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The anatomical and chemical properties of a lesser known species, Kawui wood, were investigated Two trees were examined based on IAWA, ASTM and SNI. A completely randomised design was used with radial direction of the trunk (sapwood and heartwood) as the factor, in three replications. It indicated the highest to lowest cell proportions are fibres, rays, vessels and parenchyma. The highest proportion of rays was in the sapwood, while the fibre was in the heartwood. However, the average fibre length in the sapwood was higher than the heartwood, while the lumen diameter showed the reverse. Holocellulose, α-cellulose, lignin, extractives, and ash content of the sapwood was higher than the heartwood. Based on its anatomical and chemical properties, Kawui wood can be included in grade II–IV, which is suitable for medium quality pulp and paper production. [ABSTRACT FROM AUTHOR]

The use of biomass in combined heat and power (CHP) plants with district heating and cooling is necessary for achieving decarbonization targets. While in traditional biomass plants steam temperature is below 520 °C, new developments can lead to ultra-supercritical (USC) designs with steam temperatures of 600 °C. The present study investigates the performance of such plants for covering the heat demands of the aluminum and pulp and paper industrial processes, while also producing district heating and cooling. Plant performance is assessed through sensitivity analyses covering a wide range of heat demand scenarios. In the electricity-only scenarios, the electric and exergetic electric efficiencies of the aluminum/pulp and paper plants are 43.45/44.22% and 38.93/39.62%, respectively. In the CHP scenario, when the heat demand is maximized, the electric, exergetic electric, CHP and exergetic CHP efficiencies of the aluminum/pulp and paper plants are 21.81%/34.32%, 19.54%/31.70%, 92.50%/86.76% and 39.43%/39.01%, respectively. With the integration of cooling, the electric and CCHP efficiencies of the aluminum plant are 21.60% and 89.23%, respectively. Most of the exergy is destroyed during the combustion and steam generation processes, corresponding to 67–70% and 13–16% of the total exergy destruction, respectively. • Development of supercritical CHP plant layouts featuring district heating and cooling. • Process heat integration scenarios for aluminum and pulp and paper processes. • Sensitivity analyses and mapping of plant performance for different heat demands. [ABSTRACT FROM AUTHOR]

All materials, chemicals and fuels made from fossil fuels can be made from sustainably sourced biomass. Biorefineries are key infrastructure developments needed to unlock the value from biomass and accelerate the transition to a Bioeconomy. The Forestry, Timber, Pulp & Paper industry produces lumber, pulp and paper bulk commodities to market. However, there are notable value-adding opportunities for Forestry biorefineries, since about 50% of the harvested tree biomass ends up as residues and waste. In order to assess the opportunity for Forestry biorefineries, this paper reviewed the various processing pathways, technologies and products that can be produced from wood residues and wastes from the FTPP industry (sawdust & offcuts, bark, leaves, sludge, black liquor, dregs and ash). A total of 129 chemical, thermochemical, biological and mechanical processing pathways were identified to generate 78 different unique products. We assessed the technical maturity of these processing pathways in terms of the technology readiness level and evaluated the market potential of these products to identify and classify Forestry biorefinery products as: true commodities, pseudo-commodities, fine chemicals and speciality chemicals. This study provides strategic focus for the development of Forestry biorefineries by distinguishing between un-established markets and lack of technology or innovation. Image 1 • Identification of the wastes and residues of the Forestry, Timber, Pulp and Paper Industry. • Identification of 129 processing pathways and technologies for Forestry biorefineries. • Technology Readiness Level (TRL) assessment of the of 78 unique Forestry biorefinery products. • Market potential of Forestry biorefinery products and classification according to true commodities, pseudo-commodities, fine chemicals and speciality chemicals.production value and volume. • Provides strategic focus for Forestry biorefinery research and development. [ABSTRACT FROM AUTHOR]

The U.S. pulp and paper industry consumes over $7 billion worth of purchased fuels and electricity per year. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. pulp and paper industry to reduce energy consumption in a cost-effective manner. This paper provides a brief overview of the U.S. EPA ENERGY STAR(R) for Industry energy efficiency guidebook (a.k.a. the "Energy Guide") for pulp and paper manufacturers. The Energy Guide discusses a wide range of energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. Also provided is a discussion of the trends, structure, and energy consumption characteristics of the U.S. pulp and paper industry along with a description of the major process technologies used within the industry. Many energy efficiency measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in pulp and paper mills and related industries worldwide. The information in this Energy Guide is intended to help energy and plant managers in the U.S. pulp and paper industry reduce energy consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures?as well as on their applicability to different production practices?is needed to assess their cost effectiveness at individual plants.

