Dissertations / Theses on the topic 'Adsorption Separation'

To offset rising energy costs, it is becoming a necessity to lower energy usage within industrial processes. Such can be said for the separation of olefin/paraffin mixtures. An example of such a mixture is ethylene/ethane. This highly energy intensive industrial separation employs cryogenic distillation to achieve a high purity product. Subsequently, the energy cost to run such a system is extremely high. Hybrid scenarios have been explored, with adsorption being a potential candidate. This work studied the potential of three adsorbents for the separation of ethylene/ethane: AgNO3/SiO2, CuCl/SiO 2, and CECA 13X. AgNO3/SiO2 and CuCl/SiO 2 were both prepared in the laboratory. Pure component constant volume experiments were conducted, along with binary mixture predictions for all three adsorbents at 3 different temperatures. The expected working capacities were also calculated for the three adsorbents. Finally, an economic analysis, without taking competitive adsorption in to factor, was conducted to give a rough idea of how much a potential PSA system would cost using the three adsorbents individually. CuCl/SiO2 yielded the most favorable results of the three adsorbents, but more studies were determined necessary on the optimization of the preparation of the adsorbent. AgNO3/SiO 2 was not completely ruled out, however. Both the adsorbents showed characteristics for a potential use within industry. CECA 13X was not considered a viable candidate for such a separation.

Recent years have seen a surge in interest into the properties of new materials, and their application in electronic devices. This project has used techniques common for colloidal systems in order to gain insight into these systems. The work has mainly focussed on single-walled carbon nanotubes (SWCNTs), however silicon nanowires have also briefly been studied. Pluronic block copolymers are commonly used to stabilise SWCNTs in water, most commonly F127. Such dispersions were studied using small-angle neutron scattering (SANS) experiments performed at a range of solvent contrast systems. The data were successfully fitted to a relatively simple core-shell cylinder model. Data fitting was consistent with SWCNTs present in small bundles in dispersion, with an average radius of 10 A, surrounded by a water-swollen F127 layer of 61 A thickness, with a water content of 94% in the adsorbed layer. Increasing the temperature of F127 /SWCNT /D20 systems so that they were above the critical micellisation temperature (CMT) of the polymer was seen to have only a small impact on the polymer adsorption, with the adsorbed layer thickness increasing from ~55 to 65 A, and the adsorbed amount increasing by between 50 and 100% (from ~ 1 to 1.5 mg m- 2). Dispersions of SWCNTs in surfactant mixtures of SDS and sodium cholate (SC) are often used to separate SWCNTs by electronic type. SWCNTs were dispersed with SDS and studied using small-angle scattering techniques at various contrasts. Data were fitted to a core-shell cylinder model, and the fits were consistent with small SWCNT bundles of an average radius of 10 A, surrounded by an adsorbed layer of thickness 18 A. The adsorbed amount of SDS at the SWCNT surface was calculated to be 2.5 mg m-2 , however the adsorbed amount at the SDS headgroup/water interface was calculated to be 0.85 mg m- 2 , a value closer to previously reported values for the adsorption of SDS on carbon surfaces. Subsequently, SWCNTs dispersed with SC and mixtures of SDS and SC (1:4 and 3:2 volume ratios of SDS:SC) were studied with SANS, and the dimensions of the decorated SWCNTs were not seen to vary greatly between the different surfactants studied. Finally, the separation of nanoparticles has been investigated. The separation of SWCNTs based on their electronic properties using aqueous PEG/dextran twophase polymer systems was studied. Although absorbance spectra suggested that an electronic separation of SWCNTs had occurred, the process was found to be highly irreproducible. Additionally, variations in temperature were found to have little effect on partitioning and no separation by electronic type was seen when F127-dispersed SWCNTs rather than SC-stabilised SWCNTs were used, suggesting that, unlike F127, SC adsorbs differently to SWCNTs depending on their electronic type. Silicon nanowires (SiNWs) have also been briefly studied, and separating the nanowires by length was attempted using glass bead columns, however no significant separation by length was achieved.

A study has been undertaken of the vapor-phase adsorptive separation of n-alkanes from Kuwait kerosene (Kuwait National Petroleum Company, heavy kerosene) using zeolite molecular sieves. Due to the shortage of information on the adsorption of multicomponent systems in the open literature, the present investigation was initiated to study the effect of feed flowrate, temperature, and zeolite particle size on the height of mass transfer zone (MTZ) and the dynamic capacity of the adsorbent for multicomponent n-alkanes adsorption on a fixed-bed of zeolite type-5A. The optimum operating conditions for separation of the n-alkanes has been identified so that the effluent would also be of marketable quality. The effect of multicycle adsorption-desorption stages on the dynamic behaviour of zeolite using steam as a desorbing agent has been studied and compared with n-pentane and n-hexane as desorbing agents. The separation process comprised one cycle of adsorption using a fixed-bed of zeolite type-5A. The bed was fed with vaporized kerosene until saturation had been achieved whereby the n-alkanes were adsorbed and the denormalized material eluted. The process of adsorption-desorption was carried out isobarically at one atmosphere. A mathematical model has been developed to predict the breakthrough time using the method of characteristics. The results were in a reasonable agreement with the experimental values. This model has also been utilized to develop the equilibrium isotherm. Optimum operating conditions were achieved at a feed flowrate of 33.33 x 10-9 m3/s, a temperature of 643 K, and a particle size of (1.0 - 2.0) x 10-3 m. This yielded an HMTZ value and a dynamic capacity of 0.206 m and 9.6S3 x 10-2 kg n-alkanes/kg of zeolite respectively. These data will serve as a basis for design of a commercial plant. The purity of liquid-paraffin product desorbed using steam was 83.24 wt%. The dynamic capacity was noticed to decrease sharply with the cycle number, without intermediate reactivation of zeolite, while it was kept unchanged by intermediate reactivation. Normal hexane was found to be the best desorbing agent, the efficiency of which was mounted to 88.2%.

In this study methyl chloride was selected as the main adsorbate since it is one of the volatile organic compounds produced largely in industry. Nitrogen was the other adsorbate since air is composed of nitrogen by 79%. As adsorbents one in-house adsorbent; SBA-15 and three commercial adsorbents; HiSiv-3000 (ZSM-5 zeolite), activated carbon cloth, mesoporous activated carbon were used. Experiments of constant volume technique were performed in order to obtain adsorption isotherms of methyl chloride and nitrogen with the adsorbents mentioned above up to 1.6 arm in the temperature range of 21.5 and 80°C. Langmuir, Freundlich, Sips and Toth isotherm models were fitted to these isotherms. By using the Toth isotherm parameters adsorption isosteres were obtained. Henry's Law constants and heat of adsorption values were calculated. Expected working capacities for pressure swing adsorption (PSA), vacuum swing adsorption (VSA), temperature swing adsorption (TSA) were obtained and feasibility of these processes was discussed. The binary system behavior was also predicted for HiSiv-3000 and SBA-15 by using Extended Langmuir and Ideal Adsorbed Solution models. Methyl chloride adsorption breakthrough curves with HiSiv-3000 and SBA-15 for vacuum swing adsorption application was produced. The effects of modeling parameters such as temperature, inlet concentration, flow rate and bed length were investigated. It was concluded that mesocarbon is the best adsorbent to separate methyl chloride from air. Carbon cloth has the lowest heat of adsorption for methyl chloride. Prediction of binary system behavior showed that nitrogen adsorption is negligible. Mesocarbon shows the highest expected working capacities for PSA, VSA and TSA. VSA and TSA were found to be two promising processes for separation of methyl chloride from air. (Abstract shortened by UMI.)

A new concept of a "fiber sorbent" has been investigated. The fiber sorbent is produced as a pseudo-monolithic material comprising polymer (cellulose acetate, CA) and zeolite (NaY) by applying hollow fiber spinning technology. Phase separation of the polymer solution provides an appropriately porous structure throughout the fiber matrix. In addition, the zeolite crystals are homogeneously dispersed in the polymer matrix with high loading. The zeolite is the main contributor to sorption capacity of the fiber sorbent. Mass transfer processes in the fiber sorbent module are analyzed for hydrogen recovery and compared with results for an equivalent size packed bed with identical diameter and length. The model indicates advantageous cases for application of fiber sorbent module over packed bed technology that allows system downsizing and energy saving by changing the outer and bore diameters to maintain or even reduce the pressure drop. The CA-NaY fiber sorbent was spun successfully with highly porous structure and high CO2 sorption capacity. The fiber sorbent enables the shell-side void space for thermal moderation to heat of adsorption, while this cannot be applied to the packed bed. The poly(vinyl alcohol) coated CA-NaY demonstrated the thermal moderation with paraffin wax, which was carefully selected and melt at slightly above operating temperature, in the shell-side in a rapidly cycled pressure swing adsorption. So this new approach is attractive for some hydrogen recovery applications as an alternative to traditional zeolite pellets.

