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Annsofi Jonsson - One of the best experts on this subject based on the ideXlab platform.
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On-Site Recovery of Hemicelluloses from Thermomechanical Pulp Mill Process Water by Microfiltration and Ultrafiltration
Journal of Wood Chemistry and Technology, 2019Co-Authors: Johan Thuvander, Frank Lipnizki, Annsofi JonssonAbstract:During mechanical defibration of wood, a minor fraction of the wood mass is dissolved in the process water. These dissolved substances represent an extra energy demand when they are treated in the mill’s wastewater treatment plant. Galactoglucomannan, the main hemicellulose in spruce, can be recovered from Thermomechanical Pulp mill process water by a process based on microfiltration (MF) and ultrafiltration (UF). The purpose of this work was to study the scale-up of the process from laboratory scale to continuous industrial scale. MF was first studied in the laboratory, and then combined with UF in a continuous pilot process on-site at a Pulp mill. The data obtained were used to estimate the cost of the membrane processes for galactoglucomannan recovery which was found to be about €1160 per ton hemicelluloses.
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Characterization of Irreversible Fouling after Ultrafiltration of Thermomechanical Pulp Mill Process Water
Journal of Wood Chemistry and Technology, 2018Co-Authors: Johan Thuvander, Agata Zarebska, Claus Hélix-nielsen, Annsofi JonssonAbstract:Large volumes of wastewater with dissolved wood components are treated in wastewater treatment plants at Thermomechanical Pulp mills. It has been shown previously that hemicelluloses in these wastewater streams can be recovered by membrane filtration. A serious obstacle when treating lignocellulose process streams is fouling of the membranes. Fouling not only increases operating costs but also reduces the operating time of the membrane plant. When optimizing the membrane cleaning method, it is important to know which compounds cause the fouling. In this work fouling of an ultrafiltration membrane was studied. The fouling propensity of untreated process water and microfiltrated process water was compared. Fouled membranes were analyzed using scanning electron microscopy and attenuated total reflection Fourier transform infrared spectrometry. Acid hydrolysis of membranes exposed to untreated process water and microfiltration permeate revealed that 508 mg/m2 and 37 mg/m2 of polysaccharides, respectively, rem...
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Characterization of hemicelluloses in process streams in Thermomechanical and chemi-Thermomechanical Pulp mills
Journal of Wood Chemistry and Technology, 2017Co-Authors: Tobias Persson, Annsofi JonssonAbstract:Increased interest in hemicelluloses as a renewable source of biopolymers has resulted in an interest in hemicelluloses in process streams in Pulp mills. The aim of this study was to compare potential positions for the withdrawal of hemicelluloses from mechanical Pulp mills. Samples were withdrawn at a total of fourteen positions from two Thermomechanical and two chemi-Thermomechanical Pulp mills. The molecular mass distributions of hemicelluloses and lignin were determined by size-exclusion chromatography. Hemicelluloses showed peaks in the molecular mass interval of 0.2–2 kDa and 4–60 kDa, whereas lignin showed peaks in the range of 0.5–4 kDa, but no peak in the high-molecular-mass region. Glucomannan accounts for approximately two-thirds of the hemicellulose content of softwood, and mannan and glucan were thus the dominating saccharides in all samples. Mannan was preferentially found in fractions with a molecular mass ranging from 4 to 22 kDa.
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Enzymatic treatment of hemicelluloses and lignin isolated from Thermomechanical Pulp mill process water
Chemical Engineering Journal, 2016Co-Authors: Johan Thuvander, Petri Oinonen, Annsofi JonssonAbstract:Hemicelluloses dissolved in Thermomechanical Pulp (TMP) mill process streams can be used to manufacture high-value-added products. The molecular mass of the dissolved hemicelluloses is about 10 kDa. In some applications, it would be beneficial with larger molecules. It was therefore investigated whether it is possible to increase the size of hemicelluloses isolated by microfiltration and ultrafiltration from TMP process water using enzymatic treatment with laccase. No significant increase of the size of hemicelluloses was achieved, probably due to only a small percentage of lignin carbohydrate complexes in the process water. The molecular mass of lignin increased however markedly from a peak molecular mass of 1 kDa to about 60 kDa. Diafiltration was used to purify large molecules after the enzymatic treatment. Low-molecular-mass sugar and lignin molecules in the diafiltration permeate were concentrated by nanofiltration. The retention of sugars and lignin was about 98% during nanofiltration to a volume reduction of 80%. Average flux during nanofiltration was 49 l/m2 h.
