Fernando Pessoa - Academia.edu (original) (raw)

Papers by Fernando Pessoa

Research paper thumbnail of Transgeneracionality, Losses and Places of Subjectivities

Research paper thumbnail of Solubility of Carbon Dioxide in Water and Hexadecane: Experimental Measurement and Thermodynamic Modeling

J Chem Eng Data, 2009

Direct contact between oil, gases, and water often occurs in petroleum reservoirs and in many ref... more Direct contact between oil, gases, and water often occurs in petroleum reservoirs and in many refining operations, where the phase behavior study is fundamental to design and optimization. Accurate experimental data and thermodynamic models are required for a satisfactory prediction of phase equilibrium. The objective of this work is to obtain experimental solubility data for the system of carbon dioxide + hexadecane since this organic compound has properties similar to the average properties of Brazilian heavy oil. The carbon dioxide + water system was used to validate the experimental apparatus and to obtain additional data to complete literature reports. The operational conditions used were a temperature range from (303.2 to 323.2) K and a low-pressure range from (51.7 to 535.4) kPa. Moreover, the results were correlated using a simple thermodynamic model to describe the behavior of both systems, demonstrating satisfactory bubble point calculation measurements.

Research paper thumbnail of Conservação e reúso de águas usando o método Diagrama de Fontes de Água para processos em batelada: estudo de casos

Ambiente Agua an Interdisciplinary Journal of Applied Science, 2012

Research paper thumbnail of Production of Biodiesel via Enzymatic Ethanolysis of the Sunflower and Soybean Oils: Modeling

Applied Biochemistry and Biotechnology, May 1, 2010

Biodiesel has become attractive due to its environmental benefits compared with conventional dies... more Biodiesel has become attractive due to its environmental benefits compared with conventional diesel. Although the enzymatic synthesis of biodiesel requires low thermal energy, low conversions of enzymatic transesterification with ethanol (ethanolysis) of oils to produce biodiesel are reported as a result of deactivation of the enzyme depending on the reaction conditions. The synthesis of biodiesel via enzymatic ethanolysis of sunflower and soybean oils was investigated. Kinetic parameters for the overall reactions were fitted to experimental data available in the literature with the Ping Pong Bi-Bi mechanism including the inhibition effect of the ethanol on the activity of lipase Novozyme® 435. The model was applied to a batch reactor and the experimental conversions were successfully reproduced. The modeling of a semibatch reactor with continuous addition of ethanol was also performed and the results showed a reduction of roughly 3 h in the reaction time in comparison with the batch-wise operation.

Research paper thumbnail of STEADY-STATE modeling and simulation of pipeline networks for compressible fluids

Braz J Chem Eng, 1998

ABSTRACT This paper presents a model and an algorithm for the simulation of pipeline networks wit... more ABSTRACT This paper presents a model and an algorithm for the simulation of pipeline networks with compressible fluids. The model can predict pressures, flow rates, temperatures and gas compositions at any point of the network. Any network configuration can be simulated; the existence of cycles is not an obstacle. Numerical results from simulated data on a proposed network are shown for illustration. The potential of the simulator is explored by the analysis of a pressure relief network, using a stochastic procedure for the evaluation of system performance.

Research paper thumbnail of Identification of plant genes involved on the initial contact between ectomycorrhizal symbionts ( Castanea sativa – European chestnut and Pisolithus tinctorius)

European Journal of Soil Biology, May 1, 2009

In order to contribute to the knowledge on the genes involved in the early steps of ectomycorrhiz... more In order to contribute to the knowledge on the genes involved in the early steps of ectomycorrhiza development, the transcriptional response of Castanea sativa (European chestnut) during the initial contact (6 and 12 h) with Pisolithus tinctorius was analysed by microarray. This study revealed that among the regulated plant genes, a substantial number of up-regulated transcripts showed homology with genes encoding for proteins involved in stress and defense responses, (a cystatin, a cystatin-like protein, a defensin and a universal stress protein). Early contact with the fungal mycelium also altered expression of genes that are putatively involved in cellular processes like signal transduction and communication (receptor kinase-related protein), protein fate (papain-like cystein proteinase), and water transport facilitation (water channel MipK protein). Expression profiling of the early contact between C. sativa and P. tinctorius revealed that changes in gene expression occur few hours after contact, long before the development of a functional mycorrhiza. The induction of genes involved in stress and defense suggests that the host plant reacts rapidly to the presence of the mycobiont eliciting a defense programme similar to that described for pathogenic interactions. Another plant response was the repression of genes normally implicated in water stress accounting for a water stress relief due to the initial contact with the ectomycorrhizal fungus.

