Advances in simulated moving bed : new operating modes : new design methodologies and product (FlexSMB-LSRE) development

Tese de doutoramento. Engenharia Química e Biológica. Faculdade de Engenharia. Universidade do Porto. 200

Design of Mixed-Solvent Extraction and Size-Exclusion Simulated Moving Bed Chromatography to Recover Valuable Compounds from Electronic Waste

More than one million tons of polycarbonates and over 500,000 tons of flame retardants are consigned to landfills each year in the form of waste electrical and electronic equipment. Electronic waste is the fasting growing waste steam at a rate of 3-5% per year. Two separation processes are developed to efficiently recover these valuable compounds

Compact simulated countercurrent chromatography for downstream processing of (bio)pharmaceuticals

Dissertação para obtenção do Grau de Doutor em Engenharia Química e BioquímicaFundação para a Ciência e Tecnologia - PhD gran

Enantiomers separation by simulated moving bed chromatography. Non-instantaneous equilibrium at the solid-fluid interface

The simulated moving bed (SMB) technology, first conceived for large bulk-scale separations in the petrochemical industry, has found increasingly new applications in the pharmaceutical industry. Among these, the separation of fine chemicals has been the subject of considerable study and research. This work presents the modeling, simulation and design of the operation of a SMB plant in order to separate a binary chiral mixture. The usual assumption of instantaneous equilibrium at the solid–fluid interface is questioned and a first-order kinetics of adsorption is taken into account. The cases of linear, Langmuir and modified Langmuir equilibria are studied. The equivalent true moving bed (TMB) model was used assuming axial dispersion for the fluid flow and plug flow for the solid-phase flow. Intraparticle diffusion was described by a linear driving force (LDF) approximation. Simulation results indicate that, under certain conditions, equilibrium is not actually reached at the adsorbent surface. This leads to different unit performances, in terms of product purities and recoveries, as compared to those predicted assuming instantaneous equilibrium. Moreover, SMB units may be improperly designed by the usual methods (flow-rate ratio separation regions) if non-equilibrium effects are overlooked

Proteins separation and purification by expanded bed chromatography and simulated moving bed technology

Tese de doutoramento. Engenharia Química. 2006. Faculdade de Engenharia. Universidade do Port

Compact SMB chromatography for binary separation

A thesis submitted for the degree of Doctor of PhilosophyThis thesis consists essentially of theoretical and experimental developments in the field of continuous chromatography using small-scale units. Continuous chromatographic separation processes based on the Simulated Moving Bed (SMB) technology were first patented and applied in 1961 for a large number of separations in the petrochemical industry and later for sugar separation. However, in the last two decades,due to the patent expiration, the process has been gaining great interest in the separation/purification of products in fine chemical and pharmaceutical industries. The conventional SMB comprises several identical columns which are serially connected in either a closed- or open-loop configuration. In order to simulate the movement of a solid bed in opposite direction to the fluid, the positions of the input and output streams are shifted downstream by one column, at fixed intervals, in the direction of fluid flow. With the development of new and efficient equipment and stationary phases, several new schemes of operating that differ from the conventional one have emerged. These include new concepts such as Varicol, ModiCon and PowerFeed processes, which rely on the periodic modulation of certain process parameters during the switching interval to enhance the efficiency of the separation. These advances are pushing the trend for units with a small number of columns, since the overall setup is more economical. However, when these newly schemes are applied in practice the process becomes more complex, because of the increased degrees of freedom that must be optimized. It is also less robust and more difficult to operate because it is more demanding on hardware. This additional complexity requires highly versatile SMB equipment, advanced optimization tools and robust control procedures. Experimental tools to experimentally reproduce the periodic state of multicolumn countercurrent chromatography with just one column are developed; they are economic and fast methods of experimentally exploring different column configurations and cyclic operation policies,ideally suited for applied research studies but may also be useful in the early stages of development, optimization, and validation of a new chromatographic separation. The feasibility of the proposed single-column system is experimentally demonstrated for several different column configurations, which include both synchronous and asynchronous port switchings and flow modulated schemes. Following the potentialities of these new operating schemes, a novel SMB system for binary separation that employs only two-columns is developed. The designed two-column process uses both the port switching and the flow rates modulation procedure. The process is very versatile since the cycle itself is optimized and adapted to the difficulty of the separation and process specifications. Furthermore, a simplified extension of the two-column setup which relies on a minimum pump number configuration and on a uniform flowrate scheme is built-up; additionally a further development on these simplified setup is applied which effectively enhances the process with only the cost of a small increase on the setup equipment. Potentialities of this new unit are illustrated comparing it to setups using the same amount of stationary phase.Fundação para a Ciência e Tecnologia (FCT/MCTES

