time, the E/T ratio and S/G ratio of the reaction residual lignin also followed a similar rule. At the beginning of cooking, the values of E/T and S/G decreased rapidly and then gradually rose when they reached a low point. The different initial E/T and S/G values of different raw materials lead to the disunity of cooking efficiency and the different transformation rules of different raw materials in the cooking process. Therefore, the pulping efficiency of different raw materials can be improved using different technological means. [ABSTRACT FROM AUTHOR]

Pulping of rice straw was studied using mild nitric acid in mild conditions. Spent nitric acid was chosen as soil nutrient rather than followed by the liquor recovery. The rice straw was treated with 11.03% nitric acid at 90 °C for 3 h, yielded 53.09% pulp. Nitric acid treated rice straw pulp had high residual lignin and minerals. However, further treatment with 7% potassium hydroxide reduced the residual lignin and produced pulp with kappa number 20.36. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. The spent nitric acid liquor was reused repeatedly, pulp yield decreased and residual lignin content increased in each step of spent nitric acid reusing. The spent nitric acid liquor and potassium hydroxide liquor-mixed together to get a neutral effluent liquor which was rich with potassium, nitrogen and biomass. The nutritional capacity of the effluent liquor was assessed by incubation with control soil. The labile form of organic carbon, nitrogen, potassium phosphorous and iron increased in the incubated soil. [ABSTRACT FROM AUTHOR]

Bio-derived materials are becoming increasingly sought-after as a sustainable alternative to petrochemical-derived polymers. In the present pilot-scale study, a hemicellulose-rich compression screw pressate, obtained from the pre-heating stage of thermo-mechanical pulping (TMP) of radiata pine, was purified by treatment with adsorbent resin (XAD7), then ultrafiltered and diafiltered at 10 kDa to isolate the high-molecular weight (MW) hemicellulose fraction (yield 18.4% on pressate solids), and, finally, reacted with butyl glycidyl ether to plasticise the hemicelluloses. The resulting light brown hemicellulose ethers (yield 102% on the isolated hemicelluloses) contained ca. 0.5 butoxy-hydroxypropyl side chains per pyranose unit and had weight- and number-average MWs of 13,000 Da and 7200 Da, respectively. The hemicellulose ethers may serve as raw material for bio-based products such as barrier films. [ABSTRACT FROM AUTHOR]

We investigated antifungal properties of two kraft-pulping liquors as potential environmentally friendly wood preservatives targeting in deterioration by white rot (WRF) and brown rot fungi (BRF). The in vitro antifungal activity of crude black liquor (BL) and the product from a hydrothermal gasification (BLWSupc) process were investigated. Both products showed high bioactivity, with BL completely inhibiting the activity of WRF and BRF; 80% was entirely suppressed at low BL concentrations (5–10% vol/vol). Using the BLWSupc at 2.55% wt/wt, we achieved the same inhibitory effect as BL (15% vol/vol) for the two fungi. These antifungal effects can be explained by the composition of liquors that act as antioxidants, promoting enzymatic inactivation and inhibiting the growth of WRF and BRF. BLWSupc exhibited radical quenching activity against DPPH of 43.9%, and the BL, a phenolic content about 20 times higher (23.635 mg/L) than BLWSupc (2.093 mg/L), suggesting that antifungal activity of BL and BLW is related to their chemical composition. An opportunity demonstrated by this study is the reuse of BLWSupc as a protective treatment within a sustainable chain. [ABSTRACT FROM AUTHOR]

A novel thermo-mechanical pulping (TMP) process has been developed to produce a by-product rich in high-molecular weight (MW) hemicelluloses, a potential raw material for barrier coatings and films. This process uses prehydrolysis to solubilise the hemicelluloses followed by chip compression to separate the soluble material from the wood matrix. The pressate from the chip compression stage was dark-coloured and had a high content of high-MW hemicelluloses and lignin. However, isolating the high-MW material from the pressate directly by ultrafiltration was not feasible because of membrane fouling by dissolved lignin and wood extractives, while coloured impurities are undesirable for many potential applications. To solve these problems the pressate was purified using XAD adsorbent resin to remove low-MW lignin, extractives and colour. Ultrafiltration of the purified pressate yielded lightly coloured high-MW hemicellulose with a low content of lignin and well suited for barrier films and coatings. [ABSTRACT FROM AUTHOR]