The recovery and utilisation of industrial excess heat has been identified as an important contribution for energy efficiency by reducing primary energy demand. Previous works, based on top-down studies for a few sectors, or regional case studies estimated the overall availability of industrial excess heat. A more detailed analysis is required to allow the estimation of potentials for specific heat recovery technologies, particularly regarding excess heat temperature profiles. This work combines process integration methods and regression analysis to obtain cogeneration targets, detailed excess heat temperature profiles and estimations of electricity generation potentials from low and medium temperature excess heat. The work is based on the use of excess heat temperature (XHT) signatures for individual sites and regression analysis using publicly available data, obtaining estimations of the technical potential for electricity generation from low and medium temperature excess heat (60–140 °C) for the whole Swedish kraft pulp and paper industry. The results show a technical potential to increase the electricity production at kraft mills in Sweden by 10 to 13%, depending on the level of process integration considered, and a lower availability of excess heat than previously estimated in studies for the sector. The approach used could be adapted and applied in other sectors and regions, increasing the level of detail at which industrial excess heat estimations are obtained when compared to previous studies.

This paper presents an evaluation study of wastes from pulp and paper as well as construction and demolition industries for application in cement-based materials. The alternative raw materials were used as a source of calcium carbonate (CaCO3) and as pozzolanic material (water-reactive SiO2) in partial replacement of Portland cement. In addition to the hydraulic binder, coating mortars were composed by combining the pulp and paper fluidized bed sand residue with construction and demolition wastes, both added as small aggregates. Rheological and mechanical characterization showed that the waste additions changed the behavior of the cement materials, increasing both the viscosity of the pastes (at constant shear stress or rate). The formation of agglomerates in the cement hydration process made the mortars with additions of residues (lime and ash sludge) have an increase in the mechanical strength of the hardened bodies when compared to the mortar (M0W) prepared only with the residues (fluidized bed sand and C & D) as aggregates.

With a projected growth of the Brazilian pulp and paper industry of about 20% over the period 2020–2025, the innovations in waste management and utilization of side-products originating from the pulp and paper industry may mostly contribute to sustainable development of forest-based products, e.g., by implementing the recuperation and innovative processing of side-stream products at a local level. In this study, we analyze the feasibility for the reuse of recovered cellulosic fibers collected from pulp and paper mill sludge by considering some practical issues and evaluation of the quality for different side-stream fractions originating from rejects, deinking sludge, primary sludge, and secondary sludge. The situation for the Brazilian pulp and paper industry will be used as a model, for which the potential for recovery of fibers from wastewaters will be evaluated from the analysis of available data. First, the water consumption and effluents from paper mills are reviewed together with an estimation of the fiber recovery potential from primary sludge and fine fiber rejects. Second, the specific characteristics and appearance of certain fiber fractions might imply constraints on their further processing properties. Therefore, we describe some insights into the fiber fractions that could provide the highest potential for future valorization. Based on the degree of compositional homogeneity and concentration of cellulose fibers in several waste fractions, the processing of fibers from primary sludge and/or fine fiber rejects is estimated as the most economically feasible. The homogenization of the fiber fractions yields fibrillated cellulose materials with various morphologies depending on the selection of recuperated fractions. Through thorough characterization of the resulting fiber fraction, new application markets can be selected.

The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.

