Dissertations / Theses on the topic 'Timber, Pulp and Paper'
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Saarela, J. (Juha). "Photon migration in pulp and paper." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514275845.
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Abstract
The thesis clearly demonstrates that photon migration measurements allow characterization of pulp and paper properties, especially the fines and filler content of pulp, and the basis weight, thickness and porosity of paper.
Pulp and paper are materials with a worldwide significance. Their properties strongly depend on the manufacturing process used. For efficient process control, the employed monitoring and measuring has to be fast. Therefore it is worthwhile to try to develop new approaches and techniques for such measurements. Recent advancements in optics offer new possibilities for such development.
If two samples have different optical properties their photon migration distributions are different. The measurement of a photon migration distribution allows some features between two optically slightly dissimilar samples to be distinguished. Some simple measurements, which only yielded the photons' average time of flight, were made with an oscilloscope and a time-of-flight lidar. More precise measurements yielding photon pathway distribution or some selected characteristics like light pulse rise time, broadening, or fall time were measured with a streak camera. Two methods to assess photon path length distribution were introduced: particle determination with simulation, and streak camera with deconvolution.
The basic properties for pulp are consistency and fines content and for paper the basic properties are thickness, basis weight and porosity. The influence on photon migration caused by changes in these basic properties was determined.
As pulp and paper are rarely very basic, an additional property was demonstrated for both materials. For pulp it was the content of filler talc, and for paper it was the use of beaten pulp as a raw material. These additional properties were also distinguishable.
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Marson, Andrew D. "Air flotation drying of paper pulp." Thesis, University of Manchester, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613430.
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Although much academic research has been devoted to the fields of paper drying and air impingement heat transfer, little of the resulting information is in a form usable to dryer manufacturers. The aim of this research was therefore to develop a model suitable for the designing the flotation dryers often used in the production of market pulps. The heat transfer characteristics of several commercial nozzle designs, namely flotation nozzles, slot nozzles and arrays of round orifices, were determined under conditions relevant to pulp drying. Empirical correlations for the Nusselt number for the nozzles were obtained using the property ratio method to account for the variation of the physical properties of air with temperature. The proposed correlations were shown to be in excellent agreement with the experimental results and were sufficiently accurate for use in industrial dryer design. The effect of the nozzle exit velocity and nozzle-to-surface spacing on the profile of static pressure at the impingement surface was also determined for a typical flotation nozzle design. The influence of nozzle conditions and sheet properties on the drying characteristics of papermaking pulp was determined through batch drying experiments. Over 400 experiments were performed using samples produced from four furnishes at basis weights in the range 120 g/m" to 2125 g/m2 and oven dry densities in the range 175 kg/mt to 900 kg/m'. Drying was achieved using heated air emerging from flotation nozzles at air temperatures in the range 100°C to 250°C with nozzle velocities between 15 mls and 55 mls. Temperature profiles through handsheets of both pressed and unpressed pulp were also measured during drying, which showed the presence of a quasi-constant temperature.
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Rosendal, Linnea. "Biogent kol i träbaserade produkter från svensk skogsindustri och kolets inbindningstid : En analys av potentialen att öka inbindningstiden i det årliga tillskottet av produkter." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415431.
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Nivåerna av växthusgaser i atmosfären har ökat drastiskt de senaste århundradet, till följd av mänsklig aktivitet. Det krävs en stor omställning för oss människor om klimatförändringarna ska motverkas och för att konsekvenserna för planeten inte ska bli allt för stora. Koldioxid är en av de viktigaste växthusgaserna och skogen är en viktig del i balansen av koldioxid i atmosfären genom att växter och träd binder in koldioxid och lagrar biogent kol i biomassan. Rundvirke kan användas för att producera en mängd olika produkter med olika användningsområden och varierande livslängd och det finns både globala och nationella mål som stödjer ett arbete för en minskad klimatpåverkan med skogens resurser som verktyg. Syftet med examensarbetet var att analysera inbindningen av biogent kol i det årliga tillskottet av träbaserade produkter från svensk skogsindustri, för att sedan undersöka potentialen att öka tiden för inbindning av det biogena kolet. FN:s klimatpanel (IPCC) har tagit fram en generell metod för att beräkna lagringen av kol i skördade träprodukter och beräkningarna bygger på tre produktkategorier, vilka är sågade trävaror, spånskivor och papper och kartong. Detta examensarbete har utvidgat FN:s klimatrapportering genom att studera totalt sexton produktkategorier. Flödet av biogent kol studerades genom en materialflödesanalys, som bygger på massbalans mellan ”inputs” och ”outputs” i ett system. Systemet studerades från det att råvara förbrukas till dess att produkterna går som avfall och förbränns. Statistik över råvaruförbrukning inom sågverksindustrin och massaindustrin, samt produktionsmängd av fibermassa och träbaserade produkter användes i analysen. En stor volym biomassa går dessutom direkt till förbränning och ger bioenergi. Resultatet visade att sågade trävaror från sågverksindustrin har längst medellivslängd och binder även in störst mängd biogent kol. Biobränslen har kortast medellivslängd, och koldioxid frigörs till atmosfären på mycket kortast tid. Enligt detta examensarbete innehåller träbaserade produkter från Sverige 29,0 miljoner ton koldioxid årligen. Tre strategier att förlänga inbindningstiden av biogent kol studerades, vilka är förlängd livslängd för produkter, kaskadanvändning och Bio-Energy with Carbon Capture and Storage (BECCS). Att förlänga livslängden för produkter innebär att återvinning av exempelvis cellulosabaserade textilier införs. Kaskadanvändning innebär att skogsindustrin primärt ska producera långlivade produkter och undvika att biomassa direkt går till förbränning. BECCS bygger på att träden binder in kol i sin biomassa och när en träbaserad produkt förbränns pressas frigjord koldioxid ned i marken och lagras. BECCS bedöms vara den strategi som är mest avancerad.The levels of greenhouse gases have increased drastically over the past hundred years as a result of human activity. Major actions are needed to counter climate change, if the consequences are not to be too great. Carbon dioxide is one of the most important greenhouse gases and the forest is an important part of the balance of carbon dioxide in the atmosphere, by the fact that plants and trees bind carbon dioxide and store biogenic carbon in the biomass. Roundwood can be used to produce a variety of products with different applications and varying life spans and there are both global and national goals that support a work to reduce climate change with forest resources as tools. The aim of the thesis was to analyse the storage of biogenic carbon in the annual addition of wood-based products from the Swedish forest industry, and then to investigate the potential to increase the time of storage. The UN Climate Panel (IPCC) has developed a general method for calculating the storage of carbon in harvested wood products and the calculations is based on three product categories, which are sawn wood, wood-based panels and paper and paperboard. This thesis has expanded the UN climate reporting by studying a total of sixteen product categories. The flow of carbon was studied using a material flow analysis, which is based on the mass balance of inputs and outputs in a system. The system was studied from the raw material being consumed until the products are defined as waste and incinerated. The calculations were based on statistics on raw material consumption in the sawmill industry and the pulp and paper industry, as well as production volume of fibre pulp and wood-based products. A large volume of biomass also goes directly to incineration and provides bioenergy. The binding time of biogenic carbon was analysed to explore the potential of increasing the binding time, using different strategies. Sawn timber products from the sawmill industry have the longest average life span and also bind the highest amount of biogenic carbon. Biofuels have the shortest average life span, which means that carbon dioxide is released into the atmosphere rapidly. A total of 29.0 million tonnes of carbon dioxide are stored in wood-based products annually, according to this study. Three strategies to extend the storage time of biogenic carbon were studied in this study, which were extended life span of the products, cascading wood use and so called BECCS. To extend product life means introducing recycling of, for example, cellulose-based textiles. Cascading wood use means that the forest industry primarily produce long-lived products and avoid biomass going directly to incineration. BECCS is based on the fact that trees bind carbon dioxide in their biomass and when wood-based product is incinerated, the carbon dioxide is stored in the ground. BECCS is considered to be the most advanced strategy, of the three.
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Cadete, Sonia Marisa Silva. "Enzymatic upgrading of eucalypt paper-grade kraft pulp within dissolving pulp production." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16089.
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Mestrado em Biotecnologia - Biotecnologia Industrial e AmbientalDissolving-grade pulps are commonly used for the production of cellulose derivatives and regenerated cellulose. High cellulose content, low content of non-cellulosic material, high brightness, a uniform molecular weight distribution and high cellulose reactivity are the key features that determine the quality of a dissolving pulp. The first part of this work was an optimization study regarding the application of selected enzymes in different stages of a new purification process recently developed in Novozymes for purifying an eucalypt Kraft pulp into dissolving pulp, as an alternative to the pre-hydrolysis kraft (PHK) process. In addition, a viscosity reduction was achieved by cellulase (endoglucanase) treatment in the beginning of the sequence, while the GH11 and GH10 xylanases contributed to boost the brightness of the final pulp. The second part of the work aimed at exploring different auxiliary enzyme activities together with a key xylanase towards further removal of recalcitrant hemicelluloses from a partially bleached Eucalypt Kraft pulp. The resistant fraction (ca. 6% xylan in pulp) was not hydrolysable by the different combinations of enzymes tested. Production of a dissolving pulp was successful when using a cold caustic extraction (CCE) stage in the end of the sequence O-X-DHCE-X-HCE-D-CCE. The application of enzymes improved process efficiency. The main requirements for the production of a dissolving pulp (suitable for viscose making) were fulfilled: 2,7% residual xylan, 92,4% of brightness, a viscosity within the values of a commercial dissolving pulp and increased reactivity.