Apple wood waste (AWW), mainly tree trucks, is collectible lignocellulosic biomass from orchard rotation. The biorefinery of AWW is challenging because of the hard and dense structure. In the present work, chemical composition determination and microstructure observation was performed for the first time on AWW. Alkali-preimpregnation-assisted soda cooking (APSC) was developed to separate cellulose a pulp and lignin from AWW. APSC attained pulp yield of 34.2% at 23% NaOH, showing a 13.2% improvement compared to conventional soda cooking (SC). Fiber length analysis showed APSC-AWW pulp consisted mainly of medium and short fibers, which means blending with long-fibered pulp to enhance the physical strength of pulp sheets. A blend of APSC-AWW pulp and long-fibered pulp in the proportion of 80:20 attained comparable physical strength to hardwood kraft pulp. ASPC-AWW lignin was separated from spent liquor by acidification and then purified by dialysis desalination. The purified ASPC-AWW lignin showed a weight-average molecular weight of 4462 g/mol, similar to softwood kraft lignin but more uniform. Structural analysis revealed that ASPC-AWW lignin was composed of a syringyl unit (S), guaiacyl unit(G), and p-hydroxyphenyl unit (H), and an S unit was dominant with an S/G/H ratio of 74.5:18.2:7.3. It is believed the utilization of fruit tree wood waste as the feedstock of biorefinery is attractive to countries without sufficient forestry resources. Furthermore, the developed APSC is based on conventional SC, which ensures the feasibility of an industrial application. [ABSTRACT FROM AUTHOR]

The biochemical sludge was mixed with coal-water slurry to prepare the slurry. The effect of the biochemical sludge on slurry performance and gasification performance was investigated through the analysis and research of the additive amount, slurry concentration, rheological properties, water separation rate and gasification simulation calculation. The results showed that the maximum addition amount of biochemical sludge is 10% under the condition of constant slurry concentration, and it was necessary to increase the amount of additives to maintain the slurry performance; the slurry with 10% biochemical sludge can be used for the gasification process to produce syngas, the total dry gas volume during gasification decreased by about 4.8%, the effective gas content decreased by about 1.2%,the specific oxygen consumption was basically unchanged, and the raw material consumption increased by about 6.6% . [ABSTRACT FROM AUTHOR]

Although organosolv processes using high-boiling solvents have been investigated in recent decades for developing novel industrial processes, there are potential benefits of using high-boiling point solvents for traditional sulphate-based cooking processes, both from an industrial perspective and from a laboratory perspective. Using high-boiling solvents, experiments can be done under atmospheric conditions, thus making it easier to continually monitor laboratory experiments and extracting aliquots at desired intervals. Using such a system, alkaline consumption was monitored during impregnation of spruce chips in glycerol media using chemical charges of 1 M NaOH and 0.1 M NaHS, i. e., kraft pulping conditions, and compared to a similar investigation of alkaline consumption in water media using steel autoclaves. The resulting data was fitted to a first order kinetic model, with an apparent activation energy of 22 kJ mol−1 in glycerol media. Finally, a "normal quality pulp" of kappa number 28 and a viscosity of 1113 ml g−1 was successful produced using a cooking process with an impregnation step at 140 °C for 3 h and a cooking step at 160 °C for 4 h. A nuclear magnetic resonance study on the dissolved lignin produced for said experiment showed characteristics typical of other kraft lignins. [ABSTRACT FROM AUTHOR]

