The enthalpies of solution, HS, of carbon dioxide in aqueous methyldiethanolamine were measured with an isothermal flow calorimeter over wide ranges of temperature, pressure, weight percent MDEA, and loading (gmole CO2/gmole MDEA). The values of HS (kJ/gmole CO2) were found to be constant up to the saturation concentration of CO2 in the aqueous solution. In addition, experimental data showed that HS was independent of the total pressure over the solution, but linearly dependent upon both temperature and weight percent MDEA as was given by a correlation. A computer program based upon basic thermodynamic quantities was developed to model HS of CO2 in MDEA solutions. The values of K and ΔH for each of the chemical reactions (except the MDEA protonation reaction) were fitted values from the literature. Activity coefficient correlations used in the program were also obtained from the literature. Using these data, the program was first used to find the values of K and ΔH for the MDEA protonation reaction which gave the minimum error between the model and the experimental data. Finally, the values of HS predicted by the program were compared to the experimental data and the differences were discussed.

<p>The objective of this work has been to study equilibrium and non equilibrium situations during high pressure gas processing operations with emphasis on utilization of the high reservoir pressure. The well stream pressures of some of the condensate and gas fields in the North Sea are well above 200 bar. Currently the gas is expanded to a specified processing condition, typically 40-70 bar, before it is recompressed to the transportation conditions. It would be a considerable environmental and economic advantage to be able to process the natural gas at the well stream pressure. Knowledge of thermodynamic- and kinetic properties of natural gas systems at high pressures is needed to be able to design new high pressure process equipment. </p><p>Nowadays, reactive absorption into a methyldiethanolamine (MDEA)solution in a packed bed is a frequently used method to perform acid gas treating. The carbon dioxide removal process on the Sleipner field in the North Sea uses an aqueous MDEA solution and the operation pressure is about 100 bar. The planed carbon dioxide removal process for the Snøhvit field in the Barents Sea is the use of an activated MDEA solution. </p><p>The aim of this work has been to study high-pressure effects related to the removal of carbon dioxide from natural gas. Both modelling and experimental work on high-pressure non-equilibrium situations in gas processing operations have been done. </p><p>Few experimental measurements of mass transfer in high pressure fluid systems have been published. In this work a wetted wall column that can operate at pressures up to 200 bar was designed and constructed. The wetted wall column is a pipe made of stainless steel where the liquid is distributed as a thin liquid film on the inner pipewall while the gas flows co- or concurrent in the centre of the pipe. The experiments can be carried out with a well-defined interphase area and with relatively simple fluid mechanics. In this way we are able to isolate the effects we want to study in a simple and effective way. </p><p>Experiments where carbon dioxide was absorbed into water and MDEA solutions were performed at pressures up to 150 bar and at temperatures 25 and 40°C. Nitrogen was used as an inert gas in all experiments. </p><p>A general non-equilibrium simulation program (NeqSim) has been developed. The simulation program was implemented in the object-oriented programming language Java. Effort was taken to find an optimal object-oriented design. Despite the increasing popularity of object-oriented programming languages such as Java and C++, few publications have discussed how to implement thermodynamic and fluid mechanic models. A design for implementation of thermodynamic, mass transfer and fluid mechanic calculations in an object-oriented framework is presented in this work. </p><p>NeqSim is based on rigorous thermodynamic and fluid mechanic models. Parameter fitting routines are implemented in the simulation tool and thermodynamic-, mass transfer- and fluid mechanic models were fitted to public available experimental data. Two electrolyte equations of state were developed and implemented in the computer code. The electrolyte equations of state were used to model the thermodynamic properties of the fluid systems considered in this work (non-electrolyte, electrolyte and weak-electrolyte systems).