Pastas solúveis são normalmente usadas para a produção de derivativos de celulose e celulose regenerada. Alguns dos parâmetros que determinam a qualidade de uma pasta solúvel são: um elevado teor de celulose, baixo teor de material nãocelulósico, elevada brancura, uma distribuição uniforme de pesos moleculares e elevada reactividade da celulose. Na primeira parte deste trabalho, fez-se um estudo de optimização aplicando enzimas, previamente seleccionadas, em diferentes fases de um novo processo de purificação desenvolvido na Novozymes da pasta de eucalipto Kraft em celulose solúvel, como uma alternativa ao processo convencional de pré-hidrólise kraft. Além da purificação, a aplicação de celulases (endoglucanase) no início da sequência possibilitou uma diminuição da viscosidade, enquanto que a aplicação de xilanases das famílias GH11 e GH10 contribuíram também para o aumento da brancura da pasta final. A segunda parte deste trabalho teve como objectivo explorar várias actividades enzimáticas auxiliares conjuntamente com a melhor GH11 xilanase identifcada, de modo a promover a remoção das hemiceluloses mais recalciterantes de uma pasta Kraft de Eucalipto parcialmente branqueada. Todas as combinações das enzimas testadas resultaram numa fracção resistente de xilana residual (ca. 6% na pasta) que não foi possível hidrolisar. A produção de uma pasta solúvel foi possível usando um estágio de extracção alkalino a frio (CCE) no fim de uma sequência composta pelos seguintes estágios: O-X-D-HCE-X-HCE-D-CCE. A aplicação de enzimas melhorou a eficiencia do processo. Com esta sequência,os principais requisitos para a produção de uma pasta solúvel (adequada para producao de viscose) foram cumpridos: 2,7% de xilana residual, 92,4% de brancura, uma viscosidade dentro dos valores de uma pasta solúvel comercial e elevada reactividade.
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Lundmark, Robert. "Paper recovery and investment behaviour in the European pulp and paper industry." Licentiate thesis, Luleå tekniska universitet, Samhällsvetenskap, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17295.
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This thesis consists of an introductory part followed by two self-contained papers both analysing the effect recovered paper has on the locational choice for investments in the European pulp and paper industry. In the first paper we develop a continuous Cobb-Douglas investment model with the purpose of finding and estimating the investment determinants for the European pulp and paper industry, with special focus on the impact of recovered paper. The analysis is carried out within a neo-classical locational framework in which firms minimise the production and transportation costs for both input factors and for output products. We use a panel of data consisting of ten European countries over the period 1978 to 1995. The results suggests that both short and long run aspects of wastepaper recovery tend not to be important determinants of investment activities in the pulp and paper industry, whereas the price of wood pulp and electricity together with existing capacity seem to be more important. In the second paper we employ a different approach to the same problem. In this paper we develop a conditional logit model and compile the number of investment projects that were scheduled to be finished in 16 European countries between 1985 and 1995. In contrast to the first paper, which used continuous data, this model employs discrete data for the dependent variable. A discrete variable counts the actual number of times a certain event has taken place, i.e., the number of investment projects. The same set of determinants as in the first paper is used to ease comparing the two papers. We further break down the investment projects into four paper grades, which allow us to analyse the effects of wastepaper in greater detail. The results suggest that factor input prices in general and the price for wastepaper in particular are neither statistically nor economically significant location determinants for a paper manufacturer. Furthermore, the results suggest that market size and agglomeration effects are more important than the price of raw materials for location. On the basis of the results from the two papers, we can conclude that the price of wastepaper is not an important determinant for the European pulp and paper industry when choosing investment sites. Price driven policies aimed at stimulating paper recovery may therefore fail to achieve increased investments in the industry. At the same time, both papers suggests that agglomeration effects, i.e., existing productive capacity, is an important determinant. The economic significance of the agglomeration coefficients suggests that the power of sunk costs is important. Investments are largely diverted to existing capacity and the ability to attract new establishments is limited.Godkänd; 2000; 20070315 (keni)
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Sivasundaram, Mathumathi. "Glass ceramics from pulp and paper waste ash." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0032/MQ64248.pdf.
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Ajersch, Michael. "Mechanisms of pulp loss in flotation deinking /." *McMaster only, 1997.
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Addison, Sarah Louise. "15N stable isotope probing of pulp and paper wastewaters." The University of Waikato, 2008. http://hdl.handle.net/10289/2399.
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Stable isotope probing (SIP) is an established technique that can be applied to identify the metabolically active micro-organisms within a microbial population. The SIP method utilises an isotopically-labelled substrate and PCR techniques to discern the members of a microbial community that incorporate the isotope into their DNA or RNA. The current literature gap around using 15N isotopes with RNA-SIP offers real potential and advantages for targeting and identifying active members from mixed communities involved in global biogeochemical nitrogen cycling. This study specifically investigated whether nitrogen based compounds can be used as substrates in RNA-SIP methodologies and whether they can in turn be used to probe mixed community environments known to be actively fixing nitrogen. The nitrogen-limited systems targeted represented an ideal opportunity to assess the suitability of 15N-RNA-SIP approaches due to their known high nitrogen fixation rates. Identifying these nitrogen-fixing bacteria could provide a better representation analysis of the community, leading to an improved prediction on how to manage and optimise the treatment performance of target waste systems and to exploit the unique bioconversion properties of these types of organisms. Initially, the project undertook methodological proof of concept by using a soluble nitrogen source, 15NH4Cl, to label the RNA of Novosphingobium nitrogenifigens and a mixed microbial community. Successful separation of the 14N- (control) and 15N-RNA was achieved for both pure and mixed communities using isopycnic caesium trifluoroacetate (CsTFA) gradients in an ultracentrifuge. The usefulness of this technique to identify active diazotrophs in real environmental samples was tested using a nitrogen-fixing community from a pulp and paper wastewater treatment system. After growing the mixed culture with 15N2 as the sole nitrogen source, the labelled RNA was extracted and fractionated using isopycnic centrifugation in CsTFA gradients. The community composition of the active nitrogen-fixing community in the 15N2 enriched fraction was analysed by establishing a 16S rRNA gene clone library containing over 200 members. These were analysed by comparison with published sequences and by phylogenetic analysis. It was found that the more isotopic label substrate incorporated, the further the buoyant density (BD) separation between 15N- and 14N-RNA. Novosphingobium nitrogenifigens gave an average BD shift of 0.03 + 0.004 g ml-1 (95.0 atom % 15N) with 15NH4Cl. For mixed communities the average BD shift was 0.02 + 0.004 g ml-1 (80.0 atom % 15N) with 15NH4Cl and 0.013 + 0.002 g ml-1 (32.6 atom % 15N) when using 15N2. Clone library analysis of 16S rRNA genes present in the enriched 15N-RNA fraction of the mixed community was shown to consist of a diverse population of bacteria as indicated by a Shannon Weaver index value of gt;2.8. Three dominant genera (Aeromonas, Pseudomonas and Bacillus) were identified by comparison with published sequences and phylogenetic analysis. Many other groups not known as archetypal nitrogen-fixing bacteria were also identified, demonstrating that 15N2-RNA-SIP provides a useful tool for the identification of important and previously unknown contributors to nitrogen fixation in a range of environments. Overall, this project has established that nitrogen based RNA-SIP is a powerful tool that can be used successfully and reproducibly with both pure and complex mixed microbial communities to study active diazotrophs in environmental samples.
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Peters, Jennifer. "The activated sludge treatment of pulp and paper wastewater." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0027/MQ50650.pdf.
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Peters, Jennifer 1973. "The activated sludge treatment of pulp and paper wastewater /." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21319.
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Biological treatment of pulp and paper wastes by activated sludge is widely practiced in industry to reduce the organic content and toxicity of the wastewater. Most industrial applications require the treatment of a combination of streams from various processes. The composition of the combined stream varies since shock loadings and spills may occur. The objective of this research was to determine the effects of these variations on the microbial community and, ultimately, on the kinetics of the reduction of biological oxygen demand (BOD) and chemical oxygen demand (COD). This will improve the understanding of control requirements for the process.Effluents from two mills in Quebec were examined. Initially, effluents from a chemithermomechanical pulp (CTMP) mill were used in this research. The objective was to study the effect of six different waste streams mixed with total mill effluent (0--100%) on the reduction of COD and on the microbial population. The remainder of this research focused on treating effluents from a Kraft mill and investigated the effect of hydraulic residence time (HRT) and step inputs of 1%, 2.5% and 5% black liquor on the reduction of COD and BOD5 and on the microbial population. (Abstract shortened by UMI.)
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Leal, Margarida. "Portucel: pulp and paper: the survival of the strongest." Master's thesis, NSBE - UNL, 2012. http://hdl.handle.net/10362/9896.
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Bhinge, Deepak. "Color removal from pulp and paper wastes by coagulation." Thesis, Virginia Tech, 1986. http://hdl.handle.net/10919/41569.
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Coagulation studies were conducted to determine an appropriate treatment approach to remove color and organic carbon from the pulp and paper wastes from the Union Camp Corporation, Franklin, Va.
Based on a preliminary analysis of the data collected during this research, either alum or ferric chloride may be used to remove color from pulp and paper wastes. An effluent with final residual color less than 5 color units can be generated using PAC treatment after flocculating certain waste streams with alum or ferric chloride. Higher molecular weight organics (above 5K mass units) showed a near complete removal by coagulation.