The effect of bamboo virgin pulp addition to the recycled pulp in enhancing the recycled paper's mechanical properties was evaluated. Malaysian bamboo virgin pulp used in this research were Bambusa vulgaris (Aur bamboo), Gigantochloa levis (Beting bamboo), and Gigantochloa scortechinii (Semantan bamboo). The addition of 2.5, 5, 7.5, and 10 wt% of bamboo virgin pulp improved the burst index, folding endurance, tearing index, and tensile index of the recycled paper from 2.27 to 3.17 kPa.m2/g, 7 to 15 double folds, 5.98 to 8.27 mN.m2/g, and 24.86 to 32.40 Nm/g, respectively. These were equivalent to the increment percentage for burst index, folding endurance, tearing index, and tensile index at the range of 6.61 to 39.65%, 28.57 to 114.29%, 15.72 to 38.59%, and 10.50 to 33.87%, respectively. The application of bamboo virgin pulp is very promising in improving the recycled paper's mechanical properties and this could be further extended in enhancing the other properties such as physical and optical paper properties. [ABSTRACT FROM AUTHOR]

This research aimed to investigate the efficiency of crude xylanase–pectinase in pulping of sugarcane bagasse. Optimum biopulping was obtained, using xylanase–pectinase dose 200–60 IU/g, bagasse/liquid ratio 1:10 and 1.0% Tween 80 concentration at 55 °C temperature, pH 8.5 and period of treatment 180 min. Treatment of sugarcane bagasse samples with these enzymes generated pulp with lower rejections (58.76%), total solids (12.64%), kappa number (47.77%), higher screened pulp yield (10.66%), along with enhanced optical and physical properties, in comparison with a chemical pulp. Bagasse biopulping resulted in a 13% decrease in alkali dose to obtain the optical and physical properties similar to those achieved under the 100% alkali dose. The breaking length, burst factor, tear index, double fold, gurley porosity and viscosity were improved by 15.19, 37.64, 2.47, 37.77, 35 and 23.17%, respectively, after bleaching treatment of biopulped samples. Thus, enzymatic pulping is an eco-friendly environmentally sustainable approach, since it reduces the use of pulping chemicals and simultaneously improves the paper quality. This is the first report, showing pulping of sugarcane bagasse, with crude xylanase–pectinase, produced by an isolate. [ABSTRACT FROM AUTHOR]

Pineapple leaf fibers (PALF) were biopulped using Trametes versicolor, and the resulting biopulp was bleached with xylanase-enzymatic treatments. The biopulping was extensively described using determinations of fiber morphology, color, chemical composition, extractive content, and thermal stability using the structural characteristics determined by XRD and paper properties. The results showed that the chemical and enzymatic treatments shortened the fiber, almost to 50%, and the Kappa index decreased from 27 to 13. Cellulose and holocellulose contents increased from 65% to 74% and from 86% to 91%, respectively, but extractives, lignin (from 12% to 4%), pentosans (from 25% to 14%) and the crystallinity decreased from 58% to 67% in both chemical bleaching and further xylanase-enzymatic processing. Xylanase)enzymatic processing allowed us to obtain whiter (increased lightness color and decreased redness and yellowness tonality) and heavier paper, even though it presented decreased mechanical properties (decreased stress resistance, rupture length, tear resistance and index longitudinal tearing). The xylanase-enzymatic treatment with the best pulping and paper proper)ties is when the biopulp is treated with a xylanase enzyme concentration of 0.04% (w/w). [ABSTRACT FROM AUTHOR]

The microstructural, morphological, chemical, pulp, and paper properties of four fast growing Thai bamboo species, Bambusa vulgaris, Bambusa longispiculata, Dendrocalamus membranaceus, and ×Thyrsocalamus liang, were characterized to evaluate their potential as alternative fibrous raw materials in pulping and papermaking. It was found that the chemical composition of the four bamboo species was not significantly different. The alpha cellulose, lignin, and ash contents were between 46% and 50%, 27% and 29%, and 2% and 3%, respectively. The average fiber length ranged between 1.74 and 2.16 mm and had long fibers similar to softwood fibers. The bamboo fibers were thick-walled, narrow, had a small lumen, and were rigid. The pulp yield of all the bamboo species, prepared by kraft pulping, was high between 45% and 50% and had a low rejection of 0.12–0.33%. The handsheets were prepared from the bamboo pulp using various beating time to develop strength properties. It was observed that the handsheet quality improved with increasing beating time. We conclude that these properties indicate a great potential for these bamboo species for pulp and paper production. [ABSTRACT FROM AUTHOR]