The development of new porous materials for use in applications such as gas storage and separation processes, catalysis, catalysts supports and the removal of environmentally unfriendly species has increased rapidly over the past decade. Research into the development of these new materials has been dominated by metal organic frameworks, covalent organic frameworks, nanoporous polymers and, most recently, porous organic cage molecules. This thesis describes adsorption studies of a metal organic framework, Zn (TBAPy) and a porous tetrahedral organic cage molecule of ~ 1 nm diameter formed by the condensation reaction of 1,3,5- triformylbenzene with 1,2-ethylenediamine. The development of metal organic frameworks has traditionally involved the formation of rigid network structures, analogous to that of zeolites. More recently the focus has shifted to those of dynamic, flexible framework materials, and the response of these materials to adsorption of gases and vapours. The metal organic framework Zn (TBAPy) is based on a zinc metal centre functionalised with benzoate fragments. The initial two-dimensional structure undergoes rearrangement of the paddlewheel units to form a 3D framework, Zn (TBAPy)' upon desolvation. The ability of this 3D network to separate p-xylene and m-xylene was investigated. It was found that these isomers produced different effects on the framework, with p-xylene producing a typical Type I isotherm, whereas m-xylene induced a structural change within the material, with a much slower rate of m-xylene adsorption at higher pressures. This could potentially lead to the equilibrium separation of these two isomers by the metal organic framework Zn (TBAPy)'. The 1 nm diameter tetrahedral cage molecules formed by the condensation reaction of 1,3,5-triformylbenzene with 1,2-ethylenediamine can exist in a number of stable polymorphs, Cage 1α, Cage 1β and Cage 1γ. These polymorphs can be interconverted by exposure to certain organic vapours/solvents. The conversion of Cage 1β to Cage 1α by adsorption of probe molecules ethyl acetate, 2-butanone, diethyl ether, pentane and methanol was studied. Adsorption of ethyl acetate, 2- butanone and diethyl ether produced unusual adsorption isotherms, which included desorption of adsorbed vapour with increasing pressure during the adsorption isotherms. This desorption is attributed to the structural change from Cage 1β to Cage 1α. The unusual desorption step is not observed for methanol or pentane adsorption. The adsorption of methyl acetate was studied over a wide temperature range in order to assess the thermodynamic and kinetic characteristics of the unusual desorption step. The adsorption of dichloromethane showed the reverse transformation of Cage 1α to Cage 1β, showing that the inter conversion produces stable polymorphs. The kinetics of the structural transformation followed an Avrami model and the mechanism is an activated process. Cage 1α has voids between the cages, which are connected by very narrow constrictions that allow the kinetic molecular sieving of oxygen, carbon dioxide and nitrogen. It was found that oxygen adsorbs approximately ten times faster than nitrogen on Cage 1α, with selectivity and rate constants similar to those observed for carbon molecular sieves. The thermodynamics and kinetic results are discussed in terms of structural characteristics and diffusion into molecular cage materials. The kinetic molecular sieving is not present in the polymorph Cage 1β, which has wider pores.

The thesis presents work regarding amphiphilic molecules associated in aqueous solution or at the liquid/solid interface. Two main topics are included: the temperature-dependent behavior of micelles and the adsorption of dispersants on carbon nanotube (CNT) surfaces. Various NMR methods were used to analyze those systems, such as chemical shift detection, spectral intensity measurements, spin relaxation and, in particular, self-diffusion experiments. Besides this, small angle X-ray scattering (SAXS) was also applied for structural characterization.   A particular form of phase transition, core freezing, was detected as a function of temperature in micelles composed by a single sort of Brij-type surfactants. In mixed micelles, that phase transition still occurs accompanied by a reversible segregation of different surfactants into distinct aggregates. Adding a hydrophobic solubilizate shifts the core freezing point to a lower temperature. Upon lowering the temperature to the core freezing point, the solubilizate is released. The temperature course of the release curves with different initial solubilizate loadings is rationalized in terms of a temperature-dependent loading capacity.   The behavior of amphiphilic dispersant molecules in aqueous dispersions of carbon nanotubes (CNTs) has been investigated with a Pluronic-type block copolymer as frequent model dispersant. Detailed dispersion curves were recorded and the distribution of the dispersant among different available environments was analyzed. The amount of dispersed CNT was shown to be defined by a complex interplay of several factors during the dispersion process such as dispersant concentration, sonication time, centrifugation and CNT loading. In the dispersion process, high amphiphilic concentration is required because the pristine CNT surfaces made available by sonication must be rapidly covered by dispersants to avoid their re-attachment. In the prepared dispersions, the competitive adsorption of possible dispersants was investigated that provided information about the relative strength of the interaction of those with the nanotube surfaces. Anionic surfactants were found to have a strong tendency to replace Pluronics, which indicates a strong binding of those surfactants.   CNTs were dispersed in an epoxy resin to prepare nanotube-polymer composites. The molecular mobility of epoxy was investigated and the results demonstrated the presence of loosely associated CNT aggregates within which the molecular transport of epoxy is slow because of strong attractive intermolecular interactions between epoxy and the CNT surface. The rheological behavior is dominated by aggregate-aggregate jamming.

QC 20180103

Due to environmental challenges, depleting oil resources, rising cost of oil and instability in oil-producing countries, biofuel production has attracted a lot of attention in recent decades. Biobutanol is one of the biofuels showing the most potential as an alternative for partly replacing petroleum-based fuels. Both researchers and industrialists are currently working at developing an energy-effective process to produce biobutanol at a large scale. Acetone-butanol-ethanol (ABE) fermentation is the biological process of biobutanol production and Clostridia are the most common bacteria used to produce biobutanol. However, there are several challenges in the butanol bioproduction process that should be addressed to make this process economically viable. The main challenge in the biobutanol production process is the low concentration of butanol in the ABE fermentation broth. It is therefore important to develop an efficient separation method. Several separation methods such as distillation, liquid-liquid extraction (LLE), pervaporation, gas stripping and adsorption have been considered to recover butanol from dilute solutions and ABE fermentation broths. Adsorption is considered as one of the most promising methods due to its high performance and energy efficiency for butanol separation. In this study, the focus was on developing an efficient separation method for butanol recovery from dilute model solution and fermentation broth using adsorption. A comprehensive adsorbent screening was first carried out to identify the best commercially available adsorbent among a series of potentially promising adsorbents. Activated carbon (AC) F-400 was selected for further experimentation since it showed high adsorption capacity and adsorption rate in addition to high selectivity toward butanol. AC F-400 was then tested extensively in packed adsorption column experiments for binary and ABE model solutions and fermentation broths to investigate the competitive adsorption between butanol and other components present in ABE broths. The results showed that the butanol adsorption capacity was not affected by the presence of ethanol, glucose and xylose while the presence of acetone led to a slight decrease in adsorption capacity at low butanol concentrations. On the other hand, the presence of acids (acetic acid and butyric acid) in the ABE broth showed a significant effect on the butanol adsorption capacity over a wide ii range of butanol concentration and this effect was more pronounced for butyric acid. At the end, different competitive adsorption isotherm models were also studied to appropriately represent the behaviour of the competitive adsorption. Desorption of butanol was subsequently investigated to evaluate both the desorption capacity of butanol and the capability of the adsorbent particles to be used for multiple adsorption-desorption cycles. The results of this set of experiments showed that AC F-400 can retain its initial adsorption capacity after 6 adsorption/desorption cycles. The recovery of butanol from butanol-water (1.5 wt%) binary and ABE model solutions was 84 and 80% with butanol adsorption capacity of 302 and 171 mg/g, respectively. The combination of adsorption and gas stripping techniques was also studied to investigate the performance of CO2 gas stripping of solvents from the model solutions and fermentation broths followed by adsorption. The results showed that the butanol adsorption capacity of the overall system for binary solutions (260 mg/g for a binary butanol-water solution of 15 g/L with vapour phase concentration of 5.8 mg/L), ABE model solutions (192 mg/g for a corresponding vapour concentration of 5.2 mg/L) and ABE fermentation broths (247 mg/g for a corresponding vapour phase concentration of 2.5 mg/L) was higher than what has been published in the literature. Finally, a model was developed and adequately validated the experimental data to predict the behaviour of the ABE compounds in a packed bed adsorption column for butanol separation from dilute solutions.

Metal-organic frameworks are a new class of porous materials that have potential applications in gas storage, separations, catalysis, sensors, non-linear optics, displays and electroluminescent devices. They are synthesized in a "building-block" approach by self-assembly of metal or metal-oxide vertices interconnected by rigid linker molecules. The highly ordered nature of MOF materials and the ability to tailor the framework's chemical functionality by modifying the organic ligands give the materials great potential for high efficiency adsorbents. In particular, MOFs that selectively adsorb CO₂ over N₂, and CH₄ are very important because they have the potential to reduce carbon emissions from coal-fired power plants and substantially diminish the cost of natural gas production. Despite their importance, MOFs that show high selective gas adsorption behavior are not so common. Development of MOFs for gas adsorption applications has been hindered by the lack of fundamental understanding of the interactions between the host-guest systems. Knowledge of how adsorbates bind to the material, and if so where and through which interaction, as well as how different species in adsorbed mixture compete and interact with the adsorption sites is a prerequisite for considering MOFs for adsorptive gas separation applications. In this work, we seek to understand the role of structural features (such as pore sizes, open metal site, functionalized ligands, pore volume, electrostatics) on the adsorptive separation of CO₂, CO and N₂ in prototype MOFs with the help of molecular modeling studies (GCMC simulations). Our simulation results suggest that the suitable MOFs for CO₂ adsorption and separation should have small size, open metal site, or large pore volume with functionalized groups. Some of the experimental challenges in the MOF based adsorbents for CO₂ capture include designing MOFs with smaller pores with/without open metal sites. Constructing such type of porous MOFs can lead to greater CO₂ capacities and adsorption selectivities over mixtures of CH₄ or N₂. Therefore, in the second project, we focused on design and development of small pore MOFs with/without open metal sites for adsorptive separation of carbon dioxide from binary mixtures of methane and nitrogen. We have synthesized and characterized several new MOFs (single ligand and mixed ligand MOFs) using different characterization techniques like single-crystal X-ray diffraction, powder X-ray diffraction, TGA, BET, gravimetric adsorption and examined their applicability in CO₂/N₂ and CO₂/CH₄ mixture separations. Our findings from this study suggest that further, rational development of new MOF compounds for CO₂ capture applications should focus on enriching open metal sites, increasing the pore volume, and minimizing the size of large pores. Flue gas streams and natural gas streams containing CO₂ are often saturated by water and its presence greatly reduces the CO₂ adsorption capacities and selectivities. So, in the third project, we investigated the structural stability of the developed MOFs by measuring water vapor adsorption isotherms on them at different humid conditions to understand which type of coordination environment in MOFs can resist humid environments. The results of this study suggest that MOFs connected through nitrogen-bearing ligands show greater water stability than materials constructed solely through carboxylic acid groups.

