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The effects of laboratory beating on unbleached regular grade pine kraft pulp (UPKP), pre-treated with commercial cellulase/hemicellulase enzymatic preparation (C/HEP) were assessed using degrees of Schopper-Riegler (°SR) and fibre-quality numbers (FQN). The tests showed a significant increase in the °SR (used in papermaking laboratories and industry to assess the degree of beating) of the UPKP after its enzymatic pre-treatment in the amount of 0.25 to 5.0 mL/kg of pulp and beating. However, only a several percent reduction of beating time was observed when the effect of this pretreatment of pulp on the speed of its beating was determined using another method. The treatment of the pulp selected for research with C/HEP before beating negatively influenced its strength properties after this process. The results correlated well with the most important basic fiber properties from the standpoint of papermaking. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide is an environmentally friendly bleaching chemical that is widely used in alkaline media in the pulp and paper industry. In this study, unconventional reaction conditions of the conventional bleaching Pstage were performed to evaluate its effect on cellulose. The objective was to “tailor” the cellulose degradation according to different applications, such as dissolving pulps. Different operating conditions were studied: pH variation (alkaline or acidic medium), as well as the addition of Cu(II) or the Cu(II)-phenanthroline complex. The hypotheses considered were (1) Using H2O2 in unconventional conditions will favor hemicelluloses removal after depolymerization and will lead to the desired cellulose degradation, and (2) H2O2 oxidation carried out under unconventional conditions will favor the dissolving ability of cellulose. [ABSTRACT FROM AUTHOR]

An awareness of the problems associated with the use of plastics can provide new opportunities for the paper industry. We have to try to enhance the public awareness of the environmental value of papers by using diverse advertising approaches. We have to collaborate to make paper more viable to replace plastics in many uses. The collaboration not only between industry and academia but also between countries and associations is essential to advance the age of paper. [ABSTRACT FROM AUTHOR]

Factors of manufacturing sustainability in the papermaking industry were identified and ranked using qualitative analysis and nonparametric tests. Based on a review of the literature on sustainable development and production, seven main factors of economic, environmental, technological, social, human, material and product, and regulations were identified to underpin the manufacturing sustainability in the papermaking industry, as well as some sub-factors. Then, a self-designed questionnaire was developed to take a poll among papermaking managers and experts regarding the effectiveness of the factors and sub-factors in manufacturing sustainability and their status. The factors affecting manufacturing sustainability in the papermaking industry were confirmed by the standard and significance coefficients in the structural equations and the predictive criterion. The cross-validated redundancy index showed that the data were valid enough for prediction. The research factors were ranked by the ordinal average affecting sustainability, current status, and distance to sustainability. The materials and product, environmental, technological, and economic factors had the greatest influence on manufacturing sustainability, and the regulation and human factors had the highest distance to sustainability. To achieve manufacturing sustainability in the papermaking industry, regulations and human factors need to be further studied. Their improvement has potential to achieve manufacturing sustainability. [ABSTRACT FROM AUTHOR]

Sustaining life on the Earth with its ever-growing population is forcing changes in people’s way of life, industrial and agricultural production, exploitation of energy resources, and approaches to ecology. We face continual growth in the world’s population, and the demand for materials is growing even more rapidly. Every manufacturing and consumer sector is looking for ways to save energy and materials, attempting to minimize their negative impacts on the environment. In the pulp and paper industry, one of the segments in which progress can be made and help protect the planet is to reduce the brightness of paper. Such a reduction would lead to a lowering in the energy and material costs associated with paper production.

Lignin peroxidase (LiP), which has been studied extensively in white-rot basidiomycetes and their potential to degrade dyes from textile wastewater, plays a role in the biodegradation of lignin from pulp and paper industry wastewater, as well as agricultural waste. Lignin peroxidase (LsLiP) was successfully purified from the newly isolated Lentinus squarrosulus MPN12 with a 47.1-fold purification and a 15.7% yield. After 48 h-incubation, LsLiP was able to decolorize all tested dyes up to 92% for Acid Blue 62 (NY3), followed by Porocion Brilliant blue HGR (PB, 73.5%), Acid Blue 281 (NY5, 70.5%), Acid Blue 113 (IN13, 61%), Acid red 266 (NY7, 56%), and 34.5% for Acid red 299 (NY1), compared to the negative control with the heat-denatured enzyme. The biodegradation potential of LsLiP was further suggested by the change of lignin structure based on Fourier transform infrared (FTIR) analyses. Lignin structure was noticeably changed before and after LsLiP treatment, especially in the fingerprint regions (1600 to 1000 cm-1) and 2930 cm-1 corresponding to the stretching vibrations of various groups in lignin. Thus, LsLiP has potential application in both enzyme-based decolorization of synthetic dyes and lignin biodegradation. [ABSTRACT FROM AUTHOR]

The paper industry is a high-carbon emission and energy-intensive industry. From the perspective of low-carbon trade and carbon neutrality, its energy conservation and emission reduction are worthy of attention. This study used the input-output model to calculate the embodied carbon emissions of China’s paper industry’s export trade to the United States from 2006 to 2020 and used the logarithmic mean division index (LMDI) method to analyze influencing factors of the change of embodied carbon emissions. The study found that the embodied carbon emissions of China’s paper industry’s export trade to the United States generally shows a stable downward trend after reaching the peak with the increase of export trade scale; scale effect is the main factor that causes the embodied carbon emissions, while technological progress, policy support, and environmental regulations are important driving forces to promote carbon emission reduction. The research results of this paper not only can test and guide China’s paper industry trade policies and industrial policies, but they can also provide decision-making reference for China and the United States to promote the carbon emission reduction of the paper industry. [ABSTRACT FROM AUTHOR]