</p><p>The first electrolyte equation of state (electrolyte ScRK-EOS) was based on a model previously developed by Furst and Renon (1993). The molecular part of the equation was based on a cubic equation of state (Scwarzentruber et.al. (1989)’s modification of the Redlich-Kwong EOS) with the Huron-Vidal mixing rule. Three ionic terms were added to this equation – a short-range ionic term, a long-range ionic term (MSA) and a Born term. The thermodynamic model has the advantage that it reduces to a standard cubic equation of state if no ions are present in the solution, and that public available interaction parameters used in the Huron-Vidal mixing rule could be utilized. The originality of this electrolyte equation of state is the use of the Huron-Vidal mixing rule and the addition of a Born term. Compared to electrolyte models based on equations for the gibbs excess energy, the electrolyte equation of state has the advantage that the extrapolation to higher pressures and solubility calculations of supercritical components is less cumbersome. The electrolyte equation of state was able to correlate and predict equilibrium properties of CO₂-MDEA-water solutions with a good precision. It was also able to correlate high pressure data of systems of methane-CO₂-MDEA and water. </p><p>The second thermodynamic model (electrolyte CPA-EOS) evaluated in this work is a model where the molecular interactions are modelled with the CPA (cubic plus association) equation of state (Kontogeorgios et.al., 1999) with a classical one-parameter Van der Walls mixing rule. This model has the advantage that few binary interaction parameters have to be used (even for non-ideal solutions), and that its extrapolation capability to higher pressures is expected to be good. In the CPA model the same ionic terms are used as in the electrolyte ScRK-EOS. </p><p>A general non-equilibrium two-fluid model was implemented in the simulation program developed in this work. The heat- and mass-transfer calculations were done using an advanced multicomponent mass transfer model based on non-equilibrium thermodynamics. The mass transfer model is flexible and able to simulate many types of non-equilibrium processes we find in the petroleum industry. A model for reactive mass transfer using enhancement factors was implemented for the calculation of mass transfer of CO₂ into amine solutions. The mass transfer model was fitted to the available mass transfer data found in the open literature. </p><p>The simulation program was used to analyse and perform parameter fitting to the high pressure experimental data obtained during this work. The mathematical models used in NeqSim were capable of representing the experimental data of this work with a good precision. From the experimental and modelling work done, we could conclude that the mass transfer model regressed to pure low-pressure data also was able to represent the high-pressure mass transfer data with an acceptable precision. Thus the extrapolation capability of the model to high pressures was good. </p><p>For a given partial pressure of CO₂ in the natural gas, calculations show a decreased CO₂ capturing capacity of aqueous MDEA solutions at increased natural gas system pressure. A reduction up to 40% (at 200 bar) compared to low pressure capacity is estimated. The pressure effects can be modelled correctly by using suitable thermodynamic models for the liquid and gas. In a practical situation, the partial pressure of CO₂ in the natural gas will be proportional to the total pressure. In these situations, it is shown that the CO₂ capturing capacity of the MDEA solution will be increased at rising total pressures up to 200 bar. However, the increased capacity is not as large as we would expect from the higher CO₂ partial pressure in the gas.</p><p>The reaction kinetics of CO₂ with MDEA is shown to be relatively unaffected by the total pressure when nitrogen is used as inert gas. It is however important that the effects of thermodynamic and kinetic non- ideality in the gas and liquid phase are modelled in a consistent way. Using the simulation program NeqSim – some selected high-pressure non-equilibrium processes (e.g. absorption, pipe flow) have been studied. It is demonstrated that the model is capable of simulating equilibrium- and non-equilibrium processes important to the process- and petroleum industry.</p>