CO2 capture and conversion appears to be a prominent solution to mitigate greenhouse gas emissions (GHG) and global warming issue. Among different CO2 conversion approaches, CO2 hydrogenation via reverse water gas shift (RWGS) reaction is one of the most promising technology to convert CO2 to CO. Subsequently, CO is transformed to value added chemicals or liquid fuels. To improve the overall CO2 conversion for RWGS reaction, product separation and recycling is being proposed. In this research, adsorption separation technology has been explored to selectively separate CO from CO2 in RWGS using pressure swing adsorption (PSA) process. To investigate the adsorption capacity and selectivity of CO, different porous materials have been identified for CO separation. In this research, activated carbons, ordered mesoporous silica, and metal organic framework materials were studied. Equilibrium isotherms of CO and CO2 were measured in a gravimetric system at a temperature of 25 °C for pressures up to 20 bar. Preliminary adsorption isotherm results had shown an insufficient CO uptake and low selectivity level compared to CO2, thus not justifying their application for CO separation. Herein, to improve the CO adsorption capacity and selectivity, Cu-based adsorbents were developed using copper (II) chloride (CuCl2) as a precursor to synthesize six different adsorbents. The adsorbents were prepared using two different synthesis methods; the modified polyol method for reduction and nanoparticle deposition of Cu (I) ions, and thermal monolayer auto-dispersion method. Furthermore, different copper (II) loadings were investigated to determine the monolayer dispersion capacity of CuCl2 on the support. The modified adsorbents by copper salt exhibited significantly high CO uptake with large CO/CO2 selectivity, reversing the results obtained before adsorbent modification. Thus, Cubased adsorbents are promising materials for CO separation and recovery from a gaseous mixture containing CO2.

The overall objective of this thesis is to evaluate the fundamentals of current low concentration CO2 separation technologies and to provide an alternate method using adsorption technology with existing as well as new adsorbents. Two different applications for the adsorption of CO2 are explored; Direct Air Capture (DAC) and excimer gas purification. The investigation of aerogels as possible adsorbent for these applications was also explored. The first application, DAC of CO2 using adsorbents, addresses climate change by reducing the amount of atmospheric CO2 levels that are directly correlated to global warming. Because of DAC being carbon negative, this field has gained significant attention in the literature. DAC as a CO2 reduction strategy was approached in two ways: 1. Chapter 2 investigates capturing and concentrating CO2 from 0.04% in the air to 95% to be able to sequester it into the ground. This research began by doing an adsorbent selection using pure gas gravimetric measurements on seven different commercially available type X zeolites that were determined to have potential for this separation. Breakthrough experiments were then carried out with the most promising zeolite by perturbing the bed with compressed ambient air. In the process studied, a basic four step temperature vacuum swing adsorption (TVSA) cycle was investigated comprising the following steps: pressurization, adsorption, blowdown, and desorption. Four different regeneration temperatures were tested along with four different gas space velocities. With this cycle configuration, CO2 was concentrated to 95% from 0.04% with total capture fractions as high as 81%. This study highlighted methods to reduce the energy consumption per ton of CO2 captured in the system as well as the potential of using low Si/Al ratio faujasite structured zeolites in DAC of CO2 for greenhouse gas reduction. 2. Chapter 3 expands on the research of Chapter 2 by capturing CO2 from 0.04% in the air and concentrating it to high purity CO2 levels where the cost for operating the process will be reimbursed through the value of the produced CO2. The goal of this research was to increase the CO2 to as high as possible because the purer the CO2, the more valuable it is. This research started by conducting an in-depth investigation into the pure gas adsorption of CO2, N2, O2, and Ar on the most promising zeolite from Chapter 2. The data was then fitted to the TD-Toth model which allowed for the evaluation of the TVSA cycle and showed the potential of reducing the pressure and/or elevating the temperature during the blowdown step in order to produce high purity CO2. To confirm this, the TVSA cycle was run on a fixed bed breakthrough experiment where high purity CO2 was produced between a concentration of 99.5% and 99.96% by lowering the blowdown pressure. By controlling the blowdown temperature, the concentration of the product was increased from 99.8% to 99.95%, however with a significant loss of CO2. This effect of N2, O2, and Ar desorbing during the blowdown step with CO2 desorbing during the evacuation step is shown graphically by measuring the concentration and flow rate of the exiting gas species. The results from this study show the potential for producing a valuable product of high purity CO2 from atmospheric concentrations. The second application in this thesis that is explored in Chapter 4 is the purification of trace impurities of CO2, CF4, COF2, and O2 from F2, Kr, and Ne for applications in excimer lasers. Due to the incompatibility of many adsorbents to F2 and HF, aluminas and polymeric adsorbents were selected as potentially compatible materials. To increase the compatibility of these adsorbents, the use of a cryo-cooler was determined to be feasible to precool the feed stream before separation, which increases the adsorption capacity and compatibility of the material to F2 and HF. To determine the adsorption potential in the low concentration of these adsorbents, the concentration pulse chromatographic technique was chosen to determine the Henry’s Law constants of CO2, CF4, and O2. This data was then plotted on the van’t Hoff plot and extrapolated to colder temperatures to determine the benefit of using a cryo-cooler. From this study, it was determined that HayeSep Q was the best polymeric adsorbent with significant adsorption of CO2 at temperatures below -50˚C while being the best performing CF4 adsorbent. AA-300 was the best performing alumina in this study while having significant adsorption of CF4 at temperatures below -135˚C. However, from a compatibility standpoint, both of these materials need to be tested to determine their robustness in the presence of F2 and HF at room and reduced temperatures. Chapters 5 & 6 in this thesis explore the fundamentals of adsorption on aerogels as a prelude to using aerogels as possible adsorbents for DAC of CO2. This investigation into aerogels looks at silica aerogels and carbon aerogels, which are both industrially produced and explores their adsorption with relation to like materials such as silica gel and activated carbons. Both of these Chapters utilize experimentally determined adsorption isotherms of CO2, N2, O2, and Ar as well as characterization to determine adsorption trends in the materials. Some major conclusions for silica aerogels were that common surface modifications to make the material more resilient against water adsorption impacts the adsorption of CO2 significantly with roughly 4 fold difference in adsorption capacity. For carbon aerogels some major conclusions were that the adsorption was increasingly dominated by the heterogeneous nature of the surface at lower pressures and increasingly dominated by the pore size at the higher pressures. Both chapters discuss the adsorption of air along with ideas such as the influence of gas thermal conductivity in the pores with respects to adsorption. L'objectif général de cette thèse est d'évaluer les principes fondamentaux des technologies actuelles de séparation du CO2 à faible concentration et de fournir une méthode alternative utilisant la technologie d’adsorption avec des adsorbants actuels ainsi que d'en découvrir de nouveaux. Deux applications différentes pour l'adsorption du CO2 ont été explorées; la capture directe dans l’air ambient (CAD) et la purification des gaz excimères, ainsi que la recherche d'aérogels comme adsorbant possible pour ces applications. La première application, le CAD du CO2 utilisant des adsorbants, pourrait répondre aux changements climatiques puisque les niveaux de CO2 atmosphérique sont directement corrélés au réchauffement climatique. Dernièrement, le CAD a fait l'objet d'une attention particulière en tant que stratégie de réduction du CO2, par conséquent, deux voies différentes ont été explorées dans cette thèse: 1. Le chapitre 2 étudie la capture et la concentration du CO2 de 0,04% dans l'air à 95% afin de pouvoir l’enfermer dans la terre. Pour ce faire, une sélection d'adsorbant a été effectué en utilisant des mesures gravimétriques à gaz pur sur sept zéolithes de type X disponibles dans le commerce qui ont été déterminés comme ayant un potentiel pour cette séparation. Des expériences révolutionnaires ont ensuite été réalisées avec la zéolite la plus prometteuse en perturbant le lit avec de l'air ambiant comprimé. Dans le processus étudié, un cycle basique à quatre étapes d’adsorption modulée en température et pression (AMTP) a été étudié, comprenant les étapes suivantes: pressurisation, adsorption, purge et désorption. Quatre températures de régénération différentes ont été testées ainsi que quatre vitesses spatiales de gaz différents. Avec cette configuration de cycle, le CO2 était concentré à 95% de 0,04% avec des fractions de capture totales aussi élevées que 81%. Cette étude a mis en évidence des méthodes pour réduire la consommation d'énergie par tonne de CO2 captée dans le système ainsi que le potentiel d'utilisation de zéolithes structurées à base de faujasite à faible rapport Si/Al dans le CAD du CO2 pour la réduction des gaz à effet de serre. 2. Le chapitre 3 approfondit les recherches du chapitre 2 en capturant le CO2 de 0,04% dans l'air et en le concentrant à des niveaux de très haute pureté où le processus sera remboursé par la valeur du CO2 produit. L'objectif de cette partie était d'augmenter la pureté du CO2 le plus possible car plus le CO2 est pur, plus il est précieux. Une enquête approfondie sur l'adsorption de gaz pur de CO2, N2, O2 et Ar sur la zéolite la plus prometteuse du chapitre 2. Les données ont ensuite été ajustées au modèle TD-Toth qui a permis d'évaluer le cycle AMTP et a montré le potentiel de réduire la pression et/ou d'élever la température pendant l'étape de purge afin de produire du CO2 de haute pureté. Pour confirmer cela, le cycle AMTP a été fait par le biais d’une expérience dans un lit fixe où du CO2 de haute pureté a été produit entre une concentration de 99,5% et 99,96% en abaissant la pression de purge. En contrôlant la température de purge, la concentration du produit est passée de 99,8% à 99,95%, mais avec une perte importante de CO2. Cet effet de la désorption de N2, O2 et Ar pendant l'étape de purge avec la désorption du CO2 pendant l'étape d'évacuation est illustré graphiquement en mesurant la concentration et le débit des espèces de gaz sortant. Les résultats de cette étude montrent le potentiel de production d'un produit précieux de CO2 de haute pureté à partir des concentrations atmosphériques. La deuxième application de cette thèse qui est explorée au Chapitre 4 est la purification des traces d'impuretés de CO2, CF4, COF2 et O2 de F2, Kr et Ne pour des applications dans les lasers à excimère. En raison de l'incompatibilité de nombreux adsorbants avec le F2 et le HF, les alumines et les adsorbants polymères ont été sélectionnés comme matériaux potentiellement compatibles. Pour augmenter la compatibilité de ces adsorbants, l'utilisation d'un cryoréfrigérant a été jugée possible pour pré-refroidir le flux d'alimentation avant la séparation, ce qui augmente la capacité d'adsorption et la compatibilité du matériau en F2 et HF. Pour déterminer le potentiel d'adsorption dans la faible concentration de ces adsorbants, la technique de chromatographie pulsée de concentration a été choisie pour déterminer les constantes de la loi de Henry de CO2, CF4 et O2. Ces données ont ensuite été tracées sur le graphique van’t Hoff et extrapolées à des températures plus froides pour déterminer les avantages de l’utilisation d’un cryoréfrigérant. À partir de cette étude, il a été déterminé que HayeSep Q était le meilleur adsorbant polymère avec une adsorption significative de CO2 à des températures inférieures à -50 ° C tout en étant l'adsorbant CF4 le plus performant. L'AA-300 était l'alumine la plus performante de cette étude tout en ayant une adsorption significative de CF4 à des températures inférieures à -135 °C. Cependant, du point de vue de la compatibilité, ces deux matériaux doivent être testés pour déterminer leur robustesse en présence de F2 et de HF à température ambiante et réduite. Les chapitres 5 et 6 explorent les principes fondamentaux de l'adsorption sur les aérogels en prélude à l'utilisation d'aérogels comme adsorbants possibles pour le CAD du CO2. Cette enquête sur les aérogels examine les aérogels de silice et les aérogels de carbone, qui sont tous les deux fabriqués industriellement et explore leur adsorption par rapport à des matériaux similaires tels que le gel de silice et les charbons actifs. Ces deux chapitres utilisent des isothermes d'adsorption déterminés expérimentalement de CO2, N2, O2 et Ar ainsi que la caractérisation pour déterminer les tendances d'adsorption dans les matériaux. Certaines conclusions majeures pour les aérogels de silice étaient que les modifications de surface courantes pour rendre le matériau plus résistant à l'adsorption d'eau ont un impact significatif sur l'adsorption de CO2 avec une différence d'environ 4 fois dans la capacité d'adsorption. Pour les aérogels de carbone, certaines conclusions majeures étaient que l'adsorption était de plus en plus dominée par la nature hétérogène de la surface à des pressions plus faibles et de plus en plus dominée par la taille des pores aux pressions plus élevées. Les deux chapitres discutent de l'adsorption d'air ainsi que des idées telles que l'influence de la conductivité thermique du gaz dans les pores en ce qui concerne l'adsorption.