With rising concern for environmental protection, the use of ozone has been increasingly studied in the pulp and paper industry. Feasible models for efficient quality prediction and process control are in high industrial demand. In this study, the reaction kinetics of delignification and viscosity during the ozone bleaching process (OBP) of low-consistency hardwood pulp (LCHP) are explored using exponential and zero-order response models, respectively. The effects of ozone dose, reaction temperature, reaction time, and pH on the changes in residual lignin content and pulp viscosity were analyzed. The corresponding kinetic parameters, such as the reaction order, rate constant (k), and activation energy (E), were also obtained. The models suggest that temperature should be one of the most significant factors affecting the effectiveness of the OBP system. The strategy to improve the OBP selectivity is based on reducing the reaction temperature while increasing the ozone concentration and pH in the reaction system. [ABSTRACT FROM AUTHOR]

Sustaining life on the Earth with its ever-growing population is forcing changes in people’s way of life, industrial and agricultural production, exploitation of energy resources, and approaches to ecology. We face continual growth in the world’s population, and the demand for materials is growing even more rapidly. Every manufacturing and consumer sector is looking for ways to save energy and materials, attempting to minimize their negative impacts on the environment. In the pulp and paper industry, one of the segments in which progress can be made and help protect the planet is to reduce the brightness of paper. Such a reduction would lead to a lowering in the energy and material costs associated with paper production. [ABSTRACT FROM AUTHOR]

Increasing the solids content of pulping black liquor burned in a furnace is a development trend of the alkali recovery system in the pulp and paper industry. However, the viscosity of kraft black liquor increases exponentially with an increase in solids content, especially in the case of non-wood pulping black liquor, such as bamboo. This brings great difficulties to the pulping system and atomization of black liquor at the splash-plate nozzle, which is a complete atomization unit constituted of a splash nozzle and a splash plate. To obtain instructive results for industry, a simulation of the atomization process was made using Fluent software for the bamboo kraft black liquor with solids contents of 70 wt% and 80 wt%, which flowed through splash nozzles with the diameter of 22 or 20 mm. The studies were conducted on the distribution of flow field in the nozzle and atomization region through changing the injection pressure and nozzle diameter. The variation of atomization characteristic parameters, such as liquid film thickness, and breakup length, were elucidated. The results reveal the relationship between spray atomization with injection pressure and nozzle diameter, which provides a theoretical basis for improving the concentration of black liquor entering alkali recovery in the future. [ABSTRACT FROM AUTHOR]

The thermal yellowing of hornbeam chemi-mechanical pulps (CMP) after bleaching with hydrogen peroxide and sodium dithionite was investigated. The hornbeam chips were randomly chosen from Mazandaran wood and paper industries. The CMP pulps prepared with 85% yield were separately bleached with diethylenetriamine pentaacetic acid (DTPA), without DTPA, and hydrogen peroxide. Some pulps were bleached with sodium dithionite. The optical properties of prepared hand-sheets of 60 g/m2 after spraying with 0.5% DTPA were measured using TAPPI standard methods. All prepared papers were thermally aged separately in an oven at 105 °C for 0, 10, 20, 30, and 40 h. The optical properties, such as brightness, yellowness, coefficient of absorption, k/s ratio, post color (PC) number, and a* factor, before and after thermal aging were measured. The results showed that from 0 to 40 h, the optical properties of paper increased except brightness and greenness. This increase was more extensive up to 15 h. Additionally, among the various treatments, DTPA treatment in longterm thermal aging and the use of sodium dithionite and hydrogen peroxide in the short-term aging had noticeable effects on brightness durability and decrease in the color reversion. Thus, there was an increase in the durability of the paper against thermal deterioration. [ABSTRACT FROM AUTHOR]

Foam forming technology has attracted much attention during the past few years in the paper industry. Its advantages compared to conventional water forming are a new product portfolio and increased process efficiency. To support the paper industry in pushing foam forming technology forward, process simulation is needed to provide supporting data for strategic decision-making and as a basis for equipment dimensioning. This study examined the conversion of an existing wallpaper machine from water to foam forming technology using process simulation. To determine the required process configuration and parameter changes in the existing process, both published and unpublished data on the foam forming process were collected. This paper also describes modeling of the foam phase in the selected simulation software. The suitability of existing paper process equipment for foam was analyzed. Simulations revealed that undisturbed operation with foam requires some equipment modifications and re-arrangements in water circuits. With foam forming, the water balance in both short and long circulation changes remarkably compared to conventional water forming, leading to a large increase in the long circulation volume flows. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate a potential biorefinery process to realize the high utilization of Camellia oleifera shell (COS), which is an agricultural by-product mainly composed of cellulose, hemicellulose, and lignin. Before treatment by steam explosion, the COS was impregnated with water, 3.0 wt% NaOH solution, or 3.0 wt% H2SO4 solution. The morphological structure and chemical composition of the steam-exploded COS pulp were investigated. The results indicated that the impregnation treatments increased the cellulose content of the steam-exploded COS pulp and decreased the hemicellulose and lignin content. The morphology of steam-exploded COS fiber was short, coarse and stiff. Hydrophobic and colorful handsheets were fabricated by mixing proportional bleached softwood fiber. This study demonstrated that COS was a potential material for the papermaking industry, and the combination of water impregnation and steam explosion treatment for COS was a good pulp process. [ABSTRACT FROM AUTHOR]

