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Benavente, Martha. "Adsorption of Metallic Ions onto Chitosan : Equilibrium and Kinetic Studies." Licentiate thesis, Stockholm : Kemiteknik, Chemical and Engineering and Technology, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4746.
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Ceteroni, Ilaria. "High-pressure adsorption differential volumetric apparatus (HP-ADVA) for accurate equilibrium measurements." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22274/.
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The volumetric system is a commonly used experimental method for gas adsorption measurements. Starting from the conventional volumetric system (single-branched), the development of differential (double-branched) apparatus has been proposed to overcome some criticalities connected to the original design. The following study is focused on the assessment of the high-pressure differential volumetric apparatus (HP-ADVA) built at the University of Edinburgh in order to discover and characterise system peculiarities at different experimental conditions, in terms of temperature and pressure. To do this, an integrated approach is proposed: an initial experimental campaign has been performed to take confidentiality with the apparatus, then, the experimental results were the starting point for the development of a sensitivity and error analysis aimed at describing the effect of each operating parameter into the final result. In this regard, a different analytical approach, compared to the ones commonly proposed in literature, has been proposed to closely reproduce the real system. Beyond having obtained promising results, some criticalities, matching what originally hypothesized from the experimental campaign, have been noted: valve volume effect and temperature control and measurements have been discovered being crucial aspects, and, supposedly, source of errors leading to explain the unexpected results obtained by the experimental campaign. Moreover, the importance of symmetry maintenance among the branches has been repeatedly confirmed in the analysis. Some recommendations aimed at improving the system set-up have been moved regarding the installation of a temperature control system and more accurate temperature measurement devices. Additionally, an accurate assessment and characterisation of pneumatically-actuated valves, as well as of the differential pressure transducer used for pressure measurement, before the installation, could be useful to reduce inaccuracies.
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Hendra, Adhi Pratama. "Comparison of Cs Adsorption Characteristics of Soils in Japan and Indonesia." Kyoto University, 2019. http://hdl.handle.net/2433/242915.
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Bakyayita, Kizito Grace. "Equilibrium and Kinetic Batch Studies of Cadmium and Lead sorption using Low Cost Biosorbents." Licentiate thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145004.
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Agricultural wastes; Albizia coriaria, Coffea canephora, Cyperus papyrus, Erythrina abyssinica and Musa spp were evaluated for uptake of aqueous Cd2+ and Pb2+ ions in single- and binary-component solutions. Untreated, base-treated and peroxide-treated biomasses were employed in batch studies. The optimal conditions for Cd2+ and Pb2+ ions biosorption were pH 3.5 – 5 for contact time 3.0 – 3.5 hours and biosorbent dosage 10 – 12.5 g/L. Base-treated biosorbents showed a 10 – 17 % sorption enhancement for Cd2+ ions and a 1.6 – 2.3 % uptake reduction for Pb2+ ions. The sorption capacities for Cd2+ and Pb2+ ions for base-treated biosorbents were between 1.738 and 1.760 mg g-1 compared to 1.415 – 1.539 mg g-1 for untreated materials. The maximum biosorption of peroxide treated materials in single component media was between 0.819 and 1.595 mg/g for Pb2+ ions and between 0.044 and 1.343 mg/g for Cd2+ ions while in binary component media it was between 0.472 and 1.303 mg/g for Pb2+ ions and between 0.008 and 0.195 mg/g for Cd2+ ions. The pseudo-second order kinetic model suitably fitted the Cd2+ and Pb2+ ions biosorption data with regression coefficients (R2); 0.892 – 1.000 for peroxide-treated materials and 0.9784 – 0.9999 for base-treated biosorbents which implied that the biosorption was mainly a chemisorption process. The base treated biosorbents had better sorption performance for Cd2+ ions than peroxide treated materials and untreated biomass whereas the order for Pb2+ ions biosorption was untreated > base treated > peroxide treated materials. All materials showed superior selectivity for Pb2+ ions biosorption in comparison to that of Cd2+ ions in single- and binary-component media. A. coriaria performed best of the base treated biosorbents while C. canephora performed best amongst peroxide treated materials for Cd2+ and Pb2+ ions biosorption in single-and binary-component media. In the competitive biosorption, Cd2+ ions showed higher synergistic effects than Pb2+ ions although Pb2+ ions were preferentially sequestered even when the Cd2+:Pb2+ ions ratio was increased through 3:2, 2:1, 3:1 and 5:1. Of the three isotherm models evaluated against the experimental data, the Langmuir model generally fitted the sorption data for both metals. Regression coefficients for the Langmuir model were; 0.983 ≤ R2 ≥ 1.000 for single-component and 0.939 ≤ R2 ≥ 1.000 for binary-component solutions which revealed that the biosorption was potentially monolayer. The biosorption equilibrium coefficient values and change in Gibbs’ free energy values showed that Pb2+ ions biosorption was more thermodynamically favoured than that of Cd2+ ions in single-component and binary-component media. The materials studied displayed potential for use as biosorbents for remediation of aqueous Cd2+ and Pb2+ ions.QC 20140508
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Burkhart, James D. "An assessment of the effectiveness of the Polanyi equilibrium theory at predicting adsorption isotherms." FIU Digital Commons, 1990. http://digitalcommons.fiu.edu/etd/1891.
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The Polanyi Equilibrium Theory proposes that a characteristic curve exist which can, after the application of certain abscissa scale factors, describe the adsorption of all compounds on a given carbon. A study was undertaken, using published data from several sources on a variety of compounds and carbons to challenge the most fundamental aspects of the Polanyi Adsorption Equilibrium Theory. Its effectiveness as a predictive model was tested by constructing characteristic curves and comparing the observed isotherm data to the Polanyi predictions.
The results support the existence of the characteristic curve. However, in several instances, experimental data was required to accurately determine the required scale factors. Data from several compounds indicates that these scale factors can be estimated from a single data point. A comparison of predicted to observed scale factors indicates that polarizability is effective in providing only an approximation of the true abscissa scale factors.
An additional adjustment for adsorbate density is required to correct for the theorized inefficient packing of the solids in the carbon pores. However, after these empirically determined scale factors are applied, an accurate depiction of the data results.
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Hyder, A. H. M. Golam. "Sorption Characteristics of Hexavalent Chromium [Cr(VI)] onto Bone Char and Bio-char." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171833.
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The sorption characteristics of hexavalent chromium [Cr(VI)] onto bone char and bio-char were evaluated as a function of pH, initial Cr(VI) concentration, and dosages of bone char and bio-char. Batch tests were conducted by using synthetic wastewater in this study. The effects of various initial Cr(VI) concentrations between 5 mg/L and 1000 mg/L were evaluated using bone char as a sorbent. A Cr(VI) removal efficiency of 100 % was achieved at pH 1 with 2 g of bone char in 50 mL of solution at 3 hours of reaction time using initial Cr(VI) concentration of 10 mg/L. About 100 % of Cr(VI) was removed at pH 2 with initial Cr(VI) concentrations of 10 mg/L using 4 g of bio-char in 200 mL of solution at 5 hours of reaction time. The initial Cr(VI) concentrations were varied between 10 mg/L and 500 mg/L when bio-char was used as the sorbent. The maximum sorption capacities of bone char and bio-char were determined to 6.46 mg Cr(VI)/g, and 1.717 mg Cr(VI)/g, respectively. Equilibrium, kinetics, and isotherms of the sorption process were also investigated. The sorption kinetics of Cr(VI) onto bone char and bio-char followed the second order kinetic model suggesting that the sorption reaction rate depends on two parameters, which might be the sorbate concentration and sorbent dosage. The Langmuir isotherm model was the best one for the description of sorption of Cr(VI) onto bone char and bio-char.
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Camacho, Bárbara Cassiana Rodrigues. "Experimental Gravimetric Adsorption Equilibrium of n-Alkanes and Alkenes, Carbon Dioxide and Nitrogen in MIL-53(Al) and Zeolite 5A." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/12140.
