Pulp Industry Research Articles

Assessing the role of circular economy in provincial low-carbon transitions within China’s pulp and paper industry

Assessing the role of circular economy in provincial low-carbon transitions within China’s pulp and paper industry

New Insight into Industrial Lignin Intermolecular Force Heterogeneity Mitigation: Monodispersed Lignin Colloidal Sphere Synthesis and Full Biomass Photonic Material Preparation.

Industrial lignin is an underutilized resource from the pulping industry due to its high heterogeneity. The transformation of industrial lignin into monodispersed lignin colloidal spheres (LCSs) for the preparation of advanced biomass photonic materials is particularly appealing, because of their unique biocompatibility. However, the LCSs synthesized from industrial lignin generally show a wide size distribution and thus limit this specific application. To address the issue, selective functionalization was carried out to convert phenolic and aliphatic -OH groups into ester groups, decreasing the LCS size distribution to a monodispersing degree. Simulation analysis revealed that the functionalization had narrowed the difference of C-O linkage electron cloud distribution and led to a lignin polarity decrease. Additionally, atomic force microscopy (AFM) quantification of lignin proved a force distribution index (FDI) decrease from 0.38 to 0.11, which was consistent with the LCS polymer dispersity index (PDI) decrease from 0.182 to 0.05. The photonic materials can be readily prepared from monodispersed LCSs with the color precisely adjusted by controlling LCS particle sizes.

Preparing Sustainable Membranes Made From Zeolite–Smectite for Treating Textile Wastewater and Pulp Industry Wastewater

AbstractLow‐cost separation techniques are crucial for treating wastewater. Developing inexpensive membranes made from natural materials has become a popular research area in recent years. Tubular membranes were produced by adding 10% organic additives to a mixture of 80% zeolite and 10% smectite. New composite ceramic membranes from zeolite and smectite were prepared using the extrusion method to create a plastic paste and characterized using XRD, SEM, EPMA, and FTIR. The impact of sintering temperature (Tsint, 850–950 °C) on membrane properties, such as microstructure, mechanical strength (MS), water permeability, and filtration performance, was investigated. The MS and shrinkage rate increased with Tsint. At 950 °C, the resulting composite membrane exhibited a high MS of over 65 MPa, a relatively low porosity of 30%, appropriate for membrane filtration, and a water permeability of 65 L·h⁻¹·m⁻2·bar⁻¹. When applied to remove pollutants from wastewater, this membrane demonstrated a high color retention of 98.4% from an aqueous Evans blue‐colored solution (Effluent 1). For extensive application to wastewater treatment, this membrane showed a high‐efficiency level for treating real effluent produced by the pulp industry, removing 62.4% of chemical oxygen demand, 36% of hardness, and 82% of color. Finally, an ultrasonic cleaning procedure allowed the restoration of 70% of the initial permeability after four cycles for both effluents. Thanks to the exciting properties offered by these membranes and their competitive cost of less than $ 20·m−2, these membranes are appropriate for treating industrial wastewater.

Hyperthermophilic xylanase and thermophilicity analysis by molecular dynamic simulation with quantum mechanics

Thermophilic xylanases catalyzing the cleavage of β-1,4-glycosidic bonds in xylan have applications in food, feed, biorefinery, and pulp industries. In this study, a hyperthermophilic endo-xylanase was obtained by further enhancement of thermal tolerance of a thermophilic GH11 xylanase originated from metagenome of bagasse pile based on rational design. Introducing N13F and Q34L to the previously reported X11P enzyme shifted the optimal working temperature to 85 °C and led to 20.7-fold improvement in thermostability at 90 °C along with a marked increase in Tm to 93.3 °C. X11PNQ enzyme converted xylan to prebiotic xylooligosaccharides with high specificity on xylobiose to xylohexaose and high operational stability at 85 °C, resulting in 10.3-folds yield improvement compared to the parental enzyme. Molecular dynamic simulation and quantum mechanical analysis revealed improved H-bonding networks within GH11 xylanase principal domains and greater dynamic cross-correlations. A novel thermostabilization mechanism by π-amide interaction with slightly lower interaction energy than the native H-bond, but compensated by increased occurrence frequency was firstly demonstrated for thermophilic enzymes. The enzyme represents one of the most thermostable xylanases ever reported with biotechnological potential.Key points• Hyperthemophilic xylanase X11PNQ was obtained by rational design engineering.• X11PNQ showed specificity to prebiotic xylooligosaccharides (XOS) at 85 °C with improved t1/2 at 90 °C.• Novel thermostabilization by π-amide interaction was demonstrated by MD/QM.