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separation of dispersed substances and galactoglucomannan in Thermomechanical Pulp process water by microfiltration
Separation and Purification Technology, 2011Co-Authors: Holger Krawczyk, Annsofi JonssonAbstract:Several valuable substances are released from wood during the production of Thermomechanical Pulp. These substances can be isolated and purified for use as value-added chemicals. The hemicellulose galactoglucomannan (GGM) has attracted a great deal of interest because of its possible applications as an oxygen barrier film in packaging materials, as a hydrogel in biomedical products and as an emulsion stabilizer in food and feed. In order to exploit GGM in Pulp mill process water, it must be recovered at a high concentration and high purity. The first step in the purification process is the separation of GGM and dispersed substances. In this work, the influence of membrane pore size, cross-flow velocity and backpulsing on membrane performance during the microfiltration of Thermomechanical Pulp process water was investigated. The flux of 0.4 and 0.8 μm membranes was lower than the flux of a 0.2 μm membrane, and it was not possible to recover the pure water flux of the 0.4 and 0.8 μm membranes. Increased cross-flow velocity and backpulsing had a positive effect on the flux, but only a minor influence on the retention. The mean molecular mass of GGM in the process water was 9 kg/mol. The retention was therefore expected to be 50%, irrespective of the operating conditions.
Kimberly E. Kurtis - One of the best experts on this subject based on the ideXlab platform.
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Influence of Thermomechanical Pulp Fiber Compositions on Internal Curing of Cementitious Materials
Journal of Materials in Civil Engineering, 2012Co-Authors: Andrea Mezencevova, Victor Y. Garas, Hiroki Nanko, Kimberly E. KurtisAbstract:AbstractThis research examines the efficiency of Thermomechanical Pulp (TMP) fibers, both untreated and after chemical treatment to produce holocellulose and α-cellulose, for internal curing. In addition, the effect of TMP fibers on early hydration behavior was investigated. The results show that TMP and α-cellulose fibers had a negligible effect on cement hydration. Holocellulose, conversely, significantly reduced the rate of hydration, noticeably delaying setting time. The addition of the fibers in dosages to provide an additional amount of entrained water of 0.05 g per gram of cement resulted in a decrease of early autogenous shrinkage of cement paste. Holocellulose, reducing autogenous shrinkage of cement paste by 93%, was shown to be the most effective for internal curing; however, its adverse effect on cement hydration may require acceleratory admixtures when used in concrete. Thermomechanical Pulp and α-cellulose showed a similar efficiency in mitigating autogenous shrinkage; these fibers reduced s...
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durability of Thermomechanical Pulp fiber cement composites to wet dry cycling
Cement and Concrete Research, 2005Co-Authors: B J Mohr, H Nanko, Kimberly E. KurtisAbstract:Previous research efforts on Pulp fiber-cement composites have largely concentrated on kraft Pulp fiber composites. In this research program, Thermomechanical Pulp (TMP) fibers were investigated as an economical alternative to kraft Pulp fibers as reinforcement in fiber-cement composites. Prior to wet/dry cycling, TMP composites exhibited increased first crack strength, but lower peak strength and lower post-cracking toughness, as compared to unbleached and bleached kraft Pulp composites at equivalent fiber volume fractions. It is believed that this behavior can be attributed to the lower tensile strength and shorter fiber length of TMP fibers as compared to kraft fibers. After 25 wet/dry cycles, TMP composites showed losses in first crack (peak) strength and post-cracking toughness. However, TMP composites exhibited a slower progression of degradation during wet/dry cycling than composites containing bleached or unbleached kraft fibers.
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Durability of Thermomechanical Pulp fiber-cement composites to wet/dry cycling
Cement and Concrete Research, 2005Co-Authors: B J Mohr, H Nanko, Kimberly E. KurtisAbstract:Previous research efforts on Pulp fiber-cement composites have largely concentrated on kraft Pulp fiber composites. In this research program, Thermomechanical Pulp (TMP) fibers were investigated as an economical alternative to kraft Pulp fibers as reinforcement in fiber-cement composites. Prior to wet/dry cycling, TMP composites exhibited increased first crack strength, but lower peak strength and lower post-cracking toughness, as compared to unbleached and bleached kraft Pulp composites at equivalent fiber volume fractions. It is believed that this behavior can be attributed to the lower tensile strength and shorter fiber length of TMP fibers as compared to kraft fibers. After 25 wet/dry cycles, TMP composites showed losses in first crack (peak) strength and post-cracking toughness. However, TMP composites exhibited a slower progression of degradation during wet/dry cycling than composites containing bleached or unbleached kraft fibers.