The objective of this work has been to study equilibrium and non equilibrium situations during high pressure gas processing operations with emphasis on utilization of the high reservoir pressure. The well stream pressures of some of the condensate and gas fields in the North Sea are well above 200 bar. Currently the gas is expanded to a specified processing condition, typically 40-70 bar, before it is recompressed to the transportation conditions. It would be a considerable environmental and economic advantage to be able to process the natural gas at the well stream pressure. Knowledge of thermodynamic- and kinetic properties of natural gas systems at high pressures is needed to be able to design new high pressure process equipment. Nowadays, reactive absorption into a methyldiethanolamine (MDEA)solution in a packed bed is a frequently used method to perform acid gas treating. The carbon dioxide removal process on the Sleipner field in the North Sea uses an aqueous MDEA solution and the operation pressure is about 100 bar. The planed carbon dioxide removal process for the Snøhvit field in the Barents Sea is the use of an activated MDEA solution. The aim of this work has been to study high-pressure effects related to the removal of carbon dioxide from natural gas. Both modelling and experimental work on high-pressure non-equilibrium situations in gas processing operations have been done. Few experimental measurements of mass transfer in high pressure fluid systems have been published. In this work a wetted wall column that can operate at pressures up to 200 bar was designed and constructed. The wetted wall column is a pipe made of stainless steel where the liquid is distributed as a thin liquid film on the inner pipewall while the gas flows co- or concurrent in the centre of the pipe. The experiments can be carried out with a well-defined interphase area and with relatively simple fluid mechanics. In this way we are able to isolate the effects we want to study in a simple and effective way. Experiments where carbon dioxide was absorbed into water and MDEA solutions were performed at pressures up to 150 bar and at temperatures 25 and 40°C. Nitrogen was used as an inert gas in all experiments. A general non-equilibrium simulation program (NeqSim) has been developed. The simulation program was implemented in the object-oriented programming language Java. Effort was taken to find an optimal object-oriented design. Despite the increasing popularity of object-oriented programming languages such as Java and C++, few publications have discussed how to implement thermodynamic and fluid mechanic models. A design for implementation of thermodynamic, mass transfer and fluid mechanic calculations in an object-oriented framework is presented in this work. NeqSim is based on rigorous thermodynamic and fluid mechanic models. Parameter fitting routines are implemented in the simulation tool and thermodynamic-, mass transfer- and fluid mechanic models were fitted to public available experimental data. Two electrolyte equations of state were developed and implemented in the computer code. The electrolyte equations of state were used to model the thermodynamic properties of the fluid systems considered in this work (non-electrolyte, electrolyte and weak-electrolyte systems). The first electrolyte equation of state (electrolyte ScRK-EOS) was based on a model previously developed by Furst and Renon (1993). The molecular part of the equation was based on a cubic equation of state (Scwarzentruber et.al. (1989)’s modification of the Redlich-Kwong EOS) with the Huron-Vidal mixing rule. Three ionic terms were added to this equation – a short-range ionic term, a long-range ionic term (MSA) and a Born term. The thermodynamic model has the advantage that it reduces to a standard cubic equation of state if no ions are present in the solution, and that public available interaction parameters used in the Huron-Vidal mixing rule could be utilized. The originality of this electrolyte equation of state is the use of the Huron-Vidal mixing rule and the addition of a Born term. Compared to electrolyte models based on equations for the gibbs excess energy, the electrolyte equation of state has the advantage that the extrapolation to higher pressures and solubility calculations of supercritical components is less cumbersome. The electrolyte equation of state was able to correlate and predict equilibrium properties of CO2-MDEA-water solutions with a good precision. It was also able to correlate high pressure data of systems of methane-CO2-MDEA and water. The second thermodynamic model (electrolyte CPA-EOS) evaluated in this work is a model where the molecular interactions are modelled with the CPA (cubic plus association) equation of state (Kontogeorgios et.al., 1999) with a classical one-parameter Van der Walls mixing rule. This model has the advantage that few binary interaction parameters have to be used (even for non-ideal solutions), and that its extrapolation capability to higher pressures is expected to be good. In the CPA model the same ionic terms are used as in the electrolyte ScRK-EOS. A general non-equilibrium two-fluid model was implemented in the simulation program developed in this work. The heat- and mass-transfer