Enzymatic conversion of wood materials from the pulp and paper industry

The reactivity during enzymatic hydrolysis of 8 industrially produced samples of pulps and semi-chemical pulps by enzyme preparations of glycosyl hydrolases B151 and F10 produced by a strain of ascomycete fungus Penicillium verruculosum has been determined. It is shown for the first time that among fibrous pulps available on the market of pulp and paper industry in Russia, the highest level of yield of glucose from the initial wood during biocatalysis using cellulases and hemicellulases is characteristic of semi-chemical pulps obtained after cooking of hardwood with green liquor. A high degree of enzymatic conversion of softwood bleached kraft pulp has been established, which in combination with the possibility of obtaining modified polysaccharide materials from non-hydrolysable residue makes this cellulosic substrate the most promising for the development of biological processes at pulp and paper industries. It is shown that drying of pulp negatively affects the efficiency of cellulose hydrolysis, while mechanical milling improves the performance of the enzymatic saccharification process.

Optimization of kraft pulping process for Sesbania aculeata (dhaincha) stems using RSM

Abstract The shortage of superior grade wood fibers is a prime problem faced by Indian pulp and paper industries. As a result, the pulp and paper industry find it difficult to withstand the competition in the market, which had grown extremely competitive. In order to increase the utilization of non-wood fibers resources in the production of high quality eco-friendly papers, dhaincha, a non-wood fiber resource has potential industrial application. In this research, pulp and paper were developed from Sesbania aculeata stem using kraft pulping followed by bleaching. Optimization of conditions for pulping was carried out by Response Surface Methodology. The relationship between three variables and three responses were studied using Box–Behnken experimental design. The developed pulp was evaluated for kappa number, brightness index, viscosity, FTIR and TGA. Then paper was developed by using optimized pulp and evaluated for physical properties. The statistical analysis (ANOVA) was carried out in order to establish the relationship between the concentration of NaOH, Na2S, treatment time and temperature with kappa number, brightness index and viscosity. The physical properties of pulp and developed handmade paper highlights the sustainable use of dhaincha plant in pulp and paper industry.

CFD and predictive modeling of temperature and calcination in a rotary lime kiln – Potential for steadier kiln operation

Rotary lime kilns are used in the pulp and paper industry to calcine lime mud to lime. Lime kiln models provide a means to understand the complex phenomena occurring within the kiln to aid in problem-solving during operation. A two-dimensional (2D) computational fluid dynamics (CFD) and one-dimensional (1D) bed model was previously developed for steady-state and transient analysis. This study explores data extracted from the model over a longer time period. The simulated outlet gas and shell temperature are compared to measured data for validation. The capability of using the model to estimate the production rate, accounting for the residence time within the kiln, is discussed. The maximum refractory wall temperature is analyzed during operation. Fluctuations in the calcination location are compared to outer shell heat-map data to correlate the calcination location and ring formation and growth. The model results to date indicate that fluctuations in the calcination zone may contribute to problematic ring growth, though a direct correlation has yet to be established. Additionally, a method for steadier kiln control is introduced and discussed. A machine learning model is also developed to predict the calcination start location from industrial data and is compared to the CFD model for validation. This model can generate results quickly and without the need for knowledge in CFD software and theory. Good agreement is found between the CFD and machine learning model during operation, with a mean absolute error (MAE) of 0.46 m, a mean absolute percentage error (MAPE) of 0.92%, and a root mean square error (RMSE) of 1.17 m.