It is expected that alum coagulation would involve a lesser cost in pH adjustment as compared to ferric chloride coagulation. Alum sludge dewatered and thickened more rapidly than the iron sludge; however, after mechanical dewatering, the alum cake had a slightly greater moisture content than the sludge produced after ferric chloride coagulation.
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Karlsson, Hanna. "Strength Properties of Paper produced from Softwood Kraft Pulp : Pulp Mixture, Reinforcement and Sheet Stratification." Doctoral thesis, Karlstads universitet, Avdelningen för kemiteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-5612.
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For paper producers, an understanding of the development of strength properties in the paper is of uttermost importance. Strong papers are important operators both in the traditional paper industry as well as in new fields of application, such as fibre-based packaging, furniture and light-weight building material. In the work reported in this thesis, three approaches to increasing paper strength were addressed: mixing different pulps, multilayering and reinforcement with man-made fibres. In specific: The effects of mixing Swedish softwood kraft pulp with southern pine or with abaca (Musa Textilis) were investigated. Handsheets of a softwood kraft pulp with the addition of abaca fibres were made in a conventional sheet former. It was seen that the addition of abaca fibres increased the tearing resistance, fracture toughness, folding endurance and air permeance. Tensile strength, tensile stiffness and tensile energy absorption, however, decreased somewhat. Still it was possible to add up to about 60% abaca without any great loss in tensile strength. As an example, with the addition of 30% abaca, the tear index was increased by 36%, while the tensile index was decreased by 8%. To study the effect of stratification, a handsheet former for the production of stratified sheets, the LB Multilayer Handsheet Former was evaluated. The advantage of this sheet former is that it forms a stratified sheet at low consistency giving a good ply bond. It was shown to produce sheets with good formation and the uniformity, evaluated as the variation of paper properties, is retained at a fairly constant level when the number of layers in the stratified sheets is increased. The uniformity of the sheets produced in the LB Multilayer Handsheet Former is generally at the same level as of those produced in conventional sheet formers. The effects of placing southern pine and abaca in separate layers, rather than mixing them homogeneously with softwood pulp were studied. Homogeneous and stratified sheets composed of softwood and southern pine or softwood and abaca were produced in the LB Multilayer Handsheet Former. It was found that by stratifying a sheet, so that a pulp with a high tear index and a pulp with a high tensile index are placed in separate layers, it was possible to increase the tear index by approximately 25%, while the tensile index was decreased by 10-20%. Further, by mixing a pulp with less conformable fibres and no fines with a pulp with more flexible fibres and fines, a synergy in tensile strength (greater strength than that predicted by linear mass fraction additivity) was obtained. The effects of stratifying sheets composed of softwood and abaca were compared to the effects of refining the softwood pulp. Homogeneous and stratified sheets composed of softwood with three different dewatering resistances and abaca were also produced in the LB Multilayer Handsheet Former. It was found that by stratifying the sheets the tear index was retained while the tensile index was increased by the refining. The effects of reinforcing softwood pulp of different dewatering resistances with man-made fibres with low bonding ability were also investigated. Man-made fibres (i.e. regenerated cellulose, polyester and glass fibres) were added in the amounts 1, 3, or 5 wt% to softwood pulp of three different dewatering resistances. It was found that with refining of a softwood pulp and subsequent addition of long fibres with low bonding ability the tensile-tear relationship can be shifted towards higher strength values. The bonding ability of the man-made fibres was evaluated by pull-out tests and the results indicated that, in relation to the fibre strength, regenerated cellulose (lyocell) was most firmly attached to the softwood network while the glass fibres were most loosely attached.
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Ueda, Masahiro. "Sugar in paper : topochemistry and physics /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/5484.
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Nyberg, Thomas. "Process steam : Steam conditioning at a pulp and paper mill." Thesis, Karlstad University, Division for Engineering Sciences, Physics and Mathematics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-582.
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Abstract
This report is the result of an examination work at the University of Karlstad. The purpose of this project is to examine how the condition of the steam affects the efficiency of the steam consumers and how variations in that condition affect a pulp and paper mill.
This report is meant to describe the main components regarding steam production, steam conditioning and steam consumption. It should also be able to give basic information about the significance of steam conditioning in the pulp and paper industry. It is aimed to people working with steam conditioning to increase their understanding and knowledge about it.
The aim of this report is to:
• Describe the function of the most commonly used steam generators and the difference between these.
• Identify the main steam consumers and describe their function.
• Give an introduction to steam conditioning and its role at a pulp and paper mill.
This report will try to answer the following questions:
• How does the generated power from back-pressure steam turbines vary with grade of superheat of outlet steam?
• What are the advantages with steam conditioning?
• Are the steam conditioners at Gruvöns bruk able to deliver steam at the right condition?
The conclusions from this report are that;
• If the steam conditioning valves are able to reduce small steam flows to the correct temperature, more power can be produced. The design condition of the steam turbines can than be nearer saturation.
• The temperature variations are more critical at the turbine inlet than downstream the steam conditioning valves. The valves at Gruvöns bruk who are studied in this report, are fully functioning.
• Common for the main steam consumers at pulp- and paper mills are that they are all sensitive for variations of steam temperature, especially high temperature.
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Damani, Pallavi. "Vertical Integration in American Pulp and Paper Industry, 1970-2000." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4989.
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The paper and pulp industry saw an increase in the number of mergers in 1980s and 1990s. There had been consolidation of a number of smaller companies into larger corporations, which have greater management, financial, and marketing power. This merging trend has resulted in a fewer number of firms and an increasing concentration in the industry. Although the number of firms has decreased, the total industry capacity has been increasing. The combination of these interesting factors has motivated the topic of this masters thesis. The primary purpose of this research is to explore the factors that positively influence a firms decision to vertically integrate into producing its own pulp.
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Gong, Yanyan. "Pulp and paper industry emissions and non-Hodgkin's lymphoma risk." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0009/MQ52904.pdf.
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Sundblad, Sara. "Predictions of Pulp and Paper Properties Based on Fiber Morphology." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180550.
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The aim is to investigate models that predicts the potential of pulp and evaluate the relevance of the zero-span tensile index within these. Two chemical pulps made from softwood and eucalyptus were refined in a Voith-beater with different energy input in order to study the change of fiber morphology signals and other pulp and paper properties. Chemical, THP pulp from Södra Värö is also used as an initial analysis for morphological connections to Zero-span tensile index. The L&W Fiber Tester Plus is used in order to study the pulps fiber morphology and Pulmac 2000 for zero span. Handsheets are made for mechanical tests such as tensile properties, ZD-strength and optical properties. Many of the given signals change according to clear patterns with increasing refining energy. Using least square methods, formulas describing the development with high adaptation could be formulated. Many of the measured aspects changes over already known patterns. These are then applied in the models. Three possible models is tested: linear regression, Shear-Lag and Page. Of the three, only the two first ones where able to produce reliable models, whereas the third required data that was difficult to acquire at the same time as the adaptation was very low. The only model that use exclusively morphology data is linear regression.
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Barbosa, Marcos Aurélio. "Analyses of total quality system at pulp and paper manufacturing." Universidade de Taubaté, 2004. http://www.bdtd.unitau.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=73.
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The research describe the Total Quality System implementation at a pulp and paper manufacturing. The objective was evaluate the productive process management using a Total Quality Management Model, comparing the results before and after Total Quality System implementation, using the quality efficiency index and the downtimes at two process, uncoated and coated paper process. The methodology used 38 months with the results of quality efficiency index and down time to evidence the improvement
on organization with the Total Quality System implementation. The methodology previewed a sample analyses, comparing the medium results of the index, before and after the implementation and a population analyses, using the Student test. As result, the organization had improvement increasing the quality efficiency index at both process. The organization had good results reducing the down time of the machines, increasing the production of paper. The organization had better results after the implementation using a new manufacturing management system.O presente trabalho aborda a implementação do Sistema da Qualidade Total (SQT) em uma empresa do segmento celulose e papel. O objetivo foi avaliar os ganhos obtidos pelo gerenciamento do processo produtivo utilizando-se um modelo de gestão da Qualidade Total, comparando-se os resultados antes e após implementação do SQT, por meio dos indicadores Índice de Eficiência de Acabamento (IEA), tempo de horas paradas e horas quebras em dois processos, fabricação de papel não revestido e revestido. A metodologia aplicada para evidenciar as melhorias obtidas pela organização com a implementação do SQT abordou a coleta de 38 meses do indicador IEA, tempo de horas quebras e horas paradas. Foi realizada uma análise amostral comparando-se a média das amostras antes e após implementação e uma análise populacional das amostras, utilizando-se o teste t de Student, com grau de confiabilidade de 95%. Como resultado, a organização obteve ganhos significativos como aumento do Índice de Eficiência de Acabamento em ambos os processos, permitindo a empresa disponibilizar mais produtos no mercado. A organização obteve êxito na redução de horas paradas e horas quebras nos processos de papel não revestido e revestido, permitindo aumento de produção de papel. Portanto, os indicadores após implementação apresentaram resultados bastante significativos para a organização com a adoção de um novo sistema de gestão da manufatura.
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Baker, Scott Alan. "Activated sludge biotreatability of pulp and paper bleach wastes : investigation of bleaching options." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21647.
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Rudenko, Yulia. "Reglering av pumpar: En fallstudie med jämförelseanalys mellan stryp- och frekvensreglering." Thesis, Uppsala universitet, Industriell teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448335.
