Paula Santos - Academia.edu (original) (raw)
Papers by Paula Santos
Brazilian Journal of Development, 2021
A Destilação Molecular Centrífuga (CMD) e a Destilação Molecular por Filme de Queda (FFMD) serão ... more A Destilação Molecular Centrífuga (CMD) e a Destilação Molecular por Filme de Queda (FFMD) serão apresentadas como uma importante operação unitária para obter produtos de alto valor acrescentado sem a utilização de qualquer solvente. Os carotenóides foram obtidos a partir de óleo de palma por CMD. Outra aplicação envolveu o enriquecimento de diterpenos de café a partir de óleo de café verde utilizando a Destilação Molecular por Filme de Queda (FFMD). Os destilados foram enriquecidos em ésteres de ácidos gordos diterpenos e ácidos gordos livres, enquanto os resíduos foram enriquecidos em triacilgliceróis de alta massa molar. Os ésteres de ácidos gordos diterpénicos foram enriquecidos a 42% (o óleo de café verde original tinha 24,4%) num único passo. Estas aplicações mostraram a importância e a versatilidade da destilação molecular para diferentes processos. Palavras-chave: carotenóides, diterpenos, destilação molecular, óleo de palma, óleo de café verde ABSTRACT Centrifugal Molecular Distillation (CMD) and Falling Film Molecular Distillation (FFMD) will be presented as an important unit operation to achieve high added value products without the use of any solvent. Carotenoids were obtained from palm oil by CMD. Other application involved the enrichment of coffee diterpenes from green coffee oil using Falling Film Molecular Distillation (FFMD). The distillates were enriched in diterpene fatty acid esters and free fatty acids, while the residues were enriched in high molar mass triacylglycerols. Diterpene fatty acid esters were enrichment to 42% (original green coffee oil had 24.4%) in a single-pass. These applications showed the importance and the versatility of molecular distillation for different processes.
Brazilian Journal of Development, 2020
Computer Aided Chemical Engineering, 2016
Abstract Petroleum refineries have faced many challenges to remain competitive in the world fuels... more Abstract Petroleum refineries have faced many challenges to remain competitive in the world fuels market. If, on the one hand, recovered crude oils are getting heavier and there is a decreasing demand for heating and residual fuels, on the other hand, the demand for transportation fuels and more value-added products is increasing, renewing the interest of the refineries on the bottom-of-the-barrel residue upgrading. However, the feedstock for heavy oil conversion units comprises large, multifunctional molecules. Thus, characterize it adequately is a complex task, making complicated the obtaining of accurate kinetic models. This paper proposes a proper approach to simulation, optimization and control of a delayed coking unit by using Aspen Plus software. A novel procedure to represent a given feed material by pseudocomponents is described and a stoichiometric model based on known fractional conversions was developed. PID control was implemented in the system and satisfactory results were achieved. This supposes that the proposed methodology can be useful to obtain more appropriate predictions of behaviour and yield for processes with difficult dynamics and it can be applied in several ways, as on the tracking of processes as well as on new optimization techniques and advanced control.
Procedia Food Science, 2011
Chemical Engineering Transactions, 2011
Separation and Purification Technology, 2012
ABSTRACT This work describes methyl chavicol enrichment from basil essential oil by wiped film ev... more ABSTRACT This work describes methyl chavicol enrichment from basil essential oil by wiped film evaporation (WFE) and compares its performance with published data obtained by short path evaporation (SPE). The main difference between these processes is that the WFE presents an external condenser, while the SPE uses an internal one. The evaporation processes comparison was performed based on methyl chavicol concentration level and amount of produced material. Through central composite experimental design, the influences of evaporator temperature, condenser temperature, and feed flow rate on distilled percentage and methyl chavicol concentration at the residue stream were studied. Response surface methodology based on five level-three variable was used to describe the individual and interactive effects between factors on the process. From experimental data, models were built up to describe distilled percentage and methyl concentration at the residue stream in function of operating conditions. Results showed that, in the studied range, similar methyl chavicol concentration (near to 89%) was reached using both WFE and SPE processes, however, at different operating conditions. While higher concentrations of methyl chavicol were obtained at 28 °C and 0.133 kPa using WFE, similar methyl chavicol content was obtained at 70 °C and 1.33 kPa using SPE. However, WFE presented higher separation efficiency because, although similar concentration levels were reached using both equipments, the amount of produced material in the residue stream was 10% higher in WFE.