Biofuels in lime kilns – Operating experience in the Nordic pulp and paper industry

The lime reburning process is a central part of the chemical pulp mill. It is energy intensive and consumes large amounts of fossil fuel, globally consuming about 50 terawatt-hours (TWh) of fuel per year. Conversion to operation with biofuel is interesting, both to reduce carbon dioxide emissions and to reduce costs. Researchers interviewed managers in mills that use solid, liquid, or gasified biofuels to replace fuel oil or natural gas in their lime kilns, and they conducted surveys related to fuel consumption and operations and maintenance. In Sweden and Finland, there were ten mills in 2020 using biomass powder or gasified biomass as the primary fuel, and two more installations were under construction. There were also nine installations in operation or under construction outside the Nordic countries. Fourteen mills in Sweden and two mills in Finland used tall oil pitch as the main fuel. Fuel consumption in Swedish lime kilns was 3.8 TWh in 2020, and 90% of this energy was supplied with biofuels. Of about 4.2 TWh used in Finnish lime kilns, approximately 45% was supplied with biofuels. Developments in the design of the fuel supply system include belt dryers being used in all new installations and mass flow metered dosing systems being used in most new pulverized fuel installations. Bark gasifiers have increased considerably in size. Lignin powder firing has been established as a proven option. A solution for many Swedish and Finnish mills is the use of tall oil pitch as a replacement for fuel oil.

Fractionation of Kraft Lignin for Production of Alkyd Resins for Biobased Coatings with Oxidized Lignin Dispersants as a Co-Product.

A new valorization pathway based on solvent fractionation was applied to kraft lignin, a major by-stream of the pulping industry, to extract a soluble lignin intermediate featuring an improved structural homogeneity, a low molecular weight, and a high content of phenolic hydroxyl and carboxylic acid groups to serve as a substitute of the nonrenewable polyacids in the formulation of alkyd resins, a dominant material used in the production of anticorrosion surface coatings. Herein, softwood kraft lignin was mixed in a low-cost green solvent, aqueous ethanol, prepared at different ratios, at room temperature to generate a soluble fraction of a low M w of ≤2200 g mol-1 and an insoluble fraction of a high M w of ≥3950 g mol-1 of lignin. The best combination of yields and molecular weights of soluble lignin (16-36% yield, 1740-1890 g mol-1) was attained using 50-80 vol % ethanol in fractionation. Thus, these conditions were further employed at the pilot scale to demonstrate the scalability of this technology. Soluble lignin from pilot fractionation was used to produce an optimal alkyd resin formulation and thereafter an anticorrosion coating on the metal surface, both of which matched the target properties of industrial standards well (180 s Persoz hardness and 72 gloss units of coating, 100% adhesion of paint with no cracks or peeling in the cross-cut test, no corrosion after 120 h of the salt spray test). The insoluble solids from pilot fractionation could also be valorized by alkali-O2 oxidation into lignin-based dispersants for special carbon black pigments. Overall, this study presents a new, simple strategy to develop an efficient, scalable, low-cost, and green process for upgrading kraft lignin into phenolic intermediates for biobased alkyd resins to facilitate sustainable production of high-performance anticorrosion coatings.

Phosphorus adsorption of a residue from the pulp and paper industry (grits): contributions to tertiary wastewater treatment

Phosphorus adsorption of a residue from the pulp and paper industry (grits): contributions to tertiary wastewater treatment

Enhancing water quality prediction with advanced machine learning techniques: An extreme gradient boosting model based on long short-term memory and autoencoder

Achieving carbon neutrality in the pulp and paper industry necessitates effectively recycling pulp and papermaking wastewater, where continuous monitoring of effluent quality indices is crucial. This study suggests a novel machine learning-based model named LSTMAE-XGBOOST that integrates the feature extraction capabilities of autoencoder, the sequential feature learning capabilities of LSTM, and the high prediction accuracy of XGBOOST. This model is capable of extracting the complex relationships, non-Gaussian characteristics, and time series features from the papermaking wastewater data, and it demonstrates superior predictive performance. Compared to traditional machine learning models, the proposed model exhibits higher prediction accuracy. Specifically, when contrasted with partial least squares regression, LSTMAE-XGBOOST achieves a 40% increase in R2 and a 35% reduction in RMSE. Further comparative assessments against other machine learning-based hybrid models with similar structures confirm the superiority of integrating LSTM and XGBOOST within the hybrid model approach. This study contributes a compelling methodology for modeling effluent quality indices, offering significant implications for environmental management in the pulp and paper industry.