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Dagens behov för energieffektivisering ställer höga krav på industrisektorn som anses vara den största energikonsumenten. Holmen AB är verksam inom massa- och pappersindustrin som är en energiintensiv bransch där sådana stora energianvändare som pumpapplikationer spelar en nyckelroll i produktionen. Denna studie genomfördes för att hjälpa företaget att undersöka vilka energi- och kostnadsbesparingar som kan förväntas om det befintliga pumpreglersättet ändras. Syftet med arbetet var att ta fram en metod för uppskattning av pumpenergiförbrukning, som skulle producera ett underlag för en jämförelseanalys av energiförbrukningen vid olika reglersätt. Studien fokuseras mest på centrifugalpumpar, som dominerar i industriell miljö på grund av sin robusta konstruktion, höga effektivitet och relativt låga behov för underhåll. Men det tillvägagångssätt som har använts i studien kan användas för bedömning av olika typer av pumpar och reglersätt eftersom det byggs på de grundläggande fluidmekanikslagarna. Tidigt i arbetet identifierades de viktiga parametrar som mest påverkar energiförbrukning i centrifugalpumpar och som krävs i beräkningar. Olika reglersätt diskuterades utifrån den befintliga litteraturen och forskningen. Uppskattning av energiförbrukning och energikostnader utfördes för två olika reglersätt, strypreglering och frekvensreglering. I arbetets sista skede jämfördes resultaten för de två reglersätten för att avgöra om det finns en potential för energi- och kostnadsbesparingar vid byte från strypreglering till frekvensreglering. Studiens resultat visar att övergång till frekvensreglering kommer att medföra energibesparingar och som följd besparingar i årliga driftkostnader samt LCC-kostnader. Storleken på besparingarna beror på minskning i varvtalet. Frekvensregleringen är mest lönsam då det önskade flödet skiljer sig mycket från det nominella flödet i systemet, men eventuell försämring av motor- och pumpverkningsgrad måste tas i beaktande. En mer utförlig analys av energiförbrukning vid olika flöden och olika typer av medier rekommenderas att utföras med användning av praktiskt uppmätta effektförbrukningsvärden.Today's need for energy efficiency places high demands on the industrial sector, which is considered to be the largest energy consumer. Holmen AB is a pulp and paper producer. Pulp and paper production is an energy-intensive branch where pump applications consume large amounts of energy while playing a crucial role in the production process. This study was conducted to help the company investigate what energy and cost savings can be expected if the existing pump control method is changed. The purpose of the study was to develop an approach for estimating pump energy consumption, which would produce a basis for comparative analysis of energy consumption for different control methods. The study focuses mainly on centrifugal pumps, which dominate the industrial environment due to their robust construction, high efficiency, and relatively low maintenance needs. However, this study's approach can be used to assess different types of pumps and control modes as it is based on the fundamental fluid mechanics laws. At the beginning of the study, the key parameters that affect energy consumption in centrifugal pumps were identified to be later used in calculations. Pump control methods were discussed based on the existing literature and research. Estimation of energy consumption and costs was performed for two different control methods, throttle control, and frequency control. In the last stage of the study, two control methods were compared based on the energy consumption calculation to determine whether there is a potential for energy and cost savings when switching from throttle control to frequency control. The results show that usage of frequency control would lead to energy savings and, therefore, to savings in annual operating costs and LCC costs. The amount of the savings depends on the reduction in the rotational speed of the motor. The frequency control is most advantageous when there is a significant difference between the desired flow and the nominal flow in the system. But the potential reduction of motor and pump efficiency must be taken into consideration. A more detailed analysis of energy consumption for different flows and different types of pulp is recommended, with practically measured energy consumption values.
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Wang, Gewei. "Does market concentration motivate pulp and paper mills to vertically integrate?" Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-08242005-143103/.
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Thesis (M. S.)--Economics, Georgia Institute of Technology, 2006.Haizheng Li, Committee Chair ; Patrick McCarthy, Committee Member ; Vivek Ghosal, Committee Member. Includes bibliographical references.
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Noggle, Jessica Joy. "Eastern mosquitofish as a bioindicator of pulp and paper mill effluents." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009720.
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Thesis (Ph.D.)--University of Florida, 2005.Typescript. Title from title page of source document. Document formatted into pages; contains 277 pages. Includes Vita. Includes bibliographical references.
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Azarafshar, Elham. "The Canadian pulp and paper industry: An economic and environmental analysis." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/29192.
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This thesis looks at the Canadian Pulp and Paper Industry at both the empirical level and the theoretical level. In the first half of the thesis, the empirical aspects of the industry are studied within the framework of the trade-off between environmental protection and efficiency of the plants. In the second half, several theoretical issues related to the market structure of the pulp and paper industry are analyzed. Chapter 1 provides an overview of the Canadian Pulp and Paper Industry and the various production processes. In Chapter 2, an empirical analysis is undertaken to study the relation between technical efficiency and pollution. This analysis has far-reaching policy implications as it allows us to study empirically the effect of pollution control regulations on the performance of the firms. Chapter 3 contains a study on the international trade in market pulp, with specific focus on the trade among Canada, US, and Europe. A multi-market spatial oligopoly model is formulated, calibrated, then simulated to gain insights into the workings of these interdependent markets.
In Chapter 4, an oligopoly model for the tissue and towel market in North America is formalized then calibrated. The objective of this chapter is to obtain an adequate picture of the consumer market, in which prices, qualities, and advertising are used to entice consumers. The model contains four firms, which produce a total number of ten brands among them. The simulation of the model yields detailed results on the intricate workings of the industry and results that cannot be expected from simple text-book oligopoly models.
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Karlsson, Robin. "Anaerobic digestion of biological sludge from the pulp and paper industry." Thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-60527.
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The need for - and use of non-fossile fuels such as biogas have increased due to global warming, oil depletion and stricter environmental regulations. Organic wastes can be anaerobically digested in order to produce biogas, which can be utilized to generate heat or electricity. So far, little attention has been directed towards anaerobic digestion of organic wastes from the forest industry. Due to high sludge management costs and more rigorous environmental legislation, the demand for new and/or improved disposal methodologies has increased. Substrate treatment methods such as enzyme addition and ultrasound are of interest in order to make anaerobic digestion of organic wastes, e.g. biological sludge, economically feasible. The aim of this study is to evaluate if biological sludge from the pulp and paper industry can be used for methane production in anaerobic digestion and to investigate the effects of ultrasound pre-treatment and enzyme treatment. The aim of the study was accomplished by performing four batch experiments, during 67-110 days, and a six months laboratory-scale semi-continuous digestion experiment. Substrates were provided by a chemical and a mechanical paper mill, whereas Kemzymes® from Kemira and ultrasound equipment from Ultra Sonus were used for sludge treatment. The short term average accumulation of methane per added g VS rate increased both when ultrasound pre-treatment and enzyme treatment was applied in batch experiments. The enzyme treatment was considered to have a greater potential in larger scale and was consequently used in the semi-continuous digestion experiment. Positive effects of the treatment were however difficult to prove. Adapting the enzyme treatment to be more specific for the degradation of the sludge is recommended. It is possible that there are inhibitory interactions between ultrasound pre-treatment and enzyme treatment. 75% ultrasound pre-treatment is an alternative to complete pre-treatment and renders equivalent average accumulation of methane per added g VS. Storage of ultrasound pre-treated biological sludge at 4°C for six and 13 days does not affect the average accumulation of methane per added g VS. Enzyme treatment of biological sludge enhanced the average accumulation of methane per added g VS from indigenous material in the inoculum. It is likely that anaerobic digestion of biological sludge from the pulp and paper industry can render a stable biogas production. High viscosity and agitation problems were predominant in the semi-continuous digestion experiment and can be difficult to control in larger scale. The results from the semi-continuous digestion experiment are similar with those obtained from the batch experiments. The methane production rates in this study are lower (biological sludge from chemical pulp process) or higher (mechanical ditto) in comparison to those presented data by Puhakka et al. (1992). Different types of biological sludge were used and might explain the prevailing differences.
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Zheng, Jing. "Application of GAC adsorption in pulp and paper mill effluent treatment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0019/MQ58522.pdf.
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Esty, Jessica Marie Lange Clifford R. "The effects of sulfide on pulp and paper wastewater color reversion." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/ESTY_JESSICA_37.pdf.
