A rational use of fossil fuels together with a growing concerning about environmental issues have... more A rational use of fossil fuels together with a growing concerning about environmental issues have led to many researches aiming at an improvement of energy systems performance, trying to develop more economical and also more eco-friendly solutions. A cogeneration system (Combined Heat and Power-CHP) is an alternative technique that produces heat and power consuming less of primary energy sources, especially fossil fuels. Recently trigeneration systems, also named Combined Heat, Cooling and Power (CHCP), have gained great interest for industrial and commercial applications, due to a better energetic efficiency when compared with CHP systems. CHCP is an economical and available technology, demanding a single source of primary energy, with the advantages of saving energy, money, and making a clever user of fossil fuels with benefits to the environment. The main objective of this work is to evaluate the thermodynamic performance of a trigeneration system, using a process simulation software, considering the influence of some operational variables: compression ratio in the compressor, expansion ratio and efficiency of the power cycle turbine; boiler operation pressure; and operational pressure of the absorption cycle in both sides (high and low pressure). Natural gas is used as primary energy source. In the absorption refrigeration cycle the pair solvent-refrigerant used is H 2 O-NH 3. For the base case studied total thermal efficiency was 78% and COP of the absorption refrigeration cycle was 0.57, while for the optimized case these values are 82% and 0.48. The most important operational variables to improve efficiency of the cycle are compressor ratio in the compressor and expansion ratio in the turbine.
Journal of Thermal Analysis and Calorimetry, Jun 1, 2018
Vapor-liquid equilibrium data for polar solvent-hydrocarbon mixtures are relatively plentiful for... more Vapor-liquid equilibrium data for polar solvent-hydrocarbon mixtures are relatively plentiful for paraffins and aromatics; they are somewhat less plentiful for olefins. However, almost no data a t all have been published for such mixtures wherein the hydrocarbon possesses a triple bond. This paper reports vapor-pressure measurements of binary mixtures of I-hexyne with acetone, acetonitrile, dimethyl carbonate, nitroethane and dimethyl formamide in the temperature range 0 to 70°C. The results are compared with those for polar solvent-hydrocarbon mixtures wherein the hydrocarbon is paraffinic, olefinic, or aromatic.
Brazilian Journal of Chemical Engineering, Dec 1, 2000
Gas-liquid solubility of hydrogen in methanol and ethanol systems with electrolytes was studied i... more Gas-liquid solubility of hydrogen in methanol and ethanol systems with electrolytes was studied in the temperature range from 305.15 K to 498.15 K and pressures from 4 to 10 MPa. The experimental method used was the Total Pressure Method, which eliminates sampling and analysis of the phases, determining their composition at equilibrium using the following experimental data: moles of solute and solvent in the system; pressure, temperature and volume of the system at equilibrium; together with thermodynamic equations for fluid-phase equilibria. The salts used were lithium chloride and potassium acetate. The solubility of hydrogen increases with increasing temperature and pressure and the presence of salts causes a decrease in the solubility of hydrogen, when compared with the results of systems without salts, characterizing a "salting-out" effect, which is greater in conditions of lower temperature and pressure, specially for potassium acetate.
The Journal of Chemical Thermodynamics, Feb 1, 2017
Abstract In this work, density and speed of sound of binary mixtures of {n-butylammonium butanoat... more Abstract In this work, density and speed of sound of binary mixtures of {n-butylammonium butanoate ionic liquid (N4Bu) + alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol)} have been measured as a function of composition at T = (293.15–313.15) K and atmospheric pressure. The results were used to calculate the excess molar volume, V m E , and deviation in isentropic compressibility, Δ κ S , and correlated to the Redlich-Kister polynomial equation. N4Bu was synthesized by the method of acid-base neutralization reaction using n-butylamine and butanoic acid, and characterized using 1H NMR, 13C NMR and FTIR spectroscopy techniques. For all systems studied, the values of excess molar volumes and deviations in isentropic compressibility were negative over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.