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Dissertação para obtenção do Grau de Mestre em
Engenharia Química e BioquímicaThe objective of this work was the measuring of adsorption equilibrium, by the gravimetric method. Experimental results are presented for the adsorption equilibrium of the series of n-alkanes, ethylene, nitrogen and carbon dioxide in two microporous materials, the metal-organic framework, MIL-53(Al) and zeolite 5A. Both of them have desirable characteristics for adsorption processes, such as the capture and storage of carbon dioxide, natural gas storage, separation of components of biogas, and separation of olefin/paraffin. The determination of the equilibrium of the pure components (ethane, propane, butane, ethylene, carbon dioxide and nitrogen) covers a wide range of thermodynamic conditions; temperatures between 303.15K and 373.15K, as well as pressure values between 0 and 50 bar. The adsorption equilibrium data were analyzed through the global adjustment for each adsorbate/adsorbent system, using the Sips and Toth models. The isosteric heat was also determined. The experimental data of methane, carbon dioxide and nitrogen were correlated successfully by the potential theory of adsorption collapsing into a single characteristic curve, independent of temperature. This analysis allows the extrapolation of adsorption data for other gases, for which no experimental data is still known. The adsorption capacity is generally higher in MIL-53(Al) than in zeolite 5A, and in the two adsorbents, the preferred adsorption capacity for carbon dioxide is a good indication that these materials have a strong potential in the capture and storage of carbon dioxide, in the purification of biogas or purification of methane from natural gas.
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Mofaddel, Nadine. "Contribution à l'étude de systèmes quaternaires : exploitation de sulfates alcalins et dédoublement de molécules chirales par formation de diastéréoisomères." Rouen, 1989. http://www.theses.fr/1989ROUES013.
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Dans le cadre de la détermination des domaines de cristallisation d'espèces définies dans un système d'ordre élevé, deux systèmes quaternaires sont étudiés. Le premier système est Na2So4 - K2SO4 – (NH4)2SO4 – H2O : l'isotherme 18°C est dressé, définissant les domaines de stabilité des différentes phases rencontrées. Le deuxième système est le système réciproque: l'isotherme 20°C montre la possibilité de dédoublement d'un composé racémique. Une étude critique des travaux antérieurs est apportée
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Pissetti, Fabio Luiz. "Preparação de redes modificadas de poli(dimetilsiloxano) com ion piridinio ou etilenodiamina : estudo da adsorção de ions metalicos em etanolico." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249701.
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Orientador: Yoshitaka GushikemTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Neste trabalho foram preparadas redes poliméricas com propriedades elastoméricas a partir do poli(dimetilsiloxano) (PDMS), modificadas com íon piridínio ou etilenodiamina. Os materiais preparados foram caracterizados por espectroscopia no infravermelho, análise termogravimétrica, calorimetria diferencial de varredura e ressonância magnética nuclear de C e Si. Os resultados destas análises mostraram que ambos os materiais apresentam boa estabilidade térmica e uma temperatura de transição vítrea de ~ 160 K. Os dados de RMN indicaram que rede foi formada pela reticulação das cadeias lineares de PDMS por ¿clusters¿ de siloxanos do tipo T, provenientes da hidrólise/condensação de 3-cloropropiltrimetoxissilano e do 2-aminoetil-3- aminopropiltrimetoxissilano. Além disso, por ensaios de intumescimento foi calculada a massa molecular média entre os nós da rede polimérica e também a densidade de reticulação dos materiais. Os valores encontrados sugerem um alto grau de reticulação para ambos os materiais estudados. A rede modificada com etilenodiamina apresentou a maior densidade de reticulação. Com intuito de avaliar a potencialidade dos materiais como adsorventes de íons metálicos de uma solução etanólica, foram obtidas isotermas de adsorção. Para o material modificado com o íon piridínio os metais estudados foram o Co, Cu e Fe, que foram retirados da solução com boa eficiência, 0,25, 0,29 e 0,45 mmol g, respectivamente. Os haletos metálicos foram adsorvidos pela rede polimérica modificada na forma de complexos aniônicos FeCl4¨, CuCl4 e CoCl4. Os resultados de UV-Vis sugeriram que os complexos formados na interface têm uma simetria tetraédrica ou tetraédrica distorcida. Para a rede modificada com etilenodiamina foram estudados os metais Cu, Ni e Fe. Neste caso o material apresentou uma elevada capacidade de adsorção para os cloretos de Fe (1,35 mmol g) e Cu (1,25 mmol g), enquanto que, para o Ni a capacidade de adsorção foi consideravelmente menor, 0,36 mmol g. Os resultados de espectro eletrônico para este material sugeriram que o cobre é adsorvido pela rede polimérica modificada na forma do complexo, [Cu(en)], com uma estrutura tetraédrica distorcida, enquanto que para o níquel os resultados sugeriram formação de um complexo octaédrico. Os dados obtidos nas isotermas de adsorção foram usados para calcular as constantes de equilíbrio para a adsorção dos íons metálicos. Estes resultados permitiram verificar que no material modificado com o íon piridínio a adsorção de CoCl2 e CuCl2 segue o modelo descrito por Langmuir. Para a adsorção do FeCl3 outro modelo, em que centro adsorvedor é composto por dois grupos ligantes, foi necessário para descrever o processo de adsorção. Neste caso, há um efeito cooperativo entre as espécies formadas na superfície. Para o material modificado com etilenodiamina, os cálculos mostraram que a adsorção dos três íons metálicos pode ser descrito adequadamente pelo modelo de Langmuir
Abstract: In this work elastomeric polymeric networks based on poly(dimethilsiloxane) PDMS, modified with pyridine ion or ethylenediamine, were prepared. These materials were characterized by infrared spectrometry, thermogravimetric analysis, differential scanning calorimetry and nuclear magnetic resonance (NMR) of Si and C. The results showed that both materials presented a good thermal stability and a glass transition temperature at ~ 160 K. The NMR data indicated that the polymeric network was formed by PDMS linear chain crosslinked with siloxane clusters of T Si units formed from hydrolyses/condensation of 3-chloropropyltrimethoxysilane or 2-aminoethyl-3- aminopropyltrimethoxysilane. Using the swelling measurements, the average molecular weight between crosslinking points and the polymeric network crosslinking density were calculated. The results obtained suggested a high degree of crosslinking for the prepared materials, which was higher for the ethylenediamine. To evaluate the potential use of the prepared materials as adsorbents, adsorption isotherms were obtained from an ethanolic solution. For the polymeric network modified with pyridine ion the metallic ions studied were Cu, Co and Fe, which were adsorbed with high efficiency of 0.25, 0.29 e 0.45 mmol g, respectively. Metal halides were adsorbed by the modified polymeric network as an anionic complex, FeCl4¨, CuCl4 and CoCl4. The UV-Vis data suggested that the formed complexes at surface presented a tetrahedral symmetry or distorted tetrahedral symmetry. For The polymeric network modified with ethylenediamine, the metallic ions studied were Cu, Ni and Fe. In this case, the material showed a higher capacity of adsorption for Fe (1.35 mmol g) and Cu (1.25 mmol g), while, to Ni that capacity was significantly lower, 0.36 mmol g. The electronic spectra data suggested that the copper was adsorbed by the modified polymeric network as [Cu(en)], with a distorted tetrahedral symmetry, while the nickel was adsorbed with a octahedral symmetry. From the isotherm data, the equilibrium constants of the metallic ion adsorption were calculated. These results allowed verifying that the adsorptions of CoCl2 e CuCl2 are appropriate described by Langmuir equation. For the FeCl3 another model, which two adsorptions centers are envolved was necessary to describe the adsorption process. In this case, there was a cooperative effect among the adsorbed species. The results for polymeric network modified with ethylenediamine showed an adsorption described by the Langmuir equation for all metallic ions studied
Doutorado
Quimica Inorganica
Doutor em Ciências
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Norman, Per-Albin. "Filter Materials for Sorption of Cu and Zn in Stormwater Treatment: A Batch Equilibrium and Kinetic study." Thesis, Luleå tekniska universitet, Arkitektur och vatten, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68059.
