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The corrosion and material evaluation study in (a) water‐based simulated black liquor and (b) water‐based simulated black liquor at super‐critical conditions was successful. The conclusion from the testing program was that the most resistant alloy for the defined conditions is the chromium‐rich carbon steel candidate P91 (UNS K91560). This is a type of creep strength‐enhanced ferritic alloy, which is steel designed to retain strength at high temperatures. The P91 abbreviation represents the material's chemical composition, that is, 9 wt% chromium (Cr) and 1 wt% molybdenum (Mo). Further work is required to conclude the corrosion resistance for the P91 quality at supercritical conditions in the welded condition and to better understand caustic corrosion mechanisms. [ABSTRACT FROM AUTHOR]

This study investigates the impact of lignin extraction on the rheological and combustion properties of high-solids bamboo kraft black liquor (BKBL), focusing on viscosity reduction and silicon interference mitigation. Lignin was extracted from BKBL using CO2 acid precipitation. The effects on viscosity, silicon content, calorific value, and Volumetric Isothermal Expansivity (VIE) were systematically analyzed. Extracting 25 % of lignin reduced the apparent viscosity of BKBL and achieved a 33 % desilication rate. However, this extraction also led to a proportional decrease in calorific value and VIE, with a 15 % extraction resulting in approximately 11 % and 13 % reductions, respectively. An extraction rate of 15–25 % is recommended to balance viscosity reduction and silicon removal with minimal impact on boiler combustion efficiency. This study provides practical insights into optimizing lignin extraction from BKBL, offering significant operational, economic, and environmental benefits for the bamboo kraft pulping industry. [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]

Paper-based materials made from cellulose have been sought after as a sustainable and inexpensive packaging option. However, the porous structure and high hydrophilicity of paper-based materials result in inadequate water and oil repellency, as well as a limited water vapor barrier. In this work, lignin nanoparticles (LNPs) were prepared using a high-speed homogenizer, and subsequently coated on base paper along with cationic starch to enhance its multi-barrier performance to facilitate the packaging application. The LNPs obtained through such a facile process formed stable colloidal dispersion in water, which exhibited excellent interfacial compatibility with cationic starch. During the coating process, a highly adhesive emulsion consisting of cationic starch and LNPs were coated on the surface of base paper, imparting good hydrophobic properties to the paper. The resulting paper material exhibited good water resistance (Cobb value of 37.5 g m 2), high oil resistance (Kit rating 9) and tensile strength (48.93 MPa). The reduction in water vapor transmission rate (WVTR) exceeds sixfold. This study provides a new avenue for the application of lignin in high-barrier, fluorine-free, water-and oil-resistant packaging materials. [ABSTRACT FROM AUTHOR]

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

To reduce energy consumption, a new pulping process called A-D-E-RC (acidification/desalination/electrolysis/recycle-cooking) was developed by a research group in Guangxi University of China. The present work focuses on the step of recycle cooking (RC) to further investigate the technical feasibility of A-D-E-RC methods. Golden bamboo grass was considered as fiber source material for pulp, and it was cooked with the acidic treating of wastewater from black liquor. Then, the pulp obtained from each cooking was made into paper to test the changes in its physical properties. As a result, the pulp yield increased from 43.9% to 50.2%, after re-using acidified black liquor, and the paper's tear index and tensile index were improved. Therefore, this study demonstrated the feasibility of recycle cooking (RC) fiber materials for pulp applied the acidic treating wastewater from black liquor, and thereby, it further identifies the technical feasibility of A-D-E-RC pulping methods.

Kraft pulping process is the foremost common pretreatment method utilized in pulp and paper businesses to break down the lignocellulosic linkages to urge cellulose and lignin separated. Due to higher degree of recuperation of the reagents utilized within the process of pulp production having higher cellulosic virtue, this technique rules over others since many decades. A factorial experiment may have star points and centre points added, offering three or five levels for each component. This is known as a central composite design, and it is utilised in response surface modelling. There are a few components to be considered in kraft pulping method which are temperature, retention time, % alkalinity, % sulfidity, and liquor to biomass stacking. The use of Na2S stands for a source of HS−, but too for an extra source of NaOH agreeing to the response included in this prepare. In spite of the fact that we have not taken those two components into thought, they can moreover be utilized in future inquire about. Thus, here, we utilized central composite plan to optimize our components. By taking temperature extend of 140–175 °C, time 20–80 min, and % alkalinity 10–20%, we have gotten diverse reactions of greatest bright absorbance wavelength and concentration information of black liquors. [ABSTRACT FROM AUTHOR]

Lignin, which contains aromatic phenols, is the second most abundant renewable biomass material in the world. It is the main byproduct of the paper industry and is characterized by abundant sources, renewability, and low cost. The present study focused on the extraction of lignin from poplar wood through a straightforward papermaking approach, thereafter utilizing the resultant black liquor containing lignin for synthesizing lignin-based phenolic resins. During the polymerization process, cobalt (Co) and nickel (Ni) species were introduced and, subsequently, a CoNi/biochar catalyst was obtained through pyrolysis in a nitrogen atmosphere. The prepared catalyst possessed rough spherical structures. The incorporation of Co and Ni enhanced charge redistribution, thereby imparting the catalyst with strong electron acceptance capabilities. The prepared lignin-based phenolic-resin-derived carbon was used for the electrochemical sensing of 2-nitrophenol. The limit of detection (LOD) for 2-nitrophenol was calculated to be 0.0132 µM, with good repeatability, stability, and selectivity. [ABSTRACT FROM AUTHOR]

ABSTRACT: The objective of this research was to extract lignin from Eucalyptus sp. kraft black liquor and to evaluate the influence of its addition on the properties of the lignin-phenol-formaldehyde adhesive. The adhesives were synthesized at different phenol mass percentages by lignin, called lignin-phenol-formaldehyde adhesives in the proportions of 25, 30, 50, 75 and 80%. The parameters evaluated in the adhesives were pH, total solid content, organic compound content, inorganic compound content, gelatinization time and adhesive behavior in the glue line. The pH ranged from 10.63 to 11.65. For the total solid content was found the value of 53 to 69 %. The contents of organic compounds ranged from 51 to 75% and inorganic from 25 to 49%. It was observed that with the addition of macromolecule in the adhesive formulation, the total and organic solid content was reduced proportionally while the inorganic solid was high. The gelatinization time was reduced due to the addition of lignin. The lower proportions of addition presented better penetration and fluidity in interface with the wood. The kraft lignin extracted from eucalyptus kraft black liquor is a great adhesive with potential to partially replace petroleum-derived phenol, with great potential for use and application in the aeronautical and automotive sectors, in the bonding process of structural parts.