Separation and Purification Technology, 2012
... Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Autho... more ... Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Author , Claudio Carmona c , Edgar Leonardo Martinez a ... Methyl chavicol is a natural ingredient found in several herbs as tarragon, sweet basil, sweet fennel, and their essential oils. ...
Molecular Crystals and Liquid Crystals, 2004
The effects of salt additions, LiCl and MgCl2, into the aniline-bearing HCl solutions have been s... more The effects of salt additions, LiCl and MgCl2, into the aniline-bearing HCl solutions have been studied during the oxidative polymerization with ammonium persulphate. To assess both protonic and ionic effects, LiCl or MgCl2was added maintaining the chlorine concentration constant. Three polymerization parameters were recorded: Tmax, Emaxand tmax(v = 1/tmax). Tmaxand v have been correlated with[H+]and[cation]/[H+]. The conductivity as a relevant
European Polymer Journal, 2004
Chemical syntheses of polyaniline were performed in HCl (0.4-2.51 M) containing 0.1 M aniline and... more Chemical syntheses of polyaniline were performed in HCl (0.4-2.51 M) containing 0.1 M aniline and LiCl or MgCl 2 , keeping the total amount of chloride in the reactional medium constant. This was done in order to investigate if the chloride ion, added as salt and not as acid, is incorporated from chloride containing solutions with lower total acid concentration. The synthesis processes were characterized by potentiometric and calorimetric measurements represented in curves containing kinetic parameters of the polymerization process. The analysis of the polymeric materials was performed by infrared spectroscopy, electric conductivity measurements and scanning electron microscopy. It was observed that both the acid and chloride concentration, have an influence on the polymerization rate and the properties of the polyaniline, however, the presence of monovalent (Li þ) or divalent (Mg þ2) cations does not seem to have a significant effect. Finally, the conductivity of PAni is lowered by high acid concentrations but high chloride concentrations seem to improve the conductivity.
Brazilian Journal of Development, 2021
A Destilação Molecular Centrífuga (CMD) e a Destilação Molecular por Filme de Queda (FFMD) serão ... more A Destilação Molecular Centrífuga (CMD) e a Destilação Molecular por Filme de Queda (FFMD) serão apresentadas como uma importante operação unitária para obter produtos de alto valor acrescentado sem a utilização de qualquer solvente. Os carotenóides foram obtidos a partir de óleo de palma por CMD. Outra aplicação envolveu o enriquecimento de diterpenos de café a partir de óleo de café verde utilizando a Destilação Molecular por Filme de Queda (FFMD). Os destilados foram enriquecidos em ésteres de ácidos gordos diterpenos e ácidos gordos livres, enquanto os resíduos foram enriquecidos em triacilgliceróis de alta massa molar. Os ésteres de ácidos gordos diterpénicos foram enriquecidos a 42% (o óleo de café verde original tinha 24,4%) num único passo. Estas aplicações mostraram a importância e a versatilidade da destilação molecular para diferentes processos. Palavras-chave: carotenóides, diterpenos, destilação molecular, óleo de palma, óleo de café verde ABSTRACT Centrifugal Molecular Distillation (CMD) and Falling Film Molecular Distillation (FFMD) will be presented as an important unit operation to achieve high added value products without the use of any solvent. Carotenoids were obtained from palm oil by CMD. Other application involved the enrichment of coffee diterpenes from green coffee oil using Falling Film Molecular Distillation (FFMD). The distillates were enriched in diterpene fatty acid esters and free fatty acids, while the residues were enriched in high molar mass triacylglycerols. Diterpene fatty acid esters were enrichment to 42% (original green coffee oil had 24.4%) in a single-pass. These applications showed the importance and the versatility of molecular distillation for different processes.
