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For about two millennia, paper has served as a main medium for preservation of people’s ideas, stories, contracts, and art. This article reviews what is known about the various components that make up paper from the perspective of their long-term stability under typical storage conditions. Literature evidence is considered relative to the susceptibility of different paper components to embrittlement, acid hydrolysis, microbiological attack, and discoloration, among others. The cellulose that makes up a majority of most paper items is demonstrably stable enough to persist for many hundreds of years on the shelves of archival collections, though it is susceptible to acid-catalyzed hydrolysis, which can be accelerated by byproducts of decomposition. Though less attention has been paid to the archival performance of various minor components of modern paper products, evidence suggests that at least some of them are subject to likely breakdown, embrittlement, or decay in the course of prolonged storage. Based on these considerations, one can envision different categories of paper that can be expected to meet different levels of storage stability: ancient recipes for handmade papermaking, e.g. washi and hanji, archival-grade paper products, ordinary modern alkaline paper products, and paper manufactured without concerns for its longevity.

For about two millennia, paper has served as a main medium for preservation of people’s ideas, stories, contracts, and art. This article reviews what is known about the various components that make up paper from the perspective of their long-term stability under typical storage conditions. Literature evidence is considered relative to the susceptibility of different paper components to embrittlement, acid hydrolysis, microbiological attack, and discoloration, among others. The cellulose that makes up a majority of most paper items is demonstrably stable enough to persist for many hundreds of years on the shelves of archival collections, though it is susceptible to acid-catalyzed hydrolysis, which can be accelerated by byproducts of decomposition. Though less attention has been paid to the archival performance of various minor components of modern paper products, evidence suggests that at least some of them are subject to likely breakdown, embrittlement, or decay in the course of prolonged storage. Based on these considerations, one can envision different categories of paper that can be expected to meet different levels of storage stability: ancient recipes for handmade papermaking, e.g. washi and hanji, archival-grade paper products, ordinary modern alkaline paper products, and paper manufactured without concerns for its longevity. [ABSTRACT FROM AUTHOR]

This article substantiates the possibilities of replacing commercial wood with raw materials made from industrial hemp hurd (hemp-woody core) for the production of unbleached and bleached paper pulps. A comparative analysis of the mechanical characteristics of sheets of paper prepared in the Rapid-Köthen apparatus and obtained from pulp obtained from commercial wood and hemp-woody core (HWC) was undertaken. The objective of this study was to determine the effect of mechanical refining of a pulp on the production of microcrystalline cellulose (MCC) from HWC. It was shown that an increase in the pulp refining degree from 15 °SR to 83 °SR led to a decrease in the degree of polymerisation of MCC from 272 to 75, the hydrochloric acid concentration from 73 to 45.63 g/L, and the hydrolysis time from 120 min to 60 min. With the addition of 5% MCC obtained from hemp-woody core, the mechanical properties of laboratory paper sheets from HWC were improved until they met ISO 12625-4-2017 (2017) requirements for NS-2. The results obtained support using hemp-woody core for the production of MCC.

Carbon microsphere was successfully synthesized from waste office paper via hydrothermal method and high temperature treatment in nitrogen atmosphere. The process of carbon microsphere synthesis from waste office paper fiber using concentrated sulfuric acid was studied, and the influence of H2SO4 concentration and reaction time on the hydrolysis reaction was considered. To investigate the mechanism of conversion of waste office paper to carbon microsphere, Fourier transform infrared spectrometry was used to analyze the chemical composition of the supernatant liquid product and the non-carbonized carbon microsphere. The weight loss of the non-carbonized carbon microsphere was assessed through thermogravimetry. Scanning electron microscopy was used to analyze the morphology. The hydrolysis reaction of waste office paper fiber and synthesis mechanism of carbon microsphere under different conditions were evaluated. The results showed that when the reaction time reached 24 h, the product had uniform particle size and was well dispersed, and the more sulfuric acid present led to the waste office paper fiber being more thoroughly hydrolyzed.