The valorization of black liquor, a by-product produced in considerable quantities from the paper manufacturing processes, has demonstrated the effectiveness of thermal reconversion into pyrolysis gas, bio-oil, and bio-char, a sustainable approach placing the feedstock into a circular economy concept. The present study focused on developing disposal solutions through energy recovery via pyrolysis at 300 °C and 450 °C when lignite and nanomaterials (such as Cu-Zn-MCM-41, Ni-SBA-3, or Ni-SBA16) were used as catalysts. The results were compared to those of non-catalytic pyrolysis. The use of the Cu-Zn-MCM-41 catalyst proved to be efficient for pyrolysis gas production, reaching 55.22 vol% CH4. The increase in the calorific value of the pyrolysis gas was associated with the use of the Cu-Zn-MCM-41, showing a value of 42.23 MJ/m3 compared to that of the non-catalytic process, which yielded 39.56 MJ/m3. The bio-oil resulting from the pyrolysis with Cu-Zn-MCM-41 showed the highest energy value at 6457 kcal/kg compared to that obtained with the other two nanocatalysts, Ni-SBA-3 and Ni-SBA-16, as well as that of the raw material, which had a value of 3769 kcal/kg. The analysis of bio-char revealed no statistically significant differences when comparing the outcomes from using the various nanocatalysts, suggesting their minimal impact on the energy content. [ABSTRACT FROM AUTHOR]

Lignin is one of the most abundant bio‐aromatic molecular resources, but it is currently underutilized for energy production in the pulp and paper industry. Unlocking the full potential of lignin could have a significant impact on reducing environmental pollution, increasing the use of renewable resources, and achieving environmentally beneficial economic growth. However, effective lignin valorization requires viable and integrated reaction and separation processes to produce high value monomeric phenolics, such as vanillin and syringaldehyde. The aim of this short review is to summarize the studies on different separation methods of lignin derivatives obtained from black liquor, including extraction, membrane filtration, chromatographic separation, and the combination technologies. [ABSTRACT FROM AUTHOR]

In India, cow dung is widely utilized to create formulations that serve as effective plant growth enhancers with antimicrobial properties. The cow dung-derived handmade paper manufacturing process produces two waste-liquor streams, a Raw Liquor (RL) produced through the dewatering of the cow-dung slurry and a Black Liquor (BL) produced during the soda pulping of dewatered cow dung. The present study explored the potential of these waste streams to be used as plant biofertilizers for germination and cultivation of Vigna radiata seeds (mung bean, IPM-02-03 variety). An in vitro assay for seed germination efficiency and a pot study for plant growth promotion (PGP) activity were used to assess this potential. The in vitro assay demonstrated that nutrient-rich RL, with its 100% seed germination efficiency (better than the 85.7% of tap water) was an effective biofertilizer for seed germination. In contrast, BL yielded poor seed germination efficiency. The pot study showed that water irrigation led to good seed germination, survival, plant rooting and shooting, but it was probably deprived of nutrients for inducing good grain yields. When water was replaced with RL, it was able to replicate the results, but with good grain yields. In contrast, BL produced poorer germination, seed survival and PGP results. The poor biofertilization efficiency of BL was most probably due to the nutrient losses and toxic chemicals produced in the harsh pulping process. The results showed that RL, though considered a waste stream, is sufficiently nutrient-rich to act as an effective biofertilizer for germinating mung bean seeds and promoting plant growth and grain yields. [ABSTRACT FROM AUTHOR]

Currently, many research projects are focused on the conversion of renewable raw materials into chemicals and fuels. Lignocellulosic biomass is a raw material used for the production of bio-oils and black liquors. These biomass-derived fractions offer promising paths for the production of valuable chemical products. Various catalytic methods have been investigated for upgrading the biomass-derived fractions. Researchers are interested in the hydrodeoxygenation process (HDO); in this process, the oxygen groups are eliminated by breaking the C-O bonds and water as a product. Incorporating heterogeneous catalysts (i.e., noble metals, transition metals, and metal sulfides) improves this process. Most HDO review articles describe catalytic results for model phenolic compounds. However, there is also a need to investigate the catalytic activity of real biomass-derived fractions. This paper explains research results regarding the upgrading of lignin-derived fractions (i.e., black liquors) by HDO. The paper has been organized according to the type of heterogeneous catalyst and shows compelling results based on different experimental conditions. The final sections present an analysis of the documented results and outline perspectives about integrating lignin into the biorefinery framework. [ABSTRACT FROM AUTHOR]

Manganese- and nitrogen-doped carbon materials were produced using NaOH-activated wood char and wood-processing residues such as wood chips and black liquor and evaluated as oxygen reduction catalysts for further application in fuel cells or metal–air batteries. The elemental and chemical composition, with special attention given to types of nitrogen bonds and the structure, morphology, and porosity of the obtained catalyst materials were studied. The catalytic activity was assessed in an alkaline medium using the rotating-disk electrode method. It has been shown that synthesized and doped N-Mn catalytic materials based on biomass precursors with different chemical structures are a promising alternative to modern oxygen reduction catalysts based on precious metals. [ABSTRACT FROM AUTHOR]