2024 IEEE IAS Pulp and Paper Industry Committee (PPIC) Conference [Society News

2024 IEEE IAS Pulp and Paper Industry Committee (PPIC) Conference [Society News

Unraveling latent affinity of strategically designed histidine-rich biosurfactant via tannery waste bio-upcycling in environmentally-relevant lignin removal from pulp and paper industry effluent

Bioremediation of pulp and paper industry (PPI) effluent is hindered due to biorefractory lignin. Herein, we demonstrate a lignin-specific designer biosurfactant with synergistic binding sites for enhanced lignin removal from PPI effluent. The histidine rich-cationic lipoprotein biosurfactant (HR-CLB) was synthesized by Bacillus tropicus using tanning industry solid waste, animal fleshing by de novo substrate-dependent synthesis pathway. Interestingly, the HR-CLB anchored functionalized carbon (HR-CLBAFC) demonstrated a high lignin sequestration capacity of 93.2 mg/g HR-CLBAFC at optimized time, 60 min; pH, 5; temperature, 45 °C; and mass of HR-CLBAFC, 1.0 g. The sequestration was confirmed by HR-SEM, UV–Vis., FT-IR, and WCA analyses. The isotherm studies revealed the involvement of Freundlich isotherm (regression coefficient, R2: 0.988) in regulating lignin sequestration onto HR-CLBAFC with a Freundlich constant (Kf) of 16.46 ((mg/g)(L/mg)1/n). Moreover, the kinetics studies divulged the contribution of the pseudo-second-order kinetic model (R2: 0.992) in regulating the dynamic mechanism of lignin sequestration onto HR-CLBAFC with a rate constant (k2) of 0.00022 g/mg min. Additionally, the thermodynamics studies discovered a positive Gibbs free energy (ΔG: +170 kJ/mol) and entropy (ΔS°: +130 kJ/mol), indicating the involvement of chemical interaction during the sequestration. Furthermore, the mechanistic study confirmed the role of an incomplete valence shell of nitrogen in histidine centers of HR-CLB in regulating electrostatic interaction with lignin molecules during the sequestration process. Subsequently, the HR-CLBAFC applied for lignin sequestration from the real-time PPI effluent demonstrated an outstanding sequestration efficiency (>99.4%), confirming the unequivocal potential of the HR-CLBAFC matrix in lignin sequestration from real-time PPI effluent.

Environmental Sustainability Assessment of Tissue Paper Production

The environmental performance of tissue paper varies greatly based on factors such as the type of fibre used as the raw material, the production process and the fuels used to meet the energy requirements. One possible strategy to decrease greenhouse gas emissions in tissue production is the integration of pulp and paper mills and their energy systems at the same site. However, the environmental trade-offs associated with this strategy are still unclear. Therefore, this study aimed (i) to assess for the first time the environmental impacts of tissue paper produced at a typical industrial site in Portugal using slush and market pulp as the main raw material, and (ii) to assess the environmental effects of the integration of bioenergy produced in the pulp mill in tissue production. A life cycle assessment was conducted from cradle to gate using real data from the production of eucalyptus wood, eucalyptus pulp and tissue paper. The results showed that energy consumption in tissue paper production is the main hotspot for most impact categories. When bioenergy is used in tissue production, the environmental impacts decrease by up to 20% for categories other than marine eutrophication and mineral resource scarcity. These results are relevant to support decision making concerning sustainable practices not only for the pulp and paper industry but also for the authorities in charge of defining environmental policies, incentives and tax regulations.