Waste papers, which are a major constituent of municipal wastes, can be repurposed into the production of bioethanol, a renewable and ecofriendly fuel. Many studies have produced ethanol from print-grade papers, but literature on conversion of waste cartons is sparce. In this study, waste corrugated cartons and print-grade papers were reduced into slurries and were subjected to physical and chemical tests to determine their suitability for biosynthesis. Cellulose fibers in the slurries were directly hydrolyzed into glucose without prior pretreatment by dilute hydrochloric acid, and fermented into ethanol using Saccaromyces cerevisae. Density, flammability, color, odor, non-volatile residue and other qualitative tests were conducted on the ethanol produced. Glucose yield and the extraction efficiency in cellulose hydrolysis were significantly higher for waste cartons than print paper slurries. Qualitative tests reveal that the ethanol produced from both slurries has physical and chemical characteristics that are comparable to laboratory grade ethanol, contains no toxic impurities, and is suitable for use as a biofuel.

Paper‐based cultural relics are of great value and have been facing irreversible damage caused by multiple factors, among which acid hydrolysis and ultraviolet photodegradation are the main processes leading to paper deterioration. Paper protection highly relies on a limited range of materials with single functions, and the design of new materials that ensure long‐term safety and efficiency by simultaneously addressing the issues of acidification and UV degradation in paper is highly desired. In this study, the introduction of carbon dots (CDs)‐enhanced layered double hydroxides (LDH) 0D/2D nanohybrids (CDs/Mg‐Al LDH) is proposed as novel dual‐functional materials for paper protection against UV degradation and acidification. Through a CDs‐assisted in situ growth strategy, CDs/Mg‐Al LDH with ultrathin thickness (≈9.1 nm) and CDs‐intercalated structure are achieved. The CDs/Mg‐Al LDH nanohybrids demonstrate high dispersibility, strong UV absorption, and remarkable photostability, resulting in protected‐paper with decelerated acidification, oxidation, and yellowing degradation processes under both accelerated UV‐aging and dry‐heat conditions. Additionally, the protected‐paper can emit uniform blue light under 365 nm UV excitation allows for easy identification of the distributed CDs/Mg‐Al LDH within the paper, marking a unique and practical feature. This research paces a new direction for the protection of paper‐based relics with emerging carbon dots‐based 0D/2D nanomaterials. [ABSTRACT FROM AUTHOR]

This article adds more information to the problem of natural ester use as an electroinsulating fluid in cellulose paper-oil systems, e.g., for use in power transformers. An accelerated thermal aging (120, 140 and 160 °C) of samples consisting of cellulose paper (transformerboard), a treated natural ester (filtered, basic Al2O3, 0.53% DBPC), a copper plate and moisture was studied. Research was especially focused on the impact of moisture on the aging of the above system. Samples with three different oil moisture levels (80, 143 and 305 ppm water content) were subjected to thermal aging to display the change in a selection of properties (tanδ, acid number, water content). For a study of the polarization effects, broadband dielectric spectroscopy (BDS) was performed to observe the complex permittivity and conductivity dependencies on the temperature and frequency (±30 °C, 0.01-107 Hz). Havriliak-Negami (H-N) diagrams were used to further understand the results. The degradation products during thermal aging were recognized by Fourier transform infrared (FT-IR) spectroscopy. Hydrolysis and hydrogenation occurred in the insulating system with a natural ester aged by elevated temperatures, which is in contrast to CO2 formation in the case of electric aging. The results showed an increase in the acid number, dissipation factor, and number of hydrolysis and hydrogenation products. Furthermore, changes in polarization were observed as a consequence of the thermal aging of paper-natural ester insulation system with the presence of copper and moisture.