estudo teve por objetivo determinar a composição química, densidade básica e parâmetros morfológicos dos traqueídeos da madeira de Cupressus lusitanica, visando verificar sua adequabilidade para produção de polpa celulósica. Foram utilizadas três árvores, com 16 anos, das quais extraíram-se discos que foram empregados na caracterização química, física e morfológica da madeira. A morfologia dos traqueídeos foi avaliada nos anéis correspondentes as idades 4, 7, 10, 13 e 16 anos. A partir dos parâmetros dos traqueídeos, calcularam-se os indicadores de qualidade da polpa. Foram observados baixos teores de cinzas e extrativos (0,27 e 2,13%, respectivamente), porém alto teor de lignina (32,52%). A densidade básica (0,375 g.cm-3) foi menor que de outras espécies de coníferas utilizadas para produção de celulose. Os traqueídeos apresentaram valores médios de 2,41 mm de comprimento; 31,40 µm de largura; 25,15 µm de diâmetro do lúmen e 3,12 µm de espessura de parede, que tenderam a uma elevação nos valores com o aumento da idade. De maneira geral, a madeira de C. lusitanica apresenta boas características tecnológicas para produção de celulose e papel, especialmente pelos índices morfológicos de qualidade observados. The objective of this study was to determine the chemical composition, basic density and tracheids morphological parameters of the wood of Cupressus lusitanica aiming to verify its suitability for cellulosic pulp production. Discs were collected from three 16-year-old trees to determine chemical, physical and morphological characteristics. The morphology of the tracheids was evaluated in the annual rings corresponding to the ages of 4, 7, 10, 13 and 16 years. The pulp quality parameters were calculated from the tracheid parameters. The chemical composition indicated low ash and extractive contents (0.27 and 2.13%, respectively), but high lignin content (32.52%). The basic density (0.375 g cm-3) was smaller than other species of softwood used for pulp production. The mean values of tracheids dimensions observed were 2.41 mm of length, 31.40 µm of width; 25.15 µm of lumen diameter and 3.12 µm of wall thickness, which tended to increase in values with increasing age. In general, C. lusitanica wood presents good technological characteristics for pulp and paper production, especially for the observed quality morphological index. [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.)

Objective: The main objective of this study is the evaluation of RPPW anaerobic digestion feasibility at laboratory scale under Mesophilic condition. The experiment is conducted using a two-stage biofilm digester of 5 L capacity with mobile support material. Results: Anaerobic treatment of wastewater from recycled pulp and paper industry in Morocco was tested using a laboratory-scale anaerobic biofilm digester that operated under mesophilic conditions over a 70-day. Chemical oxygen demand (COD) efficiency, volatile and total solid (VS, TS) elimination of the substrate during the process were: 78%, 52% and 48% respectively. The system was stable throughout its operating cycle with an optimum pH (7.24), alkalinity (1750 mg CaCO3/L) and a volatile fatty acid value (760 mg/L). The experimental daily biogas production measured reaches a value of 5 L/day with a composition of 71% methane, 27.6% carbon dioxide, 0.2 oxygen and 7713 ppm of the H2S. The study results show that the anaerobic biofilm reactor is a suitable technique for recycled pulp and paper wastewater (RPPW) treatment. The reactor shows high performances in terms of process stability, removal efficiency (> 70%) and biogas production. Conclusion: Anaerobic digestion is an efficient waste treatment technology that uses natural anaerobic decomposition to reduce the volume of waste while producing biogas. However, research is needed to strengthen microbial metabolism, biochemistry and the functioning of the rector to improve biogas production. The RPPW AD experiment with biofilm digester technology was stable throughout the operation period. The digester knows an overloaded in the last phase of the experiment which leads to an inhibition of biogas production. [ABSTRACT FROM AUTHOR]

Laccase has the enormous potential to be implemented as the multitasking biocatalyst in whole process of paper making. The enzyme can utilize effectively for pulping, delignification of pulps as alone or in the combination with other bleaching enzymes. Laccase has been evaluated for the biografting of pulp fibers, decolorize and stabilize the effluent of the paper mills, biotransformation of high molecular weight (HMW) lignins to lower molecular weight (LMW) aromatic compounds. Further this enzyme has the huge possibilities to apply for deinking of old newsprint (ONP) and pitch removal from varieties of the different pulps. There is no doubt on versatility mode of action of laccases in paper industry, but still there is limited commercialization of this enzyme has been possible, because of laccases has the less redox potential (E0) and needs mediators for the oxidation of non phenolic substrates, production of enzyme is cost intensive at large scale. This review is providing the proper updated information on the state of the art of different applications of laccase in paper industry. It also confer the interpretation to the readers about the areas of extensively studied and the field where there is still much left to be done. [ABSTRACT FROM AUTHOR]

The pulp and paper industry is one of the five most energy-intensive industries world-wide. In Sweden, most pulp and paper mills were certified with a standardized energy management system already in 2005. As Swedish mills have more than a decade of experience with energy management systems and energy key performance indicators (KPIs), studying KPIs within Swedish pulp and paper mills will enable both a state-of-the-art positioning of best-practice in relation to energy KPIs in pulp and paper mills, but also spot potential barriers and drivers in the utilization of energy KPIs. This paper studies the current level of implementation and operationalization of energy-related KPIs in the Swedish pulp and paper industry. The results show a potential for improvement. • Pulp and paper mills' level of implementation of energy-related KPIs is studied. • 25% of the mills apply best practice regarding the establishment of energy KPIs. • Pulp and paper mills can potentially improve their monitoring of energy KPIs. • Lack of resources is a major barrier to implementing relevant energy KPIs. [ABSTRACT FROM AUTHOR]