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Urban stormwater is today recognized as a significant source of pollution that has contributed to the deterioration of water quality in lakes and streams. Of the pollutants, metals are commonly occurring in stormwater and can cause major damage when released into the receiving waters. A promising treatment method for removing these metals before it reaches the receiving waters is to filter the water in various filter technologies such as catch basin inserts. In this study, the potential of five materials to remove dissolved copper (Cu) and zinc (Zn) from stormwater was investigated. The study was initiated with batch equilibrium tests to assess the sorption capacity of the materials at different metal concentrations relevant for stormwater. This was done in both single and binary batches to investigate whether or not any competitive sorption occurred between the metals. Langmuir, Freundlich and Sips isotherm models were adapted to the obtained data. Through geochemical modelling, it was also possible to investigate whether precipitation of metals was likely. Finally, kinetic studies were conducted to investigate whether the reaction rate of Cu and Zn was relevant in the context of catch basin inserts. The results showed that the biochar had the highest sorption capacity followed by peat, bark, milkweed, and polypropylene. It could also be noted that Cu competed with Zn binding sites at high concentrations and that the sorption capacity of biochar, peat and bark, at concentrations between 50-100 μg/l Cu and 50-500 μg/l Zn, was sufficient to meet the limits set for stormwater emissions. For these sorbents, the reaction rate was also significant. Kinetics tests showed that at an initial concentration of 1,000 μg/l, 83% of the metals were sorbed after 5 minutes and after 10 minutes this number was 93%. Bark and peat also showed low effluent pH and leaching of dissolved organic carbon (DOC). The Langmuir and pseudo-second order equation could be well adapted to the data while geochemical modelling showed that precipitation of metals was unlikely. This suggests that chemical adsorption may be the mechanism that largely accounted for the removal of Cu and Zn. The results of this study can hardly be used to estimate the field performance of stormwater filters, but can be used as a basis for comparing and selecting sorbents for subsequent column tests.I denna studie undersöktes potentialen för fem material att avskilja löst koppar (Cu) och zink (Zn) från dagvatten. Studien inleddes med skaktest för att testa sorptionsförmågan hos materialen vid olika metallkoncentrationer relevant för dagvatten. Detta gjordes i både singel och binära test för att undersöka om någon konkurrerande sorption skedde mellan metallerna. Langmuirs, Freundlichs och Sips isotermmodeller anpassades även till resultatet. Genom geokemisk modellering var det även möjlig att undersöka om utfällning av metaller var sannolik. Till sist gjordes kinetiska studier för att undersöka om reaktionshastigheten för sorption av Cu och Zn till filtermaterialen var relevanta i ett brunnsfiltersammanhang. Resultaten visar att biokol hade den största sorptionsförmågan följt av torv, bark, sidenört och polypropylen. Det kunde även konstateras att koppar konkurrerade om sorptionsplatser för zink vid högre koncentrationer och att sorptionskapaciteten för biokol, torv och bark, vid koncentrationer mellan 50-100 µg/l Cu och 50-500 µg/l Zn, är tillräckligt hög för att uppfylla gränsvärdena för utsläpp av dagvatten. För dessa sorbenter var reaktionshastigheten betydande. Kinetiktesten visade att vid en initial koncentration på 1,000 µg/L var 83% av metallerna sorberade efter 5 minuter och efter 10 minuter var denna siffra uppe i 93%. Bark and torv uppvisade även ett lågt uppmätt pH och lakade löst organisk kol (DOC). Langmuir och pseudo-andra ordningens ekvation kunde anpassas väl till datat samtidigt som den geokemiska modelleringen visade att utfällning av metaller var osannolikt. Detta antyder att kemisk adsorption kan vara den mekanism som till störst del stod för avskiljningen av Cu och Zn. Studien kan inte fastställa något om filtermaterialens fältprestanda, men kan användas som underlag för att jämföra och att välja sorbenter för efterföljande kolumntester.
Formas project 2016-75
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Dergal, Fatiha. "Captage du CO2 par les amines demixantes." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10211.
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Actuellement, le captage du CO2 par lavage aux amines est la technique la plus avancée et la plus adaptée pour répondre au besoin de tous les types d'installations industrielles émettrices de CO2. Cependant, cette technique présente un certains nombre de problèmes. Le problème principal est la forte énergie associée à la régénération du solvant qui rend le procédé de captage très couteux. Afin de réduire ce coût, différents procédés en rupture ont été étudiés dans le cadre du FUI « ACACIA » regroupant plusieurs entreprises (IFPEN, RHODIA/SOLVAY, ARKEMA, LAFARGE, Gaz de France, VEOLIA) et quatre laboratoires académiques (LMOPS, LSA, LTIM (ex-LTSP), IRCELyon): - Captage par formation d'hydrates de gaz . - Utilisation d'enzymes conduisant à des procédés moins énergivores. - Utilisation de « multiamines » en vue d'accroitre la quantité de CO2 absorbé ou d'amines « démixantes » permettant de régénérer uniquement la phase riche en CO2 (d'où minimisation de l'énergie de régénération). Notre contribution à ce consortium a été l'étude de sept amines ou multiamines démixantes : - Trois amines commerciales (la N-Méthylpipéridine, la 2-Méthylpipéridine et la molécule A). - Quatre « multiamines » de structures confidentielles synthétisées par LMOPS représentées par les sigles B, D, E, F. Le phénomène de démixtion est influencé par de nombreux facteurs tels que la température, le taux de charge et la concentration en amine de la solution. La compréhension et l'explication de ce phénomène est l'un des objectifs de cette thèse. La donnée essentielle qui permet d'évaluer les performances potentielles d'une solution absorbante est l'isotherme d'absorption du CO2. Nous avons déterminé ces isothermes aux températures proches de l'absorbeur et du régénérateur (respectivement 40°C et 80°C) pour différentes concentrations en amine (26%, 30%, 50% et 66%) et pour des pressions en CO2 variant entre 10 kPa et 200 kPa. La modélisation thermodynamique des isothermes d'absorption permet de déduire les paramètres opératoires importants du procédé qui mettraiten ouvre ces amines (capacité cyclique, enthalpie moyenne de réaction, débit de solvant…etc.) permettant ainsi le dimensionnement de l'unité d'absorption et l'estimation de sa consommation énergétique. L'étude expérimentale a été complétée par la détermination des équilibres liquide-vapeur des amines pures et des différentes solutions aqueuses d'amines au moyen de la méthode statique. Ces données permettent de prévoir les pertes possibles en amine dans le régénérateur donc le coût des appoints dans le procédé. Parmi les sept amines étudiées, l'amine nommée « F » est un bon candidat pour une application industrielle économe en énergie (bonne capacité d'absorption, faible énergie de régénération, faible volatilité)Nowadays, CO2 capture by amines solvents is the most advanced technology to reduce CO2 industrial emissions. However, this technology presents some concerns. The major problem of this process, using monoethanolamine (MEA), is the high energy needed to regenerate the solvent and makes the process of CO2 capture very expensive. In order to reduce the high cost associated to the energy of regeneration, various breakthrough processes have been studied within the framework of FUI «ACACIA» which include several companies (IFPEN, RHODIA/SOLVAY, ARKEMA, LAFARGE, Gas of France, VEOLIA) and four academic laboratories (LMOPS, LSA, LTIM (ex-LTSP), IRCELyon): - CO2 Capture with gas hydrate formation. - Use of enzymes leading to process of less energy-consuming. - Use of multiamines to increase the quantity of CO2 absorbed or demixing amines which only allow the regeneration of the rich phase in CO2 (low cost for regeneration energy). Our contribution into the consortium has been the study of seven demixing amines or multiamines: - Three commercial amines (the N-Methylpiperidine, 2-Methylpiperidine and the molecule A). - Four « multiamines » with confidentiel structures synthesized by LMOPS and denoted by the initials B, D, E, F. The demixing phenomenon is influenced by many factors such as temperature, the loading of the acid gas and the amine concentration of the solution. The understanding of this phenomenon is one of the objectives of this thesis. The essential data to estimate the potentials efficiency of solvent to capture CO2 is the isotherm of absorption. We have determined these isotherms at temperatures close to the absorber and regenerator units (respectively 40°C and 80°C) at different concentrations of amine ((26%, 30%, 50% and 66%) and pressures of CO2varying between 10 kPa et 200 kPa. The thermodynamic modelling of the isotherms of absorption allows to deduce important operating parameters of the process (cyclic capacity, average enthalpy of reaction, solvent flow...) and to dimension the absorption unit and to estimate its energy consumption. The experimental study has been completed by the determination of vapor-liquid equilibrium of pure amines and of different aqueous solutions of amines with the static method. These data allow anticipating the possible loss in amine in the regenerator. Among the studied amines, the one denoted with the initial « F » is a potential candidate for an industrial application energy-efficient (good CO2 absorption capacity, low regeneration energy, low volatility)
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PETRONI, SERGIO L. G. "Avaliacao cinetica e de equilibrio do processo de adsorcao dos ions dos metais cadmio, cobre e niquel em turfa." reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11138.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Kadaifci, Bijen. "Multicomponent Ion Exchange On Zeolite 4a." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613916/index.pdf.
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In this study binary and ternary ion exchange on Zeolite NaA using silver and cadmium ions were investigated. Ion exchange were conducted at constant temperature (25oC) and normality (0.1N) in a batch system for both binary and ternary experiments. Zeolite weights were varied between 0.1 and 1 g for binary experiments.