Research paper thumbnail of Supporting Knowledge Sharing Within an Organisation

Page 1. SUPPORTING KNOWLEDGE SHARING WITHIN AN ORGANISATION Luis Manuel Borges Gouveia†‡ † Lancas... more Page 1. SUPPORTING KNOWLEDGE SHARING WITHIN AN ORGANISATION Luis Manuel Borges Gouveia†‡ † Lancaster University, Computing Department Lancaster LA1 4YR United Kingdom luis@comp.lancs.ac.uk ‡ University ...

Research paper thumbnail of Characterization of a density by minimizing the logarithmic information of degree q

Research paper thumbnail of Influence of Chemical Contribution in the Calculation of Vle

Thermodynamic models for phase equilibrium calculations can be developed in three distinct ways: ... more Thermodynamic models for phase equilibrium calculations can be developed in three distinct ways: (i) taking into account only the physical interactions of substances (PHYC -physical contribution); (ii) taking into account only the associations, solvations (CHEC -chemical contribution); and finally, (iii) both contributions simultaneously. In various extremely non ideal systems already studied in literature, the determination of the equilibrium was carried out using an association model (CHEC) between molecules of each substance or a combination of it with physical contribution model. These strategies adopted by the authors may disclose an excessive number of parameters necessary to be estimated for an accurated characterization of the equilibrium. Therefore, the aim of this work is to study the influence of the chemical contribution in the thermodynamic models for the determination of the vapor liquid equilibrium of commonly systems presents in processes of industrial plants. For this study was used the data bank proposed by Danner and Gess (1989) in which a lot of binary systems were evaluated on its thermodynamic consistency and classified according to intermolecular forces. Beyond these systems, others had been analyzed in this work in which properly chemical reactions exist between the components (solvations). In order to take in consideration only the existing chemical contribution, characterized by intermoleculares forces and chemical reactions, was applied the Chemical Theory of Prigogine and Defay (1954) and this one was compared not only to a thermodynamic model of isolated physical contribution (UNIQUAC), but also to one with both added contributions. The results had demonstrated that only in the case where there is the existence of a chemical reaction, for example, in systems where the dimerization occurs, it has the necessity to use the Chemical Theory in the calculation of the vapor liquid equilibrium.

Research paper thumbnail of Prediction of vapor–liquid and liquid–liquid equilibria for polymer systems: Comparison of activity coefficient models

Fluid Phase Equilibria

A large number of equations of state and activity coefficient models capable of describing phase ... more A large number of equations of state and activity coefficient models capable of describing phase equilibria in polymer solutions are available today, but only a few of these models have been applied to different systems. It is therefore useful to investigate the performance of existing thermodynamic models for complex polymer solutions which have not yet been widely studied. The present

Research paper thumbnail of Atmospheric Destilation Residuum Extraction with Supercritical Propane: A Study of the Process Variables Influence

Supercritical propane is a powerful solvent in the extraction of light hydrocarbons from crude oi... more Supercritical propane is a powerful solvent in the extraction of light hydrocarbons from crude oil residues. The extraction efficiency is a function of pressure, temperature, oil composition and the ratio between solvent and oil rates. This work presents the results of computer simulation studies in the investigation of the capabilities of supercritical propane in the extraction of a light fraction from the atmospheric distillation residuum (RAT). The experimental physical-chemical characterization of the feed was used to generate a mixture of pseudo-components representing the RAT. It was observed that the extraction efficiency increases with the solvent/oil ratio and the pressure, whereas it decreases with the increasing temperature. A practically complete recovery of the light fraction was reached at 100 bar, with propane feed at 100 °C and a solvent/oil ratio of 15:1 in volumetric basis.

