Made available in DSpace on 2014-12-17T15:01:16Z (GMT). No. of bitstreams: 1 LianaFA.pdf: 575157 bytes, checksum: 8650946fd949f8eb8297ea9541d69e42 (MD5) Previous issue date: 2005-01-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The shrimp farming is a process of creation of shrimp that has been growing rapidly in the country, occupying a meaningful space in the Brazilian exporting. In 2003, this activity presented a volume of 60 millions of tons and 220 millions of dollars, being the main generator of employment and income of the primary sector of the northeast economy. However, it is a new activity with c.a. five years in the Rio Grande do Norte State and therefore needs investment in the technological area. Among the wastewaters of this activity, the sulphite solution is being usually applied in the process of fishing, i.e. retrieval of the shrimps from the farming. The aim of this work is to present the oxidation experimental results of the sulphite that may be and to determine what it s the most efficient method, trough laboratory experiments. The measurements were carried out in a mixing reactor inserting air and with hydrogen peroxide addition with and without UV light. The solutions were prepared synthetically with concentrations found in the wastewater of fishing and also collected in locu. The oxidation process using air was monitorated by iodometric analysis for the sulphite and the oxidation using hydrogen peroxide was evaluated with turbidimetric analysis for sulphate, by spectrophotometer. The sulphite was totally oxidized in both processes. The experimental results permit to conclude that the oxidation by hydrogen peroxide is more efficient and allowed to determine the optimum operational conditions in terms of concentration and time of treatment / A carcinicultura, processo de cria??o de camar?o em cativeiro, vem crescendo rapidamente no pa?s, ocupando um espa?o significativo na exporta??o brasileira. Em 2003, essa atividade apresentou um volume de 60 milh?es de ton e um faturamento de 220 milh?es de d?lares sendo tamb?m, o principal gerador de emprego e renda do setor prim?rio da economia nordestina. Por?m, por ser uma atividade nova, com pouco mais de 5 anos no Estado do Rio Grande do Norte, faz-se necess?rio investimento na ?rea tecnol?gica. Entre os efluentes dessa atividade tem-se a solu??o aquosa de sulfito, normalmente utilizada no processo de despesca retirada dos camar?es do viveiro. O objetivo desse trabalho ? apresentar os resultados da oxida??o do sulfito e concluir qual o m?todo mais eficiente entre os testados em laborat?rio. Os experimentos foram realizados em um reator injetando-se ar difuso e outro com adi??o de per?xido de hidrog?nio, na aus?ncia e presen?a de luz UV. As solu??es utilizadas foram: sint?ticas, com concentra??es semelhantes ao efluente da despesca e, coletadas in locu. A oxida??o com ar foi monitorada por an?lise iodom?trica do sulfito e com per?xido por an?lise turbidim?trica do sulfato, com espectrofot?metro. O sulfito foi totalmente oxidado em ambos os processos. Os resultados experimentais possibilitaram concluir que a oxida??o do sulfito com per?xido foi a mais eficiente e permitiram encontrar as condi??es ?timas de concentra??o do per?xido, de acordo com o tempo de tratamento