Non-ionic copolymers, such as poly(1-vinylpyrrolidone-co-styrene), are used in the production of filtration membranes and fibers because of their ability to provide both hydrophilic and hydrophobic character. However, their non-ionic character and solubility in water prevents inexpensive recovery from waste streams. Wood fibers show potential as recovery agents because they are inexpensive, environmentally friendly, and have a large surface area per unit mass (200 m2/g). However, due to the anionic nature of the fiber surface, their adsorptive behavior is often limited to cationic species. We have shown that low-dosage application of a cationic polyamide epichlorohydrin resin, Kymene 557H®, using a sequential adsorption process can alter the fiber surface charge so as to provide more neutral surface area for the non-ionic polymer to adsorb; furthermore, the adsorbed Kymene 557H® does not block the approach of poly(1-vinylpyrrolidone-co-styrene). Single-component adsorption of poly(1-vinylpyrrolidone-co-styrene) was on the order of 10-3 g/g; with Kymene 557H® adsorbed on the fiber, the adsorption increased one order of magnitude to 10-2 g/g. This significant increase is caused by neutralization of fiber surface charge via Kymene 557H® adsorption, creating a surface more favorable for adsorption and recovery of non-ionic species.

Adsorption in porous materials plays a significant role in industrial separation processes. Here, the host-guest interaction and the pore shape influence the distribution of products. Metal-organic frameworks (MOFs) are promising materials for separation purposes as their diversity due to their building block synthesis from metal corners and organic linker gives rise to a wide range of porous structures. The selectivity differs from MOF to MOF as the size and shapes of their pores are tuneable by altering the organic linkers and thus changing the host-guest interactions in the pores. Using mainly molecular simulation techniques, this work focuses on three types of separations using MOFs. Firstly, the experimental incorporation of calix[4]arenes in MOFs as a linker to create additional adsorption sites is investigated. For a mixture of methane and hydrogen, it is shown that in the calix[4]arene-based MOFs, methane is adsorbed preferentially over hydrogen with much higher selectivities compared to other MOFs in the literature. Remarkably, it was shown that extra voids created by calix[4]arene-based linkers, were accessible to only hydrogen molecules. Secondly, the strong correlation between different pore sizes and shapes in MOFs and their capabilities to separate xylene isomers were investigated for a number of MOFs. Finally, the underlying molecular mechanism of enantioseparation behaviour in a homochiral MOF for a number of chiral diols is presented. The simulation results showed good agreement with experimental enantioselectivity values. It was observed that high enantioselectivity occurs only at high loadings and when a perfect match in terms of size and shape exists between the pore size and the adsorbates. Ultimately, the information obtained from molecular simulations will further our understanding of how network topology, pore size and shape in MOFs influence their performance as selective adsorbents for desired applications.