R H Voss - One of the best experts on this subject based on the ideXlab platform.
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source and identity of compounds in a Thermomechanical Pulp mill effluent inducing hepatic mixed function oxygenase activity in fish
Environmental Toxicology and Chemistry, 1997Co-Authors: Pierre H Martel, Tibor G Kovacs, Brian I Oconnor, R H VossAbstract:The source and identity of two mixed-function oxygenase (MFO)-inducing substances present in the primary-treated effluent of a Thermomechanical Pulp (TMP) mill producing newsprint was determined. The source was pinpointed by exposing rainbow trout (Oncorhynchus mykiss) to various process effluents sampled throughout the mill. Exposure concentrations were based on the flow of these process streams in relation to the final effluent flow. Contaminated TMP steam condensates were identified as the major process source of MFO-inducing substances. Using conventional extraction and fractionation procedures, an MFO-inducing fraction was isolated. The major gas chromatographic peaks in this fraction were identified by gas chromatography/mass spectrometry as juvabione, dehydrojuvabione, and manool, all naturally occurring extractives in balsam fix (Abies balsamea). These substances were extracted and isolated from balsam fir and TMP condensates. Trout exposed to juvabione and dehydrojuvabione responded by exhibiting significant hepatic MFO inductions. No MFO induction was observed for manool. Secondary treatment in an activated sludge system effectively eliminated the MFO-inducing potential of the combined mill effluent consistent with a corresponding 90% reduction of both juvabione and dehydrojuvabione.
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effects of a secondary treated Thermomechanical Pulp mill effluent on aquatic organisms as assessed by short and long term laboratory tests
Journal of Toxicology and Environmental Health, 1995Co-Authors: T G Kovacs, J S Gibbons, Pierre Martel, B I Oconnor, R H VossAbstract:The chronic effects of secondary‐treated effluent from a Thermomechanical Pulp (TMP) mill were assessed by means of long‐term and short‐term laboratory toxicity tests. The effluent used for the tests was sampled at a western Canadian mill using mostly softwoods and <10% recycled fiber as furnish. In the long‐term test, the effects of the effluent on the life cycle of fathead minnows (Pimephales promelas.) were studied. In this experiment, which began with the egg stage and continued through to sexual maturity and reproduction, the fish were exposed in the laboratory to well water (control) and five concentrations (1.25%, 2.5%, 5%, 10%, or 20%) of effluent for 202 d. None of the effluent concentrations significantly affected the hatching of the eggs, the mortality, weight, length, gonad size, gender balance, and reproduction of the hatched fish, the prevalence of gross morphological and histopathological changes, and the hatchability of the first generation eggs. Two short‐term tests, each lasting 7 d, wer...
Tobias Persson - One of the best experts on this subject based on the ideXlab platform.
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Characterization of hemicelluloses in process streams in Thermomechanical and chemi-Thermomechanical Pulp mills
Journal of Wood Chemistry and Technology, 2017Co-Authors: Tobias Persson, Annsofi JonssonAbstract:Increased interest in hemicelluloses as a renewable source of biopolymers has resulted in an interest in hemicelluloses in process streams in Pulp mills. The aim of this study was to compare potential positions for the withdrawal of hemicelluloses from mechanical Pulp mills. Samples were withdrawn at a total of fourteen positions from two Thermomechanical and two chemi-Thermomechanical Pulp mills. The molecular mass distributions of hemicelluloses and lignin were determined by size-exclusion chromatography. Hemicelluloses showed peaks in the molecular mass interval of 0.2–2 kDa and 4–60 kDa, whereas lignin showed peaks in the range of 0.5–4 kDa, but no peak in the high-molecular-mass region. Glucomannan accounts for approximately two-thirds of the hemicellulose content of softwood, and mannan and glucan were thus the dominating saccharides in all samples. Mannan was preferentially found in fractions with a molecular mass ranging from 4 to 22 kDa.