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

A lab-scale gravity-driven bioreactor (GDB) was designed and constructed to evaluate the simultaneous treatment of black liquor and domestic wastewater. The GDB was operated with a mixture of black liquor and domestic wastewater at a ratio of 1:1 and maintained at an average organic loading rate of 1235 mg-COD/L-Day. The wastewater was fed to the primary sedimentation tank at a flow rate of approximately 12 mL/min and subsequently passed through serially connected anaerobic and aerobic chambers with the same flow rate. Each wastewater sample was allowed to undergo a hydraulic retention time of approximately 72 h, ensuring effective treatment. The GDB was actively operated for nine samples (W1–W9) at a weekly frequency. The entire process was conducted within the workstation's ambient temperature range of 30–35 °C to sustain microbial activity and treatment efficiency in an open environment. The performance of the GDB was evaluated in terms of various pollution indicators, including COD, BOD5, lignin removal, TDS, TSS, EC, PO43−, SO42−, microbial load (CFU/mL and MPN index), total nitrogen, and color reduction. The results showed that the GDB achieved promising treatment efficiencies: 84.5% for COD, 71.80% for BOD5, 82.8% for TDS, 100% for TSS, 74.71% for E.C., 67.25% for PO43−, 81% for SO42−, and 69.36% for TN. Additionally, about 80% reduction in lignin content and 57% color reduction were observed after the treatment. The GDB substantially reduced microbial load in CFU/mL (77.98%) and MPN (90%). This study marks the first to report on wastewater treatment from two different sources (black liquor and domestic wastewater) using a simple GDB design. Furthermore, it highlights the GDB's potential as a cost-effective, environmentally friendly, and efficient solution for wastewater treatment, with no need for supplementary chemical or physical agents and zero operational costs. [ABSTRACT FROM AUTHOR]

In our previous study, we demonstrated that Eucalyptus dunnii samples containing high calcium content show inferior pulping properties concerning delignification and polysaccharide degradation. This led us to investigate alternative methods for improving the pulping process of these samples. In the present work, we evaluated the effects of incorporating black and green liquors into the Eucalyptus dunnii chips before kraft pulping, aiming to enhance the pulping process and overcome the negative impact of high calcium content. The addition of both black and green liquors resulted in specific enhancements, with the green liquor having a more significant impact on the pulping process. Even wood samples with the highest calcium content demonstrated satisfactory pulping results when treated with green liquor. Delignification occurred more rapidly, and selectivity was higher for samples pre-treated with green liquor before kraft pulping. Moreover, calcium tended to follow the fiber under these conditions rather than being released into the black liquor, which may contribute to the improved pulping performance. Subsequent bleaching tests revealed that the bleachability of green liquor-treated pulp was nearly identical to that of a control pulp, while maintaining a higher viscosity. This suggests that incorporating green liquor into the pre-treatment process not only improves the pulping performance of Eucalyptus dunnii samples with high calcium content but also maintains desirable bleachability characteristics. To better understand the underlying mechanisms of these findings, we discuss the potential chemical explanations behind the observed improvements. [ABSTRACT FROM AUTHOR]

The current investigation concerns with preparation eco-friendly and cost-effective adsorbent (mesoporous silica nanoparticles (SBL)) based on black liquor (BL) containing lignin derived from sugarcane bagasse and combining it with sodium silicate derived from blast furnace slag (BFS) for thorium adsorption. Thorium ions were adsorbed from an aqueous solution using the synthesized bio-sorbent (SBL), which was then assessed by X-ray diffraction, BET surface area analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy (EDX), and Fourier transforms infrared spectroscopy (FTIR). Th(IV) sorption properties, including the pH effect, uptake rate, and sorption isotherms across various temperatures were investigated. The maximum sorption capacity of Th(IV) on SBL is 158.88 mg/L at pH value of 4328 K, and 60 min contact time. We demonstrated that the adsorption processes comport well with pseudo-second-order and Langmuir adsorption models considering the kinetics and equilibrium data. According to thermodynamic inspections results, the Th(IV) adsorption process exhibited endothermic and random behavior suggested by positive ΔH° and ΔS° values, while the negative ΔG° values indicated a spontaneous sorption process. The maximum Th(IV) desorption from the loaded SBL (Th/SBL) was carried out at 0.25 M of NaHCO3 and 60 min of contact. Sorption/desorption processes have five successive cycles. Finally, this study suggests that the recycling of BFS and BL can be exploited for the procurement of a promising Th(IV) adsorbents. [ABSTRACT FROM AUTHOR]

A techno-economic assessment and environmental and social sustainability assessments of novel Fischer–Tropsch (FT) biodiesel production from the wet and dry gasification of biomass-based residue streams (bark and black liquor from pulp production) for transport applications are presented. A typical French kraft pulp mill serves as the reference case and large-scale biofuel-production-process integration is explored. Relatively low greenhouse gas emission levels can be obtained for the FT biodiesel (total span: 16–83 g CO2eq/MJ in the assessed EU countries). Actual process configuration and low-carbon electricity are critical for overall performance. The site-specific social assessment indicates an overall positive social effect for local community, value chain actors, and society. Important social aspects include (i) job creation potential, (ii) economic development through job creation and new business opportunities, and (iii) health and safety for workers. For social risks, the country of implementation is important. Heat and electricity use are the key contributors to social impacts. The estimated production cost for biobased crude oil is about 13 €/GJ, and it is 14 €/GJ (0.47 €/L or 50 €/MWh) for the FT biodiesel. However, there are uncertainties, i.e., due to the low technology readiness level of the gasification technologies, especially wet gasification. However, the studied concept may provide substantial GHG reduction compared to fossil diesel at a relatively low cost. [ABSTRACT FROM AUTHOR]