Thermodynamic analysis of binary ion exchange between Cd2+-Na+ and Ag+-Na+ were examined and thermodynamic equilibrium constant and Gibbs free energy were calculated. Thermodynamic equilibrium constants were found as respectively 28.2 and 300.4 for Cd2+-Na+ and Ag+-Na+ binary system. Standart free energy of Cd2+-Na+ and Ag+-Na+ binary exchange were calculated as -4.1 kJ/mol and -14.1 kJ/mol
respectively. In literature Ay (2008) calculated the Gibbs free energy for Ag+-Na+ binary system as -14.4 kJ/mol and Biskup and Subotic (2010) and Gal et al. (1970) calculated the Gibbs free energy for Cd2+-Na+ binary system as -3.7 kJ/mol and -4.4
kJ/mol respectively. It is concluded Zeolite 4A has higher affinity to silver than cadmium and selectivity sequence was found asAg+>
Cd2+>
Na+. Langmuir and Freundlich isotherms were drawn to describe experimental data. As compared the R2 of isotherms, it is clearly seen that Freundlich isotherm provides better fit for Cd2+-Na+ binary ion exchange and Ag+-Na+ binary ion exchange. The ternary ion exchange isotherms were plotted using equivalent fraction of three ions (Ag+,Na+,Cd2+) which participated in ion exchange experiments to determine selectivity of zeolite 4A for cadmium and silver. Selectivity sequence was determined as Ag+ >
Cd2+ >
Na+ for ternary ion exchange.
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Teye, Frederick David. "Continuous flash extraction of alcohols from fermentation broth." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/31418.
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A new method of in situ extraction of alcohols from fermentation broth was investigated. The extraction method exploited the latent advantages of the non-equilibrium phase interaction of the fluid system in the flash tank to effectively recover the alcohol. Carbon dioxide gas ranging from 4.2L/min to 12.6L/min was used to continuously strip 2 and 12% (v/v) ethanol solution in a fermentor with a recycle. Ethanol and water in the stripped gas was recovered by compressing and then flashing into a flash tank that was maintained at 5 to 70bar and 5 to 55oC where two immiscible phases comprising CO2-rich phase (top layer) and H2O-rich phase (bottom layer) were formed. The H2O-rich bottom layer was collected as the Bottoms. The CO2-rich phase was continuously throttled producing a condensate (Tops) as a result of the Joule-Thompson cooling effect. The total ethanol recovered from the extraction scheme was 46.0 to 80% for the fermentor containing 2% (v/v) ethanol and 57 to 89% for the fermentor containing 12% (v/v) ethanol. The concentration of ethanol in the Bottoms ranged from 8.0 to 14.9 %(v/v) for the extraction from the 2 %(v/v) ethanol solution and 40.0 to 53.8 %(v/v) for the 12% (v/v) fermentor ethanol extraction. The Bottoms concentration showed a fourfold increase compared to the feed. The ethanol concentration of the Tops were much higher with the highest at approx. 90% (v/v) ethanol, however the yields were extremely low. Compression work required ranged from 6.4 to 20.1 MJ/kg ethanol recovered from the gas stream in the case of 12% (v/v) ethanol in fermentor. The energy requirement for the 2% (v/v) extraction was 84MJ/kg recovered ethanol. The measured Joule-Thompson cooling effect for the extraction scheme was in the range of 10 to 20% the work of compressing the gas. The lowest measured throttle valve temperature was -47oC at the flash tank conditions of 70bar and 25oC. Optimization of the extraction scheme showed that increasing the temperature of the flash tank reduced the amount of ethanol recovered. Increasing the pressure of the flash tank increased the total ethanol recovered but beyond 45bar it appeared to reduce the yield. The 12.6L/min carbon dioxide flow rate favored the high pressure(70bar) extraction whiles 4.2L/min appeared to favor the low pressure(40bar) extraction. The studies showed that the extraction method could potentially be used to recover ethanol and other fermentation products.Master of Science
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Silva, Bianca de Carvalho Munhoz. "Estudo da adsorção de chumbo (Pb) por ensaios de equilíbrio em lote em materiais inconsolidados: município de Eldorado Paulista (Vale do Ribeira - SP)." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-06032014-103946/.
Full textAbstract:
O conhecido histórico de contaminação por passivos da mineração de galena (PbS) da região do Vale do Ribeira (SP) faz com que seja de grande importância o estudo da adsorção de Pb com a finalidade de determinar a capacidade de sorção de materiais inconsolidados do município de Eldorado Paulista (SP) para serem empregados como barreira selante na contenção da lixiviação de metais por resíduos de mineração (com destaque para o Pb). O objetivo do presente trabalho foi avaliar a adsorção de Pb por meio de ensaios de equilíbrio em lote. Para realizar tal objetivo, foram coletadas 4 amostras de materiais inconsolidados (3 transportados e 1 residual) no município de Eldorado Paulista, anteriormente caracterizadas. Foram realizados ensaios de caracterização dos materiais (MO, \'delta\'pH, compactação e permeabilidade) visando determinar as principais características que influenciam na retenção de metais, assim como ensaios de equilíbrio em lote para avaliar a capacidade de adsorção de Pb. O ensaio BET foi realizado com amostras triplicatas dos 4 solos, empregando concentrações iniciais de Pb aproximadas de 30, 60, 90 e 120 mg L-1, massa de solo de 20 g, tempo de contato de 24 horas e razão massa/solução de 1/5. Com os resultados obtidos foram confeccionadas isotermas de sorção segundo os modelos Linear, de Freundlich e Langmuir I e II. Os resultados indicaram que os materiais inconsolidados transportados T2 e T3 são os mais adequados para o emprego em barreira selante para contenção de Pb, sendo suas capacidades de adsorção influenciadas, principalmente, pelo teor de óxidos de ferro e fração argila. As melhores sorções foram obtidas para os solos T2 e T3 para concentrações iniciais aproximadas entre 30 e 120 mg L-1. Desta forma, conclui-se que o ensaio BET foi adequado para determinação da adsorção por metais.The known history of contamination by galena (PbS) mining liabilities from Ribeira Valley region (SP) provides importance to the Pb adsorption study in order to determine the sorption by unconsolidated materials from Eldorado Paulista city (SP) to be employed as liners to contain metals leaching derived from mining (with emphasis on Pb). The objective of the current work was assess the Pb adsorption by Batch Equilibrium Tests. To accomplish this objective, 4 unconsolidated materials samples were collected in Eldorado Paulista, previously characterized. Characterization tests were performed (MO, \'delta\'pH, compaction and permeability) to determine the main characteristics that influence the retention of metals, and Batch Equilibrium Tests to assess soils capacities of Pb adsorption. BET was performed with triplicate samples of the 4 materials, applying initial Pb concentrations around 30, 60, 90 and 120 mg L-1, mass of soil about 20 g, mass/solution rate of 1/5 and 24 hours of contact time. the results provide sorption isotherms modeled by Linear, Freundlich and Langmuir I and II equations. The results indicated that unconsolidated materials T2 and T3 are the best suited for use in liners to retain Pb, and their sorption capacities are mainly influenced by iron oxides content and clay content. Best sorption were obtained to soils T2 and T3 with initial concentrations about 30 to 120 mg L-1. Thus, it is concluded that BET is appropriated to determine metals adsorption.
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Betiol, Lilian Fachin Leonardo [UNESP]. "Estudo das isotermas de adsorção do bagaço de mandioca proveniente da indústria de fécula." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/145009.
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As isotermas de sorção tornaram-se importantes para prever o comportamento da cinética de secagem e as condições de armazenamento de resíduos da indústria alimentícia. O conhecimento de tal propriedade é útil para projetar equipamentos ou operações para fins de armazenamento ou processamento. O bagaço quando é apenas descartado, representa um desperdício de matéria prima, de compostos orgânicos com categoria bioquímica definida (proteínas, açúcares, ceras, graxas, resinas), que poderia ser aproveitada. Dentro deste contexto, a presente pesquisa teve como objetivo caracterizar quimicamente o bagaço de mandioca e fazer a determinação experimental das isotermas de sorção destes resíduos da indústria de fécula, além de calcular a entalpia e entropia, temperatura media harmônica e calor isostérico de adsorção. Para isso, o teor de umidade de equilíbrio nas isotermas de sorção, de bagaço de mandioca, foi determinado utilizando o método gravimétrico estático nas temperaturas de 20 a 80 °C. Modelos teóricos e empíricos foram usados para representar os valores experimentais das isotermas de sorção, sendo que o modelo de GAB foi o que apresentou os melhores ajustes. Utilizando o modelo de GAB foi possível determinar o calor isostérico de adsorção como função do teor de umidade. A teoria da compensação foi confirmada pela relação linear entre entalpia e entropia. Maiores valores de temperatura isocinética do que a temperatura harmônica reforçam a teoria da compensação e sugeriram que a adsorção de água pelo bagaço de mandioca é considerado um processo conduzido pela entalpia.