As a global environmental problem, plastic pollution has attracted worldwide attention. Plastic wastes not only disrupt ecosystems and biodiversity, but they also threaten human life and health. Countries around the world have enacted regulations in recent years to limit the use of plastics. Paper products have been proposed as promising substitutes for plastics, which undoubtedly brings unprecedented opportunities to the pulp and paper industry. However, paper products have some deficiencies in replacing certain plastic products. Research and development to improve paper properties and reduce production costs is needed to meet such challenges. [ABSTRACT FROM AUTHOR]

Lignin is a by-product of the pulp and paper industry that can be precipitated by acidification from black liquor as a potential feedstock for valuable green materials. Precipitation and quantification of lignin from softwood black liquors have been documented and commercialized with well-established methods; however, applying those methods to the precipitation of lignin from hardwood black liquors has produced low lignin yields. A need to understand the main differences between hardwood and softwood lignin precipitation prompted the current investigation. Multiple black liquor samples from sweetgum and pine pulping were obtained at different times of standard kraft cooks. Two lignin fractions were precipitated from each of these black liquors, one at pH 9.5 and one at pH 2.5. Detailed lignin and carbohydrate material balances were performed around each of the sample sets, starting with the wood and ending with precipitated lignin fractions. For all conditions tested, the amount and purity of pine lignin precipitated were superior to sweetgum lignin. The maximum recovery for sweetgum lignin was 69.7%, while for pine lignin, it was 90.9%. [ABSTRACT FROM AUTHOR]

The outbreak of coronavirus disease 2019 (COVID-19) has made a huge impact on the global industrial supply chains. Undoubtedly, COVID-19 is posing severe challenges to the pulp and paper industry worldwide. On the other hand, this pandemic may provide unprecedented possibilities for the pulp and paper manufacturers in areas such as the increasing demand for personal hygiene paper products, food packaging products, corrugated packaging materials, medical specialty papers, etc. [ABSTRACT FROM AUTHOR]

While paper as a medium of information is declining in demand, paper as a sustainable alternative to plastic packaging is gaining interest. In light of these changes, the paper industry is seeking new growth by developing highly-functional paper material that can replace plastics. To this end, the industry needs to develop paper with high-barrier and strength properties, as well as technologies that can improve recyclability of such material. Beyond paper, the industry is also developing novel wood-based chemicals that can replace traditional fossil-fuel derivatives. For these to become commercially viable, the industry needs to focus on achieving cost-competitiveness. Finally to reinforce these two initiatives, the government needs to engage in active dialogues with the industry leaders and provide related R&D support. [ABSTRACT FROM AUTHOR]

The pulp and paper sector is undertaking several initiatives to decrease the carbon footprint of its industrial activities. To do so, any emission must be offset by introducing efficient carbon fixation strategies such as reforestation and the development of biobased products and processes. The production of drop-in fuels may play an important role in this scenario. Drop-in fuels provide a good way to add value to otherwise underutilized process streams and wastes, reducing greenhouse gas emissions, minimizing other environmental impacts, and improving process sustainability. [ABSTRACT FROM AUTHOR]

Effluent found in the pulp and paper industry can cause considerable damage if it is discharged untreated, because of the high biochemical and chemical oxygen demands. Electrocoagulation is a physicochemical process widely used in industrial wastewater treatment. The removal of different pollutants depends on the sample type and operating conditions. The aim of this research was to evaluate the efficiency of an electrocoagulation system for COD removal from recycled paper production effluent via aluminum and iron electrodes. Different operational parameters, such as the electrolysis time (5 min to 15 min), current density (7 A/m² to 11 A/m²), and distance between each electrode (5 mm to 20 mm), were evaluated. The turbidity, total suspended solids, chlorides, sulfates, and COD had removal efficiencies of 92.7%, 91.3%, 70.4%, 66.6%, and 64%, respectively. A polynomial model was generated to estimate the optimum conditions for COD removal. The optimum times for the current densities 7 A/m², 8 A/m², 9 A/m², 10 A/m², and 11 A/m² were 39.5 min, 39.5 min, 35.7 min, 34.1 min, and 32.8 min, respectively, with a 15-mm electrode gap. [ABSTRACT FROM AUTHOR]

Assembly of biofibers into paper-based products fits well into green chemistry principles. Biobased additives such as cationic starch and carboxymethyl cellulose are widely used in the paper industry. Edible additives, which often can be regarded as “safer” than regular biobased additives, may also play a role in tailorable design of paper-based products. [ABSTRACT FROM AUTHOR]