calculations were done using an advanced multicomponent mass transfer model based on non-equilibrium thermodynamics. The mass transfer model is flexible and able to simulate many types of non-equilibrium processes we find in the petroleum industry. A model for reactive mass transfer using enhancement factors was implemented for the calculation of mass transfer of CO2 into amine solutions. The mass transfer model was fitted to the available mass transfer data found in the open literature. The simulation program was used to analyse and perform parameter fitting to the high pressure experimental data obtained during this work. The mathematical models used in NeqSim were capable of representing the experimental data of this work with a good precision. From the experimental and modelling work done, we could conclude that the mass transfer model regressed to pure low-pressure data also was able to represent the high-pressure mass transfer data with an acceptable precision. Thus the extrapolation capability of the model to high pressures was good. For a given partial pressure of CO2 in the natural gas, calculations show a decreased CO2 capturing capacity of aqueous MDEA solutions at increased natural gas system pressure. A reduction up to 40% (at 200 bar) compared to low pressure capacity is estimated. The pressure effects can be modelled correctly by using suitable thermodynamic models for the liquid and gas. In a practical situation, the partial pressure of CO2 in the natural gas will be proportional to the total pressure. In these situations, it is shown that the CO2 capturing capacity of the MDEA solution will be increased at rising total pressures up to 200 bar. However, the increased capacity is not as large as we would expect from the higher CO2 partial pressure in the gas. The reaction kinetics of CO2 with MDEA is shown to be relatively unaffected by the total pressure when nitrogen is used as inert gas. It is however important that the effects of thermodynamic and kinetic non- ideality in the gas and liquid phase are modelled in a consistent way. Using the simulation program NeqSim – some selected high-pressure non-equilibrium processes (e.g. absorption, pipe flow) have been studied. It is demonstrated that the model is capable of simulating equilibrium- and non-equilibrium processes important to the process- and petroleum industry.

This work investigates the volatilities of amine solvents used in post-combustion CO₂ capture from coal-fired power plants. Amine volatility is one of the key criteria used in screening an amine solvent for CO₂ capture: (1) amine losses up the stack can react in the atmosphere to form ozone and other toxic compounds; (2) volatility losses can result in greater solvent make-up costs; (3) high losses will require the use of bigger water wash units, and more water, to capture fugitive amines prior to venting - these translate to higher capital and operating costs; (4) volatilities need to be measured and modeled in order to develop more accurate and robust thermodynamic models. In this work, volatility is measured using a hot gas FTIR which can determine amine, water, and CO₂ in the vapor headspace above a solution. The liquid solution is speciated by NMR (Nuclear Magnetic Resonance). There are two key contributions made by this research work: (1) it serves as one of the largest sources of experimental data available for amine-water volatility; (2) it provides amine volatility for loaded systems (where CO₂ is present) which is a unique measurement not previously reported in the literature. This work studied the volatility of 20 alkanolamines in water at 0.5 - 1.1 molal (m) in water (< 1.5 mol% amine) at zero loading (no CO₂) from 40 ° - 70 °C. An empirical group contribution model was developed to correlate H[subscript 'amine'] to molecular structures of both alkylamines and alkanolamines. The model incorporated additional functional groups to account for cyclic structures and to distinguish between different types of alkyl groups based on the attached neighboring groups. This model represented the experimental H[subscript 'amine'], which spanned five orders in magnitude, to well within an order of magnitude of the measured values. The second component of this research involves upgrading the AspenPlus® v.7.3 model of MDEA-PZ-CO₂-H₂O system primarily by improving MDEA thermodynamics for MDEA-H₂O, MDEA-CO₂-H₂O, and MDEA-PZ-CO₂-H₂O. A key modification was made to include the carbonate (CO₃²⁻) species into the model chemistry set which greatly improved the fit of CO₂ solubility for MDEA-CO₂-H₂O at ultra lean loading ([alpha]) for 0.001 < [alpha] < 0.01. With MDEA-PZ-H₂O, no MDEA-PZ cross interaction parameters were needed to match the