The sorption isotherms become important to predict the drying kinetics behavior and waste storage conditions of the food industry. The knowledge of such property is useful for designing equipment or operations for storage or processing. The bagasse is only when discarded, is a waste of raw materials, organic compounds with defined biochemical category (proteins, sugars, waxes, greases, resins), which could be harnessed. Within this context, this study aimed to chemically characterize the Cassava Bagasse and make the experimental determination of the sorption isotherms of these starch industry waste and calculates the enthalpy and entropy, harmonic average temperature and isosteric heat of adsorption. For this, the equilibrium moisture content in the sorption isotherms of cassava bagasse was determined using the gravimetric static method in temperatures 20-80 ° C. Theoretical and empirical models were used to represent the experimental values of sorption isotherms, and the GAB model was the one that presented the best fit. Using the GAB model was possible to determine the isosteric heat of adsorption and moisture content of the function. The theory of compensation was confirmed by the linear relationship between enthalpy and entropy. Isokinetic higher temperature values than the harmonic temperature reinforce the theory of compensation and suggested that the adsorption of water by mancioca bagasse and considered one of enthalpy driven process.
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Serarols, i. Font Joan Lluís. "Adsorció d'or i zinc amb resines impregnades XAD-2. Superfície d'Equilibri, un nou concepte per a l'adsorció." Doctoral thesis, Universitat de Girona, 2001. http://hdl.handle.net/10803/7889.
Full textAbstract:
Dins dels processos de recuperació de metalls de dissolucions diluïdes s'ha realitzat un estudi del procés d'extracció d'or i de zinc mitjançant resines amberlite XAD-2 impregnades amb sulfur de triisobutil fosfina (TIBPS) i àcid di-(2-etilhexil) fosfòric (DEHPA) respectivament.S'ha realitzat un estudi de l'equilibri de l'adsorció d'espècies metàl·liques d'aquests metalls amb les resines indicades anteriorment. Amb la metodologia emprada per a la determinació dels punts d'equilibri dels experiments en batch i en columna, s'ha vist que una única isoterma no podia descriure el fenomen global d'equilibri i que en funció de la metodologia emprada s'obtenien isotermes diferents.
Es va introduir una nova variable per poder explicar el fenomen observat, i per tant, amb aquesta nova variable l'equació de la isoterma es converteix amb l'equació d'una supèrfície que s'ha definit com a Superfície d'Equilibri.
S'han determinat les equacions de les Suprfícies d'Equilibri dels sistemes d'adsorció estudiats (Au(III) TIBPS/XAD-2 i Zn(II) DEHPA/XAD-2) observan una bona coincidència de tots els punts d'equilibri obtinguts sobre la superfície, així com, un bon ajust de totes les isotermes obtingudes en funció de les diferents metodologies emprades sobre les respectives superfícies d'equilibri. Aquest nou concepte generalitza el concepte d'isoterma d'un procés d'adsorció.
Fimalment, s'ha plantejat un model matemàtic d'adsorció per a determinar el coeficient efectiu de difusió (De) i el coeficient de transferància de matèria (kf) per ambdós sistemes d'adsorció estudiats mitjançant l'aplicació del model de difusió de sòlid homogeni (HSDM), utilitzant com a condició de contorn en el model la isoterma de Langmuir obtinguda mitjançant els experiments en columna de llit fix i emprant també l'equació obtinguda mitjançant el nou concepte de Superfície d'Equilibri.
Els resultats obtinguts són molt satisfactoris, per tant, es pot concloure que la Superfície d'Equilibri és una bona eina per a descriure l'equilibri en els processos d'adsorció d'or i zinc amb les resines amberlite XAD-2 impregnades amb TIBPS i DEHPA respectivament.
The study of the extraction process of gold and zinc with Amberlite XAD-2 resins impregnated with tri-isobutylphosphine sulfide(TIBPS) and di-(2-ethylhexyl) phosphoric acid (DEHPA), respectively, has been studied.
The equilibria governing the metallic ions adsorption by the studied systems have been established. Taking into account the methodology used to get the equilibria points corresponding to batch and column experiments performed, it was noticed that a unique isotherm could not describe the global equilibrium and that different isotherms were obtained in function of the experimental methodology carried out.
It was introduced a new variable for explaining the phenomenon observed. By doing this, the isotherm became a surface that it was called equilibrium isotherm.
The equations corresponding the Equilibrium Surfaces of the adsorption systems studied (Au(III) / TIBPS-XAD-2 and Zn(II) / DEHPA-XAD-2) were determined. The equilibria points obtained by batch and column experiments as well as obtained isotherms were very well placed on the surface. Thus, this new concept generalises the concept of isotherm in an adsorption process.
Finally, the homogeneous solid diffusion model (HSDM) was applied for performing an adsorption mathematical model for determining the effective diffusion coefficient (De) and the mass transfer coefficient (kf) of both studied systems.
The obtained results were very successful, so, it can be concluded that the Equilibrium Surface is a very good tool for describing the equilibria of the studied adsorption processes.
18
Shi, Yi-Ling, and 施易靈. "Equilibrium Isotherms of Gases from Heat Decomposition of Polymers on Activated Carbon." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/72499021669000790553.
Full textAbstract:
碩士中原大學
化學工程研究所
97
There are many polymer products used in homes and therefore there is great concern about the toxic compounds which may be produced from these polymers in case of fire. In this study, the toxic compounds and the ingredients from the heat decomposition of polymer products are analyzed. The experimental adsorption equilibrium data and the regression model for the isotherm curves of the decomposed gases as the reference of authenticate the witness at fire and the security data base for firemen. PET, Nylon6, Nylon66, PS, PP and PE have been selected to represent typical polymer products found in homes. The decomposed gases on heating from these polymers are studied by TGA-ATD-GC/MS. Part of the decomposed gases which are seriously influence the health of humen are selected as the adsorbate in the equilibrium adsorption study. These toxic gases are conducted to the adsorption equilibrium apparatus, which is designed by the weight method with a high accurate microbalance, to obtain the adsorption equilibrium isotherm data. On the basis of the adsorption equilibrium data, activated carbon was selected in this study in the adsorption of decomposed gases. The major reason is that the specific surface area of activated carbon is much larger than the other adsorbents. It provides more activated sites to the molecules of decomposed gases therefore these toxic gases adsorption is more efficient. The adsorption of aromatic, alkane, alkene, alcohol, ketone, epoxide, and acid gases form the heat decomposition of polymers is good for the adsorption by activated carbon and the adsorption uptake for acid gases is the highest. The regression model for the equilibrium isotherm data is III developed in this study also.
19
Chien, Yu-cheng, and 簡宇程. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing Butylated Hydroxytoluene." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/tf5zsf.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
99
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of 2-tert-butyl 4-methyl phenol + butylated hydroxytoluene and 2,6-di-tert-butyl phenol + butylated hydroxytoluene at temperatures from 433.15 K to 473.15 K. The experimental results showed no azeotrope formation and positive deviations from ideality in each binary system. While the vapor pressure data of pure substances were fitted to the Antoine equation , the binary VLE data were correlated with the Wilson, the NRTL and the UNIQUAC models, respectively.
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Setim, Alison Jacqueline Pestana. "Upgrade of an experimental volumetric unit for gas adsorption equilibrium studies." Master's thesis, 2014. http://hdl.handle.net/10362/13767.
Full textAbstract:
In this work, a volumetric unit previously assembled by the research group was upgraded. This unit revamping was necessary due to the malfunction of the solenoid valves employed in the original experimental setup, which were not sealing the gas properly leading to erroneous adsorption equilibrium measurements. Therefore, the solenoid valves were substituted by manual ball valves.
After the volumetric unit improvement its operation was validated. For this purpose, the adsorption equilibrium of carbon dioxide (CO2) at 323K and 0 - 20 bar was measured on two different activated carbon samples, in the of extrudates (ANG6) and of a honeycomb monolith (ACHM). The adsorption equilibrium results were compared with data previously measured by the research group, using a high-pressure microbalance from Rubotherm GmbH (Germany) – gravimetric. The results obtained using both apparatuses are coincident thus validating the good operation of the volumetric unit upgraded in this work.