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CUNHA, FABIOLA OLIVEIRA DA. "STUDY OF PRADO REGION KAOLIN PULP RHEOLOGY FOR THE PAPER INDUSTRY." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5926@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORCENTRO DE TECNOLOGIA MINERAL
Polpas concentradas de caulim (70 por cento em peso de sólidos) são utilizadas na Indústria de Papel como cobertura. Durante a aplicação da polpa são alcançadas altas taxas de cisalhamento que, associadas às altas viscosidades de polpas concentradas, provocam dificuldades no movimento da lâmina acarretando riscos, bolhas ou até mesmo rasgando o papel. Para minimizar esse efeito, são adicionados agentes dispersantes que causam a redução nos valores da viscosidade. O presente trabalho teve por finalidade caracterizar fisicamente as amostras beneficiadas do caulim da região do Prado/BA e, utilizando-se da Teoria DLVO Clássica, contribuir para uma melhor compreensão sobre os aspectos fundamentais que norteiam a reologia de polpas concentradas de caulim a partir dos fundamentos de química coloidal. A caracterização tecnológica das amostras foi efetuada pelas técnicas de difratometria de raios-X, medição de alvura, análise granulométrica e análise morfológica (MEV e MET). As amostras analisadas revelaram ser, predominantemente, de caulinita; de alvura adequada a Indústria Papeleira para as amostras Coat 90 e Coat 87; de distribuição bimodal para as amostras Coat 90 e Coat 87 e de formato lamelar de perfil irregular, tendo sido encontradas partículas de perfil hexagonal. Posteriormente, foram apreciadas as propriedades eletrocinéticas das amostras. Foi medido o potencial zeta das amostras na ausência e na presença do dispersante hexametafosfato de sódio em função do pH e da concentração do dispersante em força iônica constante. A análise dos resultados revelou: que as amostras Coat 90 e Coat 87 possuem ponto isoelétrico de 3,5, enquanto o caulim Extra Fino possui ponto isoelétrico de 3,2; que o potencial zeta assume valores mais negativos com o aumento do pH e com o aumento da concentração de dispersante e que o ânion proveniente da dissociação do hexametafosfato de sódio adsorve quimicamente à superfície das amostras. De posse dos dados de potencial zeta, utilizou-se a Teoria DLVO para calcular a energia de interação total existente entre as partículas da amostra de caulim Coat 90. Após a análise dos resultados, ficou evidente que, para valores de pH maiores ou iguais a 5, existe uma barreira energética que aumenta de intensidade com o aumento do pH e da concentração de dispersante onde, com o aumento do pH, houve uma tendência à estabilização e, no caso da concentração, foi obtido um valor máximo em 3kg/t de dispersante (após este valor não houve aumento da barreira energética). Nessas curvas também foi observada a existência de um mínimo secundário que, embora pequeno (~2kT), revelou a possibilidade de adesão reversível. A análise reológica da amostra de caulim Coat 90 foi realizada a partir da comparação das viscosidades aparentes encontradas para taxas de cisalhamento constantes (100s-1 ou 1000s-1) e após a mesma quantidade de tempo (280s) já que as polpas eram tixotrópicas. Esses dados revelaram que, com o aumento do pH, as polpas atingem valores mínimos de viscosidade, onde para cada concentração de dispersante foi atingido um patamar diferente. O menor valor de viscosidade foi obtido em 3kg/t de dispersante, onde a partir desse ponto a viscosidade passou a aumentar levemente. Finalmente, os dados reológicos foram confrontados com os calculados pela Teoria DLVO Clássica, onde foi revelada a existência de um valor de energia de interação total (~400kT) comum a todas as concentrações de dispersante que indica um grau máximo de estabilidade da polpa, isto é, as partículas encontram-se tão afastadas umas das outras que o movimento relativo entre elas durante o cisalhamento não é mais afetado. Concluiu-se que, apesar das interações interparticulares serem de natureza microscópica e a viscosidade uma medida macroscópica, a Teoria DLVO foi capaz de explicar qualitativamente o compor
Concentrated kaolin pulps (70 percent solid weight) are utilized as coatings in the paper industry. During the pulp application, high shear rates are obtained. Shear rates associated to high viscosities incite difficulties on the lamina movement generating risks, bubbles or even tearing the paper. To minimize this effect dispersant agents are added. The aim of the present work was to characterize physically the Prado region (Bahia State) kaolin particles and, using the DLVO theory, contribute for a better understanding about the fundamental aspects of kaolin concentrated pulps rheology via colloidal chemistry. Sample technological characterization was carried out with X-Ray difractometry technique, brightness measurements, size measurements, particle distribution and morphological analysis (MEV and MET). Samples were, predominantly, of kaolinite; samples Coat 90 and Coat 87 were of adequate brightness for Paper Industry and presented two peaks and all samples were platelike with irregular edges where hexagonal particles were found. Sample electrokinetic properties were appreciated afterwards. Zeta potential measurements were taken in the absence and in the presence of sodium hexametaphosphate dispersing agent as a function of pH and dispersant concentration using constant ionic strength. Result analysis revealed: Coat 90 and Coat 87 samples had 3,5 of isoelectric point, while Extra Fino sample had 3,2 of isoelectric point; zeta potential values became more negative with pH and dispersant concentration rising and the anion of sodium hexametaphosphate dissolution chemically adsorbs to sample surfaces. Zeta potential values were used to obtain total interparticular interaction energy by means of DLVO theory. These procedures were done only for Coat 90 sample. It became clear that, for pH values equals or higher than 5, exists an energy barrier whose values rise as pH and dispersant concentration increases. It has been noted that for pH increase, the tendency of energy barrier was to stabilize. In the case of dispersant concentration increase, was obtained maximum value (3kg/t). By data observation, a secondary minimum was noted. However the secondary minimum is low (~2kT), it revealed the possibility of reversible adhesion. The rheological analysis of Coat 90 kaolin sample was realized by comparison of apparent viscosities found on constant shear rates (100s-1 and 1000s- 1) and after the same time (280s) because pulps were thixotropic. The investigation showed that with pH increase, pulps had their viscosity reduced. Each dispersant concentration value generates a different viscosity, where the smallest viscosities were achieved in 3kg/t. Within the increase of dispersant concentration, viscosity had its values improved. Finally, rheological data were coordinated with those calculated from DLVO theory. It was observed that there is a total interaction energy value (~400kT) common to all dispersant concentrations. This point means that pulp stability is maximum, in other words, particles are so far from each other that relative movement among them is not affected anymore. The conclusion of this work is that, however interparticular forces are of microscopic nature and viscosity is a macroscopic measure, DLVO theory was able to explain qualitatively the rheological behavior of kaolin concentrated pulps.
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Cruz-Novoa, Alfonso. "Industrial dynamics and technological structure of the paper and pulp industry." Thesis, University of Sussex, 2011. http://sro.sussex.ac.uk/id/eprint/7604/.
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This thesis investigates the existence and form of association between the technological structure of one of the most highly capital-intensive industries in the world, the paper and pulp (p&p) industry, and its dynamic behaviour in terms of market growth and development. Industrial structure issues are particularly relevant in highly capital-intensive sectors because they reflect the influence of economies of scale and changing patterns of entry and exit. The thesis draws upon two related bodies of literature: the dynamics of industrial structure, and heterogeneity within industry. It uses a quantitative hypothesis-deductive method and two panel databases. The first of these databases identifies key characteristics of the world's 150 largest p&p firms during the period 1978-2000, accounting for two-thirds of world output. The second dataset contains annual production capacity for the entire population of US p&p companies during the period 1970-2000. The US is the largest producer and consumer of p&p, accounting for one-third of world output. The main findings are as follows. Firstly, we demonstrate that p&p firms' growth is not a 'random walk' process, a generalization referred to in the literature as Gibrat's law. Nor is there a linear relation between growth and size distribution or between time and growth rates. We find that size, technology and time matter. Secondly, we demonstrate that this departure from Gibrat's law is due to the existence of three distinctive technological configurations or strategic groups of firms: 'Large & Diversified', 'Medium & Specialized', and 'Small & Very Specialized', which show persistently heterogeneous growth performance. In contrast with the findings in most of the recent empirical literature that shows smaller firms growing faster within the industry size distribution, the medium & specialized p&p companies show systematically the highest rates of growth. Thirdly, patterns of p&p firm survival and technological adoption behaviour over the last three decades are identified and related to the principal technological advances during the period, i.e. the very rapid increase in paper machine operating speed. The research contributes to the literature by providing robust new empirical evidence of the persistence over time of an intra-industry technological structure that systematically influences the heterogeneous performance of firms with different technological configurations and whose origins are linked to firms' growth processes (industrial dynamics) in the p&p industry.
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Khan, I. (Imran). "Role of aldehydes in biomass combustion and pulp and paper industry." Master's thesis, University of Oulu, 2014. http://urn.fi/URN:NBN:fi:oulu-201405281517.
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The purpose of this study was to investigate the role of aldehydes in two industrial sectors; biomass combustion and pulp and paper industry. Aldehydes are formed as unwanted intermediate compounds during biomass combustion, however in pulp and paper industry formaldehyde could be an important end product when treating the waste gas streams. Biomass fuels are the major renewable energy sources used in industries due to their environmental benefits. Emissions from biomass combustion depend on the composition of fuel and combustion conditions.
In this work, emissions from the combustion of various solid biomass fuels in industrial scale boilers have been studied by a literature survey. It was observed that formaldehyde and acetaldehyde were the predominant intermediate compounds formed during biomass combustion. European Union directives 1999/30/EC and 2008/50/EC provide limiting values for the emissions from biomass boilers to protect human health. Aldehydes are unregulated pollutants that are toxic in nature and can cause adverse effects to human health and the environment. Black liquor is formed in pulp and paper industry during wood processing. Black liquor contains organic matter which can be used as an important biomass fuel in the recovery boiler. Pulping and bleaching processes of a pulp mill release hazardous compounds like methanol and methyl mercaptan. These compounds are commonly treated by incineration in a boiler. Incineration converts the waste stream to carbon dioxide and water thus increasing the greenhouse gases.
Currently research is in progress to develop alternative ways for utilizing methanol containing waste gas streams, by converting them to other valuable compounds. In this regard catalytic oxidation has become a very promising technology. This is an environmentally friendly way to treat these emissions and in addition it has a positive economic impact on the pulp mill. This route is in experimental level and needs further research for its application in industrial scale. Formaldehyde is a very useful compound as it can be further utilized in a number of industries for the production of other compounds.
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Hedman, Jens. "Modelling of suspended solids effluent from a pulp and paper mill." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171767.
