Treatment of Antihypertensive and Cardiovascular Drugs in Supercritical Water: An Experimental and Modeled Approach

Pharmaceutical pollutants are considered emerging contaminants, representing a significant concern to the ecosystem. Thus, this study reports on the degradation of antihypertensive and cardiovascular drugs (atenolol, captopril, propranolol hydrochloride, diosmin, hesperidin, losartan potassium, hydrochlorothiazide, and trimetazidine) present in simulated wastewater through applying the technology of oxidation using supercritical water (SCW). The operational parameters of the treatment process, particularly the feed flow rate, temperature, and concentration of H2O2, were assessed. A central composite design of experiments associated with differential evolution was employed in the optimization. Both liquid and gaseous phase products were submitted to physical–chemical characterization. As a result, the optimized conditions for the treatment were discovered to be a feed flow rate of 13.3 mL/min, a temperature of 600 °C, and a H2O2 oxidation coefficient of 0.65, corresponding to the oxygen stoichiometric coefficient in the carbon oxidation chemical reaction. Under optimal conditions, the total organic carbon (TOC) decreased from 332 to 25 mg/L (92.1%), and the pharmaceutical molecules underwent near-complete degradation. The physical–chemical parameters also met with the main environmental regulations for wastewater disposal. The compounds determined in the gaseous phase were CO2 (97.9%), H2 (1.3%), CH4 (0.3%), and CO (0.5%.). Additionally, a modeling thermodynamic equilibrium of the system was performed, based on the experimental data. The results revealed that SCW technology has a great potential to oxidize/degrade organic matter and can be applied to treat pharmaceutical pollutants

Determination of an optimum extraction region for the recovery of bioactive compounds from olive leaves (Olea europaea L.) using green dynamic pressurized liquid extraction

Pressurized liquid extraction with water and ethanol was employed to obtain high antioxidant extracts from olive leaves (Olea europaea L.). The influence of solvent ratio (100-50% v/v water/ethanol), temperature (100-200 degrees C), and solvent flow rate (1-5 mL min(-1)) on the extraction process was investigated using a Box-Behnken experimental design. ANOVA was applied to determine the overall goodness of fit of the dependent variables (extraction yield, antioxidant capacity by DPPH, total flavonoids, total iridoid-glycoside, and total phenolic content) in second-order models. For the optimization, these models were used to find the optimal conditions using the Sequential Simplex optimization procedure combined with Derringer and Suich's desirability function to maximize antioxidant capacity, total iridoid-glycoside recovery, and total phenolic content. The optimal region conditions for extraction were determined at a solvent ratio of 53-65% v/v water/ethanol, the extraction temperature of 100-120 degrees C, and a 3-4 mL min(-1) solvent flow rate. Fifteen phenolic compounds were identified in the samples using HPLC-DAD-ESI/MSn, including two phenolic acids (hydroxytyrosol and hydroxytyrosol glucoside), four flavonols (apigenin-6,8-C-dihexoside, quercetin-3-O-rutinoside, luteolin-O-hexoside, and derivatives), and nine iridoid-glycosides (verbascoside, oleuropein, and derivatives). Oleuropein and derivates were identified as the major phenolic compounds in the extract obtained at optimal conditions as a percentage of 89% of the extract composition.info:eu-repo/semantics/publishedVersio

Continuous Hydrogen Production via Hydrothermal Gasification of Biodiesel Industry Wastewater: Experimental Optimization and Energy Integration Simulation

This study reports the continuous production of H2 from the wastewater effluent of the biodiesel industry in a medium containing water under supercritical conditions. The effects of temperature and feed flow rate on the generation of hydrogen were evaluated and optimized. At a temperature of 700 °C and a 17.5 mL/min feed flow, a total gas flow of 5541 NmL/min was achieved. Among all identified gases, hydrogen represented the highest molar fraction of 73%. Under optimized conditions, a H2 yield of 357 NmL/geffluent feed was observed. The experimental results indicate a significant increase in the H2 production at the highest experimented temperatures. On the other hand, the feed flow only slightly influenced the process within the assessed range but showed a tendency to increase the H2 production at the highest values. Finally, information on energy efficiency optimization and scale-up are presented, and at the same time, different designs for industrial implementation of the hydrothermal gasification process are proposed