Furthermore, the adsorption equilibrium of CO2 at 303K and 0 - 10 bar on Metal-Organic Frameworks (MOFs) Cu-BTC and Fe-BTC was also studied. The CO2 adsorption equilibrium results for both MOFs were compared with the literature results showing good agreement, which confirms the good quality of the experimental results obtained in the new volumetric unit. Cu-BTC sample showed significantly higher CO2 adsorption capacity when compared with the Fe-BTC sample.
The revamping of the volumetric unit included a new valve configuration in order to allow testing an alternative method for the measurement of adsorption equilibrium. This new method was employed to measure the adsorption equilibrium of CO2 on ANG6 and ACHM at 303, 323 and 353K within 0-10 bar. The good quality of the obtained experimental data was testified by comparison with data previously obtained by the research group in a gravimetric apparatus.
21
Khoiroh, Ianatul, and 何安娜. "Isothermal Vapor-Liquid Equilibrium for Mixtures of Oligomeric Materials with Alcohols." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/cq9jdx.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
97
A vapor pressure apparatus was installed to measure isothermal vapor-liquid equilibrium (VLE) data for seven binary systems of polybutadiene + methylene chloride (341.1 to 409.0) K, polyethylene glycol mono-4-octylphenyl ether (PEGOPE) + methanol at (341.0 to 403.1) K, PEGOPE + ethanol at (342.6 to 454.1) K, PEGOPE + 2-propanol at (350.1 to 453.3) K, polyethylene glycol mono-4-nonylphenyl ether (PEGNPE) + methanol at (340.6 to 414.7) K, PEGNPE + ethanol at (341.9 to 414.1) K, and PEGNPE + 2-propanol at (351.5 to 454.5) K. Equilibrium pressure measurements were conducted to obtain P-T-x data. The experimental data were correlated by using the Antoine equation to regress the Antoine constants. These VLE data were further treated using the Barker’s method and correlated with the UNIQUAC and the Polymer NRTL activity coefficient models, respectively. The correlation results showed good agreement between the calculated values and the experimental data. The solvent activities of the experimental results are also reported and agree fairly well with the calculated values from the UNIQUAC equation.
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Tsai, Yu-Shiou, and 蔡瑀修. "Isothermal Vapor-Liquid Phase Equilibrium for Mixtures Containing Sulfolane or 3-Methylsulfolane." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/m2cdb7.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
107
The total pressure method was used to measure the isothermal vapour-liquid equilibrium data for the binary systems of sulfolane or 3-methylsulfolane＋1,3,5-trimethylbenzene, and ternary systems of sulfolane＋1,2,4-trimethylbenzenen-heptane, n-octane, n-nonane, methylcyclopentane or methylcyclohexane at 363.15 K, 393.15K, 433.15 K, 473.15 K in this study. There is no azeotropic behavior in any system. Additionally, the VLE data of six binary systems of sulfolane＋ benzene, toluene, o-xylene, m-xylene, p-xylene or cyclohexane were collected from open literature. The NRTL-ideal and NRTL-HOC model was applied to correlate all the VLE data and determine the optimal values of model parameters for 13 binary or ternary systems.
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Tai, Wen-ping, and 戴文平. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing Furfural and Its Derivatives." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/93511184412777568276.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
101
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of 2-methylfuran + furfuryl alcohol, isopropanol + furfuryl alcohol, and furan + furfural at 353.15 K, 373.15 K, and 408.15 K. The experimental results showed no azeotrope formation and positive deviations from ideality in each binary system. The vapor pressures of pure 2-methylfuran were also measured from 348.15 K to 409.02 K and fitted to the extended Antoine equation. The thermodynamic consistency of the new binary VLE data has been confirmed by the point, area, and infinite dilution tests. The Wilson-HOC, the NRTL-HOC, and the UNIQUAC-HOC models were used to correlate the VLE data. Satisfactory results have been obtained from each model.
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Wu, Dong-ha, and 吳東樺. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing Methanol and Methyl Esters." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/42748756038182860920.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
97
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of methanol + methyl palmitate , methanol + methyl oleate, and methanol + methyl linoleate at temperatures from 353.15 K to 403.15 K. The experimental results showed no azeotrope formation and positive deviation from ideality in each binary system. The Antoine equation fitted the vapor pressure data of pure substances to within an average absolute percentage deviations of 1 %. Binary VLE data were correlated with the NRTL-HOC, the UNIQUAC-HOC, and the Wilson-HOC models, respectively.
25
Liao, Wei-hsun, and 廖威勳. "Isothermal Vapor-Liquid Equilibrium for Mixtures Containing C4H6 Hydrocarbons and DMF or NMP." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/9y5zg9.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
102
With a synthetic method, a high-pressure phase equilibrium analyzer (PEA) with a visual-variable volume cell was used to measure the vapor-liquid phase equilibrium data for ethyl acetylene + DMF, ethyl acetylene + NMP, 1,3-butadiene + DMF, 1,3-butadiene + NMP, and 1,3-butadiene + [NMP/water = 2.09/1 (in molar ratio)] at temperatures from 298.15 K to 348.15 K and pressures from 1 bar to 10 bar. All the phase equilibrium data of binary and ternary systems were correlated with the NRTL-HOC and the UNIQUAC-HOC models, respectively, and simultaneously determined the optimal values of the binary parameters.
26
Chen, Tzu-Ying, and 陳姿穎. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures of Ethylene Glycol Purification Related Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/p6wqwn.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
103
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of solvent A + 1,2-butanediol and solvent A + ethylene glycol at 393.15 K, 423.15 K, and 453.15 K. And also measured the binary systems of solvent B + 1,2-butanediol at 353.15 K, 393.15 K, 433.15 K, and 473.15 K, and solvent B + ethylene glycol at 393.15 K, 433.15 K, and 473.15 K. The experimental results exhibit no azeotropic behavior and positive deviations from Raoult’s law for each binary system. The thermodynamic consistency of the new binary VLE data has been confirmed by the point, area, and infinite dilution tests. The Wilson-HOC, the NRTL-HOC, and the UNIQUAC-HOC models were used to correlate each binary system measured in this work. Each model yielded satisfactory results.
27
Lin, Bo-Ting, and 林柏廷. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures of Containing Water and Ionic Liquids." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/55710848611930312632.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
104
In the present study, the total pressure method was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of water + choline glycolate , water + diethylmethylammoniummethane sulfonate , water + 1-ethyl-3-methylimidazolium acetate , water + 1-ethyl-3-methylimidazolium diethylphosphate , and water + tetrabutylammorimum 2-(bis(2-hydroxyethyl)amino)acetic acid at 278.2 K to 413.2 K. The experimental results show that all binary systems are negative deviations. The UNIQUAC model was applied used to correlate the VLE data for each binary system. The correlated results are satisfactory. The thermodynamic model with the determined optimal parameters was also employed to calculate excess Gibbs free energies, excess enthalpies, and excess entropies for each investigated binary system.
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Chen, Yi-chiao, and 陳奕樵. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing Methyl Acetate, Methyl Propionate and Methyl Butyrate." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/fxyc3g.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
94
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of methyl acetate + methyl propionate, methyl acetate + methyl butyrate, and methyl propionate + methyl butyrate at temperatures from 353.15 K to 453.15 K. The experimental results exhibited no azeotrope formation and positive deviation in each binary system. The Antoine equation fitted the vapor pressure data of pure components to within an average absolute percentage deviations of 1％. Binary VLE data were correlated satisfactorily with the NRTL-HOC, the UNIQUAC-HOC and the Wilson-HOC models.
29
Shen, Chi-Jen, and 沈祈任. "Isothermal Vapor-Liquid Phase Equilibrium for Binary Systems Containing n-Nonane or Methylcyclohexane and Hydrocarbons." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/975h7q.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
107
In the present study, the static total pressure method was used to measure the isothermal vapor-liquid equilibrium (VLE) data for eight binary systems of n-nonane + n-hexane, n-nonane + n-octane, n-nonane + methylcyclopentane, n-nonane + methylcyclohexane, n-nonane + 1,3,5-trimethylbenzene, methylcyclohexane + n-octane, methylcyclohexane + methylcyclopentane, methylcyclohexane + 1,3,5-trimethylbenzene at 363.15 K, 393.15 K, 433.15 K and 473.15 K, including mole fraction of 0.2, 0.4, 0.6, 0.8. There are sixteen isothermal VLE data points for each system. The experimental results show that no azeotrope is formed over the entire temperature range. Additionally, the VLE data of three binary systems of n-hexane + n-octane, n-hexane + benzene, n-hexane + n-heptane are also obtained from open literature. In this study, the Aspen Plus is used to correlate the above VLE data with the NRTL-HOC model and determined the optimum values of the NRTL model parameters for each binary system. The results show that the NRTL-HOC model can accurately describe the VLE behavior of these eleven systems.