Upgrading of kraft lignin pyrolysis products: Managing sulfur impurities

Pyrolysis stands as a powerful method for the valorization of biomass like kraft lignin, an aromatic-rich and sulfur-containing polymeric by-product from the pulping industry. Sulfur in the raw matrix is released during thermal processes and is redistributed in pyrolysis products. However, the presence of sulfur lowers the quality of products due to its corrosive and toxic character. In this work, commercial activated carbons have been used as adsorbents to remove the main sulfur compounds from the gas phase (i.e., CH3SH, COS, H2S). The analysis of sulfur content in biochar has been performed through SEM-EDXS, while the sulfur content in oils has been obtained by GC–MS analysis. The adsorption of sulfur on the activated carbon bed results in an enhancement of the release of sulfur in the gas phase from 34 % without activated carbon to 44 %. Up to 88 % of H2S removal is achieved after the adsorption step, together with a reduction of the overall sulfur content in the bio-oil rich in intermediates such as guaiacols and alkylated phenols. The residual sulfur contained in the liquid product is lowered to 3 % of the total sulfur in the system, thus improving the quality of the liquid pyrolysis product. This process limits the amount of sulfur in the gas and improves its quality and market value. At the same time, this results in a redistribution of sulfur in pyrolysis products such as bio-oil, improving its range of application as a source of chemical intermediates from kraft lignin.

A Review of Welding Process for UNS S32750 Super Duplex Stainless Steel.

Super duplex stainless steel UNS S32750 is widely used in marine industries, pulp and paper industries, and the offshore oil and gas industry. Welding manufacturing is one of the main manufacturing processes to make material into products in the above fields. It is of great importance to obtain high-quality welded UNS S32750 joints. The austenite content and ferrite content in UNS S32750 play an important role in determining UNS S32750 properties such as mechanical properties and corrosion resistance. However, the phase proportion between the ferrite phase and austenite phase in the welded joint will be changed during welding. Lots of research has been done on how to weld UNS S32750 and how to obtain welded joints with good quality. In this work, the recent studies on welding UNS S32750 are categorized based on the welding process. The welding process for UNS S32750 will be classified as gas tungsten arc welding, submerged arc welding, plasma arc welding, laser beam welding, electron beam welding, friction stir welding, and laser-MIG hybrid welding, and each will be reviewed in turn. The microstructure and properties of the joints welded using different welding processes will also be discussed. The critical challenge of balancing the two phases of austenite and ferrite in UNS S32750 welded joints will be discussed. This review about the welding process for UNS S32750 will provide people in the welding field with some advice on welding UNS S32750 super duplex stainless steel.

Social-LCA providing new insights and learnings for social responsibility—case pulp and paper industry

Abstract Purpose This paper presents the lessons learnt from testing the ORIENTING S-LCA methodology for a case product of Stora Enso, a globally operating forest industry company. The main purpose of the study was to explore what kind of additional insights and benefits the S-LCA method could provide compared to other existing social responsibility methods and approaches used by companies. Methods The paper briefly describes the applied ORIENTING S-LCA method and its application in the case study, focusing on main learnings gained and development needs identified. The S-LCA methodology proposed in ORIENTING builds upon the UNEP Guidelines for S-LCA (UNEP 2020) and the Handbook for Product Social Impact Assessment (Goedkoop et al. 2020). S-LCA methodology relies on the reference scale approach (RSA) and combines qualitative and quantitative evaluations for assessing social performance and social risk along the product’s life cycle. Social performance assessment approach was applied for company’s own processes covering several life cycle stages and the risk assessment for assessing the supply chain. Results and discussion Based on the case company’s experience, social assessments are currently conducted mainly on company or facility level. Moving towards product-based assessments could help gaining a more transparent view of products’ value chains and bring new possibilities for example to supplier specific sustainability audits. With the product-based S-LCA, the company could more easily identify, e.g., in which life cycle stage they would have most gaps on information and on which social matters, and take different stakeholders’ needs better into consideration in different life cycle stages. Areas that require further development concern especially data availability, assessment efficacy, and formulation of social topics. Conclusions The study demonstrates that the S-LCA methodology offers several benefits when addressing social sustainability issues in the pulp and paper industry. Comprehensive view over different social topics, life cycle perspective, and stakeholder identification are key elements of S-LCA that may support identifying relevant sustainability topics for the purposes of corporate sustainability reporting. Additionally, they can support defining appropriate mitigation actions that will be required for complying with the requirements related to corporate sustainability due diligence.