blend volatility. Ultimately, both the blend volatility, at unloaded and loaded conditions, along with speciation were adequately represented by the upgraded model. The final component of this research involves screening the volatilities of novel amines at unloaded and nominal lean loading condition from 40 ° - 70 °C (absorber operating conditions). The volatility of tertiary and hindered amines, such as MDEA and AMP, respectively, is not a strong function of loading because these amines are unable to form stable carbamates. Conversely, the volatility of mono-amines and of diamines decreases by ~3 and 5-20 times, respectively, due to a much greater extent of carbamate-forming speciation. PZ or a blend having a diamine promoted by PZ would be favorable for CO₂ capture due to the low volatility of the diamines in loaded solution. . Finally, in order of increasing degree of salting out as reflected by the increasing magnitude of the system asymmetric amine activity coefficient, 7 m MDEA < 4.8 m AMP ~ 7 m MDEA/2 m PZ < 8 m PZ < 7 m MEA. / text

The solvent 7 molal (m) methyldiethanolamine (MDEA)/2 m piperazine (PZ) presents an attractive option to industry standard solvents including monoethanolamine (MEA) for carbon dioxide (CO₂) capture in coal-fired power plant flue gas scrubbing applications. The solvent was tested under thermal and oxidizing conditions, including temperature cycling in the Integrated Solvent Degradation Apparatus (ISDA), to measure rates of degradation for comparison to other solvents. Unloaded 7 m MDEA/2 m PZ was generally thermally stable up to 150 °C, exhibiting very low loss rates. However, at a loading of 0.25 mol CO2/mol alkalinity, loss rates of 0.17 ± 0.21 and 0.24 ± 0.06 mM/hr, respectively, for MDEA and PZ were measured. No amine loss was observed in the unloaded blend. Thermal degradation was modeled as first-order in [MDEAH⁺], and a universal Ea for amine loss was estimated at 104 kJ/mol. An oxidative degradation model for 7 m MDEA was developed based on the ISDA data. From the model, the rate of amine loss in 7 m MDEA/2 m PZ was estimated at 1.3 X 10⁵ kg/yr, based on a 500 MW power plant and 90% CO₂ capture. In terms of amine loss, the solvent can be ranked with other cycled solvents from greatest to least as follows: 7 m MDEA>7 m MDEA/2 m PZ>8 m PZ. Thermal degradation pathways and mechanisms for 7 m MDEA/2 m PZ include SN2 substitution reactions to form diethanolamine (DEA), methylaminoethanol (MAE), 1-methylpiperazine (1-MPZ), and 1,4-dimethylpiperazine (1,4-DMPZ). The formation of the amino acids bicine and hydroxyethyl sarcosine (HES) has been directly tied to the formation of DEA and MAE, respectively, through oxidation. As a result of the construction and operation of the ISDA for cycling of solvents from an oxidative reactor to a thermal reactor, several practical findings related to solvent degradation were made. The ISDA results demonstrated that increasing dissolved oxygen in solvents leaving the absorber will increase the rate of oxidation. A simple N2 gas stripping method was tested and resulted in a reduction to 1/5th the high temperature oxidation rate associated with dissolved oxygen present in the higher temperature regions of an absorber/stripper system. The ISDA experiments also demonstrated the need to minimize entrained gas bubbles in absorber/stripper systems to control oxidation. When the ISDA was modified to intercept entrained gas bubbles, the oxidation rate was reduced 2 to 3X. / text

Submitted by (ana.araujo@ufrpe.br) on 2016-06-28T16:52:57Z No. of bitstreams: 1 Djalma Beltrao da Costa Farias.pdf: 3013603 bytes, checksum: c297c4bbe2a4b890d5ef586151e7fc72 (MD5) / Made available in DSpace on 2016-06-28T16:52:57Z (GMT). No. of bitstreams: 1 Djalma Beltrao da Costa Farias.pdf: 3013603 bytes, checksum: c297c4bbe2a4b890d5ef586151e7fc72 (MD5) Previous issue date: 2012-03-08 / In a recent article, Leonardo Melgarejo, Joao Neiva de Figueiredo and Carlos Ernani Fries (2009) developed a study to measure the efficiency of 90 agricultural settlements in the state of Rio Grande do Sul, Brazil, using a nonparametric statistical method DEA (Data Envelopment Analysis). This method selected inputs and out-puts variables, and using linear programming suggesting values for the variables that maximize the efficiency of the DMU’s (Decision Making Units), name given by the method to the settlements. Eight inputs and four outputs variables were selected on a set of over more than 100. Values were determined for three types of efficiency, production, technology and management. From the results presented, 47% of the settlements showed an efficiency unit in all three considered and due to this, we see a low discriminatory power in