Le biométhane est une source d'énergie verte qui, de part son coût et son faible impact environnemental, peut être considéré comme une alternative au gaz naturel et au diesel. La production d'énergie primaire par l'Union Européenne, à partir du biométhane, a été multipliée par 23 en cinq ans (2011-2016), ce qui rend nécessaire et urgent la recherche de nouvelles solutions performantes pour l’épuration du biogaz, notamment la séparation du dioxyde de carbone (CO2) du méthane (CH4).Dans ce contexte, l’objectif de ce travail doctoral porte sur la détermination des indicateurs de performances (capacité d’adsoprtion, sélectivité) de charbons actifs (CAs) dans le contexte de la séparation méthane/dioxyde de carbone pour la production de biométhane. A cette fin, les isothermes d'adsorption de CH4 et CO2 ont été déterminées à partir d’un dispositif manométrique d’adsorption. Les mesures ont été effectuées à des températures de 303 et 323 K pour des pressions variant de 0.1 à 3 MPa. Dans un premier temps, l’étude a porté sur 5 échantillons commerciaux de CA différents. Les résultats montrent une corrélation entre la surface spécifique et la quantité de dioxyde de carbone adsorbée. En outre, le volume microporeux a un impact significatif lors des processus d'adsorption du CO2 tandis que le volume des mésopores n'a pas d’effet direct.Par ailleurs, l'étude complémentaire d'isothermes d'adsorption du CH4 et du CO2 purs à l’aide de trois charbons actifs, issus de noyaux d’olive, activés par différentes méthodes de synthèse, révèle que la méthode d'activation est déterminante pour modifier les propriétés chimiques et structurales des charbons actifs et donc accroitre leurs propriétés d'adsorption.En outre, la sélectivité des CAs commerciaux pour la séparation CH4/ CO2 a été calculée à partir des isothermes d'adsorption du mélange équimolaire CH4/ CO2 à une température de 303 K et pour des pressions jusqu'à une pression de 3 MPa. Les résultats obtenus montrent qu’une surface spécifique élevée (< 1500 m2 g-1) facilite l'adsorption du CO2 mais réduit le facteur de sélectivité. En parallèle, une forte porosité conduit à une séparation moins efficace des deux gaz alors que la présence de groupes basiques en surface favorise les phénomènes d’adsorption du CO2.L'ensemble des résultats montre que les charbons actifs, étudiés dans ce travail de recherche, possèdent des propriétés d'adsorption comparables à celles des charbons actifs commerciaux et sont des matériaux compétitifs pour l'épuration du biogaz
Biomethane is a proven source of clean energy, it is one of the most cost-effective and environment-friendly substitute for natural gas and diesel. The European Union primary energy production from biomethane has folded by ~23 times in a 5 years time period (2011-2016) making necessary to find new and improved solutions for the separation of methane (CH4) and carbon dioxide (CO2), main components of biogas. In this context, the objective of this doctoral thesis is the determination of performance indicators such as the adsorption capacity and selectivity of activated carbons (ACs) for the CH4/ CO2 separation. This work focuses on the adsorption properties of activated carbons for the methane/carbon dioxide separation. To this end, CH4 and CO2 pure gas experimental adsorption isotherms of activated carbons were obtained on a pressure range of 0.1 to 3 MPa) and temperatures ranging from 303 to 323 K. The first part of this thesis project consisted in the analysis of the CH4 and CO2 pure gas adsorption properties of 5 commercial activated carbons Using a set of five commercial activated carbons a linear relationship between the adsorbent surface area and the CO2 adsorption capacity was determined. The micropore volume also showed a direct influence on the adsorption capacity. The second part of this work consisted in the study of the carbon dioxide and methane adsorption behavior of biomass-based activated carbons. Using a series of 3 ACs that had been obtained from olive stones by different activation methods, the activation technique proved to be of mayor importance as it determines the textural and chemical properties of the adsorbent and thus its gas adsorption capacity.Lastly, the CH4/CO2 adsorption selectivity of the 5 commercial activated carbons was calculated from the equimolar mixture adsorption isotherms. The selectivity factor was proven to be dependent on the sum of textural and chemical properties of the samples. Although, activated carbons with high average pore sizes and surface areas depicted higher adsorbed quantities it was on detriment of their selectivity. The selectivity was found to be better for the activated carbon showing an intermediate surface area and a narrow pore size distribution. In addition, the presence of sulfur functionalities was also found to improve the adsorption selectivity. Overall, this work shows that activated carbons are competitive materials for the upgrading of biogas, displaying adsorption properties comparable to those of other commercially available materials

Equilibrium adsorption properties are studied on zeolites for the application of upgrading biogas from landfills. Pure adsorption isotherms of carbon dioxide (CO2) and methane (CH4) measured with a constant volume apparatus. The Henry's Law constant and the heat of adsorption for NaLSX is also determined. The adiabatic working capacity and selectivity of four adsorbents is compared. NaLSX showed the highest capacity for CO2 at elevated temperatures. The binary equilibrium of CO2/CH4 on NaLSX is measured in a modified gas chromatograph at total mixture pressures of 1 and 3.3 atmospheres. The adsorbed phase is dominated by CO2 with a selectivity of 20 to 100 for the separation of CO2 and CH4. The increase in total pressure resulted in an increase in adsorbent capacity and a decrease in selectivity. Finally, an economic analysis relates landfill size to PSA operational costs and returns.

A magnetic functionalization of microcrystalline MOF particles was realized using magnetic iron oxide particles. Such magnetic MOFs can be separated using a static magnetic field after use in catalytic processes and heated by an external alternating magnetic field to trigger desorption of encaged drug molecules
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

The research presented in this thesis aims to determine the effectiveness of the uptake of toxic gases by several MOFs for future use in gas-mask cartridges, and to attempt to compensate for any deficiencies they show in “real-world” conditions. The main findings of this thesis confirm that MOFs are suitable candidates for the use in respirator cartridge materials and provide high capacity for adsorption of toxic gases like ammonia and STAM-1 in particular showed an impressive improvement in humid conditions, which normally decrease the performance of MOFs made from the same materials, such as HKUST-1. STAM-1's improved performance in humid conditions is attributed to the structural shift it displays upon dehydration and rehydration and this was shown to be the case in a structural analogue, CuEtOip, which was synthesised in the author's research group. This analogue was analysed using a combination of single crystal XRD and solid state MAS-NMR, both of which showed the structural change occurring and displays similar gas sorption behaviours, suggesting that this mechanism is the source of STAM-1's improved performance in humid conditions. This thesis also examines the “Armoured MOF” process and investigates the transferability of the process of deposition of mesoporous silica onto MOFs with vastly different properties and synthetic methods compared to those published in the original publication. Alongside this, attempts to protect MOFs using mesoporous silicates were investigated for their viability.

Filtration and separation technologies remain as one of the biggest challenges humanity currently faces. The separation of different elements such as bacteria, viruses, heavy metals, particles, and chemical agents require the development of multifunctional membranes. In membrane technology, one of the most promising fabrication techniques is electrospinning, which can produce highly tailored non-woven fibrous multifunctional membranes with a high surface area. On the other hand, cellulose derivatives, like cellulose acetate, have many beneficial properties for filtering technology such as high availability and easy functionalization. Likewise, cellulose nanocrystals are used to improve mechanical properties and functionalize membranes. In this project, a cellulose nanocrystal (CNCs) functionalized cellulose acetate electrospun multifunctional membrane is developed for adsorption and separation of nanosized particles.   In this work, cellulose acetate (CA) fibers with an average fiber diameter of approximately 900 nm were electrospun and tested as membranes for size and affinity based filtration. First, the electrospinning process was optimized regarding solution and process parameters. As a result, solution parameters were found to be 12 wt% solid content CA dissolved in a 1:1 acetone:acetic acid solution. Regarding process parameters, the suitable electrospinning parameters were found to be 18 kV applied voltage, a feeding rate of 5 mL/h, and a tip-to-collector distance of 20 cm.   The electrospun CA membrane was coated with cationic (+) and anionic (-) cellulose nanocrystals up to a 25 wt% concentration. The incorporation of CNCs, of either anionic or cationic surface charge, affected membrane wettability. The neat CA membrane had a hydrophobic behavior with a contact angle of 110°. The addition of CNCs decrease contact angle, to 31.5° for CA-CNCs(-) and 50° for CA-CNCs(+), which resulted in functionalized membranes with a hydrophilic behavior. Both functionalized membranes managed to maintain high flux values. CA-CNCs(-) maintained a flux of 9500 Lm−2h−1, while CA-CNCs(+) maintained a flux of 6700 Lm−2h−1.   The addition of cellulose nanocrystals improved the mechanical properties of the CA membranes. The tensile strength increases from 410 kPa to 4990 kPa for CA-CNCs(-) membranes and 3010 MPa for CA-CNCs(+) membranes, and is accompanied by an increase in Young’s modulus as well. To evaluate the adsorption efficiency and size-exclusion filtration, an anionic dye (Congo red), a cationic dye (Victoria blue), and 500 nm model particles were used. CA-CNC(-) membranes achieved a removal efficiency of 96% of 500 nm particles with an affinity-based dye removal of 63% of Victoria blue dye. On the other hand, CA-CNC(+) membranes achieved a removal efficiency of 43% of 500 nm particles with a dye removal of 27% of Congo red dye. In this regard, CA-CNC(-) membranes were the best candidate for size-exclusion filtration, while also maintaining a good level of adsorption.   Cellulose based composite membranes were successfully produced as multifunctional filters that could act in both size-exclusion regime and affinity-based regime. A cellulose acetate fibrous membrane was produced by electrospinning, tuning for fiber size and porosity, while the incorporation of cellulose nanocrystals functionalizes the membranes and enhance mechanical properties, and wettability.