The valorization of the black liquor produced during the chemical pulping of wheat straw is the key to the sustainable use of this abundant agricultural waste. However, the silica problem has hampered the recovery process. Herein, nanoprecipitation technology was used to produce lignin nanoparticles (LNPs) from wheat straw black liquor using γ-valerolactone (GVL) as a solvent and water as an anti-solvent. The results showed that a uniform, well-dispersed, and stable LNP was produced. The particle size and Zeta potential of 161 nm and −24 mV of the LNP suspension were obtained at a GVL concentration of 87%. The chemical structure and bonding of the lignin were adequately preserved after nanoprecipitation based on two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance (2D-HSQC NMR) spectroscopy, Fourier transform infrared (FTIR) analysis, and thermal stability was improved based on thermogravimetric analysis. In addition, the abundant phenolic hydroxyl groups of LNP quantified by 31P-NMR analysis are beneficial for chemical cross-linking and modification. This work not only achieved the valorization of wheat straw black liquor but also opened up a new avenue for advanced nanomaterials. [ABSTRACT FROM AUTHOR]

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

The paper industry faces two critical challenges: the scarcity of raw materials and the environmental impact of chemical waste pollution. Addressing the first challenge involves harnessing alternative, sustainable raw materials, while the second challenge can be mitigated through the adoption of bio-bleaching processes, which significantly reduce chemical consumption while enhancing paper brightness and quality. This study proposes a solution to both challenges by using non-woody Calotropis procera (Ankara) and a xylanase-producing microbial consortium for sustainable handmade paper production, a combination not extensively explored in prior research. To evaluate this approach, the process was divided into three stages. In stage I, Ankara fibre was pulped through open hot digestion. In stage II, the pulp was subjected to bio-bleaching in two experimental setups: Set I (without sucrose) and Set II (with sucrose) for 5 days. In stage III, chemical bleaching was used to improve the final brightness of the treated pulps. A novel comparison was made between the bio-bleaching efficiency of an individual isolate g5 (BI) and a bacterial consortium (BC). This research highlighted that bio-bleaching with the consortium effectively removed lignin (140±60 mg/l) and colour (1830±50 PCU), especially in the presence of sucrose, compared to using a single xylanase isolate. Pulp residue/filtrate collected at each stage was estimated based on parameters such as colour and lignin content. After stage III (chemical bleaching), the release of colour and lignin in pulp filtrate was higher in BI compared to BC, indicating the consortium's effectiveness during bio-bleaching, which leaves fewer degradable lignin structures for the chemical bleaching stage. Papers crafted from consortium-treated pulp also exhibited higher brightness than those treated with the isolate. This study reveals the synergistic effect of microbial consortia, leading to more efficient lignin degradation and enhanced bio-bleaching capabilities, supporting the development of greener industrial processes. Ultimately, this study demonstrates a unique and eco-friendly approach to papermaking, combining C. procera and enzymatic bio-bleaching to reduce dependency on hazardous chemicals and support sustainable industry practices.

Lignin, which contains aromatic phenols, is the second most abundant renewable biomass material in the world. It is the main byproduct of the paper industry and is characterized by abundant sources, renewability, and low cost. The present study focused on the extraction of lignin from poplar wood through a straightforward papermaking approach, thereafter utilizing the resultant black liquor containing lignin for synthesizing lignin-based phenolic resins. During the polymerization process, cobalt (Co) and nickel (Ni) species were introduced and, subsequently, a CoNi/biochar catalyst was obtained through pyrolysis in a nitrogen atmosphere. The prepared catalyst possessed rough spherical structures. The incorporation of Co and Ni enhanced charge redistribution, thereby imparting the catalyst with strong electron acceptance capabilities. The prepared lignin-based phenolic-resin-derived carbon was used for the electrochemical sensing of 2-nitrophenol. The limit of detection (LOD) for 2-nitrophenol was calculated to be 0.0132 µM, with good repeatability, stability, and selectivity.

Currently, many research projects are focused on the conversion of renewable raw materials into chemicals and fuels. Lignocellulosic biomass is a raw material used for the production of bio-oils and black liquors. These biomass-derived fractions offer promising paths for the production of valuable chemical products. Various catalytic methods have been investigated for upgrading the biomass-derived fractions. Researchers are interested in the hydrodeoxygenation process (HDO); in this process, the oxygen groups are eliminated by breaking the C-O bonds and water as a product. Incorporating heterogeneous catalysts (i.e., noble metals, transition metals, and metal sulfides) improves this process. Most HDO review articles describe catalytic results for model phenolic compounds. However, there is also a need to investigate the catalytic activity of real biomass-derived fractions. This paper explains research results regarding the upgrading of lignin-derived fractions (i.e., black liquors) by HDO. The paper has been organized according to the type of heterogeneous catalyst and shows compelling results based on different experimental conditions. The final sections present an analysis of the documented results and outline perspectives about integrating lignin into the biorefinery framework.

Manganese- and nitrogen-doped carbon materials were produced using NaOH-activated wood char and wood-processing residues such as wood chips and black liquor and evaluated as oxygen reduction catalysts for further application in fuel cells or metal–air batteries. The elemental and chemical composition, with special attention given to types of nitrogen bonds and the structure, morphology, and porosity of the obtained catalyst materials were studied. The catalytic activity was assessed in an alkaline medium using the rotating-disk electrode method. It has been shown that synthesized and doped N-Mn catalytic materials based on biomass precursors with different chemical structures are a promising alternative to modern oxygen reduction catalysts based on precious metals.