Rapeseed (Brassica napus) stalks are agricultural wastes generated in important quantities as a result of rapeseed cultivation valued for edible vegetable oil or biodiesel production. This study examines the potential of using rapeseed stalks as raw material in pulp production. The obtained results pointed out to the suitability of these agricultural wastes for pulping to papermaking pulp. Chemical alkaline pulping methods such as kraft and sulphur-free soda-anthraquinone and their optimization were taken into consideration for the laboratory trials. Response surface modeling was employed for the study of process parameters impact on obtained pulps. As a result, optimal process conditions may be selected depending on the desired pulp characteristics. [ABSTRACT FROM AUTHOR]

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

The aim of this study was to identify cellulolytic fungal strains capable of degrading cellulose from an aerated lagoon in a pulp and paper mill. Four fungal strains that were found to be highly active were isolated on carboxymethyl cellulose (CMC) and suggested to be CMCase/endoglucanase. The identified strains were Aspergillus niger, Penicillium sp., Aspergillus fumigatus, and Mucor sp. All the strains were studied in terms of cultural morphological characteristics and microscopic examinations. The endoglucanase with the highest isolate production was Penicillium sp., which also showed the highest qualitative endoglucanase activity (1.3 cm), in addition to the main activity of endoglucanase with 297 mmol/mg.min after 116 h. The results indicated that CMC is able to induce endoglucanase enzyme production and that the fungal isolates showed significant cellulose degradation properties.

Recently, xylanase has attracted attention in the pulp and paper industry because of its bleach-boosting properties, which reduces chemical consumption during the bleaching process. Four fungi species, namely Penicillium oxalicum T3.3, Aspergillus niger ATCC 6275, Colletotrichum gloeosporioides, and Pycnoporus sanguineus, were studied to select which fungi can best produce cellulase-poor xylanase using rice straw as a substrate. The fungi were screened for xylanase production based on the clear zone formation on a malt extract agar (MEA) plate containing xylan. P. oxalicum T3.3 and A. niger ATCC 6275 showed greater clear zone formation on the agar plate than the other two studied fungi. These fungi were grown in a liquid medium containing rice straw as the substrate. P. oxalicum T3.3 showed the highest xylanase activity (65.89 U/mL) with lowest carboxymethyl cellulase (CMCase) (1.88 U/mL) and filter paperase (FPase) activity (0.16 U/mL) after four days of fermentation at 30 °C. P. oxalicum T3.3 produced higher xylanase activity when rice straw was used as a substrate compared to commercial xylan. Thus, cellulase-poor xylanase produced from P. oxalicum T3.3 has high potential for biobleaching application in the pulp and paper industry in terms of technical and biological performance and economical aspects.

A pilot-scale aerated lagoon was used for the aerobic treatment of pulp and paper mill effluent from September 1 to December 1, 2014. The aerated lagoon was installed at the chemistry laboratory in the Chemical Engineering Department at the Durango Institute of Technology and was fed with real pulp and paper mill effluent. The experimental work was run under various operating conditions. The operating parameters (total and volatile suspended solids (VSS) and dissolved oxygen concentration (DO)) and environmental variables (temperature, pH, COD, and BOD5 of influent water) were monitored daily. In all the experiments conducted, the aerated lagoon generated an effluent of optimal quality complying with the requirements of SEMARNAT (2003) and CONAGUA (2003). A model that explains the behavior of the system under realistic operating conditions was obtained. The model indicated an optimal DO of approximately 4 mg/L for concentrations up to 1000 mg/L, showing variations in concentrations above this value. This data indicate that the flexibility of the bacterial formulation and its ability to adapt to environmental changes play an important role in the stability of an aerated lagoon.

The performance of coir fiber in the production of linerboard made from soda-anthraquinone (soda-AQ) pulp was evaluated. Based on chemical analysis, the composition of coir fiber is suitable for the pulping process. Out of nine pulping conditions characterized, a pulping condition of 18% active alkali for 90 min cooking time was chosen. These conditions provided the highest screened yield (48.99%), a low rejection yield (0.27%), high viscosity (11.73 cP), and a kappa number (41) that is acceptable for unbleached linerboard production. Beating strengthened the coir pulp. Analyzing the beating revealed that coir pulp was optimized at 1000 to 2000 revolutions, based on a graph of freeness vs. burst index. For all beating conditions (1000 to 8000 revolutions), FESEM micrographs showed the presence of internal and external fibrillation of the fiber, which gradually increased fiber conformability and improved the inter-fiber bonding within the paper formation. Based on its burst strength of 4.57 kPa.m2/g and ring crush test of 1.76 Nm2/g, which complies with the minimum requirement of the industry standard, coir fiber can be considered an alternative fiber source for linerboard production.