Background: During the kraft process to obtain cellulosic pulp from wood, most of the lignin is removed by high-temperature alkaline cooking, released in the black liquors and usually incinerated for energy. However, kraft lignins are a valuable source of phenolic compounds that can be valorized in new bio-based products. The aim of this work is to develop laccases capable of working under the extreme conditions of high temperature and pH, typical of the industrial conversion of wood into kraft pulp and fibreboard, in order to provide extremophilic biocatalysts for depolymerising kraft lignin, and enzyme-assisted technologies for kraft pulp and fibreboard production. Results: Through systematic enzyme engineering, combining enzyme-directed evolution and rational design, we changed the optimal pH of the laccase for oxidation of lignin phenols from acidic to basic, enhanced the catalytic activity at alkaline pH and increased the thermal tolerance of the enzyme by accumulating up to eight mutations in the protein sequence. The extremophilic laccase variants show maximum activity at 70 °C and oxidize kraft lignin at pH 10. Their integration into industrial-type processes saves energy and chemicals. As a pre-bleaching stage, the enzymes promote kraft pulp bleachability and significantly reduce the need for chlorine dioxide compared to the industrial sequence. Their application in wood chips during fibreboard production, facilitates the defibering stage, with less energy required. Conclusions: A set of new alkaliphilic and thermophilic fungal laccases has been developed to operate under the extreme conditions of high temperature and pH typical of industrial wood conversion processes. For the first time basidiomycete laccases of high-redox potential show activity on lignin-derived phenols and polymeric lignin at pH 10. Considering the extreme conditions of current industrial processes for kraft pulp and fibreboard production, the new tailor-made laccases constitute a step forward towards turning kraft pulp mills into biorefineries. Their use as biocatalysts in the wood conversion sector is expected to support the development of more environmentally sound and efficient processes, and more sustainable products. [ABSTRACT FROM AUTHOR]

Plant fibers are excellent sources of biomacromolecules, but the extraction of these chemicals critically depends on pretreatments on the biomass. In this work, steam explosion followed by acetosolv or ethanosolv pulping were evaluated as pretreatments for cellulose nanocrystal and lignin extraction from oil palm mesocarp fibers. The steam explosion improves defibrillation of the biomass, deconstructs lignocellulosic material, facilitating the separation between lignin and polysaccharides by organosolv pulping. The effects of acetic acid or sodium hydroxide concentrations and reaction time for acetosolv or ethanosolv pulping were evaluated by a central composite design. Fibers and biomacromolecules were characterized using analytical methods, including SEM, TEM, DRX, zeta potential, and FTIR. The optimized conditions to obtain cellulose nanocrystals from bleached acetosolv fibers (CNCA) were 80% (w/w) acetic acid catalyzed with HCl 0.6% (w/w) for 35 min, while the optimized conditions from ethanosolv fibers (CNCE) were NaOH 4% (w/v) and ethanol 95% (v/v) for 60 min. The lignins obtained from both optimized conditions presented high purity. The acetosolv delignification was more effective to extract the insoluble lignin (yield of 36.7%) than ethanosolv (yield of 23.2%). The CNCA and CNCE presented, respectively, high crystallinity (68% and 56%) and good aspect ratio (26 and 25). [ABSTRACT FROM AUTHOR]

Keywords: Olive tree pruning residues; cellulose; optimization; Box-Behnken Design; soda-anthraquinone pulping; TCF bleaching; ; ; ; ; ; . EN Olive tree pruning residues cellulose optimization Box-Behnken Design soda-anthraquinone pulping TCF bleaching ZH . Cellulose, optimization, Box-Behnken Design, Olive tree pruning residues, soda-anthraquinone pulping, TCF bleaching. [Extracted from the article]