The use of mineral fillers in the paper industry has attracted much attention due to its low cost and ability to improve optical properties and printability. Besides the filler characteristics, paper properties, such as bulk, tensile, and opacity, are greatly affected by filler distribution in the z-direction. Therefore, optimization of filler distribution is an effective way to maximize the value of fillers. In this work, a filler distribution factor (Fc) was proposed to quantitatively describe the concentrated degree of filler distribution in the z-direction. The reduction in Fc resulted in an increase in paper bulk, porosity, and opacity, due to the generation of more interfaces between fibers and fillers. When filler particles were concentrated in one layer (Fc = 1), the tensile strength of the filled paper increased between 26 to 40% in comparison to the paper with various Fc values. For a given Fc, better tensile and opacity properties were achieved by increasing filler concentration on the surface layer of paper. [ABSTRACT FROM AUTHOR]

Proper valorization of the sawing wastes in industrial sawmills is a permanent issue with strong economic and environmental stakes. Most industrial sawmills are equipped with chipper-canter heads reducing the outer part of the logs into chips used in the pulp and paper industry. Optimization in canter use would increase the acceptable proportion of exploitable chips for this industry. With chipper-canters, the cutting direction varies along the cut. This study investigates the impact of the angle formed between the cutting direction and the grain direction on the required cutting force and the chips' geometry. Orthogonal cutting is conducted to simulate the chipper-canter machining operation on green beech. To lower the cutting forces when machining, aiming for a cutting direction as parallel as possible to the wood fiber is necessary. However, if this angle is too low, the chips' generated geometries prevent them from a proper valorization of this resource. A compromise with grain direction between 50° to 70° both limits the cutting forces and improves the steadiness of the chip fragmentation. [ABSTRACT FROM AUTHOR]

In the authors' previous studies, a bleaching process based on continuous chemical supplementation (CCS) was proposed to improve the effectiveness of peroxide bleaching of chemi-thermomechanical pulp (CTMP). In this study, the kinetic model of the CCS process of peroxide bleaching was applied to poplar CTMP to explore how the bleaching rate was affected. The model was based on the rate of chromophore elimination characterized by the brightness gains of bleached pulp. The reaction rate of chromophore destruction proceeded via a rapid initial phase followed by a slow phase. The equation of reaction rate was confirmed. The value of reaction order was -3.62, and the activation energy was 288.8 kJ/mol. The developed kinetic model was a good fit for the experimental results. [ABSTRACT FROM AUTHOR]

The search for microbial enzymatic activities applied to wastewater treatment is an important task in environmental biotechnology. Microbial enzymes have been previously explored in hostile habitats. They are increasingly important in extreme habitats; biological wastewater from the pulp and paper mill industry can harbor microorganisms with valuable enzymatic capabilities that can improve the efficiency for the same process of depuration. This study was performed to characterize and evaluate cellulolytic, amylolytic, and lipolytic activities of bacteria isolated from a pulp and paper effluent. The enzymatic activities were evaluated by the formation of a clear halo around the colonies in defined substrate media. By the use of a sequence analysis of 16S rDNA libraries, isolates were identified. The 16S rDNA libraries belong to the Bacillus subtilis, B. megaterium, B. licheniformis, B. pumilus, B. thuringiensis, B. cereus, Chryseobacterium daecheongense, and Microbacterium sediminis (an alkali-tolerant bacteria which has only been isolated from deep-sea sediment). B. cereus was the best strain for cellulose and lipase activities; moreover, C. daecheongense was best for amylase activity. The present study shows that the aerated lagoons from the pulp and paper industry are a promising source of bacterial with different enzyme activities. This data is relevant for industrial applications. [ABSTRACT FROM AUTHOR]

Alkali lignin (AL) was prepared by the acidification of black liquor obtained from a pulp and paper factory. The average molecular weight of the AL (2,530 g/mol) was determined using gel permeation chromatography (GPC). Alkali lignin modified by ethylene glycol and lignin nanoparticles (LN) were prepared via acid precipitation technology. Reactions in a pH range of 4 to 6 were evaluated while preparing the nanoparticles. Lignin nanoparticles were stable at pH 4 to 10. The sizes of the nanoparticles were assessed with dynamic light scattering (DLS); the average diameter of the nanoparticles at pH 4 was 52.7 nm, which was confirmed by SEM. LN has polar centers that can produce an interacting interface with the polymer matrix in which it will be dispersed. The morphologies and structures of combinations of AL and LN were investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysisderivative thermogravimetric (TGA-DTG). The FTIR spectra clearly showed that the positions of the peaks in lignin nanoparticles shifted to slightly lower values due to the interaction between lignin molecules and ethylene glycol. [ABSTRACT FROM AUTHOR]

People often think of paper as an environmentally harmful product because trees are cut down to make it. A new generation that has grown up in today's digital society may think that the use of digital devices is a waste-free way to protect our environment. Although the pulp and paper industry is making various efforts to preserve the environment, it has not been properly recognized. Developing new technologies to produce better products at lower cost while protecting our environment is important. But it is also important to enhance the image of the pulp and paper industry in the eyes of the public. The pulp and paper industry's efforts to reforestation for raw materials and to expand the recycling of waste paper should be more widely introduced. [ABSTRACT FROM AUTHOR]