Modelagem da extração supercritica de oleos essenciais

Orientador: Maria Angela de Almeida MeirelesTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: Este trabalho apresenta metodologias complementares e auxiliares para modelagem na extração supercrítica de óleos essenciais. A primeira metodologia consiste em um procedimento matemático para a obtenção dos coeficientes de fugacidade, a partir de uma equação de estado, os quais são necessários na modelagem termodinâmica da extração supercrítica. Neste procedimento permite-se a utilização de qualquer tipo de regra de mistura para determinação dos parâmetros de interação da equação de estado. A segunda metodologia trata-se de um procedimento para o cálculo do equilíbrio líquido-vapor a altas pressões. O equilíbrio líquido-vapor é calculado a partir de um sistema de equações envolvendo equações de balanços de massa, critérios de equilíbrio termodinâmico e restrições estequiométricas. Este procedimento permite calcular os problemas básicos de equilíbrio líquido-vapor tais como: ponto de bolha, ponto de orvalho e flash. Utilizou-se este procedimento cálculo da solubilidade de um óleo para o essencial em dióxido de carbono. A terceira consiste estimação dos parâmetros de interação binária das equações na metodologia desenvolvida de estado a partir de dados experimentais de equilíbrio líquido-vapor da literatura. Foi empregado o método de máxima verossimilhança juntamente com a segunda metodologia proposta parâmetros de interação binária das equações de estado usadas no cálculo equilíbrio líquido-vapor a altas pressões. Finalmente, foi desenvolvido um procedimento de avaliação econômica rápida para plantas industriais de extração supercrítica para produtos naturais. Esta avaliação econômica está centrada principalmente no custo energético. A quarta metodologia permite o cálculo da cinética de extração supercrítica baseado no modelo de leito fixo com difusão em sólido homogêneo. o modelo proposto deve ser aplicado para as seguintes condições: sistemas isotérmicos, sistemas monocomponentes, escoamento unidimensional, sem dispersão axial e isoterma de sorção linear. O exemplo selecionado para a aplicação das metodologias desenvolvidas foi a desterpenação do óleo essencial de laranja, de grande interesse industrial. Foram utilizadas as equações de estado de Peng-Robinson e de Soave-Redlich-Kwong.Abstract: This work presents complementary and auxiliary methodologies for modeling supercritical extraction of essential oils. The first methodology consists of a mathematical procedure to obtain the fugacity coefficients, from any equation of state. These coefficients are necessary for thermodynamic modeling of the supercritical extraction. This procedure allows to use any type of mixing rule for determination of the interaction parameters of the equation of state. The second methodology deals with the procedure to calculate the vapour-liquid equilibrium at high pressures. The vapour-liquid equilibrium is calculated from a system of equations involving the mass balance, thermodynamic equilibria relationship and stoichiometric restrictions. This procedure allows to calculate the basic problems of liquid-vapour equilibrium, such as: bubble point, dew point and flash. The solubility of an essential oil in carbon dioxide was predicted using this procedure. The third methodology was developed in order estimate binary interaction parameters of the thermodynamic equations state from literature liquid-vapour equilibrium Maximum Likelihood experimental data. The Generalized method was used together with the methodology to calculate binary interaction parameters for the liquid-vapour equilibrium at high pressures. The fourth methodology allows the study of the kinetics of supercritical extraction based on a fixed bed model with the diffusion in homogeneous solid. The adopted model can be used for the systems which are: isotherm, one dimensional, without axial dispersion and have a linear sorption isotherm. Finally, a procedure was developed for a fast economic evaluation of industrial plants of supercritical extraction of natural products. This economic evaluation takes into account the energy cost. The example selected for the application of the developed methodologies was the desterpenation of orange essential oil, which is a oil of great industrial interest. Peng-Robinson and Soave-Redlich-Kwong were the used equations of state.DoutoradoDoutor em Engenharia de Alimento

Predição do equilibrio liquido-vapor e liquido-liquido por contribuição de grupos

