Temperature dependence of vapor pressure for the ethyl myristate (ethyl tetradecanoate) has been ... more Temperature dependence of vapor pressure for the ethyl myristate (ethyl tetradecanoate) has been measured, on the temperature domain 150 to 220 °C. The experimental results are in good agreement with available literature data and satisfactorily approximated by Ceriani-Meirelles group contribution method. The experimental data were used to estimate the parameters of an Antoine type equation, predicting more accurately the vapor pressure on the investigated temperature domain.
Lucrarea prezintă dezvoltarea unui model cinetic pentru procesul de hidroformilare a propenei, pl... more Lucrarea prezintă dezvoltarea unui model cinetic pentru procesul de hidroformilare a propenei, plecând de la măsurători efectuate pe un reactor industrial. Cinetica celor trei reacţii ce caracterizează procesul chimic de hidroformilare este descrisă prin expresii de tip produs de puteri. Parametrii obţinuţi prin corelarea datelor experimentale au fost factorii preexponnenţiali, energiile aparente de activare şi ordinele parţiale de reacţie în raport cu monoxidul de carbon ale celor trei reacţii. Modelul cinetic propus asigură o bună concordanţă între valorile calculate şi cele măsurate ale vitezelor reacţiilor de formare a nbutiraldehidei, i-butiraldehidei şi, respectiv, propanului.
The increased quantities of glycerol available on the market initiated research efforts oriented ... more The increased quantities of glycerol available on the market initiated research efforts oriented to new valorization technologies, particularly by its conversion into medium tonnage chemicals, replacing petroleum derivatives. In this work it was investigated the valorization of glycerol by its transformation in glycerol acetates, by direct esterification with acetic acid, over a commercial Amberlyst-35 resin. Experiments were carried out batch-wise, in an autoclave reactor under controlled working conditions, at temperatures between 95 and 112 oC and initial acetic acid to glycerol molar ratios between 4 and 9. The experimental data evidenced that the glycerol conversion to monoacetate is faster than the next esterification steps. A relatively simple kinetic model was proposed and its parameters were evaluated from the experimental measurements. It proved reasonable predicting capacity for products distribution dependencies on the reactants molar ratio and reaction temperature.
Langmuir : the ACS journal of surfaces and colloids, Nov 7, 2017
We studied the microstructure of physical chitosan hydrogels formed by the neutralization of chit... more We studied the microstructure of physical chitosan hydrogels formed by the neutralization of chitosan aqueous solutions highlighting the structural gradients within thick gels (up to a thickness of 16 mm). We explored a high polymer concentrations range (Cp ≥ 1.0% w/w) with different molar masses of chitosan and different concentrations of the coagulation agent. The effect of these processing parameters on the morphology was evaluated mainly through small-angle light scattering (SALS) measurements and confocal laser scanning microscopy (CLSM) observations. As a result, we reported that the microstructure is continuously evolving from the surface to the bulk, with mainly two structural transitions zones separating three types of hydrogels. The first zone (zone I) is located close to the surface of the hydrogel and constitutes a hard (entangled) layer formed under fast neutralization conditions. It is followed by a second zone (zone II) with a larger thickness (∼3-4 mm), where in some...
The catalytic-distillation process for the production of t-amyl-methyl-ether (TAME) from methanol... more The catalytic-distillation process for the production of t-amyl-methyl-ether (TAME) from methanol and isoamylenes was simulated by developing the process model as a combination of unit operations from HYSYS operations palette. Geometrical characteristics of catalytic-distillation column are those of an industrial pilot plant and the results of simulation were compared with experimental data. The experimentally determined reactions kinetics was applied in the model. UNIQUAC-UNIFAC model equations were selected for the vapour-liquid equilibrium. The results show that fair agreements between the calculated and experimental data were obtained.
European Symposium on Computer Aided Process Engineering - 13 A. Kraslawski and I. Turunen (Edito... more European Symposium on Computer Aided Process Engineering - 13 A. Kraslawski and I. Turunen (Editors) 2003 Elsevier Science BV All rights reserved. Modelling and Simulation of Kinetics and Operation for the TAME Synthesis by Catalytic Distillation Grigore Bozga Gheorghe ...
... The flow rates information obtained in the previous step of analysis is implemented in the si... more ... The flow rates information obtained in the previous step of analysis is implemented in the simulator. Firstly, a column with a large number of stages and reflux is simulated to assure that ∞/∞ analysis results are correctly solved. ... global warming potential (GWP),. ...
Dynamics and Control of Chemical Reactors, Distillation Columns and Batch Processes, 1993
Abstract The paper deals with a dynamic mathematical model for a Methanol-to-Olefins (MTO) fluid ... more Abstract The paper deals with a dynamic mathematical model for a Methanol-to-Olefins (MTO) fluid bed catalytic pilot plant. The fluid bed reactor-regenerator model is used both for rapid catalyst/process analysis for design purposes and for the advanced computer control of the pilot plant. The numerical strategy for model parameters estimation and some considerations concerning the reactor steady-state multiplicity and sensitivity analysis are presented. The model predictions are in satisfactory agreement with the pilot plant experimental data.