Waste paper holds great potential as a substrate for the microbial production of bioplastic (Poly-3-hydroxybutyrate (PHB)). This study aimed to produce PHB by utilizing office paper as a substrate using Cupriavidus necator through batch and fed-batch simultaneous saccharification and fermentation (SSF) approach. For the batch experiment, different loadings of shredded office paper (3, 5 and 10%) with two different pretreatments H2O2 (OPH) and H2O2 and Triton X-100 (OPTH) were carried out. For the fed-batch experiment, paper loading started with 3% and two more additions were made at 36 and 84 h. Both experiments were conducted at 30 °C, 200 rpm and pH 7 using 55.5 FPU/g of cellulase and 37.5 CBU/g of β-glucosidase with a fixed amount of nitrogen source. High PHB yield was observed with OPH in all loadings, though the OPHT showed a better hydrolysis. Maximum PHB yield (4.27 g/L) was achieved with 10% OP on the sixth day of fermentation in batch SSF. Whereas, maximum PHB yield (4.19 g/L) was obtained within a shorter time (66 h)with OPH in the fed-batch experiment. The extracted PHB showed well-matched characteristic features to the standard PHB. Finally, this study proves the feasibility of employing the SSF process for PHB production using waste paper as an alternative approach to overcome the shortcoming of the separate hydrolysis and fermentation (SHF) process. [ABSTRACT FROM AUTHOR]

Pollution generated by solid waste has become a massive source of concern worldwide as the amount of waste being generated has become overwhelming. Waste paper contributes significantly to the overall solid municipal waste being generated daily and with control methods that are equally bad for the environment or just plain ineffective; better, effective, and environmentally friendly control solutions are required. This study reviews the use of various microorganisms as they aid in the control of waste papers in an environmentally conscious way. In addition to being an environmentally friendly solution to the issue of solid waste paper pollution, it is also a prominent source of renewable energy in the conversion of paper into fermentable sugars for the production of bio-ethanol. This review examines the vital revolution in the enzymatic hydrolysis of paper to sugar. Salient challenges that involve bioconversion were highlighted and a few solutions were suggested.

This study investigates the sulfuric acid hydrolysis process to improve the efficiency of paper waste sludge (PWS) hydrolysis in a paper recycling plant. The Response Surface Methodology (RSM) was used to evaluate the influence of factors, including liquid-to-solid ratio, acid concentration, temperature, and time on the hydrolysis process. The optimal conditions for hydrolysis were determined to be a solid-to-liquid ratio of 1/30.15, an acid concentration of 8.17 wt%, at a temperature of 91.31 °C, and a reaction time of 6.15 h, which yielded the highest sugar content of 11.12 g.L-1 (with the hydrolysis efficiency of 61.4 %). The resulting sugar solution was then fermented by Acetobacter xylinum bacteria to produce bacterial cellulose (BC) layers. This study addresses the environmental organic pollution caused by PWS and transforms it into a more valuable form with high carbon content and purity, such as BC. [ABSTRACT FROM AUTHOR]

Paper mill effluent (PME) was used as an organic feedstock for production of biohydrogen via dark fermentation using heat-shock pretreated anaerobic sludge under mesophilic conditions. The influence of substrate concentration (5, 10 and 15 g-COD/L) and the initial pH (5 and 7) on the efficiency of dark hydrogen fermentation from PME were investigated. The highest hydrogen yield of 55.4 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 5, respectively. By increasing the concentration of substrate from 5 to 10 and 15 g-COD/L, at fixed initial pH, the hydrogen production efficiency was reduced from 55.4 mL/g-COD to 38.5 and 32.7 mL/g-COD. Furthermore, by increasing pH from 5 to 7, biohydrogen efficiency was reduced up to 40.8%. Different hydrolysis of PME including acidic, acidic-thermal and alkaline hydrolysis prior to fermentation were studied which the alkaline hydrolysis led to the highest hydrogen yield of 62.2 mL/g-COD. Moreover, methane production efficiency of 569 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 7, respectively. Paper mill effluent (PME) was used as an organic feedstock for production of biohydrogen via dark fermentation using heat-shock pretreated anaerobic sludge under mesophilic conditions. The influence of substrate concentration (5, 10 and 15 g-COD/L) and the initial pH (5 and 7) on the efficiency of dark hydrogen fermentation from PME were investigated. The highest hydrogen yield of 55.4 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 5, respectively. By increasing the concentration of substrate from 5 to 10 and 15 g-COD/L, at fixed initial pH, the hydrogen production efficiency was reduced from 55.4 mL/g-COD to 38.5 and 32.7 mL/g-COD. Furthermore, by increasing pH from 5 to 7, biohydrogen efficiency was reduced up to 40.8%. Different hydrolysis of PME including acidic, acidic-thermal and alkaline hydrolysis prior to fermentation were studied which the alkaline hydrolysis led to the highest hydrogen yield of 62.2 mL/g-COD. Moreover, methane production efficiency of 569 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 7, respectively.