The efficient utilization of lignin from the papermaking black liquor has attracted interest due to its carbon-neutral value and industrial application. This work illustrates a simple support-phosphate-pretreatment strategy to develop superdispersed Ni species in activated carbon (AC) to enhance the hydrodeoxygenation (HDO) reactions of the lignin model compound guaiacol into biohydrocarbons under alkaline conditions. For the first time, sodium polyphosphate was applied as a pretreatment agent for coconut carbon in the synthesis of carbon-supported Ni catalysts. Superdispersed Ni nanoparticles were achieved on Ni/NaP n OAC with a particle size of 2.5 nm, which was much smaller than that on unmodified Ni/C (13.1 nm). The characterization results and reactions revealed that the P−O that formed served as anchoring sites for the Ni species and strengthened the interaction between the Ni species and support (SMSI), which resulted in significantly improved dispersion of the Ni metal sites and, thus, a nearly 6-fold greater yield of hydrocarbons was obtained on Ni/NaP n OAC (58.1 %) than on Ni/C (10.1 %). In addition, compared with Ni 2 P/NaP n OAC and NiS/NaP n OAC, Ni/NaP n OAC exhibited higher HDO activity, especially higher direct deoxygenation (DDO) activity and higher benzene yield, reducing hydrogen consumption during the HDO reaction. [Display omitted] • A super-dispersed Ni catalyst was synthesized with a support-pretreated method. • Ni nanoparticle of extra-small size at 2.5 nm was successfully obtained. • The formed P-O served as anchoring sites for Ni species. • The as-prepared catalyst exhibited high HDO efficiency in alkaline conditions. • Ni0 state catalyst exhibited high DDO activity. [ABSTRACT FROM AUTHOR]

Kraft lignin is a major byproduct of pulp and paper processing, presenting outstanding properties, including antioxidant action and UV and visible light absorption. Despite being a promising low-cost and renewable ingredient for dermo-cosmetic formulations, lignin use is restricted primarily because of its unpleasant odor and poor dispersibility in water. This study presents an integrated and environmentally friendly method to eliminate lignin odor, followed by improving its dispersibility in water through lignin nanoparticle (LNP) production, and, finally, evaluating their application in cosmetic formulations to act as antioxidant and UV-blocker. Starting with black liquor, Kraft lignin was precipitated and washed with water at 70°C, effectively removing lignin odor by a straightforward method, reducing its sulfur content from 5.6 to 2.9 wt%, and the ashes to negligible values without compromising the lignin structure. LNPs were successfully produced by the self-assembly method, yielding spherical and colloidally stable particles (zeta potential ca. −30 mV) with diameters ranging between 25 and 200 nm, outperforming particles prepared by sonication and bulk lignin itself. LNPs prepared by self-assembly method showed exceptional antioxidant activity, eliminating up to 79.2 % of DPPH• radicals (52 % more than bulk lignin) and showing in vitro SPF of ca. 15 with only 0.5 wt% of particle concentration, in addition to the improved dispersibility in cosmetic formulation. [Display omitted] • Tinted sunscreens based on Kraft lignin nanoparticles were developed. • Washing Kraft lignin with hot water reduced its odor, sulfur and ash content. • Preparation of nanoparticles improved lignin antioxidant and UV-Vis properties. • Nanoparticles are easily dispersed in water and can be incorporated into cosmetics. [ABSTRACT FROM AUTHOR]

[Display omitted] • HCs with high mesoporous ratio of 58 % were synthesized from papermaking wastes. • HCs can be obtained from BL solid direct pyrolysis without the need for separation. • Chlorides derived from DS were used as pore-enlarging agents to make mesopores. • DSCl x improves electrochemical performance of the synthesized HC anodes efficiently. • This study presents an economical and eco-friendly method for recycling BL and DS. Porous hard carbon anodes, with large interlayer space and high adsorption ability, can offer much better cycle stability and higher discharge capacity for potassium-ion batteries compared to commercial graphite anodes. However, most commercial hard carbons are synthesized from relatively expensive high-molecular polymers. In this study, pulping and papermaking wastes were utilized as precursors for producing hard carbons and pore-enlarging agent, respectively. Specifically, after thorough mixing through ball milling, black liquor solids and deinking sludge were utilized to produce porous hard carbon anodes via co-pyrolysis. The results show that direct pyrolysis of black liquor can produce hard carbons efficiently, eliminating the need to extract lignin from black liquor. Moreover, it is shown that the pore-enlarging agent derived from deinking sludge can enlarge much portion of pores on hard carbons, resulting in abundant mesopores. Electrochemical tests demonstrate that the synthesized porous hard carbon anodes can achieve highest specific capacity of 303.5 mAh g−1 at 100 mA g−1 using a 1.0 M potassium hexafluorophosphate electrolyte in a mixture of diethyl carbonate and ethylene carbonate. Additionally, the synthesized porous hard carbon anodes exhibit low average capacity decay per cycle of 0.06 % at 100 mA g−1 when tested with a 1.0 M potassium bis(fluorosulfonyl)imide electrolyte in the same solvent mixture after 500 cycles. Therefore, recycling black liquor and deinking sludge to produce porous hard carbon anodes for potassium-ion batteries is a promising approach for environmental and energy sustainability. [ABSTRACT FROM AUTHOR]

Black liquor, primarily consisting of lignin, polysaccharides, and inorganic substances, is a potential precursor of porous carbon materials for high-performance supercapacitors. However, the laborious purification of black liquor lignin and the introduction of exogenous heteroatoms have hindered their practical applications. Herein, the full components of black liquor were utilized to synthesize hierarchical porous sulfur self-doped lignin carbons (S-LCs) through a self-activation process aimed at improving the performance of supercapacitors. Benefiting from the intensified reactivity and crosslinking degree of the polysaccharide component and the sulfur self-doping and self-activation effect of inorganic substances, the resulting S-LCs exhibit a high specific surface area (SSA), abundant porous structure, and enhanced defect activity, all contributing toward increasing the energy storage capacity of supercapacitors. The as-obtained S-LC-G250/700 features a high SSA of 892.94 m 2  g -1 and a sulfur content of 3.3 at.%. The S-LC-G250/700 demonstrates excellent specific capacitance (e.g., 405.06 F g -1 at 0.5 A g -1 ), remarkable stability (103 % capacity retention after 10,000 cycles), and high energy density of 30.4 Wh kg -1 . Density functional theory calculations verified the advantages of the high-content sulfur self-doping of black liquor, suggesting that self-doped sulfur contributes to charge adsorption on porous carbon surfaces and promotes electron transfer in the electrolyte., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