Time-domain reflectometry (TDR) can be used to predict the moisture content in porous materials, including soil, and is an exciting tool that could be used to measure the moisture content in wet-stored wood. Three-rod probes with 127 mm- or 152 mm-long rods were inserted into 62 loblolly pine and 34 sweetgum saturated bolts. The bolts were air dried over a span of five weeks. TDR waveforms and moisture content were periodically recorded. In total, 534 and 482 readings were taken for the loblolly pine and sweetgum bolts, respectively. An algorithm in R was written to automatically analyze the apparent length of the TDR rods. Calibration models were developed between moisture content and X (apparent length / actual rod length). A three-parameter logistic model was developed for loblolly pine (R2=0.64) and sweetgum (R2=0.84). The process was repeated using shorter bolts and 152 mm-long rods, resulting in improved models for loblolly pine (R2=0.99) and sweetgum (R2=0.97). Overall, TDR and the algorithm written to analyze the waveforms were accurate in predicting moisture content and could be used to monitor moisture in wet-decks.

This study examines the possibilities of making pulp from sorghum grown in Bartın via the NaOH method. While setting the cooking conditions for producing pulp from annual plants, NaOH was used in quantities that amounted to 14, 16, 18, and 20% of the total weight of the dry sample. Optimum conditions were established relative to pulp yield, Kappa number, and a scoring table based on mechanical, optical, and physical values. Accordingly, optimum conditions for pulp production from sorghum stalks occurred when 20% NaOH was used at 120 °C, a 5:1 solution-to-stalk ratio, and a cooking time of 60 min.

Abstract Environmental DNA (eDNA) is an emerging biological monitoring tool that can aid in assessing the effects of forestry and forest manufacturing activities on biota. Monitoring taxa across broad spatial and temporal scales is necessary to ensure forest management and forest manufacturing activities meet their environmental goals of maintaining biodiversity. Our objectives are to describe potential applications of eDNA across the wood products supply chain extending from regenerating forests, harvesting, and wood transport, to manufacturing facilities, and to review the current state of the science in this context. To meet our second objective, we summarize the taxa examined with targeted (PCR, qPCR or ddPCR) or metagenomic eDNA methods (eDNA metabarcoding), evaluate how estimated species richness compares between traditional field sampling and eDNA metabarcoding approaches, and compare the geographical representation of prior eDNA studies in freshwater ecosystems to global wood baskets. Potential applications of eDNA include evaluating the effects of forestry and forest manufacturing activities on aquatic biota, delineating fish-bearing versus non fish-bearing reaches, evaluating effectiveness of constructed road crossings for freshwater organism passage, and determining the presence of at-risk species. Studies using targeted eDNA approaches focused on fish, amphibians, and invertebrates, while metagenomic studies focused on fish, invertebrates, and microorganisms. Rare, threatened, or endangered species received the least attention in targeted eDNA research, but are arguably of greatest interest to sustainable forestry and forest manufacturing that seek to preserve freshwater biodiversity. Ultimately, using eDNA methods will enable forestry and forest manufacturing managers to have data-driven prioritization for conservation actions for all freshwater species. Graphical abstract Unlabelled Image Highlights • eDNA can evaluate management effects on biota or delineate fish-bearing streams. • eDNA can monitor wastewater treatment performance and evaluate effluent effects. • Fish and invertebrates are well-represented by targeted and metagenomic eDNA studies. • Sensitive species are least studied with eDNA, but are important to forestry. [ABSTRACT FROM AUTHOR]

Abstract Indian pulp and paper industry is one of the fastest emerging business sector of the country which has shown tremendous growth in last few years. Governments policies are creating sustain pressure on paper industries to preserve the clean and pollution free environment at any price. As a result industries are pondering to replace the chemical bleaching processes with facile bio-based cost effective technologies. Eco-friendly bleaching enzymes like xylanases and laccases have the potential for biobleaching of wood and agro-based pulps at industrial scale. In India, enzymatic prebleaching of pulp is widely being investigated and has achieved favorable outcomes but at laboratory scales only and commercial application of enzymes for the delignification of pulp is still at budding stage. This article tends to draw the attention on significant efforts which have been continually attributed by indigenous research laboratories and industries to replace the chemical bleaching with enzymes. [ABSTRACT FROM AUTHOR]