Separação de compostos bioativos recorrendo à tecnologia de leito móvel simulado

The pharmaceutical industry is developing a growing interest in natural compounds with biological and nutritional properties. Betulinic and oleanolic acids are two naturally occurring triterpenic acids, which possess such characteristics. These two compounds can be extracted from natural resources, i.e., from the bark of Eucalyptus globulus. However, their separation is difficult because these compounds present similar structures (they are constitutional isomers). In this work, the chromatographic separation of betulinic and oleanolic acids from representative extracts of E. globulus was studied. High performance liquid chromatography (HPLC) assays were initially performed using an Acclaim C30 column as stationary phase. Through these tests it was found that the mobile phase methanol/acetonitrile 50/50 (%, v/v) is the most suitable for the separation of both triterpenic acids. In order to determine the equilibrium constants () and the global linear driving force mass transfer coefficients (), several breakthrough experiments of pure acids (unary solutions) were carried out. The two parameters were correlated using experimental data and then validated by simulating the breakthrough curve of a binary mixture containing the same proportion of betulinic and oleanolic acids found in E. globulus extracts. The outcomes of all experiments were modeled using Carta’s analytical solution. In parallel, the method of moments was also used to obtain the transport parameters. The results were consistent. Lastly, the separation of betulinic and oleanolic acids by simulating moving bed (SMB) has been studied, carrying out simulations using the transport parameters obtained before from the breakthrough assays. Two different column configurations (1-1-1-1 and 2-2-2-2) and column lengths (from 10 to 25 cm) were adopted. It was concluded that using an SMB unit is able to separate betulinic and oleanolic acids with purity higher than 99 % both in extract and raffinate for all the scenarios presented. Posteriorly, the recovery of both triterpenic acids from the extract and raffinate streams of a future process was also investigated, taking advantage of their low solubility in water. Accordingly, the solubility of each triterpenic acid in solvent mixtures of increasing water concentration was experimentally measured and discussed.A indústria farmacêutica tem manifestado um crescente interesse em compostos naturais com propriedades biológicas e nutricionais. Os ácidos betulínico e oleanólico são dois ácidos triterpénicos que ocorrem naturalmente na natureza e que possuem tais características. Estes dois compostos podem ser extraídos de recursos naturais, tais como da casca do Eucalyptus globulus. No entanto, a sua separação é difícil, pois os compostos apresentam estruturas muito semelhantes (são isómeros constitucionais). Neste trabalho estudou-se a separação cromatográfica de uma amostra representativa dos extratos de E. globulus dos ácidos betulínico e oleanólico. Inicialmente foram realizados testes cromatográficos em cromatografia líquida de alta eficiência, recorrendo à fase estacionária Acclaim C30. Através destes ensaios determinou-se que a fase móvel metanol/acetonitrilo 50/50 (%, v/v) é a mais adequada para a separação destes ácidos triterpénicos. De modo a averiguar as constantes de equilíbrio () e os coeficientes globais de transferência de massa (), foram determinadas as curvas de rutura dos ácidos puros (soluções unárias). Estes parâmetros foram correlacionados recorrendo a dados experimentais e posteriormente validados pela simulação da curva de rutura de uma mistura binária contendo a mesma proporção de ácido betulínico e oleanólico encontrada no E. globulus. Os dados advindos deste ensaio foram modelados pela solução analítica de Carta. Paralelamente, foi também usado o método dos momentos para obter os parâmetros de transporte. Os resultados obtidos foram consistentes. Por fim, estudou-se a separação dos ácidos betulínico e oleanólico por leito móvel simulado (SMB), realizando simulações utilizando os parâmetros de transporte obtidos anteriormente pela modelação das curvas de rutura. Foram adotadas duas configurações diferentes (1-1-1-1 e 2-2-2-2) e diferentes comprimentos de coluna (variando dos 10 aos 25 cm), usando os parâmetros de transporte obtidos. Foi concluído que usando uma unidade SMB é possível separar os ácidos betulínico e oleanólico com purezas superiores a 99 % tanto no extrato como no rafinado para todos os cenários apresentados. Posteriormente, foi analisada a recuperação dos ácidos triterpénicos das correntes de extrato e rafinado de um futuro processo, tirando vantagem da sua baixa solubilidade em água. Por conseguinte, a solubilidade de cada ácido triterpénico em misturas de solventes com o aumento da concentração de água foi medida e discutida.Mestrado em Engenharia Químic

Regional flow model of west Cape Cod and optimization analysis

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1997.Includes bibliographical references (leaves 48-51).by Susanna Galloni.M.Eng