This study investigates the production of lignin/silica hybrid nanoparticles (LSNPs) from rice husks, an abundant agricultural waste, and their capacity to stabilize Pickering emulsions for biocatalysis. Lignin extracted from rice husks under alkaline conditions was co-precipitated with silica to produce LSNPs in the presence or absence of ethanol as a co-solvent. Characterization of LSNPs revealed that ethanol played a key role in forming uniform, spherical nanoparticles and minimizing aggregation. Lignin imparted amphiphilicity to the LSNPs, which significantly improved their capacity to form stable Pickering emulsions. LSNPs were able to form stable oil-in-water Pickering emulsions while droplet size and emulsion stability were influenced by LSNPs concentration, oil/water ratio, temperature and pH. LSNPs-stabilized Pickering emulsions were evaluated for lipase-mediated biosynthesis of phytosterol esters, which are plant bioactive compounds that can reduce dietary cholesterol uptake. LSNPs-stabilized emulsions provided 1.915 × 10 6 times larger interfacial areas compared to conventional biphasic systems which facilitated improved mass transfer and lipase activity. Under optimal conditions, LSNPs-stabilized Pickering emulsion systems delivered 90.6% phytosterol ester conversion in 4 h, compared to 10 h in biphasic systems. This research highlights the potential of sustainable, biomass-derived nanoparticles in Pickering emulsion applications and offers an environmentally friendly approach to produce bioactive compounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The sustainable management of residual waste streams generated from the pulp and paper industry (PPI) has garnered increasing concerns due to the energy crisis and the pressing environmental threats posed by substantial effluent discharges. Using renewable lignocellulosic waste for resource generation presents a revolutionary approach to achieve environmental sustainability. Integrating the PPI with biorefinery processes allows for diversification beyond paper production and facilitates resource recovery. This review critically evaluates the valorization of waste streams from the PPI, with a pronounced emphasis on expanding into bioenergy and biofuels production, while also fostering the development of innovative biomaterials, such as biochar and activated carbon for applications with high added-value, such as environmental remediation and supercapacitors development, thus ensuring long-term sustainability. The review also emphasizes the significance of adopting a circular economy and its role in achieving environmental sustainability, with a particular emphasis on thermochemical technologies, which hold promise for resource recovery from wastewater. Furthermore, the review identifies critical bottlenecks in the path of waste stream valorization and engages in a forward-looking discussion on future prospects within the PPI. [Display omitted] • Black liquor contains major inhibitors e.g., furfural, 5-hydroxymethylfurfural. • Black liquor is used as a low-cost sugar, to produce e.g., bioethanol, biobutanol. • Paper mill wastewater used e.g., graphene sheet development, biochar, carbon fuel cell. • Porous carbon by black liquor showed capacitances for supercapacitor electrode. • Integrated biorefineries can achieve sustainability by Kraft pulp conversion. [ABSTRACT FROM AUTHOR]

The escalating industrialization trend underscores the imperative for sustainable waste management practices. The present investigation explores a sustainable methodology for managing the waste generated from the kraft process by directly converting it into activated carbon (BLAC) through a cost-effective hydrothermal-assisted activation method. The research involved a comparative analysis of BLAC with acid-washed black liquor lignin-derived activated carbon (ABLAC) and commercial lignin-derived activated carbon (SALAC). The analysis revealed that BLAC possesses a well-developed micro and mesoporous structure, yielding a significantly higher surface area of 2277.2 m2/g as compared to ABLAC (1260 m2/g) and SALAC (1558.4 m2/g). The presence of inherent alkali in the black liquor is the main factor influencing the surface area of the BLAC. Furthermore, it demonstrated impressive electrochemical performance, showing a specific capacitance value of 871.4 F/g at 1 A/g current density, positioning it as a formidable electrode material for supercapacitor applications. The proposed direct conversion strategy will eliminate the need for high-temperature pre‑carbonization and additional lignin extraction, reducing chemical usage and presenting a greener approach. [Display omitted] [ABSTRACT FROM AUTHOR]

The paper industry faces two critical challenges: the scarcity of raw materials and the environmental impact of chemical waste pollution. Addressing the first challenge involves harnessing alternative, sustainable raw materials, while the second challenge can be mitigated through the adoption of bio-bleaching processes, which significantly reduce chemical consumption while enhancing paper brightness and quality. This study proposes a solution to both challenges by using non-woody Calotropis procera (Ankara) and a xylanase-producing microbial consortium for sustainable handmade paper production, a combination not extensively explored in prior research . To evaluate this approach, the process was divided into three stages. In stage I, Ankara fibre was pulped through open hot digestion. In stage II, the pulp was subjected to bio-bleaching in two experimental setups: Set I (without sucrose) and Set II (with sucrose) for 5 days. In stage III, chemical bleaching was used to improve the final brightness of the treated pulps. A novel comparison was made between the bio-bleaching efficiency of an individual isolate g5 (BI) and a bacterial consortium (BC). This research highlighted that bio-bleaching with the consortium effectively removed lignin (140±60 mg/l) and colour (1830±50 PCU), especially in the presence of sucrose, compared to using a single xylanase isolate. Pulp residue/filtrate collected at each stage was estimated based on parameters such as colour and lignin content. After stage III (chemical bleaching), the release of colour and lignin in pulp filtrate was higher in BI compared to BC, indicating the consortium's effectiveness during bio-bleaching, which leaves fewer degradable lignin structures for the chemical bleaching stage. Papers crafted from consortium-treated pulp also exhibited higher brightness than those treated with the isolate. This study reveals the synergistic effect of microbial consortia, leading to more efficient lignin degradation and enhanced bio-bleaching capabilities, supporting the development of greener industrial processes. Ultimately, this study demonstrates a unique and eco-friendly approach to papermaking, combining C. procera and enzymatic bio-bleaching to reduce dependency on hazardous chemicals and support sustainable industry practices., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