The study aims to explore the beneficial use of fly ash and its effectiveness as low cost adsorbent for wastewater treatment of Pulp and paper industry. A comparative study was also carried out for the better colour reduction of industrial effluent using fly ash and commercial activated carbon. Batch mode adsorption experiments were carried out to optimize the different experimental conditions like adsorbent dose, contact time, rotation per minute (RPM) and pH. The treatment showed that the removal efficiency of colour increased to 86% with the increase in adsorbent dose (0.5 - 10 g), time (30-240 min), RPM (50 - 150) and pH (4-12) of pulp and paper industry wastewater. The removal efficiency of activated carbon was found to be 100% using 1 g adsorbent dose of commercial grade activated carbon. The Scan Electron Microscope (SEM) results of the fly ash showed that the particles looked like somewhat spherical large particles. It was concluded that though the activated carbon was very efficient adsorbent in comparison to fly ash, the better solution for disposal of solid waste such as fly ash can be good a substitute as the adsorbent for the colour reduction of the paper mill wastewater. [ABSTRACT FROM AUTHOR]

Abstract Although paper production demonstrates high energy and water sensitivity in their life cycles, only a few systematic analyses have focused on these issues. Therefore, an energy and carbon coupled water footprint analysis of five types of Kraft wood pulp-based paper (i.e., specialty-, art-, household-, light coated-, and tissue paper) is conducted in this study to help improve the environmental performance of the paper industry. All investigations are conducted with an impact-oriented approach based on ISO standards. Results show that elemental-chlorine-free bleaching is more environmentally friendly than chlorination-alkaline extraction-hypochlorite bleaching, specifically for global warming, aquatic eutrophication, and human health (i.e., carcinogens and non-carcinogens). Gray water footprint along whole life cycles of each product is approximately twice of blue water footprint. Direct processes contribute approximately 50% to water scarcity, while their impact on aquatic eutrophication ranges from 0.002% to 50.72%. For other midpoints, indirect processes dominate the influences. Meanwhile, COD, BOD 5 , CO 2 , TP, Cr (Ⅵ), Ti, Hg, and As are key contributors. Finally, reusing sludge by direct burning in the recovery furnace, reclaiming organic compounds in black liquor before alkali recycling, and integrating black liquor gasification technology are expected to provide substantial environmental benefits. Amelioration of wastewater treatment, optimization of the national energy structure, and improvement of the efficiency of chemicals and freshwater are recommended. Highlights • Energy and carbon coupled water footprint analysis of Kraft pulp paper is applied. • The environmental benefit of black liquor recovery is dominated by reused alkali. • Direct processes contribute a lot to water scarcity and aquatic eutrophication. • COD, BOD, TP, and heavy metals are key substances. • Optimizing waste reuse and availability efficiency of chemicals is recommended. [ABSTRACT FROM AUTHOR]

Melia dubia is a recently identified hardwood for papermaking. This study reports oxygen delignification of its kraft pulp. Modeling of O 2 delignification was done implementing central composite design taking temperature, time and NaOH charge as process parameters while pulp yield, kappa number, intrinsic viscosity and brightness were the process outputs. The high precision quadratic models developed for O 2 delignification revealed antagonistic, synergistic and significant interaction effects between temperature, time and NaOH charge. The optimum values of process parameters estimated were 90 °C, 90 min and 1.39% respectively which gave pulp yield 96.64%, total kappa number 10.52, intrinsic viscosity 628.54 cm 3 /g and brightness 42.52% which were very much comparable to other papermaking raw materials. On the whole, the optimization desirability obtained for O 2 delignification was 0.621. The overall O 2 delignification efficiency based on the total kappa number and the true lignin kappa number was found to be 30.33% and 38.23% respectively. The O 2 delignification practiced in this investigation led to 10.42% increase in brightness and 19.93% reduction in viscosity which would prove advantageous for subsequent elemental and total chlorine free bleaching. [ABSTRACT FROM AUTHOR]