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Ho, Yon Ling, and 何永齡. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing Methanol, Glycerol, n-Butylamine and Methyl Ester." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/cw247f.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
95
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of methanol + glycerol , n-butylamine + glycerol at temperatures from 353.15 K to 403.15 K, and methanol + methyl palmitate at temperatures from 333.15 K to 373.15 K. The experimental results exhibited no azeotrope formation in each binary system. The Antoine equation fitted the vapor pressure data of pure components to within an average absolute percentage deviations of 1.5％. Binary VLE data were correlated satisfactorily with the NRTL-HOC, the UNIQUAC-HOC and the Wilson-HOC models.
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Hähnel, T., S. Frenzel, J. Möllmer, C. Reichenbach, and G. Kalies. "Immersion enthalpies and adsorption isotherms of liquids on carbon molecular sieves." 2017. https://ul.qucosa.de/id/qucosa%3A31665.
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連萬智. "The numerical investigation for the equilibrium solution paths of a Non-isothermal diffusion and reaction model." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/22855710201699155013.
Full textAbstract:
碩士國立新竹教育大學
人資處數學教育碩士班
94
The purpose of this paper is to numerically investigate the equilibrium solution paths of non-isothermal diffusion and reaction model. The main theories we used are Newton iterative method, Implicit Function Theorem, local continuation method, Secant Predictor and Pseudo-arclength continuation algorithm to find out the multiple solutions within limited range of parameters. Therefore we can investigate and change various parameters to gain different solutions. Finally we will determine all the turning points.
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Ho, Hsiao-yun, and 賀孝芸. "Isothermal Vapor-Liquid Equilibrium for Binary Mixtures Containing the Major Compounds of Diphenyl Carbonate Production System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/75653281225613832607.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
102
A static-type apparatus with a liquid-phase circulation loop was used to measure isothermal vapor-liquid equilibrium (VLE) data for the binary systems of ethyl acetate + diethyl carbonate, ethyl acetate + diphenyl carbonate, diethyl carbonate + diphenyl carbonate and phenyl acetate + diphenyl carbonate at 373.15 K, 413.15 K, and 453.15 K. And also measured the binary systems of ethyl acetate + phenyl acetate, and diethyl carbonate + phenyl acetate at 373.15K.The experimental results exhibit no azeotropic behavior and positive deviations from Raoult’s lawfor each binary system. The thermodynamic consistency of the new binary VLE data has been confirmed by the point, area, and infinite dilution tests. The Wilson-HOC, the NRTL-HOC, and the UNIQUAC-HOC models were used to correlate each binary system measured in this work.Each model yielded satisfactory results.
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錢元俊. "Phase equilibria isothermal section and liquidus projection of thermoelectric Co-Sb-Ga alloys." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/47618064835598764992.
Full textAbstract:
碩士國立清華大學
化學工程學系
101
CoSb3 is an important thermoelectric material. Recent studies indicate that Ga alloying in CoSb3 could further improve its figure of merit, zT. The Co-Sb-Ga ternary system is thus of high interests for thermoelectric applications. Phase diagrams are fundamental for understanding of phase transformation and materials microstructures, which are closely related to the materials thermoelectric properties. Phase diagrams are thus crucial for development of thermoelectric materials. The Co-Sb-Ga liquidus projection and the 650℃ Co-Sb-Ga phase equilibria isothermal section are constructed in this study. As-cast Co-Sb-Ga alloys were prepared, and their primary solidification phases were determined. The Co-Sb-Ga liquidus projection was constructed based on the experimental results of primary phases, and the phase diagrams of its three constituent binary systems. The primary solidification phases are the three terminal solid solution phases, six binary compounds: CoGa, CoGa3, GaSb, CoSb3, CoSb2, CoSb and a ternary compound- Co3Sb2Ga4 which has not been reported before; Ternary Co-Sb-Ga alloys equilibrated at 650℃ as well. The equilibrium phases and their compositions were determined. Four three-phase regions and one two-phase region have been determined. The liquidus projection and the 650℃ isothermal section were also calculated using Calphad method. Both experimental determinations and the calculated results are qualitatively in good agreement.
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Chiu, Chen-nan, and 邱政男. "Isothermal phase equilibria and liquidus projection of the quaternary Sn-Ag-Cu-Ni system." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/47150919794036449258.
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Viddal, Candice April Harder. "Non-equilibrium effects in nanoparticulate assemblies, bond-disordered ferromagnets, and collections of two-level subsystems." 2009. http://hdl.handle.net/1993/3123.
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The central concern of this thesis is the study of non-equilibrium behaviour in magnetic materials and its interpretation within the framework of the Preisach model of hysteresis. Comprehensive experimental characterizations of the field and temperature and time dependence of a suite of standard magnetic response functions have been performed on a variety of magnetic materials, including a naturally occurring mineral of nanodimensional titanomagnetite particles embedded in volcanic glass, a compressed powder of nanodimensional magnetite particles immobilized in an organic binder, a thin film of nanodimensional Fe particles embedded in alumina, and a series of sintered, bond-disordered CaxSr1-xRuO3 ferromagnets. The measurements were compared with numerical simulations based on a model Preisach ensemble of thermally activated two-level subsystems, characterized individually by a double well free energy profile in a two-dimensional configuration space, an elementary moment reversal, a dissipation field and a bias field, and characterized collectively by a distribution of these characteristic fields. Our efforts were concentrated on two principal spheres of investigation. (1) By performing detailed numerical simulations of the relaxation response of model Preisach collections of two-level subsystems under the same field and temperature protocols used to probe experimentally the relaxation dynamics of spin glasses, we have been able to show that aging, memory and rejuvenation effects are ubiquitous features of all materials which possess a broad distribution of free energy barriers which block the approach to thermal equilibrium. (2) We propose a general strategy for isolating and quantifying the two principal mechanisms, thermal fluctuations and barrier growth, which are jointly responsible for shaping the measured temperature dependence of the magnetic properties of all magnetic materials which exhibit a history dependent response to an external field excitation, and is based on the analysis of viscosity isotherms and, in particular, on a plot of T ln(tr/0) versus Ha , where tr is the time at which a viscosity isotherm measured in a field Ha at temperature T reverses sign. When thermal activation dominates barrier growth, this plot will yield a universal curve while, in the opposite limit the plot fractures into a family of isothermal curves. The strategy is applied to the analysis of each magnetic material listed above.February 2009
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Pandey, Vijai B. "Adsorption column studies to predict the flow of nutrients through heterogenous porous media under equilibrium and isothermal conditions." 2012. https://scholarworks.umass.edu/dissertations/AAI3536052.