This study aimed to investigate a novel method for the green synthesis of iron nanoparticles (FeNPs) using marigold extract (Calendula officinalis L), kraft pulping black liquor, and nanocellulose. Then, the efficacy of FeNPs as a direct nanofertilizer on the growth parameters of marigold was investigated. Characterization techniques including FESEM, EDX, VSM, and FTIR were used to confirm the successful synthesis of FeNPs. The characterization results confirmed the formation and presence of FeNPs in the 20–100 nm range. FeNPs synthesized with nanocellulose notably enhanced marigold growth parameters compared to other materials. However, all nanoparticle variants, including those from marigold extract and black liquor, improved germination, plant height, root length, and plant dry weight compared to the control. Moreover, treatments exhibited higher available iron and total plant iron levels than the control. Thus, employing 10 mg FeNPs (prepared with 5.0 % nanocellulose) appears optimal for enhancing marigold growth and yield. [ABSTRACT FROM AUTHOR]

Kraft lignin (KL), isolated from black liquor, serves as a significant feedstock for the production of bio-aromatics by catalytic fast pyrolysis (CFP). First, the influence of pH on the chemical structure of KL isolated by the gradient acid precipitation (GAP) was investigated. Then, the dual-catalyst CFP (DC-CFP) was employed to convert KL into light aromatics by using the hierarchical Nb 2 O 5 (Hie-Nb 2 O 5) and the microporous HZSM-5 as catalyst. Results showed that the decrease of pH during GAP promoted the breakage of the ether bond of KL, resulting in lower molecular weight and less content of hydroxyl group in KL. Among the four types of metal oxides (Hie-Nb 2 O 5 , Al 2 O 3 , MgO, and CaO), the synergistic effect of dual-catalyst grouped by Hie-Nb 2 O 5 and HZSM-5 was best for the production of light aromatics. In addition, the maximum production of light aromatics was reached at the pH of 2 and the mass ratio of Hie-Nb 2 O 5 -to-HZSM-5 at 2:2. [Display omitted] • Kraft lignin precipitated from black liquor by the gradient acid precipitation. • The lower precipitation pH was more conducive to the cleavage of ether bonds in lignin. • Dual-catalyst catalytic fast pyrolysis was developed for production of bio-aromatics. • Synergistic effect between the Nb 2 O 5 and HZSM-5 was observed. • The mass ratio of Nb 2 O 5 and HZSM-5 had influence remarkably on bio-aromatics yield. [ABSTRACT FROM AUTHOR]

Pursuing green and recyclable biocomposites is crucial to promoting sustainable development and carbon balance in the wood-based panel industry. In this study, bamboo and lignin were used as raw materials to create a high-performance biocomposite with better mechanical properties. The biocomposite demonstrates an impressive flexural strength of 97.20 MPa and a tensile strength of 41.43 MPa. These values represent a remarkable increase of 121% and 133%, respectively, compared to traditional fibreboard. This could be due to the lignin in the black liquor undergoing a glassy state transformation during hot pressing and acting as an adhesive to bind bamboo fibres tightly. As a result, the fibres are interconnected by hydrogen bonds and strong chemical bonds. During the recycling experiment, the Hot-pressed B&B20 underwent crushing and partial mixing with bamboo powder in a 1:3 ratio. Despite undergoing this process three times, its strength remained relatively unchanged, with tensile strength ranging from 89.53 to 98.32 MPa and static bending strength ranging from 38.79 to 40.52 MPa. Furthermore, the Hot-pressed B&B20 exhibits excellent machinability, hydrophobicity, heat resistance, and environmental friendliness, which makes it a highly competitive product. [Display omitted] • Glue-free biocomposites produced via hot pressing of bamboo and lignin. • Cell wall collapses enhanced mechanical bonding of fibrous components. • Depolymerization and repolymerization of lignin enhanced hydrogen bonding. • Biocomposites obtained can potentially replace traditional artificial board. • Biocomposites can be recycled after being discarded. [ABSTRACT FROM AUTHOR]

Lignin, isolated from black liquor, is an important feedstock to produce bio-aromatics through catalytic fast pyrolysis. First, the variation in chemical structure among the Kraft lignin precipitated by the organic acids (acetic acid and citric acid) and the inorganic acids (hydrochloric acid and sulfuric acid) was investigated. Then, a sustainable production approach of light aromatics from Kraft lignin was developed, namely the dual-catalyst catalytic fast pyrolysis (DC-CFP) by using the mesoporous Nb 2 O 5 and microporous HZSM-5 as catalyst. Results showed that the molecular weight of lignin isolated by inorganic acids (1674–1841 g/mol) was much lower than that of lignin isolated by organic acids (2040–2441 g/mol), caused by the fact that inorganic acids promoted the breakage of ether bonds in lignin. In addition, compared with lignin precipitated by the organic acids, the CFP of lignin precipitated by the inorganic acids has a higher yield of light aromatics, especially the lignin precipitated by the hydrochloric acid, reaching 1.39 × 108 a. u./mg. Among the different layout modes of catalyst, Model II (Meso-Nb 2 O 5 blended with lignin, HZSM-5 placed separately from lignin) presented highest yield of light aromatics during DC-CFP of lignin, reaching 1.78 × 108 a. u./mg. [Display omitted] • Kraft lignin precipitated from black liquor by the organic and inorganic acids. • Inorganic acids promoted the cleavage of ether bonds in lignin. • Dual-catalyst catalytic fast pyrolysis was developed for production of bio-aromatics. • Synergistic effect between the Nb 2 O 5 and HZSM-5 was observed. • Layout mode of catalyst and lignin had influence remarkably on bio-aromatics yield. [ABSTRACT FROM AUTHOR]