Orientador: Saul Gonçalves D'AvilaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: Neste trabalho foi explorada a potencialidade do método de contribuição de grupos ASOG aplicado ao equilíbrio de fases, abordando-se três tópicos: Estudo comparativo dos desempenos dos métodos ASOG/ELV e INIFAC/ELV aplicando ao equilíbrio líquido-vapor (ELV); Obtenção de novos parâmetros ASOG/ELV contribuindo para diminuir as lacunas na atual matriz; Extensão da aplicabilidade do método ASOG/ELV ao equilíbrio líquido-líquido (ELL). Usando as versões mais recentes das matrizes ELV dos métodos ASOG e UNIFAC, verificou-se que ambos apresentarem desempenhos equivalentes em cálculos de ponto de bolha e orvalho de misturas binárias. A potencialidade do método ASOG/ELL na predição de dados de equilíbrio líquido-líquido foi demonstrada, determinando-se parâmetros de interação entre sete grupos estruturais, incluindo o grupo H2O. Foi verificada a adequação do método na predição de sistemas comumente encontrados em equipamentos industriais envolvendo água, hidrocarbonetos, álcoois e ésteres. Foi observado que o método ASOG/ELL apresenta resultados equivalentes aos do método ASOG/ELL em cálculos de equilíbrio de misturas binárias, ternárias e quaternáriasAbstract: In this work the potentially of the ASOG group contribution method was explores when applied to phase equilibrium comprehending three topics: A comparative study of the performace of the ASOG/VLE and UNIFAC/VLE methods apllied to liquid-vapor equilibrium (VLE); Acquisition of news ASOG/VLE parameters helping to reduce the gaps in the present parameter matrix; Extension of the applicability of the ASOG/VLE method liquid-liquid equilibrium (LLE). Using more recent versions of the VLE matrix of the ASOG and UNIFAC methods, both showed equivalent performances concerning the prediction of the bubble and dew points for binary mixtures. The potentiality of the ASOG/LLE method to predict liquid-liquid equilibrium data was demonstrated determining interaction parameters among seven structural groups, including the H2O group. The metod adequacy for prediction of system usually found in industries was verified, covering water, hydrocarbon, alcohol end ester. It was observed, that the ASOG/LLE gives results equivalent to those of the UNIFAC/LLE method for equilibrium calculations of binary, ternary and quaternary mixturesMestradoMestre em Engenharia Químic

Simulação do processo de desterpenação supercrítica do óleo essencial de laranja

O objetivo deste trabalho é simular um processo de extração supercrítica com o Aspen-Plus. Os equipamentos para a simulação do processo foram selecionados de acordo com a literatura especializada e envolvem dois vasos de extração, dois reservatórios, seis trocadores de calor, dois separadores e uma bomba, bem como as condições de operação sugeridas para o processo especificamente escolhido. A escolha foi motivada pelo crescente interesse na extração supercrítica com dióxido de carbono, um solvente com algumas características altamente desejáveis: não-tóxidez, não-inflamabilidade, moderada pressão crítica e baixas temperaturas de ponto de bolha. Os altos custos envolvidos com esse tipo de processo, tendo como principal item o consumo de energia, exigem análises econômicas rápidas. O Aspen-Plus representa um instrumento rápido e eficiente para o cálculo da energia envolvida, apesar da limitação de modelos disponíveis no simulador. O método pode ser estendido a processos similares envolvendo outros produtos e condições de operaçã

<b>Solid-liquid equilibrium measurements for the ternary system PCL + chloroform + nonsolvents (n-hexane, ethanol, methanol, isopropanol) at 303.15 K</b> - doi: 10.4025/actascitechnol.v36i1.16615

This work reports experimental data of polycaprolactone (PCL) polymer solubility in chloroform as solvent and n-hexane, methanol, ethanol and isopropanol as nonsolvents, at atmospheric pressure (about 1,0 bar) and temperature of 303.15 K. It was used PCL with 70000-90000 and 2000 molar mass (MM). The experiments of solubility were performed using a jacketed-cell with temperature controlled by an ultrathermostatic bath, in which a turbidity method was adopted and used. From the obtained results it should be observed that the n-hexane presented a more pronounced anti-solvent effect in the PCL solubility, where the heterogeneous region (solid phase presence) was broader than when other nonsolvent. It was also observed that the binodal curves measured with the high molar mass polymer showed similar results compared to the low molar mass one