Structure direction in the synthesis of phosphate-based materials (aluminophosphates, AlPOs; magnesiumaluminophosphates, MgAPOs; silicoaluminophosphates, SAPOs; magnesiumsilicoaluminophosphates, MgAPSOs), has been investigated through co-templating synthesis studies supported by molecular modelling. These solids have been characterised by diffraction and solid-state NMR, and their properties in gas adsorption and catalysis have been measured. The parameters in the hydrothermal synthesis of SAPO STA-7, St Andrews porous solid number 7, (SAV), in which the macrocycle 1,4,7,11- tetraazacyclotetradecane (cyclam) and tetraethylammonium (TEA) cations are used as co-templates, were investigated in detail. A new route involving a reversal of the mixing order of reagents leads to the formation of single crystals up to 50 μm with perfect tetragonal prismatic morphology that was not achieved via previous synthetic routes. For the first time in SAPO STA-7, X-ray diffraction locates the tetraethylammonium cation (TEA) in tg.tg. conformation. The synthesis and full characterisation of a novel aluminophosphate structure designated STA-14 (KFI) represents the first example of a designed synthesis of a zeotype. The synthesis route is based on a co-templating approach supported by molecular modelling to design the specific template for one of the two types of cages within the structure. The first, a larger type of cage, also present in AlPO-42 (LTA), is templated by the azaoxacryptand 4,7,13,16,21,41-diaza-1,10-bicyclo[8,8,8]- hexocosane (‘Kryptofix 222’, hereafter K222). The modelled co-template configuration, in this case TEA in the tt.tt configuration, was experimentally observed by X-ray diffraction. Modifying the gel chemistry leads to SAPO and MgAPSO STA-14, which display high pore volumes for N₂ adsorption, similar to those of STA-7 and SAPO-34 (CHA). Furthermore, during these synthetic studies, a novel fully tetrahedrally- coordinated magnesiumaluminophosphate layer phase has been prepared, with a structure of relevance to hypothetical VPI-5 (VFI) type extended structures. Molecular modelling was also applied in another aluminophosphate-based material, that of STA-2 (SAT), to predict a template that could be prepared from inexpensive reagents. Existing routes required the use of expensive quinuclidine as a precursor to the template 1,4-bisquinuclidinium butane. The template suggested by modelling, 1,4-diazabicyclo (2,2,2)octane butane (NC₆H₁₂N⁺-C₄H₈-⁺NC₆H₁₂N), labelled DABCO_C4, templated AlPO STA-2 successfully. Structure characterisation of the as- prepared form of AlPO STA-2 using X-ray synchrotron data suggest the formation of Al- OH-Al units to accommodate the positively-charged template within the neutral framework and a combination of ¹³C, ¹⁴N and ¹⁵N NMR studies have been used to give further details of the template environment in the cages. The gas adsorption behaviour of the stable materials STA-7, STA-14 and STA-2 was evaluated for CO₂. High pressure adsorption (0 to 40 bars) on STA-7 and STA-14 shows similar behaviour due to their structural and chemical similarities. The total uptake of CO₂ for SAPO STA-7 is less than for the zeolite NaX (FAU) (3.4 and 5.2 mmolg -1 respectively at 373 K and 12 bars) but the usable capacity for pressure swing adsorption technology (PSA) between 1 to 20 bar for STA-7 is twice the value for NaX. The affinity of adsorption towards CO₂ and its low uptake at 1 bar made SAPO STA-7 a desirable sorbent for PSA. The zeotype affinity of adsorption for different probe gases is different, CO₂ >> CH₄ > CO, to that for zeolite NaX CO₂ >> CO > CH₄. Low pressure CO₂ adsorption (0 to 1 bar) in STA-7, STA-14 and STA-2 at temperatures between 273 and 303 K demonstrates that the topology and therefore the total free pore volume accessible to the gas molecules is the most important factor in determining the uptake in these solids, but that the composition and distribution of the silicon cations within the framework also has an important effect. For example at 273 K and 1 bar, the uptake of the STA-2 framework in the SAPO form is ca. 2wt% higher than in the AlPO form, but compared with SAPO STA-7, the uptake due to pore volume limitations is 10wt% lower under same conditions. In addition, the high quality of the SAPO STA-7 crystals obtained by the new route made them suitable in collaborations for the direct observation of diffusion of methanol by interference microscopy (IFM) and the study of their crystal growth by combined atomic force microscopy (AFM) and high resolution scanning electron microscopy (HRSEM). The catalytic applications of the STA-7 and STA-14 for the methanol-to-olefins reaction (MTO) and the argon adsorption at 87 K were also performed collaboratively. The results are reported and discussed here in the light of their structure and composition.

A magnetic functionalization of microcrystalline MOF particles was realized using magnetic iron oxide particles. Such magnetic MOFs can be separated using a static magnetic field after use in catalytic processes and heated by an external alternating magnetic field to trigger desorption of encaged drug molecules.
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Les Metal-Organic Framework (MOF) sont des adsorbants très prometteurs pour la séparation des gaz. Formés de centres métalliques reliés par des ligands organiques, ces matériaux présentent une structure organisée avec des pores de taille contrôlée ainsi que des surfaces et des volumes poreux très élevées. La possibilité de faire varier à la fois le centre métallique et le ligand organique donne aux MOFs une très grande diversité qu'on ne retrouve pas chez les zéolithes et les charbons actifs.L'objectif de cette étude a été d'évaluer le potentiel des MOFs en tant qu'adsorbants pour quatre procédés de séparation de gaz. En raison du grand nombre de MOFs disponibles, il a été nécessaire d'élaborer une stratégie pour identifier les matériaux les plus prometteurs dans chaque cas. Cette méthodologie comprend quatre étapes : une étape de criblage, une étape expérimentale, une étape de calcul et une étape d'évaluation.Pour l'étape de criblage, un nouvel appareil dit « à haut débit » a été développé pour mesurer des isothermes approximatives. Ensuite, un certain nombre de matériaux ont été retenus pour faire une étude plus approfondie de leurs propriétés d'adsorption. Des isothermes très précises ont été mesurées par gravimétrie tandis que les enthalpies d'adsorption ont été obtenues par microcalorimétrie. Dans l'étape de calcul, le modèle IAST a été utilisée pour prédire les sélectivités à partir des données en gaz pur. Enfin, les adsorbants ont été classés à l'aide d'un nouveau paramètre de sélection qui regroupe la sélectivité, la capacité efficace et l'enthalpie d'adsorption, où l'importance de chacun des paramètres peut être ajustée en fonction des besoins du procédé
Metal-Organic Frameworks (MOFs) are seen to be one of the most promising classes of adsorbents for gas separations. Consisting of metal clusters connected by organic linkers to form a fully crystalline network, these materials have record breaking surface areas and pore volumes as well as a wide variety of pore structures and sizes. This, coupled with the possibility to use virtually any transition metal as well as functionalized linkers, gives MOFs the chemical and physical versatility often lacking in traditional adsorbents such as zeolites and activated carbons.The purpose of this study was to evaluate the potential of MOFs as adsorbents for four gas separations of interest to the petrochemical industry. Because of the diversity and number of MOFs available, a methodology was needed to help identify the most promising materials in each case. The proposed methodology comprises four stages: a screening step, an experimental step, a computational step and finally an evaluation step. For the first stage, a high-throughput setup was developed to measure rough adsorption isotherms. A number of materials were then selected for a more thorough investigation of their adsorption properties. Highly accurate isotherms were measured gravimetrically while precise adsorption enthalpies were obtained by microcalorimetry. Step three involved predicting the co-adsorption behaviour from the pure gas isotherms using the Ideal Adsorbed Solution Theory. Finally, the adsorbents were ranked based on a new selection parameter regrouping selectivity, working capacity and adsorption enthalpy where the importance of each term can be adjusted depending on the requirements of the process

This work concerns the functionalisation of a variety of carbon materials for the selective adsorption of carbon dioxide. A key challenge in post-combustion capture from gas fired power plants is related to the low CO2 concentration in the flue gas (4- 8%). Therefore highly selective adsorbents have the potential to improve the efficiency of the separation of carbon dioxide from gas mixtures. The study was performed in conjunction with the EPSRC funded project ‘Adsorption Materials and Processes for Carbon Capture from Gas-Fired Power Plants – AMPGas’. The carbon materials investigated included multi-walled carbon nanotubes, a microporous activated carbon, two types of mesoporous activated carbon and multi-walled carbon nanotube/polyvinyl alcohol composite aerogels. The uptake of carbon dioxide by these materials was enhanced through the addition of basic amine groups to the materials. The adsorption properties of the samples were tested by the zero-length column technique, thermal gravimetric analysis and breakthrough experiments. The materials were generally tested at conditions representative of those found in the flue gas of a fossil fuel power plant: 0.1 bar partial pressure of CO2. Two approaches were adopted for the chemical functionalization of the solid carbon supports. First, amine groups were covalently grafted directly to the surface and secondly amine molecules were physically adsorbed within the porous structure of the material by wet impregnation. It was seen that wet impregnation enabled the incorporation of a greater number of amine groups and the CO2 capacity of the materials was investigated with respect to the carbon support structure, the type of amine and the amount of amine loading. Larger pore volume mesoporous carbon materials were seen to provide a more efficient support for the amine to interact with the CO2. A greater than 12-fold increase in the CO2 capacity was observed when the amine impregnated carbon material was compared to the raw starting material. The extended zero-length column was introduced and fully characterized as a novel breakthrough experiment. It requires a small sample mass (~50 mg) and it allows binary selectivities to be calculated. It was shown, through multiple experiments and simulations that the breakthrough experiments were conducted under close to isothermal conditions which greatly simplifies the analysis of the breakthrough curves. In addition, a new zero-length column model was proposed to account for the reaction between the amine and the CO2 in the adsorbed phase and fitted to experimental data. An interesting double curvature was observed in the concentration profile during the desorption step which was attributed to the kinetics of the amine-CO2 reaction. A brief investigation was carried out into the binary separation of biogas (45% CO2: 55% CH4) by zeolite 13X, activated carbon and an amine impregnated activated carbon. Finally, initial investigations into the properties of low density carbon nanotube aerogels which have a large accessible pore volume, were carried out. Their potential as highly efficient supports for amine impregnation was investigated. It was found that amine functionalized carbons strongly interact with carbon dioxide and have the potential to be integrated as an adsorbent in a rapid temperature swing process that separates carbon dioxide from dilute gas streams.