Low-temperature soaking can be used to extract the majority of the hemicellulose and lignin from bagasse without substantially changing its structure.The effects of temperature, alkali concentration, and treatment duration on the extraction of hemicellulose and lignin from bagasse via low-temperature alkaline soaking were investigated. Acid precipitation provided a solution by separating lignin from black liquor and enabled the categorization of the lignin into different groups based on the reduced pH of the solution. The precipitation of hemicellulose and lignin from black liquor under different pH conditions was investigated. The optimal pretreatment conditions for bagasse were determined to be an alkali concentration of 75 g L–1 at 35 °C for 8 d, achieving a pentose selectivity of 0.97. The main organic components of lignin and carbohydrates precipitated in different pH environments. The highest xylose content in the precipitate was obtained at pH 13.65 (above 85%), whereas the lignin content was above 90% at pH 2. The results of fourier transform infrared (FTIR) spectroscopy and two-dimensional nuclear magnetic resonance (2D NMR) analyses showed that the structure of the water-soluble substances and precipitates slightly changed during alkali pretreatment, which allowed for increased accessibility in subsequent biorefineries, such as in catalytic hydrogenolysis. [Display omitted] • Alkali soaking extracts enriched hemicellulose and lignin. • Optimal pretreatment achieves high pentose selectivity. • Acid precipitated lignin appeared subtle structural changes. [ABSTRACT FROM AUTHOR]

Efficient separating of organic components and recovering alkali are key technical issues to realize the valorization of black liquor. Acid precipitation and ethanol extraction have been adopted to extract high-quality bio-oil and inorganic salts and to purify lignin in this study. It was found that 64.29% purified lignin with 95.16% analytical purity can be obtained, and only 0.08% ash content existed, 84.02% of the remaining organic matter can be extracted as biofuel which has better performance than the biomass-pyrolysis bio-oil, and 97.31% alkali can be recycled and reused as cooking white liquor. The indicators of wastewater are much smaller than the sewage condensate discharged in traditional alkali recovery systems such as COD, BOD 5 , pH, etc., and the calcium sulfate generated can further increase the added value of this technology. Compared with the traditional alkali recovery system, Acid-Ethanol extraction systems can obtain $50.14 of extra profits for dealing 1 ton of dilute black liquor, it is expected to update the traditional alkali recovery process, achieve the valorization of black liquor, and support the development of "dual carbon". • A process was designed to efficiently extract bio-oil, purify lignin, and recover alkali systematically. • Lignin with 95.16% analytical purity and high calorific value of bio oil can be obtained, 97.31% alkali is recovered. • Compared with the traditional system, $50.14 per ton black liquor of extra profits can be obtained. [ABSTRACT FROM AUTHOR]

• A new software addresses the rapid analysis of black liquor evaporation plants. • An intuitive interface with equipment widgets allows different plant configurations. • EVATool includes a dashboard for easy visualization of the main results. • Software validation including different plants examples was accurate and reliable. • EVATool provides insights for operational evaporation processes decision-making. The energy recovery capability of a kraft pulping process is crucial for its feasibility, and the evaporation process of black liquor is very important for a successful energy recovery since it is the first stage of the recovery system. Despite the apparent simplicity of the process, black liquor evaporation involves multiple evaporators and complex unit operations. Therefore, analyzing and simulating different operational scenarios is essential before proposing changes. A new software tool was developed to address the limited offer of specific software for analyzing black liquor evaporation plants. It focuses on fast analysis of these plants by estimating the heat transfer coefficient, steam consumption, steam economy, black liquor mass fraction between effects, and others. The tool was developed in Python and provides an interface resembling the supervisory system used by operators and offers equipment widgets for creating plant diagrams. EVATool also presents a dashboard for easy visualization of the main results. Software validation using examples of evaporation plants has confirmed its capability to simulate plants in different modes. In an industrial setting, the dashboard enables the comparison of simulated values with project indicators unavailable through operational instrumentation. While improvements are possible, this software shows great potential for industrial implementation, contributing to operational decision-making in daily operations of the evaporation process in pulp mills. [ABSTRACT FROM AUTHOR]

Traditional wood-based panels composed of wood and petroleum based adhesives is widely used in furniture manufacturing and construction industries. However, these adhesives are not biodegradable, inhibiting the recycling of artificial board. More seriously, the emission of carcinogenic formaldehyde will lead to severe pollution and environmental issues. This study presents a method for preparing self-bonding composites. Waste poplar powder is used as raw material in the biocomposite, in which exogenous lignin is added, and lignin is extracted from the waste of the paper industry - black liquor, which is beneficial to the environment and the recycling of resources. The resulting biocomposites are characterized by aldehyde-free, better strength, and water stability. The dimensional stability and mechanical strength, bending strength (84.40 MPa), and tensile strength (35.40 MPa) of the biocomposite are 2.0 and 1.6 times that of composites obtained by hot pressing without pretreatment and are 2.7 and 2.4 times that of medium density fiberboard (MDF), lignin plays an important role as an adhesive, which is the key to improving mechanical properties. Moreover, the biocomposite features higher water stability and fire resistance than the traditional wood fiberboard. In conclusion, the developed black liquor-wood biocomposites are potential alternatives used to replace the formaldehyde wood-based fiberboard. [Display omitted] • An aldehyde-free wood-based panel was prepared by a resource-saving method. • The flexural and tensile strengths are 84.40 MPa and 35.40 MPa. [ABSTRACT FROM AUTHOR]