Research paper thumbnail of The synthesis of biodiesel via enzymatic ethanolysis of the sunflower and palm oils: kinetic modeling

Research paper thumbnail of Assessment of Catalytic Properties in Aqueous and Media of Aspergillus Niger Lipase Immobilized on Supports Vitreous

Research paper thumbnail of Enthalpy of Dissociation of Simple and Mixed Carbon Dioxide Clathrate Hydrate

Research paper thumbnail of Production Planning of Oil-Refinery Units for the Future Fuel Market in Brazil

RESUMO -The oil industry in Brazil has accounted for US$ 300 billion in investments over the last... more RESUMO -The oil industry in Brazil has accounted for US$ 300 billion in investments over the last 10 years and further expansions are planned in order to supply the needs of the future fuel market in terms of both quantity and quality. This work analyzes the Brazilian fuel production and market scenarios considering the country's planned investments to prevent fuel deficit of around 30% in 2020. A nonlinear (NLP) operational planning model and a mixed-integer nonlinear (MINLP) investment planning model are proposed to predict the national overall capacity for different oil-refinery units aggregated in one hypothetical large refinery considering four possible future market scenarios. For the multi-refinery case, a phenomenological decomposition heuristic (PDH) method solves separated the quantity and logic variables in a mixed-integer linear (MILP) model, and the quantity and quality variables in an NLP model. Iteratively, the NLP model is restricted by the MILP results.

Research paper thumbnail of Continuous biosorption of Cu and Zn by immobilized waste biomass Sargassum sp

Process Biochemistry, 2001

Biosorption of copper and zinc by the residual biomass of the alga Sargassum sp. was investigated... more Biosorption of copper and zinc by the residual biomass of the alga Sargassum sp. was investigated in a mini packed-bed column. The biomass was immobilized in a polymeric matrix to improve its physicochemical properties for continuous biosorption of heavy metals from aqueous ...

Research paper thumbnail of Diagrama de Fontes de Água: Uma Ferramenta Sustentável para a P+L na Minimização de Águas e Efluentes Industriais

A prática de Produção mais Limpa (P+L) no ambiente industrial requer a perfeita compreensão das c... more A prática de Produção mais Limpa (P+L) no ambiente industrial requer a perfeita compreensão das características dos processos produtivos. Quando o foco está voltado para a minimização do consumo hídrico e dos impactos ocasionados pela geração de efluentes, torna-se importante rever os processos hídricos de modo a prover o sistema com ações sustentáveis, como o reúso de águas e efluentes. O desenvolvimento de tecnologias como suporte para uma bem planejada gestão dos recursos hídricos tem sido motivado pela maior necessidade de se estabelecer programas de reúso de água nos diversos setores, principalmente no meio industrial. O campo da Engenharia de Processos Químicos, particularmente da Integração de Processos, vem contribuindo para o desenvolvimento de ferramentas voltadas para a sistematização desta prática. Uma importante ferramenta é o Diagrama de Fontes de Água (DFA), que procura otimizar a destinação de correntes aquosas, por meio de regras heurísticas, estabelecendo uma adequada configuração de reúso e regeneração de correntes. Este trabalho tem como objetivo adotar o procedimento algorítmico DFA como um importante instrumento para a avaliação de práticas voltadas para a redução do consumo de água e da geração de efluentes, no contexto da P+L. É mostrado um estudo de caso para ilustrar a aplicabilidade do procedimento, indicando o cenário de realocação das correntes, bem como a redução de vazão alcançada. Sua vantagem está na realização de cálculos rápidos e a geração simultânea de fluxogramas alternativos sem modificações substanciais do processo, facilitando a sistematização da prática de reúso.

Research paper thumbnail of Reúso de efluentes industriais em refinarias de petróleo usando o método DFA para sistemas regenerativos

Ambiente & Água - An Interdisciplinary Journal of Applied Science

Wastewater reuse practices in the industry require an adequate understanding of the characteristi... more Wastewater reuse practices in the industry require an adequate understanding of the characteristics of the manufacture processes, to minimize the water consumption and the generation of effluent. The objective of this work was to apply the WSD method, used to defining the target of minimum process water consumption in a case study of oil refinery, by means of the reuse and recycling operations, including regeneration processes. The importance and influence of the wastewater treatment plant in the regeneration quality, including intermediate process streams, for the reuse and the recycling operations, were evaluated. Furthermore, centralized and distributed treatment flowsheet configurations were tested. Thus, this work presented the solution of a case study with three contaminants in water streams processes, different interconnections approaches, used to illustrate the application of this procedure showing the reduction of water flow rate and total costs compared to the original flo...