The pulp and paper industry in Europe produces over 11 million tons of waste per year. Given high landfill operational costs, thermal coprocessing with biomass may be a viable management and valorisation option for such wastes. In this work, the analysis of biomass (wood sawdust), mixture of primary and secondary pulp mill sludge and their respective blends (50 wt.%, 60 wt.%, 70 wt.% of sludge) was assessed by thermogravimetric analysis. One of the possibilities to ensure valorisation of paper pulp mill sludge is its combustion in the form of pellets containing a different amount of sludge. Production of pellets samples was realised on laboratory experimental device. The measurements showed that increasing the content of paper sludge in the produced pellets reduced the calorific value and increased the ash content. This research deals also with the effect of paper sludge on the ash melting temperatures. The results indicated that a higher content of paper sludge in the pellets increased the ash melting temperatures. This advantage of paper sludge can be utilized in co-combustion of biomass with a low ash melting temperature. [ABSTRACT FROM AUTHOR]

To utilize the lignin generated by the paper industry and reduce the cost of poly(lactic acid) (PLA), PLA/lignin composites were prepared from PLA and different ratios of lignosulfonate (LS) or desulfonated lignosulfonate (DLS) particles using a casting method. The physicochemical properties of the lignins were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation-high performance liquid chromatography (GPC), and elementary analysis. The results indicate that the sulfur content of the original LS was successfully reduced to half by desulfonation to produce DLS, which was found to have a higher thermal stability and a lower average molecular weight than LS. Additionally, the thermal stability, crystallization, compatibility, mechanical, hydrophobicity, and optical properties of the PLA/lignin composites were also meticulously evaluated. Comparison of the PLA/DLS and PLA/LS composites revealed that the incorporation of DLS into PLA improved compatibility, thermal stability (T5% and Tmax), and hydrophobicity, while the mechanical properties remained almost unchanged. In addition, both PLA/DLS and PLA/LS exhibited UV light absorption capacity. Finally, the low-rate addition of both LS (10%) and DLS (5%) accelerated the crystallization of PLA, but crystallization was delayed with higher lignin content. [ABSTRACT FROM AUTHOR]

Sudan has rich sources of lignocellulose materials from agricultural waste that have potential to be used as a papermaking furnish following adequate chemical compositions, elemental analysis, fibre dimensions, and morphology of millet stalks and date palm leaves. Paper sheet properties from the various pulps made were investigated, and it was found that there was no difference in the polysaccharide (cellulose and hemicelluloses) content between millet stalks and date palm leaves, although millet stalks had a high lignin content of 18.20% relative to date palm leaves' content of 15.34%. Moreover, millet stalks showed a high pulp yield (42.04%) with a viscosity of 665 mL/g compared to that (34.43%, 551 mL/g) and (38.50% and 534 mL/g) of date palm leaves and the blend, respectively. Papers produced from date palm leaves and millet stalk blends showed better physical properties compared to that of pure millet stalks and date palm leaves. The Scanning Electron Microscopy (SEM) analysis showed that fibres in the blend were more closely packed than that of the pure millet stalks and date palm leaves fibers. Based on their physical and chemical composition properties, millet stalks and date palm leaves have a high potential as a furnish for pulp and papermaking. [ABSTRACT FROM AUTHOR]

Compared to chemical pulp, mechanical and chemi-mechanical pulps (CMP) are limited in regards to the manufacturing of high quality paper. Chemical additives are an effective way to enhance the properties of paper; however, the effectiveness depends on the additive type and dosage. The utilization of cationized natural polymers has been shown to offer a promising solution. In this study, softwood long fiber (SLF) and CMP were cationized by 3-chloro-2-hydroxypropyl-trimethylammoniumchloride (CHPTAC), and the effects of cationization on the properties of CMP pulp were studied. Cationization was characterized by FTIR and the nitrogen content, and its effect on the CMP properties was evaluated through mechanical tests and fines retention. Cationization at low and moderate levels and in higher mixing rates improved the mechanical properties of CMP. Compared to cationized CMP, the addition of cationized SLF (CLF) improved the strength and fines retention properties. The CLF application to CMP at a CHPTAC dosage of 5% increased the tensile, burst, and tear strengths by 66.4%, 100%, and 3.6%, respectively. The cationized SLF increased the fines retention by 12.7%. [ABSTRACT FROM AUTHOR]

Pulp mills are making increasing efforts to reduce fossil fuel use and carbon dioxide emissions. Lime kilns, which are typically fired with fuel oil or natural gas, use the most fossil fuel in modern pulp mills. A modern kraft pulp mill can be fossil fuel-free during normal operation if fossilbased lime kiln fuels are substituted with renewable alternatives. This study compared the production and use of various renewable fuels, namely, hydrogen, producer gas, torrefied biomass, lignin, and pulverized biomass, in lime kiln operations in a 1.5 Mt/a kraft pulp mill in South America to define the techno-economic optimum for the fossil fuelfree operation of the pulp mill. The attractiveness of each of the concepts was dependent on local conditions and especially the prices of fossil fuels and electricity. The results showed, however, that feasible options exist for the replacement of fossil fuels in lime kiln operations. [ABSTRACT FROM AUTHOR]