DEA method. In this dissertation we recalculate the values of the article, and then apply the method MDEA (Multiple Data Envelopment Analysis) which consists in dividing the entire space of the variables in subspaces across all possible combinations of inputs and outputs and in each one of these combinations DEA is applied, generating a large number of efficiencies for each DMU. A average is calculated and we consider this number the better representation of the efficiency of a DMU because involves all contexts between the inputs and outputs. For some DMU’s projected values are suggested by MDEA method for its vari-ables. We calculate mean, median, and mode of the values. We make comparisons with the DEA method used in the article by Melgarejo et.al, some simulations are done and we reach very interesting conclusions. / Em um artigo recente, Leonardo Melgarejo, João Neiva de Figueiredo e Carlos Ernani Fries (2009) desenvolveram um estudo para medir a eficiência de 90 assentamentos agrários no estado do Rio Grande do Sul utilizando um método estatís-tico não paramétrico DEA (Data Envelopment Analysis ou Análise Envoltória de Dados). Nesse método são selecionadas variáveis de entradas (insumos ou inputs) e saídas (produtos ou outputs), e através de programação linear chega-se a valores sugeridos para as variáveis, que maximizam a eficiência das DMU’s (Decision Making Units ou Unidades Tomadoras de Decisão), nome dado pelo método aos assen-tamentos. Foram selecionadas 8 variáveis de entrada e 4 de saída em um conjunto de mais de 100 escolhidas. Foram medidos os valores de três tipos de eficiência, a produtiva, a técnica e a de manejo. Em face dos resultados apresentados, em que 47% dos assentamentos mostraram eficiência unitária em todas as três consideradas, vê-se um baixo poder discriminatório no método DEA. Nesse trabalho de dissertação refazemos os cálculos do artigo, e depois aplicamos o método MDEA (Multiple Data Envelopment Analysis) que consiste em dividir todo o espaço das variáveis em subespaços através de todas as combinações possíveis entre as entradas e as saídas e em cada uma dessas combinações o DEA é aplicado, gerando um grande número de valores de eficiências para cada DMU. Calculamos a média desses valores, que consideramos a forma mais justa de representarmos a eficiência de uma DMU pois essa média envolve todos os contextos entre as entradas e as saídas. Para algumas DMU’s verificamos os valores projetados sugeridos pelo método MDEA para suas variáveis, extraímos médias, medianas, e modas das sugestões, fazemos comparações com o método DEA aplicado no artigo de Melgarejo et. al., e algumas simulações, chegando a conclusões muito interessantes.

Em todo o mundo é crescente o uso drogas de abuso sintéticas conhecidas com designer drugs. Os principais representantes desta classe são o Ecstasy ou 3,4-metilenodioximetanfetamina (MDMA) e o Eve ou 3,4-metilenodioxietilanfetamina (MDEA), substâncias com efeitos estimulantes e alucinógenos. No Brasil é crescente sua divulgação pela mídia e o uso recreacional tem sido constatado em vários pacientes que buscam tratamento nas clínicas para dependentes. O presente trabalho constitui validação de metodologia analítica para o diagnóstico laboratorial do uso de MDMA, MDEA e seu produto de biotransformação, o 3,4-metilenodioxianfetamina (MDA), em sangue total e urina, por cromatografia líquida de alta eficiência com detecção por fluorescência. Os métodos desenvolvidos mostraram boa linearidade, precisão, exatidão, rendimento e capacidade de detectar os analitos mesmos quando presentes em baixas concentrações, o que permite sua aplicação na verificação da intoxicação aguda quanto no uso recreacional destas drogas de abuso. / There is a worldwide increase in the use of the synthetic drugs of abuse known as designer drugs. The main representatives of this class are Ecstasy or 3,4-methylenodioxymethamphetamine (MDMA) and Eve or 3,4- methylenodioxyethylamphetamine (MDEA), substances with stimulant and hallucinogenic effects. In Brazil media coverage of them is on the increase and their recreational is in evidence by the growing numbers of patients who seek treatment at drug treatment centers. This paper validates the analytical methodology for the laboratory diagnosis of the use of MDMA, MDEA and their product of biotransformation, 3,4-methylenodioxyamphetamine (MDA), in whole blood and urine by high performance liquid chromatography with fluorescence. The developed methods showed good linearity, precision, accuracy, yield and capacity to detect analytes even when present in low concentrations, which enables its application in cases high intoxication as well as in cases of the recreational use of these drugs of abuse.