A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal–organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

L'objectif de ce travail est de mettre au point et de qualifier un modele de simulation de l'adsorption en contre-courant simule, applique a la separation du paraxylene des hydrocarbures en c8 aromatiques. La separation par adsorption en contre-courant simule est une technique complexe derivee de la chromatographie en phase liquide. Deux types de modeles de chromatographie en phase liquide sont donc tout d'abord elabores: ils prennent en compte la dispersion axiale, et l'equilibre phase liquide-phase adsorbee est decrit par des selectivites binaires constantes. Dans le premier modele a etages theoriques l'hypothese de l'equilibre local instantane est faite. Par contre, le second modele de type continu (avec resolution des equations aux derivees partielles par la methode des differences finies) integre une cinetique de diffusion entre la phase liquide interstitielle et la phase liquide presente dans la macro-mesoporosite de la zeolithe. Le modele du contre-courant simule, avec permutation periodique des points d'introduction-prelevement des fluides, est realise sur la base du premier modele a etages theoriques; il permet de decrire le regime transitoire ainsi que le regime pseudo-stationnaire atteint. Trois techniques experimentales sont mises en uvre pour quantifier l'importance relative des differents phenomenes mis en jeu, caler les differents parametres des modeles et tester leur capacite predictive: un dispositif de mesure des equilibres d'adsorption, un montage de chromatographie frontale et un pilote de separation du paraxylene par adsorption en contre-courant simule. Le modele du contre-courant simule a permis d'etudier la sensibilite des performances du procede aux parametres physiques et aux variables operatoires et de tester une variante du schema de procede

Dissertação para obtenção do grau de Mestre em Engenharia Química e Bioquímica
In this thesis, an experimental unit based in the volumetric adsorption method was designed and constructed. This unit allows the realization of simultaneous experiments in order to obtain adsorption equilibria data of several adsorbents quickly and efficiently. Following the construction of the unit, it was necessary to develop the respective interface for acquisition and control. This interface was developed using the LabVIEW software and aims to monitor the system variables, to control the functions of solenoid valves present in the unit, as well as to register the measured data for further analysis. After the development of the interface, a volume calibration was performed. Then the unit was ready to be experimentally validated. For this validation, two porous materials, already analysed by an adsorption gravimetric method, were selected: an activated carbon, ANGUARD 5 (Suttclife Speakman, UK) and a metal-organic framework (MOF) MIL-53 (Al) (Basolite A100 ®, BASF SE, Germany). Two gases with high potential for separation and storage were chosen for study: Carbon Dioxide (CO2) and Nitrogen (N2). The unit consists of two independent lines so both materials were studied simultaneously in every test. Tests at different temperatures and for different pressure ranges for both materials were performed. CO2 tests were performed on both materials at 30°C, 80°C and 150°C. The pressure range for the first test was between 0 and 10 bar and for the last two was between 0 and 15 bar. A test with N2 at 50 ° C was also performed for both materials. After, a comparison of the results obtained with other results obtained with the gravimetric method was accomplished. The results obtained are in accordance with the previously obtained gravimetric data which prove that the unit developed is working properly. The error for each measurement was obtained considering the possibility of a multivariate and cumulative error.

Membranes composed of zeolite crystals, in which gas molecules are transported by surface diffusion, are promising for gas separation applications. Since this mode of mass transfer mechanism is controlled by synergistic adsorption and diffusion phenomena, the separation of gas mixtures is not solely dependent on molecular size. However, undesirable defect pathways in zeolite membranes are often present due to factors such as incomplete crystal growth and/or thermal stresses during membrane synthesis and calcination. These pathways cause molecules to bypass the selective zeolite crystal layer and adversely affect membrane performance. Since the fabrication of defect-free zeolite membranes is very challenging, their widespread adoption for industrial processes has been impeded. Quantification of defects in zeolite membranes is therefore important to improve synthesis protocols of these membranes. In this research, zeolite membranes composed of silicalite crystals have been fabricated using the pore plugging method, and their performance was evaluated by developing a method that can be used to describe the selective and non-selective channels that are present in any zeolite membrane. Unlike the other destructive and sophisticated methods, which already exist to discern this information, the proposed method requires only a limited number of in-situ permeation experiments to be conducted using He – a non-adsorbing gas, and N2 – an adsorbing gas. With this method, the volume fraction, effective length, and size of the selective and non-selective channels of multiple membranes have been quantified, and these parameters were used to predict membrane performance at untested conditions, as well as with untested gases such as CH4 and CO2. In addition, by separating surface diffusion from the flow through the defects in gas separation tests with CO2/N2 mixture, the respective transport diffusivities and exchange diffusivity coefficients, which account for mass transfer in zeolite crystals were determined using the Maxwell-Stefan model. These determined exchange diffusivity coefficients are not equal to each other and challenge the Vignes correlation. In addition, transport diffusivities determined in mixed gas permeation experiments at University of Ottawa have then been validated by large single crystal transport diffusivities for mixed gases that were determined from molecular uptake experiments conducted at University of Leipzig in Germany, using Infra-Red Micro-imaging.

Le dioxyde de carbone (CO2), principal contaminant des gaz naturels bruts et du biogaz doit être extrait en vue d’un enrichissement en méthane (CH4) compatible avec les spécifications d’injection en réseaux de gaz naturel. Au cours des dernières années, une famille de matériaux poreux de type réseaux organométalliques à base de magnésium (Mg-MOF-74) a ouvert une nouvelle perspective à cet effet en raison d’une excellente affinité des sites métalliques exposés au sein de la structure cristalline pour l’adsorption du CO2. Ce matériau est un adsorbant potentiellement bon candidat pour l’enrichissement en CH4 de gaz naturel et de biogaz par des procédés opérant en modulation de pression. La présente étude propose d’examiner l’amélioration des performances d'adsorption du CO2 en mélange avec le CH4 par dopage du matériau Mg-MOF-74 avec des nanotubes de carbone et de l'oxyde de graphène. L'objectif est d'améliorer les propriétés texturales pour favoriser la diffusion des molécules des gaz dans les micropores et leur accessibilité aux sites d'adsorption. Les matériaux ont été synthétisés sous réaction solvothermique et caractérisés par DRX, IRTF, MEB, ATG et physisorption d’azote à 77K. Les équilibres et énergies d'adsorption ont été mesurées suivant une méthode manométrique dans une gamme de pression allant jusqu'à 35 bar et à 25°C, 50°C et 75°C. La cinétique de sorption a été étudiée à partir d’expériences de manométrie et de la méthode dite « Zero Length Column » à 25°C, 50°C et 75°C. A une teneur optimisée à 0,3% en masse d’agent dopant, le modèle de Brunauer–Emmett–Teller montre que la surface spécifique des matériaux dopés est augmentée de plus de 21% par rapport à celle du matériau non-dopé. Les données d'équilibre indiquent que la capacité d’adsorption en CO2 est sensiblement améliorée pour les matériaux dopés dans toute la gamme opératoire étudiée, tandis qu’ils démontrent une sélectivité comparable ou améliorée, dépendante de la température
Carbon dioxide (CO2), which is the major contaminant present in raw natural gas and biogas need to be extracted to increase their methane (CH4) content and match the standards of pipeline injection. In recent years, a family of porous materials, magnesium-based Metal Organic Framework (Mg-MOF-74), has opened new perspectives for this purpose thanks to strong adsorption affinity of CO2 with exposed metallic sites in the crystalline network. This material is a potential good adsorbent candidate for the enrichment in CH4 of natural gas and biogas by Pressure Swing Adsorption processes. The present study proposes to examine the CO2 adsorption performances and separation ability from CH4 of Mg-MOF-74 materials doped with carbon nanotubes and graphene oxide. The objective is to improve the texture of the materials to promote the diffusion of gas molecules into micropores and their accessibility to adsorption sites. The materials were synthesized under solvothermal reaction and characterized by PXRD, FTIR, FESEM, TGA and physisorption of nitrogen at 77K. The adsorption equilibria and energies were measured using manometric method in a pressure range up to 35 bar and at 25°C, 50°C and 75°C. The sorption kinetics of CO2 and CH4 on the materials were studied from manometric experiments and using the Zero Length Column method at 25°C, 50°C and 75°C. At an optimized content of the doping agents of 0.3 wt%, Brunauer–Emmett–Teller model shows that the specific surface area is increased for both composites, by more than 21% compared to the pristine material. The equilibrium data indicates that the CO2 adsorption capacity is significantly improved in the whole range of operating conditions for both composites compared to the pristine material, whereas the CO2/CH4 adsorption selectivity appears either comparable or better as a function of temperature