Bio-treated pulping wastewater (BTPW) was further treated using a combination of ozonation and biotreatment processes. The effect of ozonation on chemical oxygen demand (CODCr) removal and biodegradability enhancement of the BTPW was investigated. The results showed that the ozonation was effective for degrading the pollutants in the BTPW and improving its biodegradability. The CODCr removal reached approximately 34.8%, and the BOD/COD ratio increased from less than 0.15 to 0.36, after ozonation for 30 min. The raw BTPW biodegrades poorly, and treatment using a combination of ozonation with biotreatment could eliminate most of the refractory substances from the BTPW. The CODCr removal rates of the BTPW were 55.4% and 64.3% for the treatments using ozonation for 30 or 60 min, respectively, before subsequent biotreatment for 14 days. The CODCr removal rates were higher than that of the biological treatment alone by 44.7% and 53.6%, respectively. [ABSTRACT FROM AUTHOR]

The influence of atmospheric high consistency refining (AHCR) on the properties of bleached chemical reed pulp was investigated. Fiber quality, water retention value (WRV), dynamic drainage, and physical properties of handsheets were determined. The results showed that compared with low consistency refining (LCR), AHCR maintained reed pulp fiber length, had lower fines generation, produced more fiber curl and kink, and improved WRV and dynamic drainage. Compared with LCR pulp, the tear index, folding strength, and tensile energy absorption (TEA) of AHCR pulp were increased, while tensile index was maintained at the same value. A mill trial was performed to demonstrate the benefits of using AHCR, which was to improve machine runnability and to enhance the performance of the paper made from reed pulp. [ABSTRACT FROM AUTHOR]

In the conventional pulp and papermaking process, lignin in black liquor is mostly burned for energy. It has not been widely used as a functional polymer. To use both cellulose and lignin component, unique kraft cooking conditions were used in bamboo cooking in this study, and acid precipitation was used to extract lignin from the black liquor. Under different pH values, the precipitated lignins were characterized and compared by gel permeation chromatography (GPC), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). Lignin dissolution in acidic conditions was studied. Pulps with high lignin content were used to synthesize oil absorption materials, which were prepared by grafting butyl methacrylate (BMA) onto the cellulose chain. Sodium silicate was used as an initiator, and 1,4-butane dioldimethacrylate (BDDMA) was used as a crosslinker. The structures of grafted copolymers were characterized by FTIR, scanning electron microscopy (SEM), and thermogravimetry (TG). The acid precipitation process was found to be effective and has important implications for the further lignin applications. The grafting reaction between pulps and BMA was successful. The silicone oil absorption capacity of the obtained materials was 15.3 g/g. [ABSTRACT FROM AUTHOR]

Corrugating medium was made from the solid waste of bamboo paper sludge and old corrugated container (OCC) pulp. The medium also incorporated additions of anion polyacrylamide as a retention agent and cationic starch as a strengthening agent. The estimated molecular mass of anion polyacrylamide, the addition level of anionic polyacrylamide, and the addition level of cationic starch were optimally designed using singlefactor analysis. On this premise, the optimum addition level of the solid waste of bamboo paper sludge was found. The best process conditions for the corrugating medium included a base weight of 120 g/m-2, 10 wt.% bamboo paper sludge solid waste, 0.3 wt.% APAM (Estimated molecular mass of 600 × 104 Daltons), and 1.5 wt.% cationic starch. The apparent density, breaking length, and ring crush index were 0.53 g/cm-3, 2.51 km, and 7.48 N/mg-1, respectively, under the best process conditions. This finding could help satisfy the demand for materials used for making the corrugating medium and could support the full utilization of the solid waste of bamboo paper sludge to achieve higher value. [ABSTRACT FROM AUTHOR]

Paper strengthening agents play an important role in the papermaking industry with the increase of secondary fiber applications. The objective of this study was to create a dry-strength agent by esterification. The fines from the pulp were collected and modified with trimesic acid and citric acid, respectively, to obtain the dry-strength agent. The influences of acid type and dosage on the enhancing effect were investigated. Compared with the control sample, the physical properties of paper sheet were improved after adding modified fines. The properties of recycled paper were also improved by the modified fines. When the dosage of citric acid agent was 7%, the effect on paper properties saw the greatest improvement. The tensile index, burst index, and folding endurance were increased by 60.3%, 18.3%, and 146.2%, respectively, compared with the control. The improvement of paper properties was due to the increase of carboxyl content in the modified fines. Based on the findings, it can be concluded that the esterification is an effective approach for producing paper dry-strengthening agent. [ABSTRACT FROM AUTHOR]

As a widely distributed and fast growing graminaceous plant, bamboo has emerged as an important raw material for pulping and papermaking to mitigate the shortage of wood resources, at least in the East Asia region. New technologies such as silicon removal have been developed to overcome the disadvantage of bamboo as a pulping raw material, as well as to improve the quality of bamboo pulp products. The bamboo pulping capacity in China is continuing to increase in the near future. [ABSTRACT FROM AUTHOR]

It was demonstrated that a photochromic paper could be made through the atom transfer radical polymerization (ATRP) method by grafting spiropyran ether methacrylate (SPMA) onto the fiber surface. The surface composition and topography of the grafted paper were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectra (XPS), and scanning electron microscopy-energy dispersive spectrometer (SEM-EDS). Crystal structures of the cellulosic fibers were also examined after the grafting reaction. The characteristic absorption bands detected in the FTIR spectrum after grafting suggested that a new functional group was formed by the reaction. The XPS and SEM results confirmed that SPMA was grafted onto the surface of the fibers successfully. The grafted spiropyran groups exhibited reversible photochromic properties when exposed to UV light irradiation and visible light. The modified paper showed a purple color under UV light irradiation and changed back to its original color when exposed to visible light. This surface modification using ATRP was demonstrated to be a feasible way to prepare photochromic paper. [ABSTRACT FROM AUTHOR]