Em todo o mundo é crescente o uso drogas de abuso sintéticas conhecidas com designer drugs. Os principais representantes desta classe são o Ecstasy ou 3,4-metilenodioximetanfetamina (MDMA) e o Eve ou 3,4-metilenodioxietilanfetamina (MDEA), substâncias com efeitos estimulantes e alucinógenos. No Brasil é crescente sua divulgação pela mídia e o uso recreacional tem sido constatado em vários pacientes que buscam tratamento nas clínicas para dependentes. O presente trabalho constitui validação de metodologia analítica para o diagnóstico laboratorial do uso de MDMA, MDEA e seu produto de biotransformação, o 3,4-metilenodioxianfetamina (MDA), em sangue total e urina, por cromatografia líquida de alta eficiência com detecção por fluorescência. Os métodos desenvolvidos mostraram boa linearidade, precisão, exatidão, rendimento e capacidade de detectar os analitos mesmos quando presentes em baixas concentrações, o que permite sua aplicação na verificação da intoxicação aguda quanto no uso recreacional destas drogas de abuso. / There is a worldwide increase in the use of the synthetic drugs of abuse known as designer drugs. The main representatives of this class are Ecstasy or 3,4-methylenodioxymethamphetamine (MDMA) and Eve or 3,4- methylenodioxyethylamphetamine (MDEA), substances with stimulant and hallucinogenic effects. In Brazil media coverage of them is on the increase and their recreational is in evidence by the growing numbers of patients who seek treatment at drug treatment centers. This paper validates the analytical methodology for the laboratory diagnosis of the use of MDMA, MDEA and their product of biotransformation, 3,4-methylenodioxyamphetamine (MDA), in whole blood and urine by high performance liquid chromatography with fluorescence. The developed methods showed good linearity, precision, accuracy, yield and capacity to detect analytes even when present in low concentrations, which enables its application in cases high intoxication as well as in cases of the recreational use of these drugs of abuse.

Cette thèse porte sur l'étude de l'enthalpie de dissolution du dioxyde de carbone dans des solutions aqueuses d'amine. Pour développer des modèles théoriques décrivant les systèmes (CO2-amine-eau) pour les conditions appliquées aux procédés industriels, il est nécessaire d'avoir des données expérimentales reliant la solubilité et l'enthalpie. Dans cette étude, nous avons utilisé une unité de mélange construite au laboratoire que nous avons adapté à un calorimètre SETARAM C-80 pour mesurer l'enthalpie de solution du CO2 dans cinq solutions aqueuses d'amine, (la 2-Amino-2-méthyl-1-propanol (AMP), la monoéthanolamine (MEA), la diéthanolamine (DEA), la triéthanolamine (TEA) et la méthyldiéthanolamine (MDEA) (15 et 30 mass%) à des températures comprises entre 322.5 K et 372.9 K et des pressions allant de 0.5 à 5 MPa. Les données de la littérature ont été utilisées pour ajuster deux modèles thermodynamiques d'équilibre de phases (un simple et un rigoureux). Le premier modèle résume l'absorption du CO2 par une seule réaction, tandis que le second prend en compte toutes les réactions à l'équilibre. Le modèle simple reproduit nos enthalpies expérimentales à plus ou moins 10%, tandis que le modèle rigoureux reproduit nos données avec un écart compris entre 5 et 20% selon l'amine considérée. Le calcul de l'enthalpie dans le modèle rigoureux est fortement dépendant des données de la littérature utilisées pour la réaction de protonation de l'amine. Ceci souligne la nécessité d'acquérir de nouvelles données expérimentales sur ces constantes d'équilibre pour améliorer le modèle.