Temperature dependence of vapor pressure for the ethyl myristate (ethyl tetradecanoate) has been ... more Temperature dependence of vapor pressure for the ethyl myristate (ethyl tetradecanoate) has been measured, on the temperature domain 150 to 220 °C. The experimental results are in good agreement with available literature data and satisfactorily approximated by Ceriani-Meirelles group contribution method. The experimental data were used to estimate the parameters of an Antoine type equation, predicting more accurately the vapor pressure on the investigated temperature domain.
Lucrarea prezintă dezvoltarea unui model cinetic pentru procesul de hidroformilare a propenei, pl... more Lucrarea prezintă dezvoltarea unui model cinetic pentru procesul de hidroformilare a propenei, plecând de la măsurători efectuate pe un reactor industrial. Cinetica celor trei reacţii ce caracterizează procesul chimic de hidroformilare este descrisă prin expresii de tip produs de puteri. Parametrii obţinuţi prin corelarea datelor experimentale au fost factorii preexponnenţiali, energiile aparente de activare şi ordinele parţiale de reacţie în raport cu monoxidul de carbon ale celor trei reacţii. Modelul cinetic propus asigură o bună concordanţă între valorile calculate şi cele măsurate ale vitezelor reacţiilor de formare a nbutiraldehidei, i-butiraldehidei şi, respectiv, propanului.
The increased quantities of glycerol available on the market initiated research efforts oriented ... more The increased quantities of glycerol available on the market initiated research efforts oriented to new valorization technologies, particularly by its conversion into medium tonnage chemicals, replacing petroleum derivatives. In this work it was investigated the valorization of glycerol by its transformation in glycerol acetates, by direct esterification with acetic acid, over a commercial Amberlyst-35 resin. Experiments were carried out batch-wise, in an autoclave reactor under controlled working conditions, at temperatures between 95 and 112 oC and initial acetic acid to glycerol molar ratios between 4 and 9. The experimental data evidenced that the glycerol conversion to monoacetate is faster than the next esterification steps. A relatively simple kinetic model was proposed and its parameters were evaluated from the experimental measurements. It proved reasonable predicting capacity for products distribution dependencies on the reactants molar ratio and reaction temperature.
Langmuir : the ACS journal of surfaces and colloids, Nov 7, 2017
We studied the microstructure of physical chitosan hydrogels formed by the neutralization of chit... more We studied the microstructure of physical chitosan hydrogels formed by the neutralization of chitosan aqueous solutions highlighting the structural gradients within thick gels (up to a thickness of 16 mm). We explored a high polymer concentrations range (Cp ≥ 1.0% w/w) with different molar masses of chitosan and different concentrations of the coagulation agent. The effect of these processing parameters on the morphology was evaluated mainly through small-angle light scattering (SALS) measurements and confocal laser scanning microscopy (CLSM) observations. As a result, we reported that the microstructure is continuously evolving from the surface to the bulk, with mainly two structural transitions zones separating three types of hydrogels. The first zone (zone I) is located close to the surface of the hydrogel and constitutes a hard (entangled) layer formed under fast neutralization conditions. It is followed by a second zone (zone II) with a larger thickness (∼3-4 mm), where in some...
The catalytic-distillation process for the production of t-amyl-methyl-ether (TAME) from methanol... more The catalytic-distillation process for the production of t-amyl-methyl-ether (TAME) from methanol and isoamylenes was simulated by developing the process model as a combination of unit operations from HYSYS operations palette. Geometrical characteristics of catalytic-distillation column are those of an industrial pilot plant and the results of simulation were compared with experimental data. The experimentally determined reactions kinetics was applied in the model. UNIQUAC-UNIFAC model equations were selected for the vapour-liquid equilibrium. The results show that fair agreements between the calculated and experimental data were obtained.
European Symposium on Computer Aided Process Engineering - 13 A. Kraslawski and I. Turunen (Edito... more European Symposium on Computer Aided Process Engineering - 13 A. Kraslawski and I. Turunen (Editors) 2003 Elsevier Science BV All rights reserved. Modelling and Simulation of Kinetics and Operation for the TAME Synthesis by Catalytic Distillation Grigore Bozga Gheorghe ...
... The flow rates information obtained in the previous step of analysis is implemented in the si... more ... The flow rates information obtained in the previous step of analysis is implemented in the simulator. Firstly, a column with a large number of stages and reflux is simulated to assure that ∞/∞ analysis results are correctly solved. ... global warming potential (GWP),. ...
Dynamics and Control of Chemical Reactors, Distillation Columns and Batch Processes, 1993
Abstract The paper deals with a dynamic mathematical model for a Methanol-to-Olefins (MTO) fluid ... more Abstract The paper deals with a dynamic mathematical model for a Methanol-to-Olefins (MTO) fluid bed catalytic pilot plant. The fluid bed reactor-regenerator model is used both for rapid catalyst/process analysis for design purposes and for the advanced computer control of the pilot plant. The numerical strategy for model parameters estimation and some considerations concerning the reactor steady-state multiplicity and sensitivity analysis are presented. The model predictions are in satisfactory agreement with the pilot plant experimental data.
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