The article provides data on radioisotope device, including a radioisotope level meter – a radioisotope indicator of the level of petroleum coke and a radioisotope density meter. The article describes the methods of calibration of radioisotope density meter Gammapilot (Endress+Hauser AG, Switzerland). An ionizing radiation source of Cesium-137 GCS7.021.1 type with an activity of 3.06 × 109 Bq (82.7 mCi) was used to complete the radioisotope densitometer, and its tightness was checked using the immersion method with 8% ortophosphoric acid as the immersion liquid. To calibrate radioisotope densitometers, simulator stands and liquid simulators of various densities were made based on a mixture of tribromomethane and ethyl alcohol solutions. Radioisotope density meters were calibrated for low pulp emulsion density, medium pulp emulsion density, and high pulp emulsion density. In calibrated radioisotope density meters, upon reaching the lower limit of the pulp density in the detection unit, an output electrical signal appears at the "0–5 mA" connector, and when the upper limit of the pulp density is reached, an output electrical signal appears at the "4–20 mA" connector. [ABSTRACT FROM AUTHOR]

The feasibility of the pulping technology depends on the efficiency of by-products and solvent recovery. In this regard, the development of an environmentally friendly peracetic method of delignification should be accompanied by the development of an effective method of lignin disposal. Usually, delignification methods are characterized without a detailed study of the by-products. Herein, let's describe the structural and chemical characteristics of lignin, as well as its sorption properties. Pulping liquors after peracetic delignification of rapeseed straw were used in this work. The application of sodium tungstate and sodium molybdate as catalysts gave a significant effect on the dissolution of lignin during pulping. The composition, structure and functional groups of lignins were investigated. Application of catalysts in organosolv pulping resulted in small amounts of carbohydrates in lignins if compare to lignins after non-catalytic pulping. As catalysts, Na2WO4 and Na2MoO4 exhibited no obvious differences in carbohydrate contents and in molecular weights of organosolv lignin (Mw = 4910–5640 g/mol, Mn = 2350–2500 g/mol). The obtained lignin was successfully used for Methylene Blue adsorption due to high content of functional groups (R-OH = 1.72 mmol/g, Ph-OH = 5.72 mmol/g, R-COOH = 0.88 mmol/g) despite the poorly developed porous structure (11.03 ± 0.35 m2/g). Lignin has potential applicability as a biosorbent for wastewater treatment to solve environmental problems of water pollution. [ABSTRACT FROM AUTHOR]

An integrated and feasible approach was proposed using the underutilized grass fibre (stem) derived from Napier grass and sugarcane for paper production in this study. To enhance paper strength, pre-hydrolysis and beating techniques have been used to improve the chemical pulps and mechanical pulping process, respectively. Napier grass and sugarcane are promising non-wood sources for pulp production, owing to their high cellulose and low lignin and extractive content. With the additional mild alkaline pre-treatment to the mechanical pulping process, the lignin content was greatly reduced. The results reveal that the mechanical pulping with alkaline pre-treatment may indeed potentially replace the most prevalent pulping process (chemical pulping). As evidenced by the paper strength properties, mechanical pulping is far more suitable for grass-type biomass, particularly Napier grass, which had a folding endurance capability five times greater than chemical pulping. Furthermore, the remaining high hemicellulose content from mechanical pulping contributed to a high pulp yield, while also facilitating the fibrillation on the sugarcane's laboratory paper handsheet. The findings also demonstrated that the additional beating process from chemical pulping causes the fibres to be drawn toward each other, resulting in a more robust fibre network that contributes to good paper strength. Consequently, this work sheds new light on the development of advanced paper derived from grass fibre. [ABSTRACT FROM AUTHOR]