Die Festigkeitseigenschaften des Papiers hängen vom Gehalt und der Verteilung der Hemicellulosen über den Querschnitt der Faserwand ab. Hemicellulosen werden durch verschiedene Bleichverfahren unterschiedlich stark angegriffen und herausgelöst. Durch Untersuchungen an einem Fichtensulfitzellstoff ist es gelungen, die Auswirkungen einzelner Bleichstufen [Peroxidverstärkte Sauerstoffstufe (EOP), Ozonstufe (Z) und Peressigsäurestufe (PAA)] und Bleichsequenzen (EOP-Z-P, EOP-PAA-P) auf Faseroberfläche, Hemicellulosenzusammensetzung und -verteilung sowie auf die optischen und mechanischen Eigenschaften des daraus gebildeten Papiers aufzuzeigen. Um die Verteilung der Hemicellulosen über den Querschnitt der Faser zu beschreiben, wird das Verfahren des chemischen Abschälens verwendet und schrittweise die Faserwand entfernt. Der gebleichte bzw. abgeschälte Zellstoff wird rasterelektronenmikroskopisch untersucht, hydrolysiert und anschließend die Hemicellulosenzusammensetzung quantitativ mittels Hochdruckflüssigkeitschromatographie (HPLC) unter Nutzung eines Flüssigkeitsmassenspektrometers (LCMS) als Detektor bestimmt. Zusätzlich erfolgt die Bestimmung der Papiereigenschaften. Diese Untersuchungen bestätigen, dass die verschiedenen Hemicellulosengehalte nach den Bleichstufen Unterschiede bei den Festigkeitseigenschaften bewirken. Die Untersuchungen zeigen den positiven Effekt der Peressigsäurestufe für die Papierherstellung im direkten Vergleich zur Ozonstufe. Zusätzlich wurde auch der Einfluss des Aufschlusses geprüft. Hierzu wurden die endgebleichten Sulfitzellstoffe mit einem endgebleichten Sulfatzellstoff verglichen. / The mechanical strength of paper pulp depends strongly on the hemicellulose content and the hemicellulose distribution across the cell wall layers. Hemicelluloses get differently attacked and dissolved by different bleaching methods. The investigations with a paper grade sulphite pulp show the influence of the separate bleaching steps [hydrogen peroxide reinforced oxygen stage (EOP), ozone (Z) und peracetic acid (PAA)] and bleaching sequences (EOP-Z-P, EOP-PAA-P) of the fibre surface, hemicellulose content and distribution as well as the optical and mechanical characteristics of paper. To describe the hemicellulose distribution across the cell wall layers a procedure of a precise chemical peeling was used in order to remove stepwise the cell wall. The bleached and peeled pulp was investigated by scanning electronic microscope (SEM) to get more information about the penetration of the bleaching chemicals into the fibre surface. The hemicelluloses were determined by high performance liquid chromatography (HPLC) using a liquid chromatography mass spectrometer (LCMS) after hydrolysing polysaccharides to monosaccharides. In addition to this paper properties were analysed. This research confirms the effect of different hemicellulose compositions of the mechanical strength. The analyses represent the positive effect for paper production of the peracetic acid step in contrast to the ozone step. Additional the influence of the pulping process was determined by a sulphate pulp comparing with the sulphite pulp.

The control of batch pulp digesters is hampered by insufficient measurements as well as nonlinearity and weak correlation between consecutive cooks. This makes a model-based approach to control attractive. Due to the age of the industry, many legacy controllers are in place on digesters around the world. The theoretical variance obtained by Monte Carlo modelling of a new controller is used as a benchmark for performance comparison between an old control system (S-factor) and a new model based controller developed by the University of Pretoria (the UP controller). This study covers the development of the controller, Monte Carlo modelling of the old and new controllers and in-situ testing of the UP controller on an operating digester. During Monte Carlo simulation, the UP controller outperformed the legacy controller, obtaining a theoretical overall variance of 3,07 (which will be used as the baseline for performance measurement) while also showing larger responses to tuning factors. The S-factor performed at 6,8 times the theoretical optimum variance during in situ testing, while the UP controller performed at 3,9 times the theoretical optimum (43% better than the S-factor controller). An average error 90% lower than that of the S-factor controller was obtained when using the UP controller. Additional benefits of the new controller include easy inclusion of new measurements and clear relations between the tuning parameters used and the conditions in the digester. / Dissertation (MEng (Control))--University of Pretoria, 2003. / Chemical Engineering / unrestricted

This master thesis is focused on comparing the options available to accelerate thematuring period of brick dough. There were four types of brick clay from differentfactories of the Czech Republic. From each of these four earth were created by three tests. One dough was stored in the laboratory, the second was heated in an oven and the third dough was added sulphite liquor. In these tests was studied mainly maturing and then further the effect the swallowed sulphite liquor on other properties (plasticity, sensitivity to drying, drying change of length and flexural strength). The result of job evaluation should be, how much time and how it will reduce the time of maturing.