Thermothelomyces thermophilus cultivated with residues from the fruit pulp industry: enzyme immobilization on ionic supports of a crude cocktail with enhanced production of lichenase.

β-Glucans comprise a group of β-D-glucose polysaccharides (glucans) that occur naturally in the cell walls of bacteria, fungi, and cereals. Its degradation is catalyzed by β-glucanases, enzymes that catalyze the breakdown of β-glucan into cello-oligosaccharides and glucose. These enzymes are classified as endo-glucanases, exo-glucanases, and glucosidases according to their mechanism of action, being the lichenases (β-1,3;1,4-glucanases, EC 3.2.1.73) one of them. Hence, we aimed to enhance lichenase production by Thermothelomyces thermophilus through the application of response surface methodology, using tamarind (Tamarindus indica) and jatoba (Hymenaea courbaril) seeds as carbon sources. The crude extract was immobilized, with a focus on improving lichenase activity, using various ionic supports, including MANAE (monoamine-N-aminoethyl), DEAE (diethylaminoethyl)-cellulose, CM (carboxymethyl)-cellulose, and PEI (polyethyleneimine)-agarose. Regarding lichenase, the optimal conditions yielding the highest activity were determined as 1.5% tamarind seeds, cultivation at 50°C under static conditions for 72h. Moreover, transitioning from Erlenmeyer flasks to a bioreactor proved pivotal, resulting in a 2.21-fold increase in activity. Biochemical characterization revealed an optimum temperature of 50°C and pH of 6.5. However, sustained stability at varying pH and temperature levels was challenging, underscoring the necessity of immobilizing lichenase on ionic supports. Notably, CM-cellulose emerged as the most effective immobilization medium, exhibiting an activity of 1.01 U/g of the derivative (enzyme plus support), marking a substantial enhancement. This study marks the first lichenase immobilization on these chemical supports in existing literature.

Conversion of Lignin to Nitrogenous Chemicals and Functional Materials.

Lignin has long been regarded as waste, readily separated and discarded from the pulp and paper industry. However, as the most abundant aromatic renewable biopolymer in nature, lignin can replace petroleum resources to prepare chemicals containing benzene rings. Therefore, the high-value transformation of lignin has attracted the interest of both academia and industry. Nitrogen-containing compounds and functionalized materials are a class of compounds that have wide applications in chemistry, materials science, energy storage, and other fields. Converting lignin into nitrogenous chemicals and materials is a high-value utilization pathway. Currently, there is a large amount of literature exploring the conversion of lignin. However, a comprehensive review of the transformation of lignin to nitrogenous compounds is lacking. The research progress of lignin conversion to nitrogenous chemicals and functional materials is reviewed in this article. This article provides an overview of the chemical structure and types of industrial lignin, methods of lignin modification, as well as nitrogen-containing chemicals and functional materials prepared from various types of lignin, including their applications in wastewater treatment, slow-release fertilizer, adhesive, coating, and biomedical fields. In addition, the challenges and limitations of nitrogenous lignin-based materials encountered during the development of applications are also discussed. It is believed that this review will act as a key reference and inspiration for researchers in the biomass and material field.

Catalytic influence of alkali and alkali earth metals in black liquor on the gasification process: a review

AbstractDuring the pulping process, either alkali or alkali earth metals are added in a cooking solution to turn wood chips into pulp, and these alkali and alkali earth metals (AAEMs) end up in the black liquor. These AAEMs are known to catalyze the gasification process, by lowering the reaction temperature and degrading tar in the syngas. Of the various black liquor valorization methods, gasification is a promising process that can be integrated into existing pulping processes to recover the process energy via syngas utilization. It is, therefore, important to firmly understand how AAEMs in black liquor catalyze the gasification process. This review paper also discusses how black liquor is generated from both the Kraft pulping and the sulfite pulping process. The paper also examines advances that have been made in terms of an integrated gasification process into the existing pulping process. The paper explores the supercritical water gasification of back liquor and syngas as fuel in the pulp and paper industry. A discussion of the co-gasification of black liquor with either fossil fuels or biomass, focusing on the catalytic effect of AAEMs in the co-gasification process as well as the synergistic effects of fossil fuels and biomass is presented.