[Display omitted] • Calcium peroxide mediated disperser disintegration is a novel approach. • Acidic-calcium peroxide mediated disperser method solubilizes organics efficiently. • Bacillus aryabhattai amasses 85% polyhydroxybutyrate using pretreated sample. • Pretreated settled sludge yields 167 mL/g chemical oxygen demand of biogas. The proposed research envisioned to improve the accessibility of organics and hydrolysis of paper mill waste activated sludge for polyhydroxybutyrate production and anaerobic digestion. In order to fill this research gap an exploration has been made by adding lower dosage of calcium peroxide at acidic pH for the removal of exopolymeric substances thereby improving the disintegration efficacy. The results indicate that the calcium peroxide dosage of 0.06 g/g SS at pH 5 was optimum for floc fragmentation. The influence of floc fragmented sludge on disintegration by disperser shows the solubilization and solid decrement of 18.8% and 12.4% at the specific energy input of 4729.24 kJ/kg total solid. The impact of pretreated supernatant on polyhydroxybutyrate accumulation shows the maximum polyhydroxybutyrate content of 85.03 % while utilizing 60% (v/v) of pretreated sludge supernatant as a carbon source at 42 h. Subsequently, the settled sludge was directed towards an anaerobic biodegradability assay and found about 167 mL/g of chemical oxygen demand of biogas generation, which is higher than the crude sample (52 mL/g of chemical oxygen demand). The higher solubilization in pretreated sample reveals the easier accessibility of substrate by the microorganisms, thereby enhances bioenergy and valued product generation. [ABSTRACT FROM AUTHOR]

The cost-effective implementation of nanofibrillated cellulose (CNF) at industrial scale requires optimizing the quality of the nanofibers according to their final application. Therefore, a portfolio of CNFs with different qualities is necessary, as well as further knowledge about how to obtain each of the main qualities. This paper presents the influence of various production techniques on the morphological characteristics and properties of CNFs produced from a mixture of recycled fibers. Five different pretreatments have been investigated: a mechanical pretreatment (PFI refining), two enzymatic hydrolysis strategies, and TEMPO-mediated oxidation under two different NaClO concentrations. For each pretreatment, five high-pressure homogenization (HPH) conditions have been considered. Our results show that the pretreatment determines the yield and the potential of HPH to enhance fibrillation and, therefore, the final CNF properties. These results enable one to select the most effective production method with the highest yield of produced CNFs from recovered paper for the desired CNF quality in diverse applications. [ABSTRACT FROM AUTHOR]

The pulp and paper industry produces about 300–350 million tons of paper mill sludge (PMS) annually and majority is disposed of by landfill. PMS contains up to 75% carbohydrates. In this study, PMS was treated by de-ashing, fiber regeneration and enzymatic hydrolysis. The PMS hydrolysate was used for butyric acid production by Clostridium tyrobutyricum B-67062/RPT 4213. We reported that 8.52 and 8.35 gL −1 butyric acid was produced from 4 L batch fermentation in MRS and RCM4 medium respectively. Moreover, nearly 7 gL −1 butyric acid was produced by using PMS hydrolysates from two different mills when combined with a fraction of MRS, and over 6 gL −1 butyric acid was produced from hydrolysate combined with a fraction of RCM4 medium. This study suggested that beside agricultural lignocellulosic biomass feedstocks, low valued waste materials from the pulp and paper industries could also be used for the sustainable production of butyric acid. [ABSTRACT FROM AUTHOR]