Målet med detta examensarbete har varit att utföra en energikartläggning på Nymölla Bruk med utgångspunkt i företagets befintliga energiaspektregister. Syftet har varit att tydliggöra hur energianvändningen på Nymölla Bruk ser ut. Bakgrunden till detta arbete är företagets deltagande i programmet för energieffektivisering i energiintensiv industri (PFE). I examensarbetet har en energikartläggning på Nymölla Bruk för år 2010 utförts. Fallstudien delades in i två steg där första steget i studien var att kartlägga energiflödena in och ut från bruket.Andra delen av studien innefattade att kartlägga de interna processerna och deras energiflöden. Energiflödenas storlekar baseras främst på mätdata från processerna, som erhållits från Nymölla Bruks interna loggnings- och mätsystem WinMops. Antaganden som i vissa fall varit nödvändiga bygger på uppskattningar som genomförts i samråd med medarbetare på Nymölla Bruk med insikt i och kunskap om respektive delprocess. Enligt detta examensarbete förbrukades år 2010 cirka 510 GWh el, varav massafabriken förbrukade 50 % och pappersbruket 46 %. Resterande andel utgörs bland annat av mät- och överföringsförluster. Under året tillfördes totalt 2060 GWh bränsle där luten står för cirka 75 %. Från bränslena tillfördes 1800 GWh nyttig värme till ångproduktionen. Total energimängd i producerad ånga uppgick till cirka 2190 GWh (från referensnivå). De största förbrukarna av ånga var papperstillverkningen som använde 32 % och indunstningen som använde 19 % av total energimängd distribuerad med ånga. / The aim of this study was to perform an energy survey of Nymölla Mill on the basis of the company's existing energy aspect register. The aim has been to clarify how the energy at Nymölla Mill is used. The background to this thesis is the company's participation in the Programme for Improving Energy Efficiency in Energy Intensive Industries (PFE). In this thesis an energy survey based on 2010 of Nymölla Mill has been performed. The case study was divided into two stages where the first step in the study was to identify the energy flows in and out of the mill. The second part of the study included identifying the internal processes and their energy flows. Energy flows are based primarily on data from processes, obtained from Nymölla Mill's internal logging and measuring system WinMops. Necessary assumptions were made based on estimates provided in consultation with employees on Nymölla Mill with knowledge and understanding of each sub-process. According to this thesis approximately 510 GWh of electricity were consumed in 2010 of which the pulp factory consumed 50 % and the paper mill 46 %. The remaining portion consists of measurement and transmission losses. A total of 2060 GWh of fuel was added of which liquor accounts for about 75 %. From fuels 1800 GWh of useful heat was added to the steam production. The total amount of energy in the steam was about 2190 GWh (from baseline). The largest consumers of steam was the paper productioning unit using 32 % and the evaporation unit using 19 % of total energy distributed by steam.

Die Festigkeitseigenschaften des Papiers hängen vom Gehalt und der Verteilung der Hemicellulosen über den Querschnitt der Faserwand ab. Hemicellulosen werden durch verschiedene Bleichverfahren unterschiedlich stark angegriffen und herausgelöst. Durch Untersuchungen an einem Fichtensulfitzellstoff ist es gelungen, die Auswirkungen einzelner Bleichstufen [Peroxidverstärkte Sauerstoffstufe (EOP), Ozonstufe (Z) und Peressigsäurestufe (PAA)] und Bleichsequenzen (EOP-Z-P, EOP-PAA-P) auf Faseroberfläche, Hemicellulosenzusammensetzung und -verteilung sowie auf die optischen und mechanischen Eigenschaften des daraus gebildeten Papiers aufzuzeigen. Um die Verteilung der Hemicellulosen über den Querschnitt der Faser zu beschreiben, wird das Verfahren des chemischen Abschälens verwendet und schrittweise die Faserwand entfernt. Der gebleichte bzw. abgeschälte Zellstoff wird rasterelektronenmikroskopisch untersucht, hydrolysiert und anschließend die Hemicellulosenzusammensetzung quantitativ mittels Hochdruckflüssigkeitschromatographie (HPLC) unter Nutzung eines Flüssigkeitsmassenspektrometers (LCMS) als Detektor bestimmt. Zusätzlich erfolgt die Bestimmung der Papiereigenschaften. Diese Untersuchungen bestätigen, dass die verschiedenen Hemicellulosengehalte nach den Bleichstufen Unterschiede bei den Festigkeitseigenschaften bewirken. Die Untersuchungen zeigen den positiven Effekt der Peressigsäurestufe für die Papierherstellung im direkten Vergleich zur Ozonstufe. Zusätzlich wurde auch der Einfluss des Aufschlusses geprüft. Hierzu wurden die endgebleichten Sulfitzellstoffe mit einem endgebleichten Sulfatzellstoff verglichen. / The mechanical strength of paper pulp depends strongly on the hemicellulose content and the hemicellulose distribution across the cell wall layers. Hemicelluloses get differently attacked and dissolved by different bleaching methods. The investigations with a paper grade sulphite pulp show the influence of the separate bleaching steps [hydrogen peroxide reinforced oxygen stage (EOP), ozone (Z) und peracetic acid (PAA)] and bleaching sequences (EOP-Z-P, EOP-PAA-P) of the fibre surface, hemicellulose content and distribution as well as the optical and mechanical characteristics of paper. To describe the hemicellulose distribution across the cell wall layers a procedure of a precise chemical peeling was used in order to remove stepwise the cell wall. The bleached and peeled pulp was investigated by scanning electronic microscope (SEM) to get more information about the penetration of the bleaching chemicals into the fibre surface. The hemicelluloses were determined by high performance liquid chromatography (HPLC) using a liquid chromatography mass spectrometer (LCMS) after hydrolysing polysaccharides to monosaccharides. In addition to this paper properties were analysed. This research confirms the effect of different hemicellulose compositions of the mechanical strength. The analyses represent the positive effect for paper production of the peracetic acid step in contrast to the ozone step. Additional the influence of the pulping process was determined by a sulphate pulp comparing with the sulphite pulp.