Research paper thumbnail of PHORBOL ESTERS EXTRACTION FROM Jatropha curcas SEED CAKE USING SUPERCRITICAL CARBON DIOXIDE

Jatropha curcas seeds contain 40–60% of oil, which can be converted to high quality biodiesel. Ho... more Jatropha curcas seeds contain 40–60% of oil, which can be converted to high quality biodiesel. However the seeds contain many toxic compounds with the most important ones known as phorbol esters (PEs). Phorbol esters are derivatives of the tigliane compound and they are considered toxic and maybe with carcinogenic activity. It is reported in the literature that it is possible to have four to six types of phorbol esters or its derivatives. Different chemical and physical methods have been employed for the removal or inactivation of phorbol esters present in different raw materials. This study has as aim the study of the technical feasibility in the use of supercritical fluid for the extraction of phorbol esters present in the Jatropha seed cake. The operational conditions investigated were 70ºC -100Bar; 50ºC – 160Bar; 90ºC – 160Bar; 40ºC -300Bar; 70ºC -300Bar; 50ºC -440Bar and 90ºC -440Bar. Defatted Jatropha curcas seed cake was obtained by a screw press.

Research paper thumbnail of Simulation of a Supercritical Process to Concentrate Natural Products from Deodorizer Distillates of Vegetable Oils

This work has as an objective the simulation of a process, using supercritical fluid, to concentr... more This work has as an objective the simulation of a process, using supercritical fluid, to concentrate the vitamin E (tocopherol) present in the by-product of the refining process of different vegetable oils, like corn, sunflower, canola and soybean, known as the deodorizer distillate (DD). This by-product is rich in high aggregated value compounds like the sterols, tocopherols, squalene and fatty

Research paper thumbnail of Transgeneracionality, Losses and Places of Subjectivities

Research paper thumbnail of Solubility of Carbon Dioxide in Water and Hexadecane: Experimental Measurement and Thermodynamic Modeling

J Chem Eng Data, 2009

Direct contact between oil, gases, and water often occurs in petroleum reservoirs and in many ref... more Direct contact between oil, gases, and water often occurs in petroleum reservoirs and in many refining operations, where the phase behavior study is fundamental to design and optimization. Accurate experimental data and thermodynamic models are required for a satisfactory prediction of phase equilibrium. The objective of this work is to obtain experimental solubility data for the system of carbon dioxide + hexadecane since this organic compound has properties similar to the average properties of Brazilian heavy oil. The carbon dioxide + water system was used to validate the experimental apparatus and to obtain additional data to complete literature reports. The operational conditions used were a temperature range from (303.2 to 323.2) K and a low-pressure range from (51.7 to 535.4) kPa. Moreover, the results were correlated using a simple thermodynamic model to describe the behavior of both systems, demonstrating satisfactory bubble point calculation measurements.

Research paper thumbnail of Conservação e reúso de águas usando o método Diagrama de Fontes de Água para processos em batelada: estudo de casos

Ambiente Agua an Interdisciplinary Journal of Applied Science, 2012

Research paper thumbnail of Production of Biodiesel via Enzymatic Ethanolysis of the Sunflower and Soybean Oils: Modeling

Applied Biochemistry and Biotechnology, May 1, 2010

Biodiesel has become attractive due to its environmental benefits compared with conventional dies... more Biodiesel has become attractive due to its environmental benefits compared with conventional diesel. Although the enzymatic synthesis of biodiesel requires low thermal energy, low conversions of enzymatic transesterification with ethanol (ethanolysis) of oils to produce biodiesel are reported as a result of deactivation of the enzyme depending on the reaction conditions. The synthesis of biodiesel via enzymatic ethanolysis of sunflower and soybean oils was investigated. Kinetic parameters for the overall reactions were fitted to experimental data available in the literature with the Ping Pong Bi-Bi mechanism including the inhibition effect of the ethanol on the activity of lipase Novozyme® 435. The model was applied to a batch reactor and the experimental conversions were successfully reproduced. The modeling of a semibatch reactor with continuous addition of ethanol was also performed and the results showed a reduction of roughly 3 h in the reaction time in comparison with the batch-wise operation.