In traditional paper pulp deinking, sodium hydroxide (NaOH) is used as a hydrolysing agent for fibers in concentrations that set the pH of the medium to values greater than 10; however, substantial amounts of solid and liquid waste are created, and their management is problematic and dangerous. Recently, the implementation of biological treatments, for example, enzymatic deinking, is presented as an option to deink mixed office prints at neutral pH; that is, with the minimum use of chemical reagents and, therefore, better waste management and less environmental impact. The main objective of this research work is to study the mechanism of hydrolysis, detachment and ink capture in the bubble-enzyme-ink particle system, during the deinking of office paper type MOW (Mixed Office Waste), using a laboratory column flotation. The cellulase enzyme Trichoderma sp. was used. To compare the deinking efficiency of office paper using enzymes, deinking experiments were performed according to the traditional procedure using sodium hydroxide. The quality of the deinked fibers by measuring their optical properties (whiteness, reflectance, opacity, black spots and tonality) was performed in the Laboratory of the Paper Industry Bio Papel Scribe SA de CV, located in the city of Morelia, Michoacán, México. The operational variables of the flotation column were established through experiments in the water-air system and adding 100 ppm of pine oil as a surfactant (surface tension of the liquid in 56.6 dynes / cm). The superficial air flowrate was set at 1.27 cm / s (6 LPM), whereas the pulp feed flow rate was 0.88 cm / s. The experimental results show the feasibility of recycling MOW-type office paper by using the enzyme cellulase Endo-β-1,4-D-glucanase and the amino acids Aspartate, Glutamate and Asparagine; the latter, individually and mixed. The optical properties of the sheets of paper formed with the cellulose deinked by this procedure, were better than those evaluated to sheets of paper formed with fibers of recycled and deinked paper by the traditional procedure. In the case of the combined use of the three amino acids, the ISO whiteness is 90.8%, 303.4 ppm of black spots, reflectance of 47.1% and 89.5 of opacity. By the traditional procedure, the reported whiteness is 80.2%, the reflectance is 57.4%, and the opacity is 99.6%. [ABSTRACT FROM AUTHOR]

The degradation and embrittlement of paper is due to the depolymerization of cellulose fibers; this is induced by acidity and oxidation. An important part of dealing with these chemically unstable materials is the neutralization of acid and deposition of a buffer reservoir to protect the fibers from introduction of acid in future. Paper deacidification is a fundamental process for achieving this goal. Any deacidification method chosen must be able to treat large numbers of items, safely, quickly and cheaply. The main goal of this paper was to investigate the effect of two deacidification solutions, which have never been used in Egypt, on the chemical and physical properties of different types of paper in order to find an alternative to Calcium hydroxide the most common deacidification method used in Egypt. Magnesium salts have been chosen to produce two deacidification methods, one of them in aqueous media, and the other in nonaqueous media; however, the magnesium has excellent deacidification properties and never have been applied in Egypt before. This paper is concerned with the Evaluation of Magnesium Bicarbonate (MBC) and Methyl Magnesium Carbonate (MMC), as neutralization agents, on the stability of paper substrate before and after accelerated ageing. Deacidification of acid paper samples (old book and newspaper) coming from wood pulp (20 century) and whatman paper samples, has been carried out with elaborate findings. Examinations and scientific analyses have been used in the assessment of treated samples, to figure out the efficacy of the two methods on the paper stability. Both methods have adequate deacidification properties; the pH value of paper has increased after deacidification. Mechanical testing and Fourier-transform infrared spectroscopy (FTIR) have proven considerable stability of mechanical and chemical properties of deacidified paper after accelerated ageing. [ABSTRACT FROM AUTHOR]

The vast majority of power transformers have an insulation system consisting of both insulating mineral oil and Kraft paper. The principal oil degradation agents are oxygen and temperature, whereas the main mechanisms of insulating Kraft paper degradation are water and acids (acidic hydrolysis degradation), temperature (pyrolytic degradation), and oxygen (oxidative degradation). [ABSTRACT FROM AUTHOR]