The work studies the possibilities of the utilization of secondary raw materials produced by power industry. It addresses mainly the gypsum by-products and fluidized coal combustion ash. As for the secondary raw materials the content of sulphites is observed and the dependences of their transformation to sulphides via natural oxidation by air oxygen or by addition of adequate oxidant are studied. The work follows with describing the effect of sulphides contained in raw materials on the mechanical properties of composites prepared from several various matrices such as alumina or portland cement, lime or portland clinker. As for pure portland clinker the ability to retard the setting is also observed. The amount of contained sulphites is measured volumetrically via indirect titration of iodine surplus by sodium thiosulphate with the starch size as the indicator.

<p><strong>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</strong></p><p>Nastajanje i inhibicija stvaranja melanoidina u nečistim rastvorima saharoze je ispitivana na uzorcima neafinisanog i afinisanog C produkta na 80 [&deg;C].</p><p>Utvrdjena je zavisnost obrazovanja bojenih materija tipa melanoidina od vremena reakcije, od sadržaja suve materije, kao i od sadržaja i vrste aminokiselina.<br />Smanjenje obojenosti rastvora zavisi od koncentracije natrikum-sulfita i matematički je definisano Baule-Mitscherlichovim krivama zasićenja. Maksimalni efekat odbojavanja koji se može postići iznosi 30 [%] na 560 [nm], odn. 20 [%] na 420 [nm], ne razlikuje se za rastvore neafinisanog i afinisanog C produkta, a ostaje nepromenjen u vremenu od 1620 [min].</p><p>Povećanje koncentracike vodonik-peroksida je praćeno porastom količine bojenih materija prevedenih u leuko oblike, i produžavanjem vremena oksidacije. U odsustvu slobodnog vodonik-peroksida dolazi do reverzije boje rastvora.<br />Smanjenje obojenosti rastvora neafinisanog i afinisanog C produkta je signifikantno veće pri uzastopnom delovanju oksidacionog i redukcionog sredstva od smanjenja obojenosti postignutog njihovim pojedinačnim delovanjem. Efekti uzajamnog delovanja se ne menjaju u ispitivanom vremenu.</p> / <p><strong>Abstract was processed by technology for Optical character recognition (OCR).</strong></p><p>Reaction and inhibition of melanoidine formation in inpure solutions of sucrose were investigated on affinated and unaffinated C sugar samples carried out on 80 [&deg;C].<br />Melanoidin type colour formation dependending on reaction time, dry matter content and content and variety on amino acids has been studied.<br />Colour decrease in solutions depended on concentration of sodium sulphite and was mathematically defined by Baule-Mitscherlich curve of saturation. Maximum effect of colour decrease wich can be obtained was 30 [%] at 560 [nm], and 20 [%] at 420 [nm] wavelength respectively, and without any difference between affinated and unaffinated C sugar solutions, but it has stayed unchanged during reaction time of 1620 [min]. Hydrogen peroxide concentration rise was followed by increasing amounts of colour compounds transferred in leuco forms and by prolonged oxidation time. Absence of free hydrogen peroxide has induced the reverse formation of colour solutions.</p><p>Colour decrease in unaffinated and affinated C sugar solution was significantly larger, during subsequent treatment of oxidizing and reducing compounds, than during separate reactions. During reaction time the mutual treatment effect was unchangeable.</p>

Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions. The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions. The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose. The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps. Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers. <b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan

<p>Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions.</p><p>The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions.</p><p>The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose.</p><p>The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps.</p><p>Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers.</p><p><b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan</p>