Research paper thumbnail of STEADY-STATE modeling and simulation of pipeline networks for compressible fluids

Braz J Chem Eng, 1998

ABSTRACT This paper presents a model and an algorithm for the simulation of pipeline networks wit... more ABSTRACT This paper presents a model and an algorithm for the simulation of pipeline networks with compressible fluids. The model can predict pressures, flow rates, temperatures and gas compositions at any point of the network. Any network configuration can be simulated; the existence of cycles is not an obstacle. Numerical results from simulated data on a proposed network are shown for illustration. The potential of the simulator is explored by the analysis of a pressure relief network, using a stochastic procedure for the evaluation of system performance.

Research paper thumbnail of Identification of plant genes involved on the initial contact between ectomycorrhizal symbionts ( Castanea sativa – European chestnut and Pisolithus tinctorius)

European Journal of Soil Biology, May 1, 2009

In order to contribute to the knowledge on the genes involved in the early steps of ectomycorrhiz... more In order to contribute to the knowledge on the genes involved in the early steps of ectomycorrhiza development, the transcriptional response of Castanea sativa (European chestnut) during the initial contact (6 and 12 h) with Pisolithus tinctorius was analysed by microarray. This study revealed that among the regulated plant genes, a substantial number of up-regulated transcripts showed homology with genes encoding for proteins involved in stress and defense responses, (a cystatin, a cystatin-like protein, a defensin and a universal stress protein). Early contact with the fungal mycelium also altered expression of genes that are putatively involved in cellular processes like signal transduction and communication (receptor kinase-related protein), protein fate (papain-like cystein proteinase), and water transport facilitation (water channel MipK protein). Expression profiling of the early contact between C. sativa and P. tinctorius revealed that changes in gene expression occur few hours after contact, long before the development of a functional mycorrhiza. The induction of genes involved in stress and defense suggests that the host plant reacts rapidly to the presence of the mycobiont eliciting a defense programme similar to that described for pathogenic interactions. Another plant response was the repression of genes normally implicated in water stress accounting for a water stress relief due to the initial contact with the ectomycorrhizal fungus.

Research paper thumbnail of Supporting Knowledge Sharing Within an Organisation

Page 1. SUPPORTING KNOWLEDGE SHARING WITHIN AN ORGANISATION Luis Manuel Borges Gouveia†‡ † Lancas... more Page 1. SUPPORTING KNOWLEDGE SHARING WITHIN AN ORGANISATION Luis Manuel Borges Gouveia†‡ † Lancaster University, Computing Department Lancaster LA1 4YR United Kingdom luis@comp.lancs.ac.uk ‡ University ...

Research paper thumbnail of Characterization of a density by minimizing the logarithmic information of degree q

Research paper thumbnail of Influence of Chemical Contribution in the Calculation of Vle

Thermodynamic models for phase equilibrium calculations can be developed in three distinct ways: ... more Thermodynamic models for phase equilibrium calculations can be developed in three distinct ways: (i) taking into account only the physical interactions of substances (PHYC -physical contribution); (ii) taking into account only the associations, solvations (CHEC -chemical contribution); and finally, (iii) both contributions simultaneously. In various extremely non ideal systems already studied in literature, the determination of the equilibrium was carried out using an association model (CHEC) between molecules of each substance or a combination of it with physical contribution model. These strategies adopted by the authors may disclose an excessive number of parameters necessary to be estimated for an accurated characterization of the equilibrium. Therefore, the aim of this work is to study the influence of the chemical contribution in the thermodynamic models for the determination of the vapor liquid equilibrium of commonly systems presents in processes of industrial plants. For this study was used the data bank proposed by Danner and Gess (1989) in which a lot of binary systems were evaluated on its thermodynamic consistency and classified according to intermolecular forces. Beyond these systems, others had been analyzed in this work in which properly chemical reactions exist between the components (solvations). In order to take in consideration only the existing chemical contribution, characterized by intermoleculares forces and chemical reactions, was applied the Chemical Theory of Prigogine and Defay (1954) and this one was compared not only to a thermodynamic model of isolated physical contribution (UNIQUAC), but also to one with both added contributions. The results had demonstrated that only in the case where there is the existence of a chemical reaction, for example, in systems where the dimerization occurs, it has the necessity to use the Chemical Theory in the calculation of the vapor liquid equilibrium.