Sewage sludge is a byproduct of wastewater treatment. When processed, this residue can also be used as adsorbent. The aim of this study was to produce adsorbents from the sewage sludge, characterize its structure and evaluate the efficiency in adsorption of lipophilic wood compounds. The sewage sludge was calcinated at seven temperatures (400-1000°C) for five hours. The morphology and texture properties of the materials were evaluated by scanning electron microscopy and nitrogen isotherms. The presence of chemical functional groups at their surface was analyzed by Fourier transformed infrared spectroscopy. Lipophilic compound adsorption rate was evaluated by gas chromatography-mass spectrometry. The results were compared with talc, an adsorbent traditionally used by the industry. The increase in temperature directly contributed to a decrease in the specific surface area. The adsorbents obtained between 600 and 700°C removed more than 60% of the lipophilic wood compounds, corresponding to 94.1% of the total amount of lipophilic compounds. These values are much higher than those presented by talc, being 2 and 11.8%, respectively. Therefore, the produced adsorbents can be studied as a new material in the removal of lipophilic wood compounds. [ABSTRACT FROM AUTHOR]

The pulp and paper industry, which provides cellulose pulp and paper, bio-based energy and chemicals, is one of the largest energy consumers, greenhouse gases (GHG) and pollutant emitters among manufacturing industries. Although the environmental impact of the pulp and paper industry has been extensively studied, life cycle assessment (LCA) results have not yet reached a consensus. By means of a systematic review and meta-analysis, this article contributes to the quantification and harmonization of the life cycle environmental impacts of pulp making and paper making systems. Based on the screening of 45 cases of paper making and 18 cases of pulp making, we found that 1 t of paper results in about 950 kg carbon dioxide (CO 2 ) equivalent (CO 2 -eq) GHG emissions on average. However, there are distinct differences between countries and pulp and paper categories. The dominant factor influencing GHG emissions is energy use. In paper making, the pulp making process is responsible for 62% of energy use, 45% of GHG emissions, 48% of acidification potential, and 49% of eutrophication potential. The kg CO 2 -eq emissions of three different types of pulp were as follows: Kraft, 508 kg CO 2 -eq/t; chemi-mechanical, 513 kg CO 2 -eq/t; and recycled pulp, 408 kg CO 2 -eq/t. Excluding emissions from electricity and steam production, the convergence of carbon emissions is observed within the same categories of pulp. Straw-based pulp caused far more environmental impact than any other type because of the intensive inputs in agricultural activities as well as in the pulp making process. This research highlighted the inconsistencies in functional units, system boundaries, and methodologies and carbon neutrality assumptions in different LCA studies of pulp and paper making. Future studies should focus on the environmental impact of straw-based pulp making, system boundary unification, and calculation of biogenic carbon emissions. [ABSTRACT FROM AUTHOR]

In this paper, the thermodynamic and economic efficiency of three different heat supply processes are compared, based on exergy flows and costs of heat. A gas turbine process with a heat recovery boiler, a gas and steam turbine combined cycle process and a high temperature heat pump system recovering waste heat are analysed. The aim is to provide heat as 4 bar(abs) saturated steam. The economic analysis bases on the comparison of the consumption-related costs of heat, the capital-related costs of heat, and the operation-related costs of heat. The results show that the heat pump system has higher exergetic efficiency than the gas turbine or the gas turbine combined cycle process. For the consumption related costs, the economic calculation shows that the operation of a heat pump, working with a coefficient of performance of four and for a natural gas price of 25 €/MWh, is the cheapest way of heat production as long as the electricity price is lower than 45 €/MWh. For the period from January 2013 until June 2016 the total costs of heat, based on real gas and electricity prices from the European Energy Exchange, are calculated and analysed. The results show that the share of heat provided by the heat pump system varies between 45% and 76%. Especially in 2013 and 2014, the economic conditions for operating heat pumps were very good. Since October 2015 the natural gas prices have seen a decrease which favours industrial heat supply with combined heat and power systems. [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.)