There are various applications of organosilicon compounds in papermaking. Additionally, organosilicons have been applied to improve the water resistance of some lignocellulosic materials. The performance, however, of such compounds for the hydrophobation of paperboard is unclear. In this study, an organosilicon solution was internally and externally applied to old corrugated container (OCC) paperboard at ambient temperature. Examination of the infrared spectra of treated paperboard confirmed the presence of CH2 groups and hydrophobic organic chains of organosilicon in the treated paperboard. Both internal and external treatment of the paperboard helped its resistance to water, though external treatment was more successful in the late reduction of the contact angle of water droplets and also in reducing water uptake. [ABSTRACT FROM AUTHOR]

Cellulosic fibers were efficiently disintegrated from bamboo pulp as raw material and then oxidized using sodium periodate to introduce dialdehyde groups on their surfaces. The resultant fibers were characterized using Fourier transform infrared spectroscopy (FT-IR), Xray diffraction (XRD), and thermogravimetric analysis (TGA). FT-IR spectra demonstrated that the characteristic absorption band of aldehyde groups was present at 1735 cm-1, confirming that aldehyde groups were successfully introduced. XRD showed that the nature of bamboo pulp fibers changed slightly after oxidation, except in the reduction of crystallinity. The aldehyde content increased with the sodium periodate content and reached a maximum of 1.41 mmol/g. The yield loss maximum was 32.4 wt%. TGA results showed that the temperature at the initial and final decomposition of the oxidized fibers was subject to the periodate dosage and that the thermal stability decreased to some extent. [ABSTRACT FROM AUTHOR]

The activated sludge process is a well-established technology in the secondary treatment of pulp and paper mill wastewater. Maintaining the activities of microorganisms and allowing them to thrive, metabolize, and grow robustly is essential for efficient biological reactions. To this end, a scientific formulation of growth-promoting ingredients (containing stimulants, buffers, micronutrients, etc) provides a useful strategy for addressing the impact of fluctuations in process conditions involved in the pulp and paper production. Lots of potential exists in terms of the use of these "smart" ingredients to meet stricter discharge limits. [ABSTRACT FROM AUTHOR]

The pulp and paper (P&P) industry worldwide has achieved substantial progress in treating both process water and wastewater, thus limiting the discharge of pollutants to receiving waters. This review covers a variety of wastewater treatment methods, which provide P&P companies with costeffective ways to limit the release of biological or chemical oxygen demand, toxicity, solids, color, and other indicators of pollutant load. Conventional wastewater treatment systems, often comprising primary clarification followed by activated sludge processes, have been widely implemented in the P&P industry. Higher levels of pollutant removal can be achieved by supplementary treatments, which can include anaerobic biological stages, advanced oxidation processes, bioreactors, and membrane filtration technologies. Improvements in the performance of wastewater treatment operations often can be achieved by effective measurement technologies and by strategic addition of agents including coagulants, flocculants, filter aids, and optimized fungal or bacterial cultures. In addition, P&P mills can implement upstream process changes, including dissolved-air-flotation (DAF) systems, filtration save-alls, and kidney-like operations to purify process waters, thus reducing the load of pollutants and the volume of effluent being discharged to end-of-pipe wastewater treatment plants. [ABSTRACT FROM AUTHOR]

The increasing consumption of regenerated cellulose, in particular the viscose fiber, has led to a significant development of dissolving pulps in the last decade. In this review paper, the current status of dissolving pulp with respects to raw materials, manufacturing processes, and some key issues are discussed. Non-wood materials and the process concept of upgrading paper-grade pulp into dissolving pulp are also included. Some recent developments related to the analytical methods of the purity and molecular weight distribution based on the ion chromatography and gel permeation chromatography are discussed. Finally, further processing improvements of purification, such as mechanical, chemical, and enzymatic treatment, and their combinations during the manufacturing process of dissolving pulp, are included. [ABSTRACT FROM AUTHOR]

Marine angiosperms could inevitably offer considerable potential resources for their fiber, yet little research has been conducted, especially in Malaysia. Fiber characteristics of five species of seagrass - Enhalus acoroides, Cymodocea serrulata, Thalassia hemprichii, Halophila ovalis, and Halophila spinulosa - were evaluated. Fiber dimensions were studied to determine slenderness ratio, flexibility coefficient, Runkel's ratio, and Luce's shape factor species selection. The seagrass species have the potential in papermaking production as they possessed slenderness ratio >33 (98.12 to 154.08) and high Luce's shape factor (0.77 to 0.83); however the species exhibited low flexibility coefficient <50 (30.07 to 35.18) and >1 Runkel's ratio (1.11 to 1.60), which indicate rigid fiber. The five seagrass species have high cellulose >34% (40.30 to 77.18%) and low lignin content <15% (5.02 to 11.20%), which are similar to those encountered in non-wood plant species. Handmade paper sheet of Enhalus acoroides using pulp subjected to mechanical blending exhibited the highest tensile strength (4.16 kN/m) compared to hand-beaten pulp (3.46 kN/m). The highest breaking length (3.43 km) was achieved by a paper sheet of Thalassia hemprichii using hand-beaten pulp. Based on their physical and chemical composition properties, seagrass have potential as sources of fibrous material for handmade papermaking. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate a popular reinforcing agent in the papermaking industry through a quick, environmentally friendly, microwave-assisted method. The preparation and characterization of cellulose-CaCO3 composites through this route, in a mixed solution of an ionic liquid and ethylene glycol, can occur within a 10-min timeframe. The chemical compounds, calcium acetate and sodium carbonate, were used as reactants for the as-obtained CaCO3 crystals. A NaOH-urea aqueous solution was used to treat the cellulose and prepare cellulose- CaCO3 composites. It was discovered that the addition of ionic liquids favors the preparation of cellulose-CaCO3 composites. [ABSTRACT FROM AUTHOR]