Research paper thumbnail of Prediction of vapor–liquid and liquid–liquid equilibria for polymer systems: Comparison of activity coefficient models

Fluid Phase Equilibria

A large number of equations of state and activity coefficient models capable of describing phase ... more A large number of equations of state and activity coefficient models capable of describing phase equilibria in polymer solutions are available today, but only a few of these models have been applied to different systems. It is therefore useful to investigate the performance of existing thermodynamic models for complex polymer solutions which have not yet been widely studied. The present

Research paper thumbnail of Atmospheric Destilation Residuum Extraction with Supercritical Propane: A Study of the Process Variables Influence

Supercritical propane is a powerful solvent in the extraction of light hydrocarbons from crude oi... more Supercritical propane is a powerful solvent in the extraction of light hydrocarbons from crude oil residues. The extraction efficiency is a function of pressure, temperature, oil composition and the ratio between solvent and oil rates. This work presents the results of computer simulation studies in the investigation of the capabilities of supercritical propane in the extraction of a light fraction from the atmospheric distillation residuum (RAT). The experimental physical-chemical characterization of the feed was used to generate a mixture of pseudo-components representing the RAT. It was observed that the extraction efficiency increases with the solvent/oil ratio and the pressure, whereas it decreases with the increasing temperature. A practically complete recovery of the light fraction was reached at 100 bar, with propane feed at 100 °C and a solvent/oil ratio of 15:1 in volumetric basis.

Research paper thumbnail of The synthesis of biodiesel via enzymatic ethanolysis of the sunflower and palm oils: kinetic modeling

Research paper thumbnail of Assessment of Catalytic Properties in Aqueous and Media of Aspergillus Niger Lipase Immobilized on Supports Vitreous

Research paper thumbnail of Enthalpy of Dissociation of Simple and Mixed Carbon Dioxide Clathrate Hydrate

Research paper thumbnail of Production Planning of Oil-Refinery Units for the Future Fuel Market in Brazil

RESUMO -The oil industry in Brazil has accounted for US$ 300 billion in investments over the last... more RESUMO -The oil industry in Brazil has accounted for US$ 300 billion in investments over the last 10 years and further expansions are planned in order to supply the needs of the future fuel market in terms of both quantity and quality. This work analyzes the Brazilian fuel production and market scenarios considering the country's planned investments to prevent fuel deficit of around 30% in 2020. A nonlinear (NLP) operational planning model and a mixed-integer nonlinear (MINLP) investment planning model are proposed to predict the national overall capacity for different oil-refinery units aggregated in one hypothetical large refinery considering four possible future market scenarios. For the multi-refinery case, a phenomenological decomposition heuristic (PDH) method solves separated the quantity and logic variables in a mixed-integer linear (MILP) model, and the quantity and quality variables in an NLP model. Iteratively, the NLP model is restricted by the MILP results.

Research paper thumbnail of Continuous biosorption of Cu and Zn by immobilized waste biomass Sargassum sp

Process Biochemistry, 2001

Biosorption of copper and zinc by the residual biomass of the alga Sargassum sp. was investigated... more Biosorption of copper and zinc by the residual biomass of the alga Sargassum sp. was investigated in a mini packed-bed column. The biomass was immobilized in a polymeric matrix to improve its physicochemical properties for continuous biosorption of heavy metals from aqueous ...