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This study examines the wastewater treatment system on BillerudKorsnäs integrated pulpand paper mill at Karlsborg, with focus on the effluent of suspended solids. Due to lowerregulatory limits for the emissions of suspended solids BillerudKorsnäs is looking forways to improve the efficiency of the wastewater treatment. Therefore, this study seeksto create a statistical model for the emissions of suspended solids and to find which factorsin the production, wastewater treatment and surrounding environment that affects theemissions. The purpose of the study is to extend the current understanding of the treatmentsystem to create a base for future decisions. The methods used for the modelling areElastic net regression and Random forest classifier, which were selected for the variableselection properties they provide. Unfortunately, the results show that the fitted modelscan only explain a small part of the variation of the emissions of suspended solids.The lack of fit in the models indicate that the current data is not sufficient to explain thevariation in the emissions of suspended solids. During the study deficiencies in the datacollection has been detected and improvements to overcome these deficiencies are proposedin the hope of creating more reliable data for the company and to create a betterbasis for future studies.Denna studie undersöker avloppsvattenreningen på BillerudKorsnäs integrerade massaoch pappersbruket i Karlsborg, med fokus på utsläppen av suspenderade ämnen. Pågrund ut av sänkta gränser för utsläppen av suspenderade ämnen undersöker BillerudKorsnäsmöjligheter för att öka effektiviteten i avloppsvattenreningen. Därför försöker dennastudie att skapa en statistisk modell för utsläppen av suspenderade ämnen och undersökavilka faktorer i produktion, avloppsvattenrening, och omgivande miljö som påverkar utsläppen.Syftet med studien är att förbättra förståelsen för avloppsvattenreningen och attskapa beslutsunderlag för framtida förbättringar. Metoderna som används i modellernaär Elastic net regression och Random forest classifier, vilka valdes för deras variabel selectionegenskaper. Resultaten för modellerna visar att modellerna endast kan förklara enliten del av variationen i utsläpp av suspenderade ämnen. Det dåliga resultatet indikeraratt nuvarande data inte är tillräckligt för att skapa den typ av modeller som används. Understudien så har brister i datainsamlingen upptäckts, och förbättringar för att överbryggadessa brister är föreslagna med ändamål att göra insamlad data mer pålitlig och skapa enbättre bas för framtida studier.
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Joyce, Jim. "Color and TOC removal from pulp and paper wastes by ultrafiltration." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91035.
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Ultrafiltration studies were conducted to determine a treatment approach to remove color and organic carbon from the pulp and paper wastewaters at the Union Camp Corporation, Franklin, VA.
Analysis of data collected during this research indicate that ultrafiltration can produce an effluent with less than 5 color units and less than 5 mg/L TOC (99% and 97% removal respectively). The data also indicate that biotreatment of the wastes prior to ultrafiltration removes the smaller molecular weight organic compounds, making ultrafiltration more effective.
Pretreatment by pH adjustment and alum coagulation were not effective in improving ultrafiltration performance. Concentration studies indicate that volume reductions up to 95% may be accomplished without excessive membrane fouling. Membrane cleaning with caustic, hypochlorite and detergent produced identical results.
It is expected that ultrafiltration would be a more cost effective method of color and TOC removal than coagulation, and would not require sludge disposal.M.S.
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Oliveira, Gonçalo Vieira Saraiva de. "Removal of pharmaceuticals from water using paper pulp-based carbon adsorbents." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22241.
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Mestrado em Biotecnologia Industrial e AmbientalThe occurrence of pharmaceuticals in the environment, mainly aquatic, is a worrying issue, with Wastewater Treatment Plants (WWTP) being the main entry route of these compounds due to their inefficient ability to remove them from contaminated water. Adsorption is a very effective method for this purpose, with activated carbons being the most commonly used adsorbents. Considering that commercial activated carbons are expensive, in part due to the price of their precursors, the production of adsorbents from alternative raw materials is an interesting solution and fits within the concept of sustainable economy. In this work, two type of pulps, bleached (BP) and raw pulp (RP), derived from the pulp and paper production process, were used as precursors for production of non-activated and activated carbons. For activated carbons, the pulps were impregnated with two chemical activating agents (K2CO3 or H3PO4), and then pyrolysed and washed with acid. After production, the materials were physically and chemically characterized. To test the performance of these carbons as adsorbents, batch adsorption tests were performed with ultra-pure water and with WWTP effluents, using two pharmaceuticals: the anti-epileptic carbamazepine (CBZ) and the antibiotic sulfamethoxazole (SMX). For the amounts of carbon tested, in ultra-pure water, the results showed no adsorption for non-activated carbons and good adsorption capacities for the activated ones. Comparing the adsorption tests in real effluents with CBZ and SMX, tests with SMX presented low adsorption capacities, probably due to the different interactions establish between the two pharmaceuticals and carbons surface, in the presence of high organic load. Tests with real effluents presented better adsorption capacities for carbons activated with H3PO4 and produced from BP: 92 ± 19 mg g-1 for CBZ and 13.0 ± 0.6 mg g-1 for SMX. These results indicate the potential of these pulps to be used as precursors for activated carbons that can be applied in wastewater treatment.
A existência de fármacos no meio ambiente, em particular ambientes aquáticos, constitui um problema preocupante, sendo as Estações de Tratamento de Águas Residuais (ETAR) a principal via de entrada destes compostos no meio, devido à sua ineficácia para os remover das águas contaminadas. A adsorção é um método bastante eficiente, sendo os carvões ativados os adsorventes mais comummente utilizados. Uma vez que os carvões ativados comerciais são caros, em parte devido ao preço dos seus precursores, a produção de adsorventes a partir de matérias-primas alternativas é uma solução interessante que se enquadra no conceito de economia sustentável. Neste trabalho foram utilizados dois tipos de pasta, branqueada (BP) e crua (RP), derivadas do processo de produção da pasta de papel, como precursores para a produção de carvões ativados e não ativados. Na ativação, as pastas foram impregnadas com dois agentes químicos ativantes (K2CO3 ou H3PO4) e posteriormente pirolisadas e lavadas com ácido. Após a produção, os materiais foram física e quimicamente caraterizados. De forma a testar o desempenho dos carvões enquanto adsorventes, foram realizados testes de adsorção em descontínuo com água ultrapura e com efluentes recolhidos em ETAR, utilizando dois fármacos: o antiepilético carbamazepina (CBZ) e o antibiótico sulfametoxazol (SMX). Para as quantidades de carvão utilizadas, os resultados em água-ultrapura mostraram adsorção nula para os carvões não ativados e boas capacidades de adsorção para os carvões ativados. Comparando os testes realizados para os efluentes reais com CBZ e SMX, os testes com SMX apresentaram baixas capacidades de adsorção, provavelmente devido às diferentes interações estabelecidas entre as superfícies do fármaco e do carvão, na presença de elevada carga orgânica. Os testes com efluentes reais apresentaram melhores capacidades de adsorção para carvões ativados com H3PO4 e produzidos a partir da BP: 92 ± 19 mg.g-1 para a CBZ e 13.0 ± 0.6 mg.g-1 para o SMX. Estes resultados refletem as potencialidades destas pastas para serem utilizadas como precursoras de carvões ativados, os quais podem ser aplicados no tratamento de águas residuais.
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Maung, Maung Thant Kitikorn Charmondusit. "Measurement of eco-efficiency for pulp and paper production in Myanmar /." Abstract, 2007. http://mulinet3.li.mahidol.ac.th/thesis/2550/cd398/4837461.pdf.
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Quiddington, Christopher John. "Stabilisation of high-yield pulp against photo-induced discolouration." Thesis, University of Kent, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342138.
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Biniaris, Andreas. "Insight on the effect of contour height in pressure screening." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/754.
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The main purpose of this study was to determine the effect of contour height on the passage ratio of pulp through screen apertures, and determine which operating variable has the greatest affect on screen performance. In addition, a freeness model was to be developed, in hopes of helping to predict the freeness drop between feed and accepts.
The study was conducted at The University of British Columbia (UBC) using a laboratory scale pressure screen. Slot velocity, feed consistency and contour height were the changing variables. Samples were collected from which passage ratio, freeness, fibre length and coarseness were determined.
From the studies conducted it was found that slot velocity had the greatest influence on the screen operation. As the slot velocity increased a greater force was applied to the fibre to help push it through the screen aperture. However, this increase in slot velocity decreases the fractionation ability (separation of fibres into different lengths) of the screen.
The second most important variable was the contour height. The main function of the contour height is to disrupt the flow of thick stock at the wall of the screen and allow for unhindered movement of fibre to the screen wall. The greater the contour height is, the greater the passage ratio (pulp fibre passing through screen). However, there is a decrease in fractionation.
The third most important factor was the feed consistency. At low feed consistencies there is less crowding in the screen. Less crowding leads to more loosely-formed flocs, which are easier for the contour height and the rotor to dissipate and thus leads to unhindered movement. Thicker feed stock has a negative effect on passage
A Freeness model was developed that showed that freeness had a power law relationship to passage ratio. The passage ratio was raised to a constant B, which is a function of the contour height and the feed consistency.
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Bjarnhagen, Rikard. "Service Enhancer Tool : Design of a new Service Enhance Tool for Metso refiners." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-79533.