Based on the reduction of environmental pollution, a biological enzyme assisted alkali-oxygen pulping method was explored to improve the delignification efficiency and fiber accessibility of wheat straw and improve the properties of wheat straw pulp. In this paper, lipase and xylanase were used to pretreat wheat straw and the effects of different enzyme types and enzyme dosage on the microstructure and pulp properties of wheat straw were investigated and experimented. The results showed that the lipase can remove fat and wax on the surface of wheat straw, while xylanase degraded the hemicellulose components, such as xylan, of wheat straw fiber, destroyed the structure of the lignin-carbohydrate complex, increasing lignin removal as a result and enhancing the impregnating, diffusion and penetration of alkali. Compared with wheat straw without enzyme pretreatment, the skeleton of wheat straw pretreated by enzyme became looser, the internal cavity appeared and the wall cavity became thin and transparent. The fines decreased obviously and the length of fibers increased. After combined pretreatment with lipase (15 U·g−1) and xylanase (15 U·g−1), the pulping performance of wheat straw was improved and the tensile index (97.37 N·m·g−1), brightness (40.9% ISO) and yield (58.10%) of the pulp increased by 12.9%, 19.9% and 9.9%, respectively. It can be seen that enzyme pretreatment is a green and effective approach to improving the alkali-oxygen pulping performance of wheat straw. [ABSTRACT FROM AUTHOR]

The production of bioethanol from materials of renewable origin is an important matter for a more sustainable economic development, and at the same time it challenges researchers to seek more efficient technologies that can make it viable. Wood is a profitable and advantageous option, with special emphasis on eucalyptus, whose cultivation has high turnover in Brazil, where land is available for this purpose. Therefore, the goal of this research was to optimize the hydrolysis stage using acid instead of enzymes for the conversion of chips of Eucalyptus urograndis into bioethanol, with additional co-production of furfural and commercial lignin, in order to make the process more advantageous. To obtain bioethanol, a pre-treatment adapted from autohydrolysis was performed to remove the hemicelluloses, followed by soda pulping to remove the lignin and, finally, the acid hydrolysis of the β-(1→4) glycosidic bonds between the C1–C4 cellulose carbons releasing β-D-glucose monomers to be fermented into bioethanol. In the acid hydrolysis step, sulfuric acid of concentration 1127 gL−1 was used. After the experimental analyses performed, it could be observed that in acid hydrolysis, treatments using 70 mL and 80 mL of sulfuric acid did not differ statistically in relation to glucose production. However, by increasing the volume of acid to 90 mL, there was an increase in the production of fermentable sugars into bioethanol, 63.7 %, which began decreasing when adding acid above 93 mL, because the excess of acid also caused the degradation of sugars into 5-hydroxymethylfurfural (HMF); and in the treatment of 100 mL there was a higher production of HMF. The production of bioethanol proved to be competitive after the fermentation of the sample from the 90 mL treatment with a production of 103.7 L of bioethanol/ton of wood, in addition to being beneficial to the process as a whole with the co-production of furfural, 28.8 kg of furfural ton−1 of wood, and commercial lignin, 428.3 kg of lignin per ton of wood, precursors to various chemicals such as resins, coatings and inks. [ABSTRACT FROM AUTHOR]

Research by the paper industry into new materials to expand the raw material base for pulp is on the ascendancy due to growing demand for pulp and paper products. This study assessed the anatomical, chemical, and pulping characteristics of four varieties of Cocos nucifera husk to ascertain their suitability as raw material for pulp and paper production. The measured and calculated chemical (Klason Lignin, 1% NaOH solubility and Holocellulose contents) and anatomical (Fiber dimensions, Runkel Ratio, Slenderness Ratio, Flexibility Coefficient, Coefficient of Rigidity, Luce's Shape Factor and Solids Factor) properties of the Cocos nucifera husks mostly did not meet the standard requirements for a good pulp and paper material. However, the Local Tall Yellow variety of the Cocos nucifera husk was favorable in terms of Runkel Ratio, Slenderness Ratio, Flexibility Coefficient, and Coefficient of Rigidity and can be considered for the production of pulp for writing and printing papers. In spite of the limitations of the other three varieties for making quality paper, they could be used for fiber plate, rigid cardboard, and cardboard production. [ABSTRACT FROM AUTHOR]