Industriella processer inom livsmedelsindustrin ger ofta upphov till förorenade luftflöden. Föroreningarna förekommer både i partikulär- och gasform. En anledning till att vidta åtgär-der för att kontrollera utsläppet kan både vara förknippat med krav från myndigheter eller med hänsyn till krav från omgivningen. Det övergripande målet med examensarbetet var att konstruera ett lättportabelt luftreningssy-stem i pilotskala som skulle användas till förtester på förorenad luft från industriella proces-ser. Driftsdata från sådana körningar ger värdefull information om hur ett storskaligt renings-system kan konstrueras för att uppnå önskad reningsgrad. Arbetet var ett uppdrag från företaget Ozone Tech Systems. Företaget är specialiserat på re-ning med ozon, men tillhandahåller även andra tekniska lösningar som tas fram utifrån kun-dernas behov. Arbetet har utförts i nära relation med leverantörer samt personalen på företa-get. Pilotsystemet konstruerades med utgångspunkt från den typ av förorenad luft som uppkom-mer vid varmrökning av fisk med träspån av al, men ska även kunna användas till andra pro-cesser som ger upphov till liknande typ av förorenad luft. Genom utnyttjande av emissions-faktorer men även tillgänglig fakta från litteraturen samt uppmätta värden, gick det att upp-skatta föroreningsinnehållet och tillståndet för luften. Reningskravet som designen utgick ifrån var både EUs krav för TOC <50 mg/m3 (n) samt att reducera oönskad lukt. Odören vi-sade sig framförallt uppkomma från flyktiga organiska föreningar (VOC). Pilotsystemet var förutbestämt att bestå av en primär partikelavskiljare, oxidation med ozon, sekundär partikelavskiljning med ett HEPA 13 filtersteg samt slutligen ett adsorptionssteg med aktivt kol. I designprocessen beslutates sedan att använda en venturiskrubber som en primär partikelavskiljare samt att placera förfilter innan HEPA 13 filtret. Arbetet har resulterat i en teoretiskt framtagen design för luftreningssystemet. Apparatdelarna är isärtagbara för enkel transport samt möjlighet till anpassad appartturkombination. Inköpet av apparatdelarna har inte varit en del av examensarbetet men samordning av inköpet har genomförts till den nivån att inköpet direkt skulle kunna genomföras vid projektets slut. För att systemet ska fungera krävs att en fläkt för att motverka tryckfallet samt rörkopplingar mellan apparatdelarna dimensioneras och inhandlas, vilket inte ingick i projektet.
Industrial processes in the food industry very often produce airstreams of contaminated air. The impurities can be both particulates and gaseous compounds. Controlling these emissions is of a great concern both regarding governmental and social requirements. The overall aim with the thesis was to construct an easily portable, pilot scale air purification system. The main purpose with the pilot scale system was to enable testing of contaminated air generated from industries. The results from the industry tests with the pilot scale system would reveal valuable information that could be used later for the design of a large scale cleaning system. The work was assigned by Ozone Tech Systems. The company is specialized in ozone treat-ments intended for industrial and domestic uses. The work done within the thesis project was performed in close relations with equipment suppliers and Ozone Tech System personnel. The design of the pilot scale air purification system was based on contaminated air, generated from fish smokehouses. The smoke that is involved in the hot smoking process is derived in conjunction with alder chips smoldering. Although the pilot scale system was designed for purifying air generated from fish smokehouses, it should also suit other processes that gener-ate similar air emissions. Emission factors, literature data and measured values played an im-portant role for estimating the air composition in the air generated from the specific process. The treatment objective was determined by European regulations as well as a desired reduc-tion of unwanted odors. The odor was found to mainly be caused by volatile organic com-pounds (VOC). The pilot system was predefined to consist of a primary step of particle separation, oxidation with ozone, particle separation consisting of a HEPA 13 filtration stage and at last adsorption with activated carbon. During the design process it was decided to use a venturi scrubber as the primary particle separator and to add a pre-filter stage before the HEPA 13 filter. The work has resulted in a theoretical design of the air purification system. The units are de-tachable which provides a simple transportation as well as the possibility to use an adaptable combination of the units. The purchase of equipment was not a part of the thesis, but the coordination of the purchase has been completed ensuring that the purchase could be done after the end of the project. In order for the system to work, a fan needs to be installed and pipe connections between the units have to be designed and purchased, but this was not a part in the project.

A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal–organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported.
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Porous inorganic solids including mesoporous silicas, zeolites and silicoalumnio-phosphates have been investigated as adsorbents for carbon dioxide, particularly in relation to uptake from flue gases at 0.1 bar and ca. 298 K, but also at higher pressures. The mesoporous silicas SBA-1 and SBA-2, with mesocages separated by narrower windows, have been prepared, calcined at various temperatures and also nitrided with ammonia at high temperature. Nitridation has resulted in framework nitrogen incorporation, but this gave only small increases in the uptake of CO₂ of these mesoporous silicas, which are very low (< 0.2 mmol g⁻¹) at flue gas conditions (0.1 bar, 298 K). A series of cationic forms of the small pore zeolites, chabazite, ZK-5 and Rho, have been prepared by exhaustive cation exchange (and pre-calcination of the as-prepared form of Rho). In addition, a series of ultrastabilised zeolite Rho samples has been prepared to investigate the influence of extra-framework aluminium species on CO₂ uptake. For comparison, the silicoaluminophosphate versions of ZK-5 (SAPO STA-14) and Rho (SAPO(RHO)) have been prepared. Adsorption on Li-, Na-, K- and Ca-forms of chabazite (Si/Al = 3.0) has been related to the crystal structures of their dehydrated forms, as determined by Rietveld refinement against powder X-ray diffraction data (PXRD). For Na- and K-chabazite the structure has been measured in situ by PXRD during CO₂ adsorption. Li-chabazite has the highest uptake from all chabazite cationic forms (4.3 mmol g⁻¹). PXRD of K-chabazite reveals cation migration from eight-membered ring sites to six-membered ring sites upon CO₂ adsorption. Na-chabazite shows partial transformation from rhombohedral to monoclinic symmetry upon prolonged evacuation at high temperature, with resultant non-Type I CO₂ adsorption behaviour. Li-, Na- and K-forms of ZK-5 (Si/Al = 4.16) show high CO₂ uptakes at 0.1 bar and 298 K (Li-ZK-5, 4.7 mmol g⁻¹, which is the highest of the solids measured here). Like all H-forms, H-ZK-5 shows weaker uptake. None of the ZK-5 forms show high selectivity for CO₂ over small hydrocarbons, because cations do not block eight-membered ring windows and the structures do not distort upon dehydration. Uptake of CO₂ on univalent cation forms of zeolite Rho has been studied at low (up to 1 bar) and high (up to 10 bar) pressures. All cationic forms (but not H-Rho) show distortion (Im3̅m to I4̅3m) upon dehydration. Forms of zeolite Rho in which cations occupy window sites in the eight-membered rings between α-cages show hysteresis in their CO₂ isotherms, the magnitude of which (Na⁺,NH₄⁺ < K⁺ < Cs⁺) correlates with the tendency of cations to occupy double eight-membered ring sites rather than single eight-membered ring sites. Additionally, reversible CO₂ uptake using the Zero Length Column method on fully and partially cation exchanged samples has been measured. In situ synchrotron PXRD of CO₂ adsorption on Na-Rho indicates Na cations remain in window sites on the time average, indicating CO₂ uptake must occur by a 'trapdoor mechanism' by which Na cations move away from the windows to allow CO₂ to adsorb. In addition, in situ PXRD reveals the adsorption sites of CO₂ bound cations. Adsorption of small hydrocarbons does not occur on Rho, even at high pressure, indicating that adsorption is selective, and depends on the degree of interaction with the adsorbate rather than simply on the molecular size. Na-Rho is therefore a selective adsorbent for CO₂ over CH₄ with selectivities of 150–25 at 1–9 bar and 298 K, predicted from the single component isotherms, and an uptake of 3.07 mmol g⁻¹ at 0.1 bar. High ‘selectivities' are also observed over K-, Cs- and Ca-forms, examples of a novel type of adsorption selectivity.

The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources.
Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006.
Ching-Hua Huang, Committee Co-Chair ; F. Michael Saunders, Committee Member ; Jae-Hong Kim, Committee Chair.

The equilibria of adsorption on calcium and hydrogen forms of zeolite Y by equimolar solutions of 12.5 %, 20%, 25%, 30% and 35% w/v of mixtures of glucose, G and fructose, F
also the non-equimolar mixtures of 20% w/v glucose - 30% w/v fructose, 30% w/v glucose - 20% w/v fructose, 25% w/v glucose &ndash
35% w/v fructose, and 35% w/v glucose-25% w/v fructose solutions, which were prepared 24 hours in advance at the experimental temperature, have been studied batch wise at 50º
C. Glucose adsorption, in solutions that had adsorption differences, was fast on both zeolites, on the contrary of slow adsorption of fructose with the stable dynamics. Both adsorptions had small amounts of adsorption changes after minute 30. The treatments made under the same conditions with the same mixtures showed Ca-Y zeolite had better separation capacity compared to H-Y zeolite. Some trials were repeated with CaCl2 added to the solutions. The slowed down affection of fructose adsorption in spite of the small change of glucose adsorption led to better separation. Samples were analyzed by classical methods, not HPLC. All the data were considered with various models and their convergence numbers were tested for their closeness to reality. The models were analyzed by response surface methodology and some of those models had correlation factors as high as 88% at the equilibrium points at 30th minutes. Besides, time dependent models have been considering the lag times with a time dependent variable included all the data of all treated solutions with correlation as high as 79.5%.

Protein phosphorylation is a very common posttranslational modification (PTM), which lately has been found to hold the keyrole in the development of many severe diseases, including cancer. Thereby, phosphoprotein analysis tools, generally based on specific enrichment of the phosphoryl group, have been a hot topic during the last decade. In this thesis, two new TiO2-based on-target enrichment methods are developed and presented together with enlightening fundamental results. Evaluation of the developed methods was performed by the analysis of: custom peptides, β-casein, drinking milk, and the viral protein pIIIa. The results show that: i) by optimizing the enrichment protocol (first method), new phosphorylated peptides can be found and ii) by the addition of a separation step after the enrichment (second method), more multi-phosphorylated peptides, which usually are hard to find, could be detected. The fundamental part, on the other hand, shows that the phosphopeptide adsorption is caused by electrostatic interactions, in general follows the Langmuir model, and the affinity increases with the phosphorylation degree. Here, however, the complexity of the system was also discovered, as the adsorption mechanism was found to be affected by the amino acid sequence of the phosphopeptide.