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isolation of hemicelluloses by ultrafiltration of Thermomechanical Pulp mill process water influence of operating conditions
Chemical Engineering Research & Design, 2010Co-Authors: Tobias Persson, Annsofi JonssonAbstract:Hemicelluloses could be used to replace fossil-based materials in several high-value-added products. Today, vast amounts of hemicelluloses are discharged from Pulp mills all over the world as waste, but these could be isolated by membrane filtration, and utilized in various applications. In this study, the hemicellulose galactoglucomannan was isolated from process water from a Thermomechanical Pulp mill using ultrafiltration. The retention of hemicelluloses and lignin, and the flux and fouling of three ultrafiltration membranes (ETNA01, ETNA10 and UFX5) were studied at various operating conditions. One of the membranes (UFX5) was found to have a high hemicellulose retention (above 90%) independent of flux and pressure. With the ETNA01 membrane it was impossible to combine a high flux with high hemicellulose retention, while with the ETNA10 membrane the hemicellulose retention could be increased above 90% by running at transmembrane pressures above the critical flux. The UFX5 membrane could be used at the temperature of the process water in the Pulp mill (75-85 degrees C), while the ETNA10 membrane could only withstand temperatures below 60 degrees C, increasing the cost due to the need to cool the process water. However, the susceptibility of UFX5 to fouling was much greater than for ETNA10, which would increase the cleaning cost of the UFX5 membrane. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. (Less)
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isolation of hemicelluloses by ultrafiltration of Thermomechanical Pulp mill process water influence of operating conditions
Chemical Engineering Research & Design, 2010Co-Authors: Tobias Persson, Annsofi JonssonAbstract:Hemicelluloses could be used to replace fossil-based materials in several high-value-added products. Today, vast amounts of hemicelluloses are discharged from Pulp mills all over the world as waste, but these could be isolated by membrane filtration, and utilized in various applications. In this study, the hemicellulose galactoglucomannan was isolated from process water from a Thermomechanical Pulp mill using ultrafiltration. The retention of hemicelluloses and lignin, and the flux and fouling of three ultrafiltration membranes (ETNA01, ETNA10 and UFX5) were studied at various operating conditions. One of the membranes (UFX5) was found to have a high hemicellulose retention (above 90%) independent of flux and pressure. With the ETNA01 membrane it was impossible to combine a high flux with high hemicellulose retention, while with the ETNA10 membrane the hemicellulose retention could be increased above 90% by running at transmembrane pressures above the critical flux. The UFX5 membrane could be used at the temperature of the process water in the Pulp mill (75-85 degrees C), while the ETNA10 membrane could only withstand temperatures below 60 degrees C, increasing the cost due to the need to cool the process water. However, the susceptibility of UFX5 to fouling was much greater than for ETNA10, which would increase the cleaning cost of the UFX5 membrane. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. (Less)
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Fractionation of process water in Thermomechanical Pulp mills.
Bioresource Technology, 2010Co-Authors: Tobias Persson, Holger Krawczyk, Anna-karin Nordin, Annsofi JonssonAbstract:In this work process water from a Thermomechanical Pulp mill was divided into five fractions by filtration and membrane filtration. Suspended matter was mainly isolated in the retentate from the drum filter, extractives in the microfiltration retentate, hemicelluloses in the ultrafiltration retentate and lignin in the nanofiltration retentate. The final water fraction was of fresh water quality. For each tonne of Pulp produced, about 10kg of suspended matter, more than 0.3kg of extractives, 11kg of hemicelluloses and 8kg of aromatic compounds (lignin) could be recovered from the drum filtration retentate, the microfiltration retentate, the ultrafiltration retentate and the nanofiltration retentate, respectively. About 40% of the treated process water could be recovered as fresh water.
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Purification of process water in a Thermomechanical Pulp mill by nanofiltration
2009Co-Authors: Tobias Persson, Jun-li Ren, Annsofi JonssonAbstract:Process water from a Swedish Thermomechanical Pulp mill was purified by consecutive treatment by microfiltration, ultrafiltration and nanofiltration. In the present study the nanofiltration step was studied. The flux and retention of four nanofiltration membranes were compared. The NF99HF membrane (Alfa Laval, Lund, Sweden), had significantly higher flux and higher retention of lignin and charged compounds (measured as conductivity) compared to the others. The flux was 220 l/m2 h and the retention of calcium ions was 99% at 20 bar transmembrane pressure and a temperature of 50°C. At the same conditions, the conductivity (measured at 20°C) was decreased from 1 500 µS/cm in the feed solution to 150 µS/cm in the nanofiltration permeate.