Bioethanol is considered to be a possible substitute for non‐renewable fossil fuels. Biofuels, including bioethanol, are gradually replacing coal and oil for energy production. It is expected that, by 2040, fossil fuels' contribution to the world's energy demands will only be 25% with the remaining contribution made up by biofuels. One of the major factors affecting ethanol production is the cost of raw materials, which can be substantially reduced by utilizing industrial or agricultural lignocellulosic wastes. Using waste paper as a feedstock for bioethanol production would reduce the production cost and may eliminate problems in managing this waste material in the environment. The cellulose, hemicellulose, and lignin in waste paper are less complicated and so only mild pretreatment is needed before enzymatic hydrolysis and fermentation. This review covers topics such as bioethanol as a promising alternative to petroleum fuels, feedstocks for bioethanol production, lignocellulosic technology and challenges for ethanol production, advantages and disadvantages of pretreatments methods, waste paper as feedstock for ethanol production, processing of waste paper to ethanol, and the different integration methods of hydrolysis and fermentation. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We are the first to use paper pulp to produce biobutanol. • A consolidated fermentation system with in situ product recovery was designed. • Production of 19.2–22.0 g L−1 butanol in the designed fermentation system. • Improved butanol yield to broth medium (20.6 g L−1-medium) by reusing TY medium. Abstract Utilization of lignocellulosic biomasses for biobutanol fermentation usually requires costly processes of pretreatment and enzymatic hydrolysis. In this study, paper pulp (93.2% glucan) was used as a starting biomass material to produce biobutanol. We conducted enzymatic semi-hydrolysis of paper pulp without pretreatment and with low enzyme loading, which produced high concentrations of cellobiose (13.9 g L−1) and glucose (21.3 g L−1). In addition, efficient fermentation of the semi-hydrolysate was achieved similar to that with the use of commercial sugars without inhibitors. Finally, we designed a novel non-isothermal simultaneous saccharification and fermentation with in situ butanol recovery, which was composed of a repeated semi-hydrolysis process and successive butanol-extractive fermentation process under the respective optimal conditions. The consolidated system improved butanol production, butanol yields, and butanol productivities and enabled repeated use of medium when compared with other integrated hydrolysis and fermentation processes. [ABSTRACT FROM AUTHOR]

• Preservation of rumen fluid at 20 °C inhibits the hydrolysis of the waste paper. • Preservation at 35 °C increases the loss of organic carbon from rumen fluid. • Fibrolytic enzyme activity and protozoa of rumen fluid are retained at 4 °C. • Preservation at 4 °C reduces the loss of CO 2 production from rumen fluid. It is necessary to preserve rumen fluid for transport from slaughterhouses to the pretreatment facilities for use in treating lignocellulosic biomass. In this study, we investigated how the preservation of rumen fluid at various temperatures affects its use in hydrolysis of waste paper. Rumen fluid was preserved anaerobically at 4, 20, and 35 °C for 7 days. The number of protozoa and fibrolytic enzyme activity after preservation at 4 °C were significantly higher than that after preservation at either 20 or 35 °C. Waste paper was subsequently treated with preserved rumen fluid at 37 °C for 48 h. Preservation at 20 °C remarkedly decreased the hydrolysis of waste paper. Xylanase activity in rumen fluid preserved at 35 °C increased during the treatment, which enhanced the solubilization of waste paper as comparable to the control and preservation at 4 °C. Pretreatment of waste paper with rumen fluid preserved at 4 °C showed that the fluid retained high fibrolytic activity, and reduced the loss of organic carbon as substrate for methanogens. Our results suggest that preservation of rumen fluid at 4 °C is most suitable for efficient pretreatment and methane fermentation of waste paper. [ABSTRACT FROM AUTHOR]