Research paper thumbnail of Diagrama de Fontes de Água: Uma Ferramenta Sustentável para a P+L na Minimização de Águas e Efluentes Industriais

A prática de Produção mais Limpa (P+L) no ambiente industrial requer a perfeita compreensão das c... more A prática de Produção mais Limpa (P+L) no ambiente industrial requer a perfeita compreensão das características dos processos produtivos. Quando o foco está voltado para a minimização do consumo hídrico e dos impactos ocasionados pela geração de efluentes, torna-se importante rever os processos hídricos de modo a prover o sistema com ações sustentáveis, como o reúso de águas e efluentes. O desenvolvimento de tecnologias como suporte para uma bem planejada gestão dos recursos hídricos tem sido motivado pela maior necessidade de se estabelecer programas de reúso de água nos diversos setores, principalmente no meio industrial. O campo da Engenharia de Processos Químicos, particularmente da Integração de Processos, vem contribuindo para o desenvolvimento de ferramentas voltadas para a sistematização desta prática. Uma importante ferramenta é o Diagrama de Fontes de Água (DFA), que procura otimizar a destinação de correntes aquosas, por meio de regras heurísticas, estabelecendo uma adequada configuração de reúso e regeneração de correntes. Este trabalho tem como objetivo adotar o procedimento algorítmico DFA como um importante instrumento para a avaliação de práticas voltadas para a redução do consumo de água e da geração de efluentes, no contexto da P+L. É mostrado um estudo de caso para ilustrar a aplicabilidade do procedimento, indicando o cenário de realocação das correntes, bem como a redução de vazão alcançada. Sua vantagem está na realização de cálculos rápidos e a geração simultânea de fluxogramas alternativos sem modificações substanciais do processo, facilitando a sistematização da prática de reúso.

Research paper thumbnail of Reúso de efluentes industriais em refinarias de petróleo usando o método DFA para sistemas regenerativos

Ambiente & Água - An Interdisciplinary Journal of Applied Science

Wastewater reuse practices in the industry require an adequate understanding of the characteristi... more Wastewater reuse practices in the industry require an adequate understanding of the characteristics of the manufacture processes, to minimize the water consumption and the generation of effluent. The objective of this work was to apply the WSD method, used to defining the target of minimum process water consumption in a case study of oil refinery, by means of the reuse and recycling operations, including regeneration processes. The importance and influence of the wastewater treatment plant in the regeneration quality, including intermediate process streams, for the reuse and the recycling operations, were evaluated. Furthermore, centralized and distributed treatment flowsheet configurations were tested. Thus, this work presented the solution of a case study with three contaminants in water streams processes, different interconnections approaches, used to illustrate the application of this procedure showing the reduction of water flow rate and total costs compared to the original flo...

Research paper thumbnail of PHORBOL ESTERS EXTRACTION FROM Jatropha curcas SEED CAKE USING SUPERCRITICAL CARBON DIOXIDE

Jatropha curcas seeds contain 40–60% of oil, which can be converted to high quality biodiesel. Ho... more Jatropha curcas seeds contain 40–60% of oil, which can be converted to high quality biodiesel. However the seeds contain many toxic compounds with the most important ones known as phorbol esters (PEs). Phorbol esters are derivatives of the tigliane compound and they are considered toxic and maybe with carcinogenic activity. It is reported in the literature that it is possible to have four to six types of phorbol esters or its derivatives. Different chemical and physical methods have been employed for the removal or inactivation of phorbol esters present in different raw materials. This study has as aim the study of the technical feasibility in the use of supercritical fluid for the extraction of phorbol esters present in the Jatropha seed cake. The operational conditions investigated were 70ºC -100Bar; 50ºC – 160Bar; 90ºC – 160Bar; 40ºC -300Bar; 70ºC -300Bar; 50ºC -440Bar and 90ºC -440Bar. Defatted Jatropha curcas seed cake was obtained by a screw press.

Research paper thumbnail of Simulation of a Supercritical Process to Concentrate Natural Products from Deodorizer Distillates of Vegetable Oils

This work has as an objective the simulation of a process, using supercritical fluid, to concentr... more This work has as an objective the simulation of a process, using supercritical fluid, to concentrate the vitamin E (tocopherol) present in the by-product of the refining process of different vegetable oils, like corn, sunflower, canola and soybean, known as the deodorizer distillate (DD). This by-product is rich in high aggregated value compounds like the sterols, tocopherols, squalene and fatty