This work discusses the preparation and characterization of hollow nanospheres based on kraft lignin (KL). Kraft lignin is a by-product of the papermaking industry and an abundant renewable resource. It was determined that adding water to a KL/THF solution induced KL to form hollow nanospheres via self-assembly. Scanning electron microscopy and transmission electron microscopy confirmed the hollow nanosphere morphology. The shell thickness of the hollow nanospheres was tunable by adjusting the initial KL concentration in THF, making the nanospheres a potential material for the encapsulation and controlled release of guest molecules. Ultraviolet (UV) and Fourier transform infrared (FTIR) spectroscopy confirmed the p-p stacking of aromatic rings as an important and distinctive mechanism for the formation of hollow KL nanospheres. The nanospheres were obtained simply and inexpensively, and they exhibited the characteristics of biocompatibility, biodegradability, and low toxicity. These advantages make hollow KL nanospheres attractive for applications in nanoscience and nanotechnology. This study developed an economically feasible and facile strategy for the effective use of biomass waste in sustainable chemistry. [ABSTRACT FROM AUTHOR]

Different modification routes using fly ash-based calcium silicate (FACS) with starch/sodium stearate were explored to mitigate the negative effect of filler on paper strength and allow for improved filler content. The morphology of the modified fillers and the properties of the filled paper were investigated. The modification route was found to be critical to the amount of starch/sodium stearate deposited on the surface of the filler particles. The most suitable modification route using FACS filler was as follows: starch (20% dosage on o.d. filler) was cooked, filler was added, and then sodium stearate was added (4% dosage on o.d. filler). The tensile index of the FACS-filled paper could be increased by 22% at 30% filler content under the best modification route. The brightness and bulk of the filled paper were also improved. However, the opacity of the filled paper was slightly decreased due to the deposition of starch/sodium stearate on the porous surface of the filler particles. [ABSTRACT FROM AUTHOR]

Specialty paper products made using natural pulps is an attractive field for the paper industry and for researchers. Studying the thermal dynamics of plant pulps is an important step toward improving the thermal stability of papers. This study has the aim of gaining detailed insight into the thermal properties of softwood, hardwood, flax, hemp, mulberry, bamboo, bagasse, and esparto pulps. Chemical composition and thermogravimetric analyses of these non-wood pulps were performed to find the correlations between the chemical, structural, and thermal properties of these pulps. In addition, the Malek model for kinetics of the thermo-decomposition process of pulps is proposed. The kinetics of the most probable mechanism function for G(α) = 1-(1-α) 1/2 of the thermo-decomposition process of plant fibers from 200 to 400 °C is deduced using the Malek model. This study also provides a method to help select the most promising pulps for specialty materials. [ABSTRACT FROM AUTHOR]

Primary refined coarse softwood thermomechanical pulp was treated with alkaline peroxide prior to low-consistency (LC) refining. The effects of the pre-treatments on pulp quality, refinability, and electrical energy consumption were assessed. Four pre-treatments were conducted with alkali charges of 2.5 and 6% and peroxide charges of 3 and 4%. The pulps were refined to specific energies up to 600 kWh/t by multiple passes through an LC refiner at intensities of 90 and 150 kWh/t. It was found that alkaline peroxide treatments increased tear strength and protected the fibre from cutting, especially during high intensity refining below a specific energy of 300 kWh/t. Treatment with 6% NaOH and 4% or 3% H2O2 led to lower brightness gains and scattering coefficients but increased the tensile strength index by 31%, potentially lowering the total electrical energy required to achieve strong pulp. The enhancement of tensile strength caused by the highly alkaline peroxide mostly resulted from increased bonding, which was attributable to acid group generation rather than the promotion of further fibrillation during LC refining. [ABSTRACT FROM AUTHOR]

Predicting paper properties based on a limited number of measured variables can be an important tool for the industry. Mathematical models were developed to predict mechanical and optical properties from the corresponding paper density for some softwood papers using support vector machine regression with the Radial Basis Function Kernel. A dataset of different properties of paper handsheets produced from pulps of pine (Pinus pinaster and P. sylvestris) and cypress species (Cupressus lusitanica, C. sempervirens, and C. arizonica) beaten at 1000, 4000, and 7000 revolutions was used. The results show that it is possible to obtain good models (with high coefficient of determination) with two variables: the numerical variable density and the categorical variable species. [ABSTRACT FROM AUTHOR]