Annually a tremendous amount of office waste paper (OWP) is discarded creating environmental pollution. Therefore, how to make this paper from waste to wealth and use it in new approaches have become a meaningful and challenging work. In this work, OWP being a cellulose rich biomass was employed for the production of cellulose nanocrystals (CNCs) by acid hydrolysis with different acid concentrations but without subjecting OWP to alkali and bleaching treatments. The testing results showed that CNCs prepared using sulfuric acid concentration of 59% with respect to OWP had the highest crystallinity and this concentration was the transition concentration for the production of opaque CNCs film with convoluted nanofibers to transparent one with orientated nanofibers. Besides, CNCs prepared using acid concentration of 65% coated on PET sheet not only had a better water vapor barrier property but also was on a par with the transparency of PET, which was hopeful to be used as coating materials in packaging materials. [ABSTRACT FROM AUTHOR]

This article presents the development of a method to prepare nanocrystalline cellulose (NCCs) from laser-printed waste paper using factorial design 2³ experiments by controlled acid hydrolysis of the waste paper. The method applies high gain ultrasound and subsequent flotation, washing, and bleaching stages. Characterization of the raw material, prepared pulp, test sheets, and NCCs is presented. Optimum conditions to obtain high quality NCCs were found to be 65% acid, for 40 min time of treatment, and residual load in the range of 130 to 570 mmol/kg of NCCs. The obtained NCCs were 80 to 700 nm long depending on the acid hydrolysis conditions. They exhibited high values of whiteness (90.3% Elrepho), α-cellulose contents (95%), degree of polymerization (731), viscosity (9.59 cP), and chemical compositions similar to that of Whatman paper. [ABSTRACT FROM AUTHOR]

Waste paper, a major fraction of municipal solid waste, has a potential to serve as renewable feedstock for the biorefineries of fuels, chemicals and materials due to rich in cellulose and abundant at low cost. This study evaluates the possibility of waste office paper (WOP) to serve as a potential feedstock for the biorefinery production of poly (3-hydroxybutyrate). In this study, the WOP was pretreated, enzymatically saccharified and the hydrolysate was used for PHB production. The hydrolysate mainly consists of glucose (22.70 g/L) and xylose (1.78 g/L) and the corresponding sugar yield was about 816 mg/g. Ammonium sulphate and C/N ratio 20 were identified as most favorable for high yield of PHB. The batch fermentation of Cupriavidus necator using the pretreated WOP hydrolysate resulted in cell biomass, PHB production and PHB content of 7.74 g/L, 4.45 g/L and 57.52%, respectively. The volumetric productivity and yield achieved were 0.061 g/L/h and 0.210 g/g sugar, respectively. The results suggested that WOP could be a potential alternative feedstock for the biorefinery production of bioplastics. [ABSTRACT FROM AUTHOR]

Nano-TiO pigments in pure crystallographic anatase and rutile phases have been successfully prepared by hydrothermal at 120°C and hydrolysis methods, respectively. The laboratory-prepared pigments were characterized parallel to two commercial pigments of the same crystal structure. All pigments were applied in paper coating mixtures, and their influence on coated paper properties was systematically investigated. X-ray diffraction investigation showed that the laboratory-prepared pigments using the hydrothermal method at 120°C were pure anatase, whereas hydrolysis method produced pure rutile phase pigment. The application of the prepared nanopigments and the corresponding commercial TiO phases in paper coating revealed that clay/rutile nano-TiO pigments in paper coating mixture decreased coated paper roughness more than blending clay with anatase nano-TiO pigments. Commercial nano-TiO pigments increased porosity of coated paper at both the 30% and 50% addition of nano-TiO pigments to clay, while laboratory-prepared nano-TiO pigments highly decreased it at 30% addition of nano-TiO to clay, compared to clay only. Blending of clay/nano-TiO pigments improved both brightness and opacity of the coated paper where commercial pigments are more effective. Burst, tensile strength, stretching, and TEA were improved in the case of all pigments. The 50% addition of the prepared and commercial nanopigments in conjunction with clay improved the mechanical coated paper properties more than 30% addition (except the cases of stretching and TEA of the commercial pigments). The coated paper samples were offset printed. It was found that blending of clay/nano-TiO pigments improved print density. Commercial nano-TiO pigments improved print gloss more than the laboratory-prepared ones. This result was found consistent with the results of coated paper roughness. [ABSTRACT FROM AUTHOR]

The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved. [ABSTRACT FROM AUTHOR]