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Metso develops (among many other things) refiners. The refiner grinds the wood chips intopulp. The grinding is done by segments that are placed on a rotor inside the refiner hosing.In time this segments wear and needs to be replaced.When changing refiner segments or performing service to the refiner the rotor needs to berotated. To perform the rotating motion today the overhead crane is used. This procedure isboth impractical, dangerous and takes precious time from the overhead crane. Because ofthis Metso wanted to create a new way to rotate the rotor.The aim of this thesis is to create a tool or equipment which can be used to rotate therefiner rotor and can be installed as an upgrade on all Metso refiner models.The proposed design is driven with a 1.1 kW electrical motor and a gearbox with a gear ratioof approximately 1:217. The torque is transferred from the outgoing gearbox shaft to therefiner shaft with the help of gearwheels. To connect the gearbox gearwheel with the refinershaft gearwheel, the gear motor has to be moveable in a radial direction. This is done by themeans of two shafts that glides in four bushings. On the gearbox shaft a gearwheel with 120mm of face width is mounted. The large face width is used to take up the axial movement ofthe refiner shaft.The proposed concept fulfills all of the demands set in the pilot study. The design is goodbecause of the low cost and straight forward design that is easy to build and simple to use.The disadvantage is that the equipment is a bit large and heavy, but as stationary equipmentthis should not be a problem.
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Zhou, Ya Jun. "The effect of ageing on alkyl ketene dimer sizing." Thesis, University of Manchester, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337537.
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Mesfun, Sennai. "Design of integrated industrial sites based on Kraft pulp and paper mills." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26544.
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Godkänd; 2014; 20140414 (senmes); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Sennai Mesfun Ämne: Energiteknik/Energy Engineering Uppsats: Design of Integrated Industrial Sites Based on Kraft Pulp and Paper Mills Examinator: Professor Andrea Toffolo, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Diskutant: Assistant Professor Karin Pettersson, Institutionen för energi och miljö, Chalmers tekniska högskola, Göteborg Tid: Tisdag den 20 maj 2014 kl 14.00 Plats: E632, Luleå tekniska universitet
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Klein, Stephen Richard. "A regional analysis of supply in the Canadian pulp and paper sector." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24826.
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The purpose of this thesis was to analyse the supply of pulp and paper products in the three major producing provinces of Canada, namely British Columbia, Ontario and Quebec. A translog restricted profit function and its first partial derivatives were estimated using the iterative seemingly unrelated regressions procedure. Derived demand equations for energy, fibre, labour and supply equations for net market pulp, newsprint and 'other paper and paperboard", (net market pulp and 'all paper and paperboard' for British Columbia) were obtained with net supplies as a function of each input and output price.
The success of the model in representing the industry was mixed. Derived demand own price elasticities were, in almost all cases, negative as expected a priori. Negative own price elasticities were also found in many end product supply functions suggesting a misspecification of the supply relationship. The unexpected supply function results bring up questions about the degree of competitiveness in pulp and paper markets, and thus the validity of using the perfectly competitive market assumption in empirical studies. Finally the model was evaluated in the context of using the results in a spatial equilibrium model of the North American pulp and paper sector.Forestry, Faculty of
Graduate
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Renner, Victoria Emily. "Sources and ecology of Escherichia coli in pulp and paper mill biosolids." Thesis, University of Ottawa (Canada), 2007. http://hdl.handle.net/10393/27549.
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Pulp and paper mills generate biosolids as a by-product of their effluent treatment systems. These biosolids show excellent potential as a soil conditioner. However, the detection of high levels of E. coli (10 2 to 105 CFU/gdw), in the absence of any significant fecal loading, has caused concern among effluent treatment system operators, land applicators and regulators. This research examines the sources and ecology of E. coli strains comprising the population of E. coli in the biosolids of an eastern Ontario pulp and paper mill by applying the molecular microbial source-tracking tool repetitive sequence-based polymerase chain reaction. Confirmed E. coli were successfully isolated from 2 forested sites, treated mill process feed water, storm effluent, mill fibres, wood chips, primary and secondary clarifier effluents and sludges, and biosolids. While laboratory isolates could be accurately distinguished from forest and industrial isolates, cluster and jackknife analyses were incapable of differentiating reliably among isolates from the forest, on-site inputs, effluent treatment system and biosolids (average rates of correct classification values ranged from 43.9% to 72.9%). No input could be excluded as a source of E. coli to the effluent treatment system. Many fingerprint types were unique to the primary and secondary clarifiers; however, only a subset of the fingerprint types recovered from the primary and secondary clarifiers were detected in the biosolids. This suggests that the E. coli strains found in mill biosolids were those able to survive the hot, desiccating conditions of dewatering. Highly similar fingerprint types (> 80% similarity) were recovered repeatedly over an 8-month period from the effluent treatment system (primary and secondary clarifiers) and biosolids. These results are consistent with growth within the effluent treatment system and biosolids, rather than fecal loading. Over a 3-year period the pulp and paper mill effluent treatment system underwent large-scale changes, including a 50% reduction in effluent volume upon the elimination of on-site pulping activities. New fingerprint types were detected in the biosolids following the restructuring, and the Shannon index of diversity increased. Disruption of established operating conditions could have opened niches, allowing new strains to colonize the mill effluent treatment system successfully.
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Aitomäki, Yvonne. "Towards a measurement of paper pulp quality : ultrasonic spectroscopy of fibre suspensions." Licentiate thesis, Luleå tekniska universitet, EISLAB, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18216.
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For the paper and pulp industry in Sweden and Finland to remain competitive against countries with lower overheads, they have to constantly strive to improve the quality and the efficiency of the manufacturing processes. One of the ways of doing this is to introduce sensors that will provide valuable online feedback on the characteristics of the pulp so that adjustments can be made to optimise the manufacturing process. The measurement method proposed in this thesis is based on ultrasound, since it is rapid, inexpensive, non-destructive and non-intrusive. Thus could be done online. Since ultrasound propagation and attenuation depends on the material properties through which is propagates, it has the potential to provide measurements of material properties such as pulp fibre density and elasticity. The aim of this thesis is to investigate the possibility of using ultrasound to measure pulp fibre material properties. The idea is to solve the inverse problem of estimating these properties from attenuation measurements and to establish the degree of accuracy to which this can be done. Firstly a model is developed and is tested with synthetic fibres to establish is validity. It is then used to solve the inverse problem of estimating material properties from attenuation measurements, again with synthetic fibres, to test the accuracy to which these properties can be estimated. Resonance peaks in the frequency response of the attenuation were found. On closer investigation it was established that the location of these peaks in the frequency domain is sensitive to the diameter of the fibres and their material properties. If the diameter is known, these peaks improve the accuracy of the estimation process. The results of the estimation process for synthetic fibre suspensions show values for the shear modulus are within known ranges but the estimation of Poisson's ratio and Young's modulus is poor. Improving the model or the estimation procedure may lead to better results. For the method as it is to have application in the paper and pulp industry there are certain conditions that need to be fulfilled. These are that we find peaks in the frequency response of the attenuation in pulp, know the diameter distribution of the fibres and the hollow nature of the fibres does not significantly alter the results. We can then, potentially, be able to establish the shear modulus of the pulp fibres. If the shear modulus is a factor in paper quality, we may be close to an online measurement of paper pulp quality using ultrasonic spectroscopy. Improving the model may allow us to estimate further properties and take into account the fibres being hollow. The thesis consists of two parts. The first part includes an overview of the pulp and paper industry and current testing methods, background theory on which the model is based and an overview of the model that is used in predicting ultrasound attenuation. There then follows a summary of the work done, some addition points are raised in the discussion before drawing conclusions. Finally we discuss what needs to be done to take this further. The second part contains a collection of four papers describing the research.Godkänd; 2006; 20061115 (ysko)
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Carter, Shane Basil. "Adsorption of Colour from Pulp and Paper Mill Wastewaters onto Diatomaceous Earths." The University of Waikato, 2007. http://hdl.handle.net/10289/2400.
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Abstract Production of pulp and paper from raw wood involves the washing of substantial quantities of highly coloured material from the wood pulp. Although most of this colour is trapped within the mill and the mills wastewater treatment system, discharge of coloured wastewater remains a problem of public concern. Lake Rotorua, New Zealand is filled with sediment consisting almost exclusively of diatoms. The most abundant species, Aulacoseira, has been shown to have very small pores, less than 200 nm, that could be very useful for the capture and holding of large organic molecules. Lake Rotorua is situated close to the two largest pulp and paper mills in New Zealand and may have to be dredged to solve a problem of eutrophication. Wastewaters generated at the Kinleith (Tokoroa) and Tasman (Kawerau) mills in the North island of New Zealand have been used to assess the characteristics of colour removal by Lake Rotorua diatoms. Vacuum filtration through the diatoms succeeded in removing colour but proved to be impractically slow as an industrial process. Addition of diatoms to wastewater streams in stirred experiments showed that significant adsorption took place. The majority of the colour was removed within 30 seconds of mixing. The efficiency of colour removal was found to vary between wastewater streams within the mills. The pH dependency of this removal was tested and found to be most effective in a pH range of 3.6 to 5. Attempts to reuse the diatoms showed that chemical backwash regimes were more effective than calcination. This study concluded that surface silanols were likely to be the principle agent in forming coagulants with the colour material and were subsequently trapped on the diatom surfaces, but more importantly within the pores.
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Aitomäki, Yvonne. "Towards a measurement of paper pulp quality : ultrasonic spectroscopy of fibre suspensions /." Luleå : Luleå tekniska universitet/Systemteknik/EISLAB, 2006. http://epubl.ltu.se/1402-1757/2006/20/index.html.