Brazilian Journal of Development, 2020
Computer Aided Chemical Engineering, 2016
Abstract Petroleum refineries have faced many challenges to remain competitive in the world fuels... more Abstract Petroleum refineries have faced many challenges to remain competitive in the world fuels market. If, on the one hand, recovered crude oils are getting heavier and there is a decreasing demand for heating and residual fuels, on the other hand, the demand for transportation fuels and more value-added products is increasing, renewing the interest of the refineries on the bottom-of-the-barrel residue upgrading. However, the feedstock for heavy oil conversion units comprises large, multifunctional molecules. Thus, characterize it adequately is a complex task, making complicated the obtaining of accurate kinetic models. This paper proposes a proper approach to simulation, optimization and control of a delayed coking unit by using Aspen Plus software. A novel procedure to represent a given feed material by pseudocomponents is described and a stoichiometric model based on known fractional conversions was developed. PID control was implemented in the system and satisfactory results were achieved. This supposes that the proposed methodology can be useful to obtain more appropriate predictions of behaviour and yield for processes with difficult dynamics and it can be applied in several ways, as on the tracking of processes as well as on new optimization techniques and advanced control.
Procedia Food Science, 2011
Chemical Engineering Transactions, 2011
Separation and Purification Technology, 2012
ABSTRACT This work describes methyl chavicol enrichment from basil essential oil by wiped film ev... more ABSTRACT This work describes methyl chavicol enrichment from basil essential oil by wiped film evaporation (WFE) and compares its performance with published data obtained by short path evaporation (SPE). The main difference between these processes is that the WFE presents an external condenser, while the SPE uses an internal one. The evaporation processes comparison was performed based on methyl chavicol concentration level and amount of produced material. Through central composite experimental design, the influences of evaporator temperature, condenser temperature, and feed flow rate on distilled percentage and methyl chavicol concentration at the residue stream were studied. Response surface methodology based on five level-three variable was used to describe the individual and interactive effects between factors on the process. From experimental data, models were built up to describe distilled percentage and methyl concentration at the residue stream in function of operating conditions. Results showed that, in the studied range, similar methyl chavicol concentration (near to 89%) was reached using both WFE and SPE processes, however, at different operating conditions. While higher concentrations of methyl chavicol were obtained at 28 °C and 0.133 kPa using WFE, similar methyl chavicol content was obtained at 70 °C and 1.33 kPa using SPE. However, WFE presented higher separation efficiency because, although similar concentration levels were reached using both equipments, the amount of produced material in the residue stream was 10% higher in WFE.
Separation and Purification Technology, 2012
... Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Autho... more ... Author Contact Information , E-mail The Corresponding Author , E-mail The Corresponding Author , Claudio Carmona c , Edgar Leonardo Martinez a ... Methyl chavicol is a natural ingredient found in several herbs as tarragon, sweet basil, sweet fennel, and their essential oils. ...
Molecular Crystals and Liquid Crystals, 2004
The effects of salt additions, LiCl and MgCl2, into the aniline-bearing HCl solutions have been s... more The effects of salt additions, LiCl and MgCl2, into the aniline-bearing HCl solutions have been studied during the oxidative polymerization with ammonium persulphate. To assess both protonic and ionic effects, LiCl or MgCl2was added maintaining the chlorine concentration constant. Three polymerization parameters were recorded: Tmax, Emaxand tmax(v = 1/tmax). Tmaxand v have been correlated with[H+]and[cation]/[H+]. The conductivity as a relevant
European Polymer Journal, 2004
Chemical syntheses of polyaniline were performed in HCl (0.4-2.51 M) containing 0.1 M aniline and... more Chemical syntheses of polyaniline were performed in HCl (0.4-2.51 M) containing 0.1 M aniline and LiCl or MgCl 2 , keeping the total amount of chloride in the reactional medium constant. This was done in order to investigate if the chloride ion, added as salt and not as acid, is incorporated from chloride containing solutions with lower total acid concentration. The synthesis processes were characterized by potentiometric and calorimetric measurements represented in curves containing kinetic parameters of the polymerization process. The analysis of the polymeric materials was performed by infrared spectroscopy, electric conductivity measurements and scanning electron microscopy. It was observed that both the acid and chloride concentration, have an influence on the polymerization rate and the properties of the polyaniline, however, the presence of monovalent (Li þ) or divalent (Mg þ2) cations does not seem to have a significant effect. Finally, the conductivity of PAni is lowered by high acid concentrations but high chloride concentrations seem to improve the conductivity.