The cellulose nanocrystals (CNCs) were produced from spruce wood using less hazardous and toxic reagents with understanding of influence of process parameters on CNCs properties. This study employed acetosolv pulping followed by alkaline-peroxide bleaching, eliminating highly reactive chemicals such as Na-chlorites and Na-sulfite for cellulose pulp extraction from spruce wood. Cellulose pulp yield of 41.5 ± 0.7 wt% of dry wood was obtained from pulping followed by bleaching treatment. Cellulose pulp was hydrolyzed with 59.0–65.0 wt% sulfuric acid followed by ultrasonic treatment to produce CNCs. CNCs yield of 8.0 ± 3.2 wt% of dry wood was obtained at 65 wt% acid concentration and yield of 25.1 ± 0.7 wt% at 62 wt% acid concentration. The optimization of acid hydrolysis and ultrasonic treatment resulted in CNCs with high aspect ratios (length/width) up to 48.1. It was demonstrated that higher acid concentration requires lower intensity of ultrasonic treatment for CNCs dispersion, and that higher intensity could enhance aspect ratio without impacting the crystallinity index. However, ultrasonic treatment for longer than 5 min led to destruction of the whisker morphology of CNCs. The extracted CNCs possess high crystallinity index of 80.8 ± 1.7 %, low residual hemicellulose (<2.0 %) and lignin (<0.7 %), and high-char content of 26.7 wt% from thermal degradation. [Display omitted] • S and Cl free pulping and bleaching processes were used for cellulose extraction. • Pure cellulose nanocrystals from spruce were obtained in high yield. • High aspect ratio of up to 48 and crystallinity index of 80.8 ± 1.7 % were achieved. • Ultrasonic treatment showed no negative impact on the crystallinity index of CNCs. [ABSTRACT FROM AUTHOR]

The spleen is a large and highly vascularized secondary lymphatic organ. Spleen injuries are among the most frequent trauma‐related injuries in the abdominal region. The aims of the study were to assess the volume fractions of the main splenic tissue components (red pulp, white pulp, trabeculae and reticular fibres) and to determine the severity of splenic injury due to the experimental impact test. Porcine spleens (n = 17) were compressed by 6.22 kg wooden plate using a drop tower technique from three impact heights (50, 100 and 150 mm corresponding to velocities 0.79, 1.24 and 1.58 m/s). The pressure was measured via catheters placed in the splenic vein. The impact velocity was measured using lasers. The severity of induced injuries was analysed on the macroscopic level. The volume fractions of splenic components were assessed microscopically using stereology. The volume fraction of the red pulp was 76.4%, white pulp 21.3% and trabeculae 2.7% respectively. All impact tests, even with the low impact velocities, led to injuries that occurred mostly in the dorsal extremity of the spleen, and were accompanied by bleeding, capsule rupture and parenchyma crushing. Higher impact height (impact velocity and impact energy) caused more severe injury. Porcine spleen had the same volume fraction of tissue components as human spleen, therefore we concluded that the porcine spleen was a suitable organ model for mechanical experiments. Based on our observations, regions around hilum and the diaphragmatic surface of the dorsal extremity, that contained fissures and notches, were the most prone to injury and required considerable attention during splenic examination after injury. The primary mechanical data are now available for the researchers focused on the splenic trauma modelling. [ABSTRACT FROM AUTHOR]

In this study, the sulphur oxide anions profile at all stages of the Mg acid sulphite pulping process was evaluated by Ion Chromatography (IC). The concentration of bisulphite anions decreased almost two-third along the cooking, while the sulphate concentration increased progressively. Of the bisulphite consumed, only a third was converted to sulfates. Unexpectedly, the maximum thiosulphate concentration was found in the pulping acid filling step, being further decreased along the cooking. The chloride ions rise progressively during the cooking being extracted essentially from the wood, although a noticeable part of the phosphate anions belongs to pulping reagents and inlet water. The low molecular weight fraction of lignosulphonates (LS) appeared in the cooking liquor in the residual delignification step and, together with xylonic acid, contributed to an overestimation of the fluoride concentration determined by the IC due to the same retention time in the chromatographic column during the analysis. [ABSTRACT FROM AUTHOR]