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Rice, Matthew. "New Techniques for Continuous Chemical Analysis in the Pulp&Paper Industry." Doctoral thesis, Stockholm : Tekniska högsk, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3131.
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Boissinot, Philippe. "Photooxidation of a TM pulp and paper mill effluent with hydrogen peroxide." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24051.
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The photooxidation of a Thermo-Mechanical (TM) pulp and paper mill effluent with hydrogen peroxide $ rm(H sb2O sb2)$ was investigated at different experimental conditions by using a batch photochemical reactor operating at a dominant UV light wavelength of 253.7 nm. Photolysis of $ rm H sb2O sb2$ produces hydroxyl radicals ($ cdot$OH), which are very powerful oxidizing species. The effluent consisted of a "heat condensate" obtained from toxic vapors generated during various stages of the pulping process. Several operational parameters were varied and their effects on the process were observed and analyzed, in order to achieve its optimization. In addition, heterogeneous photocatalysts such as cupric oxide (CuO) were also investigated as a complement to the photooxidation process.The main parameter used to determine the quality of the wastewater before and after photooxidation was the Chemical Oxygen Demand (COD), using a closed reflux standard procedure. COD values of the treated solution were determined at subsequent time intervals and used to draw curves illustrating the rate of oxidation of the wastewater. Other parameters, such as Dissolved Organic Carbon (DOC) and dissolved lignin concentration, were investigated towards the end of the research in order to obtain a more complete characterization of the quality of the wastewater after treatment.
The experimental data reveal that there is an optimal $ rm H sb2O sb2$ concentration that is best suited for the photooxidation of the effluent. Moreover, an increase in temperature accelerates the rate of elimination of COD. An increase in effluent concentration is detrimental to the speed of the process, since it causes an increase in its absorbance which can act as a barrier against UV light. The efficiency of the photooxidation process is not affected by variations in the initial pH of the wastewater. Cupric oxide (CuO), when exposed to UV light, efficiently catalyzes the production of OH radicals and is therefore very beneficial to the photooxidation process.
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Morais, Ismarley Lage Horta. "Biological treatment of pulp and paper mill effluents with aerobic granular sludge." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/9372.
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O tratamento de águas residuárias com lodo aeróbio granular apresenta muitas vantagens em comparação ao processo convencional de lodos ativados com lodo floculento. Os grânulos são agregados microbianos densos e compactos que possibilitam uma maior retenção de biomassa no reator biológico e uma elevada capacidade de sedimentação, favorecendo a remoção biológica de matéria orgânica, nutrientes, compostos tóxicos e clarificação final do efluente devido à estrutura e propriedade de sedimentação do lodo. Estes benefícios resultaram em um aumento do interesse de implantação do processo de tratamento com lodo aeróbio granular e a busca de maiores informações à respeito da formação, estabilidade e a influência dos parâmetros operacionais sobre a granulação. Assim, este trabalho apresenta uma revisão bibliográfica com a compilação das informações recentes sobre o lodo aeróbio granular incluindo a possibilidade de utilização dos grânulos aeróbios em biorreatores a membrana, em elevadas temperaturas e as aplicações em plantas de tratamento de larga escala. Foi realizada, ainda, a avaliação da adição de 100 mg.L-1 e 200mg.L-1 de cálcio na estabilidade, resistência mecânica e diâmetro dos grânulos formados em reatores em batelada sequencial alimentados com efluente de uma fábrica de polpa celulósica kraft. Os reatores apresentaram eficiências similares de remoção de matéria orgânica e o diâmetro médio dos grânulos foi de cerca de 11 mm em todos os reatores, embora os grânulos formados no reator que recebeu 100 mg.L-1 de Ca2+ apresentou velocidade de sedimentação 36% superior aos demais e maior resistência mecânica. A melhoria da granulação pode ser obtida ainda pela seleção de microrganismos que contribuem para a formação dos agregados. A produção de substâncias poliméricas extracelulares (SPE) pelas bactérias é um dos fatores que influencia a agregação celular, uma vez que as SPE agem como agente cimentante e atuam na adesão entre as células. A produção de SPE de dezenove isolados microbianos, obtidos de grânulos aeróbios formados no tratamento de efluente de fábrica de papel reciclado foi avaliada e seis isolados dos gêneros Staphylococcus, Agrobacterium, Enterobacter e Rhodococcus melhoraram a granulação biológica. A ausência destes isolados nos testes de co-agregação reduziu a relação entre proteínas e polissacarídeos (relação PN/PS) e diminuiu a formação de agregados.
Aerobic granular sludge wastewater treatment has many advantages over the conventional activated sludge process. The granules are dense and compact microbial aggregates that allow a higher biomass retention in the biological reactor and a high settling velocity, favoring the biological removal of organic matter, nutrients, toxic substances and improves wastewater clarification. Due to the sludge structure and settleability, these benefits have attracted considerable interest in the implementation of the aerobic granular sludge process and givenrise to the need for better understanding of the formation, stability and influence of the operational parameters on the granulation. Thus, this work was divided into three chapters. Chapter 1 presents a review of recent developments on aerobic granular sludge including the possibility of using aerobic granules in membrane bioreactors, at high temperatures and for a full-scale implementation. The addition of divalent cations in the reactors can enhance granulation and granule stability. In Chapter 2, the effect of the addition of 100 mg.L-1 and 200 mg.L- of calcium in the stability, mechanical strength and diameter of the granules formed in sequential batch reactors (SBR) fed with pulp mill effluent was evaluated. The reactors showed similar organic matter removal efficiencies and granule size was approximately 11 mm in all SBR, although the granules formed in the reactor with addition of 100 mg.L- of Ca2+ had a settling velocity 36% higher and greater mechanical resistance than the others. Granulation can also be enhanced by the selection of microorganisms that contribute to the aggregates formation. Bacterial extracellular polymeric substances (EPS) production is one factor that contributes to cell aggregation, since EPS acts as an intercellular cement that may reinforce cohesion inside the bacterial clusters. In Chapter 3, EPS production of nineteen microbial isolates obtained from aerobic granules formed in the recycled paper wastewater treatment was evaluated and six isolates of the genera Staphylococcus, Agrobacterium, Enterobacter and Rhodococcus contributed to biological granulation. The absence of these isolates in the co-aggregation tests reduced the protein-polysaccharide ratio (PN / PS ratio) and reduced the aggregates formation.
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Biasca, James E. "Oriented fiber refining application of individual modes of mechanical action to single pulp fibers /." Diss., Available online, Georgia Institute of Technology, 1989:, 1989. http://etd.gatech.edu/theses/available/ipstetd-446/biasca%5fje.pdf.
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Forsström, Jennie. "Fundamental aspects on the re-use of wood based fibres : porous structure of fibres and ink detachment /." Stockholm, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-84.
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Osong, Sinke Henshaw. "Mechanical Pulp Based Nano-ligno-cellulose : Production, Characterisation and their Effect on Paper Properties." Licentiate thesis, Mittuniversitetet, Avdelningen för kemiteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-21555.
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Almost all research on biorefinery concepts are based on chemical pulping processes and ways of utilising lignin, hemicelluloses and extractives as well as a part of the remaining cellulose for production of nano materials in order to create more valuable products than today. Within the Forest as a Resource (FORE) research program at FSCN we are utilising the whole chain of unit processes from forestry to final products as paper and board, where the pulping process research focus on high yield process as TMP and CTMP. As these process solutions are preserving or only slightly changing the properties of the original wood polymers and extractives, the idea is to find high value adding products designed by nature. From an economic perspective, the production of nanocellulose from a chemical pulp is quite expensive as the pulp has to be either enzymatically (e.g. mono-component endoglucanase) pre-treated or chemically oxidised using the TEMPO (2,2,6,6 - tetramethyl-piperidine-1-oxil) - mediated oxidation method in order to make it possible to disrupt the fibres by means of homogenisation. In high yield pulping processes such as in TMP and CTMP, the idea with this study was to investigate the possibility to use fractions of low quality materials from fines fractions for the production of nano-ligno-cellulose (NLC). The integration of a NLC unit process in a high yield pulping production line has a potential to become a future way to improve the quality level of traditional products such as paper and board grades. The intention of this research work was that, by using this concept, a knowledge base can be created so that it becomes possible to develop a low-cost production method for its implementation. In order to study the potential of this concept, treatment of thermo-mechanical pulp (TMP) fines fractions were studied by means of homogenisation It seems possible to homogenise fine particles of thermo-mechanical pulp (1% w/v) to NLC. A correspond fines fraction from bleached kraft pulp (BKP) was tested as a reference at 0.5% w/v concentration. The objective presented in this work was to develop a methodology for producing mechanical pulp based NLC from fines fractions and to utilise this material as strength additives in paper and board grades. Laboratory sheets of CTMP and BKP, with addition of their respective NLC, were made in a Rapid Köthen sheet former. It was found that handsheets of pulp fibres blended with NLC improved the z-strength and other important mechanical properties for similar sheet densities. The characterisation of the particle size distribution of NLC is both important and challenging and the crill methodology developed at Innventia (former STFI) already during the 1980s was tested to see if it would be both fast and reliable enough. The crill measurement technique is based on the optical responses of a micro/nano particle suspension at two wavelengths of light; UV and IR. The crill value of TMP and CTMP based nano-ligno-cellulose were measured as a function of the homogenisation time. Results showed that the crill value of both TMP-NLC and CTMP-NLC correlated with the homogenisation time.