Background: Biochars are the new generation of sustainable soil amendments which may be applied both to fertilize and remediate the impacted soils. The aim of current research has been synthesis and characterization of pulp and paper-derived biochars and determination of their mechanisms in simultaneous immobilization of heavy metals (Cu2+, Pb2+, and Zn2+) within contaminated soil. In a novel attempt, three different solid wastes of Mazandaran Wood and Paper Industries (barks and effluent sludge) were utilized to produce biochars. Methods: The thermogravimetric behavior of the three selected biomasses were initially analyzed and the proper pyrolysis condition has been determined, accordingly. Alterations in surface active groups, before and after the pyrolysis process, have been detected by Fourier transform infrared (FTIR) spectroscopy. Elemental analysis and acid digestion procedure have been employed to measure C, H, N, S, O, and P contents of the biochars. Moreover, porosity and morphological characteristics have been monitored by Brauner-Emmet-Teller (BET) porosimetry and scanning electron microscopy (SEM). Batch adsorption tests have been designed and carried out. Finally, a set of soil sequential extraction experiments was performed over both amended/unamended soils which together with a post-sorption FTIR analysis, explained the possible competitive immobilization mechanism. Results: Porosimetry study indicated the nanoporosity of the chars and the distribution pattern of adsorbed metals over the char samples. Batch sorption tests suggested remarkable uptake capacity for each char. The results of post sorption tests suggested that Cu is mainly involved in organic bonds of -NH2, -OH and -COOH groups, Pb forms insoluble hydroxide, phosphate or carbonate precipitates, and Zn is mostly engaged in the residual fraction. Conclusions: Accordingly, the bulky wastes are confirmed to have the potential to form sustainable biochar soil amendments. [ABSTRACT FROM AUTHOR]

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Waste from the global paper life cycle can be a lost economic opportunity and a risk to the natural environment and human health. This study assesses the recovery potential of major waste flows in the global paper life cycle to support improvements in material use. The “recovery potential” indicator shows the technical possibility for extracting value from waste through recycling and other forms of recovery. The potential is identified through a review of recovery technologies that are currently applied or likely to be commercially available by the year 2050. The analysis compares current material use in the global paper life cycle with an ideal scenario in which the recovery potential of all major waste flows is fulfilled. In the ideal scenario, the Recycled Input Ratio (RIR) is increased from 38% to 67%–73% and the landfill intensity is reduced from 331–473 kg/t paper to 0–2.6 kg/t paper. The reduction in required landfill space is achieved mainly through increased consumer waste recycling. Better management of industrial waste from the paper sector has a rather limited impact on the RIR and landfill intensity. The conditions for successful recovery of waste are discussed separately. The analysis shows that the recovery potential indicator can be usefully applied to estimate potential improvements in complex material systems and the findings may inform policies for resource efficiency and the circular economy. [ABSTRACT FROM AUTHOR]

The activated sludge process within the pulp and paper industry is generally run to minimize the production of waste activated sludge (WAS), leading to high electricity costs from aeration and relatively large basin volumes. In this study, a pilot-scale activated sludge process was run to evaluate the concept of treating the wastewater at high rate with a low sludge age. Two 150 L containers were used, one for aeration and one for sedimentation and sludge return. The hydraulic retention time was decreased from 24 hours to 7 hours, and the sludge age was lowered from 12 days to 2-4 days. The methane potential of the WAS was evaluated using batch tests, as well as continuous anaerobic digestion (AD) in 4 L reactors in mesophilic and thermophilic conditions. Wastewater treatment capacity was increased almost four-fold at maintained degradation efficiency. The lower sludge age greatly improved the methane potential of the WAS in batch tests, reaching 170 NmL CH4/g VS at a sludge age of 2 days. In addition, the continuous AD showed a higher methane production at thermophilic conditions. Thus, the combination of high-rate wastewater treatment and AD of WAS is a promising option for the pulp and paper industry. [ABSTRACT FROM AUTHOR]

Energy efficient cultivation is the major bottleneck for microalgal biomass production on a large scale and considered very difficult to attain at northern latitudes. In this study an unconventional method for industrial microalgae cultivation for bio-oil production using pulp and paper mill waste resources while harvesting only once a year was performed, mainly in order to investigate the energy efficiency of the process. Algae were cultivated for three months in 2014 in covered pond systems with access to flue gas and waste heat from the industry, and the biomass was recovered as thick sediment sludge after dewatering. The cultivation systems, designed to manage the waste resources, reached a promising photosynthetic efficiency of at most 1.1%, a net energy ratio (NER) of 0.25, and a projected year-round energy biomass yield per area 5.2 times higher than corresponding rapeseed production at the location. Thus, microalgae cultivation was, for the first time, proven energy efficient in a cold continental climate. Energy-rich indigenous communities quickly out-competed the oleaginous monocultures used for inoculation. The recovered biomass had higher heating values of 20–23 MJ kg − 1 and contained 14–19% oil dominated by C16 followed by C18 fatty acids. The cultivation season at 59°15′N, 14°18′E was projected to be efficient for 10 months and waste heat drying of the biomass is suggested for two winter months. The technique is proposed for carbon sequestering and energy storage in the form of microalgal sludge or dry matter for later conversion into biochemicals. [ABSTRACT FROM AUTHOR]