M. Courbalay - One of the best experts on this subject based on the ideXlab platform.
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recovery of lignin and lignans enriched fractions from Thermomechanical Pulp mill process water through membrane separation technology pilot plant study and techno economic assessment
Journal of Cleaner Production, 2020Co-Authors: Maud Villaingambier, M. Courbalay, A. Klem, Stéphane Dumarçay, Dominique TrébouetAbstract:Abstract Membrane process is a viable option for valuable compounds such as lignin and lignans recovery in aqueous discharges of Thermomechanical Pulp industries. Recovery of lignin and lignans with continuous mode ultrafiltration/nanofiltration installation has not been studied in detail previously. After flotation used to remove lipophilic matter of Pulp mill effluent, the three steps membrane process was composed of a clarification step by a 150 kDa ultrafiltration used to remove suspended matter, followed by two nanofiltrations of 1 kDa and 300 Da to respectively retain lignin and lignans. A techno-economic evaluation of this process has been performed. The process with a plant capacity of 60 m3 h−1 was able to produce 12 tons of lignin and 825 kg of lignans per month. The influence of plant capacity between 0.1 and 60 m3 h−1 on extracts production cost allows determining a production cost equal or below 10 €.kg−1 as plant capacity reached 10 m3 h−1. Valorization of lignin and lignans as parts of the formulas of high added value products could allow Thermomechanical plants to head towards biorefinery and cleaner production concepts. Furthemore, the 300 Da permeate possessed the required characteristics to be re used and save fresh water utilization.
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Recovery of lignin and lignans enriched fractions from Thermomechanical Pulp mill process water through membrane separation technology: Pilot-plant study and techno-economic assessment
Journal of Cleaner Production, 2020Co-Authors: M. Villain-gambier, M. Courbalay, A. Klem, S. Dumarçay, D. TrebouetAbstract:Membrane process is a viable option for valuable compounds such as lignin and lignans recovery in aqueous discharges of Thermomechanical Pulp industries. Recovery of lignin and lignans with continuous mode ultrafiltration/nanofiltration installation has not been studied in detail previously. After flotation used to remove lipophilic matter of Pulp mill effluent, the three steps membrane process was composed of a clarification step by a 150 kDa ultrafiltration used to remove suspended matter, followed by two nanofiltrations of 1 kDa and 300 Da to respectively retain lignin and lignans. A techno-economic evaluation of this process has been performed. The process with a plant capacity of 60 m(3) h(-1) was able to produce 12 tons of lignin and 825 kg of lignans per month. The influence of plant capacity between 0.1 and 60 m(3) h(-1) on extracts production cost allows determining a production cost equal or below 10 V.kg(-1) as plant capacity reached 10 m(3) h(-1). Valorization of lignin and lignans as parts of the formulas of high added value products could allow Thermomechanical plants to head towards biorefinery and cleaner production concepts. Furthemore, the 300 Da permeate possessed the required characteristics to be re used and save fresh water utilization. (C) 2019 Elsevier Ltd. All rights reserved.
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Fractionation of polyphenols from Thermomechanical Pulp mill process water by flotation and membrane integrated process
Environmental Technology, 2019Co-Authors: M. Courbalay, Maud Villain-gambier, A. Klem, Stéphane Dumarçay, Dominique TrébouetAbstract:Fractionation of phenolic compounds in Thermomechanical Pulp mills was performed with a coupling of a prior treatment realized by flotation and a ceramic membrane process. Two lines of membranes filtration were tested. After a common 150 kDa clarification, 1 kDa filtration was performed with or without previous 5 kDa filtration. Flotation was shown to be inevitable to retain lipophilic compounds which cause severe membrane fouling. 150 kDa permeate flux was 20% higher when process water was firstly floated and was around 260 L h−1 m−2. 1 kDa membrane was fouled with 31% of irreversible fouling without previous 5 kDa filtration and phenolic compounds purity reached only 26% in this 1 kDa permeate. Phenolic compounds as lignin-like substances which might be attached to hemicelluloses were recovered in 5 kDa retentate. Retentate of 1 kDa might contain a major fraction of lignin derivatives with molecular weights around 1 kDa free or linked with phenolic acids. Permeate of 1 kDa contained 14% of phenolic compounds such as lignans and free phenolic acids purified at 50%.
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Fractionation of polyphenols from Thermomechanical Pulp mill process water by flotation and membrane integrated process.
Environmental Technology, 2018Co-Authors: M. Courbalay, Maud Villain-gambier, A. Klem, Stéphane Dumarçay, Dominique TrébouetAbstract:ABSTRACTFractionation of phenolic compounds in Thermomechanical Pulp mills was performed with a coupling of a prior treatment realized by flotation and a ceramic membrane process. Two lines of memb...