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Because of the endangerment of life of the human beings due to the environmental pollution, a serious study of the pollution of the environment is most vital. Because of increasing surface water pollution there is great hazard of ground water pollution. About half the United States of America derives drinking water from aquifers and much of the projected demand is expected to be met from subsurface sources. Therefore, a study was needed to determine the process of ground water contamination due to nutrients, especially Nitrogen, its degree and Length and Time of Travel and factors inhibiting its flow through soil. The present study was undertaken at the 'Pine Crest Duck Farm' at Sterling, Massachusetts, where the nature of the soil was Gravely Sandy Loam and Three unlined (from the side and bottom) waste stabilization ponds existed and there was a great danger of ground water contamination due to Nitrogen in the vicinity of ponds and further. In the field, observation wells were installed along the redial line and bi-monthly samples of water were taken to monitor the levels of B.O.D., Ammonium, Nitrate and Nitrite Nitrogen. Since the Adsorption of the Nitrogen by the soil is great inhibitor in the movement of the Nitrogen through soil profiles, this study was undertaken to study the adsorptive capacity of the soil in 'Bench Tests' and to test the applicability and validity of various adsorption isotherms of nitrogen in the soil; to develop a dimensional model or prediction equation for the nitrogen in the soil under natural flow conditions by studying the effects of varying concentration and flow rates on the adsorptive capacity of the soil, based on the principles of similitude; to correlate adsorption values in bench and column tests; and to determine the length and time of travel of nitrogen through soil. The soil from the Farm was obtained from a depth of six feet with enough care so that original structure was maintained. Adsorptive capacity of the soil was determined through series of 'Bench Tests' and 'Soil Adsorption Columns' in the laboratory under temperature controlled chambers. From the Bench Tests Adsorption values of the soil at various concentrations of Ammonium, Nitrate and Nitrite Nitrogen were determined and validity and applicability of Adsorption isotherms were confirmed. To study the Adsorption Process under natural flow conditions 'Soil Adsorption Column Tests' were done by using never done before Dimensional Model Analysis of Factors affecting Adsorption and getting dimensionless numbers and further obtaining 'Break Through Curves' at different Concentration and flow rates and Adsorption Values were obtained for Ammonium Nitrogen and Nitrite Nitrogen. Finally, Component and Prediction Equations were obtained for Ammonium Nitrogen and Nitrate Nitrogen. By knowing the Adsorption Values of the soil Length and Time of Travel of Ammonium and Nitrate Nitrogen through soil was calculated at various Concentration Levels. A mathematical Prediction Equation was also obtained between Bench and Column Tests and Length of Time of Travel, t predict the adsorption values under natural flow conditions by just performing less time consuming Bench Tests. It was also found that under equilibrium Bench Test conditions and natural flow conditions, adsorption of Ammonium, Nitrate and Nitrite Nitrogen increased with increasing solution concentration and adsorption of Ammonium Nitrogen was considerably higher than Nitrate and Nitrite Nitrogen. It was further found that for solution concentrations of 20, 40, 60, 80 and 100 mg/l Ammonium Nitrogen and nitrate nitrogen will travel one foot distance in 183 and 115 days; 168 and 111 days; 148 and 98 days; 145 and 81 days; 130 and 98 days; and 127 and 97 days respectively. It was determined that at the present time contamination of shallow water wells does not pose Nitrogen contamination problem and installation of these wells beyond 300 feet radial distance from the waste stabilization ponds was safe.
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Jiann-Jyh, Shiau, and 蕭建智. "Isothermal Vapor-Liquid Equilibria for Mixtures of Methyl Acetate,Ethyl Acetate,and Methyl tert-Butyl Ether." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/65527716183273629154.
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WANG, YI-LIN, and 王一霖. "Isothermal Vapor-Liquid Equilibria for Mixtures Containing Water, Propylene Glycol Monomethyl Ether, and Propylene Glycol Monomethyl Ether Propionate." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/5k4z7n.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
100
A static-type apparatus equipped with a visual cell was utilized in the present study to measure isothermal vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE) data over a temperature range of 318.15 K to 363.15 K. The VLE data were determined experimentally for the binary systems of propylene glycol monomethyl ether (PGME) + propylene glycol monomethyl ether propionate (PGMEP). The VLLE data were also measured for water + PGMEP and water + PGME + PGMEP. The experimental data of the binary systems can be correlated well with the NRTL-HOC and the UNIQUAC-HOC models by using linearly temperature-dependent parameters. The ternary VLLE properties can not be estimated accurately by using the parameters determined from the phase equilibrium data of the constituent binaries. The ternary VLLE data were also used to test the validity of various versions of the UNIFAC model. The representation of the ternary VLLE properties is substantially improved as the parameters of the NRTL and the UNIQUAC models are determined simultaneously from the ternary VLLE data.
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YAO, JUN-XU, and 姚俊旭. "Isothermal phase equilibria of carbon dioxide with aromatics, heavy n-paraffins and heavy n-alkanol at subcritical and supercritical states." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/56999676364453247057.
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(5930285), Karen N. Son. "Improved Prediction of Adsorption-Based Life Support for Deep Space Exploration." Thesis, 2019.
Find full textAbstract:
Adsorbent technology is widely used in many industrial applications including waste heat recovery, water purification, and atmospheric revitalization in confined habitations. Astronauts depend on adsorbent-based systems to remove metabolic carbon dioxide (CO2) from the cabin atmosphere; as NASA prepares for the journey to Mars, engineers are redesigning the adsorbent-based system for reduced weight and optimal efficiency. These efforts hinge upon the development of accurate, predictive models, as simulations are increasingly relied upon to save cost and time over the traditional design-build-test approach. Engineers rely on simplified models to reduce computational cost and enable parametric optimizations. Amongst these simplified models is the axially dispersed plug-flow model for predicting the adsorbate concentration during flow through an adsorbent bed. This model is ubiquitously used in designing fixed-bed adsorption systems. The current work aims to improve the accuracy of the axially dispersed plug-flow model because of its wide-spread use. This dissertation identifies the critical model inputs that drive the overall uncertainty in important output quantities then systematically improves the measurement and prediction of these input parameters. Limitations of the axially dispersed plug-flow model are also discussed, and recommendations made for identifying failure of the plug-flow assumption.
An uncertainty and sensitivity analysis of an axially disperse plug-flow model is first presented. Upper and lower uncertainty bounds for each of the model inputs are found by comparing empirical correlations against experimental data from the literature. Model uncertainty is then investigated by independently varying each model input between its individual upper and lower uncertainty bounds then observing the relative change in predicted effluent concentration and temperature (e.g., breakthrough time, bed capacity, and effluent temperature). This analysis showed that the LDF mass transfer coefficient is the largest source of uncertainty. Furthermore, the uncertainty analysis reveals that ignoring the effect of wall-channeling on apparent axial dispersion can cause significant error in the predicted breakthrough times of small-diameter beds.
In addition to LDF mass transfer coefficient and axial-dispersion, equilibrium isotherms are known to be strong lever arms and a potentially dominant source of model error. As such, detailed analysis of the equilibrium adsorption isotherms for zeolite 13X was conducted to improve the fidelity of CO2 and H2O on equilibrium isotherms compared to extant data. These two adsorbent/adsorbate pairs are of great interest as NASA plans to use zeolite 13X in the next generation atmospheric revitalization system. Equilibrium isotherms describe a sorbent’s maximum capacity at a given temperature and adsorbate (e.g., CO2 or H2O) partial pressure. New isotherm data from NASA Ames Research Center and NASA Marshall Space Flight Center for CO2 and H2O adsorption on zeolite 13X are presented. These measurements were carefully collected to eliminate sources of bias in previous data from the literature, where incomplete activation resulted in a reduced capacity. Several models are fit to the new equilibrium isotherm data and recommendations of the best model fit are made. The best-fit isotherm models from this analysis are used in all subsequent modeling efforts discussed in this dissertation.
The last two chapters examine the limitations of the axially disperse plug-flow model for predicting breakthrough in confined geometries. When a bed of pellets is confined in a rigid container, packing heterogeneities near the wall lead to faster flow around the periphery of the bed (i.e., wall channeling). Wall-channeling effects have long been considered negligible for beds which hold more than 20 pellets across; however, the present work shows that neglecting wall-channeling effects on dispersion can yield significant errors in model predictions. There is a fundamental gap in understanding the mechanisms which control wall-channeling driven dispersion. Furthermore, there is currently no way to predict wall channeling effects a priori or even to identify what systems will be impacted by it. This dissertation aims to fill this gap using both experimental measurements and simulations to identify mechanisms which cause the plug-flow assumption to fail.
First, experimental evidence of wall-channeling in beds, even at large bed-to-pellet diameter ratios (dbed/dp=48) is presented. These experiments are then used to validate a method for accurately extracting mass transfer coefficients from data affected by significant wall channeling. The relative magnitudes of wall-channeling effects are shown to be a function of the adsorption/adsorbate pair and geometric confinement (i.e., bed size). Ultimately, the axially disperse plug-flow model fails to capture the physics of breakthrough when nonplug-flow conditions prevail in the bed.
The final chapter of this dissertation develops a two-dimensional (2-D) adsorption model to examine the interplay of wall-channeling and adsorption kinetics and the adsorbent equilibrium capacity on breakthrough in confined geometries. The 2-D model incorporates the effect of radial variations in porosity on the velocity profile and is shown to accurately capture the effect of wall-channeling on adsorption behavior. The 2-D model is validated against experimental data, and then used to investigate whether capacity or adsorption kinetics cause certain adsorbates to exhibit more significant radial variations in concentration compared than others. This work explains channeling effects can vary for different adsorbate and/or adsorbent pairs—even under otherwise identical conditions—and highlights the importance of considering adsorption kinetics in addition to the traditional dbed/dp criteria.
This dissertation investigates key gaps in our understanding of fixed-bed adsorption. It will deliver insight into how these missing pieces impact the accuracy of predictive models and provide a means for reconciling these errors. The culmination of this work will be an accurate, predictive model that assists in the simulation-based design of the next-generation atmospheric revitalization system for humans’ journey to Mars.