Revista dos Trabalhos de Iniciação Científica da Unicamp, Dec 4, 2018
Resumo Este projeto avaliou o desempenho termodinâmico de um ciclo de refrigeração em cascata, op... more Resumo Este projeto avaliou o desempenho termodinâmico de um ciclo de refrigeração em cascata, operando com diferentes configurações e refrigerantes naturais. Realizou-se a otimização do sistema, com o intuito de obter o valor máximo do coefiiente de desempenho do ciclo.
Industrial & Engineering Chemistry Research, Nov 27, 2020
A 2D steady-state phenomenological model used for sizing a multitubular catalytic reactor for wat... more A 2D steady-state phenomenological model used for sizing a multitubular catalytic reactor for water-gas shift reaction is presented. The model contemplates momentum, mass, and energy balances. In addition, the thermodynamic behavior is described by the Peng−Robinson−Stryjek−Vera equation of state. After the model validation, a set of equations was used in an optimization procedure to find the optimal reactor's dimensions and operational conditions, minimizing both capital and operating expenses. The results were compared with data from the literature, and the water-gas shift reaction has proven disadvantageous at a low temperature, with heat exchange, because this considerably increases the required catalyst amount. The multitubular reactor has shown to be appropriate in the studied temperature range (430−520 K) only for a more active catalyst or for a more exothermic reaction.
The Journal of Chemical Thermodynamics, Oct 1, 2023
An apparatus is newly designed and constructed for investigation of high-pressure vapor-liquid eq... more An apparatus is newly designed and constructed for investigation of high-pressure vapor-liquid equilibrium in the temperature range-50°C to 50°C at pressures up to 100 atm. The visual type of static apparatus is distinguished by the inclusion of a specially designed sampling device for liquid phase to reduce experimental error during the sampling, and of a magnetically driven agitator by which the vapor phase is dispersed into the liquid phase within the cell. Using this apparatus, the binary vapor-liquid equilibrium data for the ethylene-propylene system at-10.08°, 0.07°, 10.07°and 20.14°C, and ethylene-1-butene at-0.01°, 10.01°and 20.20°C are measured. The data obtained are correlated by using three equations of state. The predicted results are in good agreement with the experimental data except in the region close to the critical point.
A rational use of fossil fuels together with a growing concerning about environmental issues have... more A rational use of fossil fuels together with a growing concerning about environmental issues have led to many researches aiming at an improvement of energy systems performance, trying to develop more economical and also more eco-friendly solutions. A cogeneration system (Combined Heat and Power-CHP) is an alternative technique that produces heat and power consuming less of primary energy sources, especially fossil fuels. Recently trigeneration systems, also named Combined Heat, Cooling and Power (CHCP), have gained great interest for industrial and commercial applications, due to a better energetic efficiency when compared with CHP systems. CHCP is an economical and available technology, demanding a single source of primary energy, with the advantages of saving energy, money, and making a clever user of fossil fuels with benefits to the environment. The main objective of this work is to evaluate the thermodynamic performance of a trigeneration system, using a process simulation software, considering the influence of some operational variables: compression ratio in the compressor, expansion ratio and efficiency of the power cycle turbine; boiler operation pressure; and operational pressure of the absorption cycle in both sides (high and low pressure). Natural gas is used as primary energy source. In the absorption refrigeration cycle the pair solvent-refrigerant used is H 2 O-NH 3. For the base case studied total thermal efficiency was 78% and COP of the absorption refrigeration cycle was 0.57, while for the optimized case these values are 82% and 0.48. The most important operational variables to improve efficiency of the cycle are compressor ratio in the compressor and expansion ratio in the turbine.
Journal of Thermal Analysis and Calorimetry, Jun 1, 2018
Vapor-liquid equilibrium data for polar solvent-hydrocarbon mixtures are relatively plentiful for... more Vapor-liquid equilibrium data for polar solvent-hydrocarbon mixtures are relatively plentiful for paraffins and aromatics; they are somewhat less plentiful for olefins. However, almost no data a t all have been published for such mixtures wherein the hydrocarbon possesses a triple bond. This paper reports vapor-pressure measurements of binary mixtures of I-hexyne with acetone, acetonitrile, dimethyl carbonate, nitroethane and dimethyl formamide in the temperature range 0 to 70°C. The results are compared with those for polar solvent-hydrocarbon mixtures wherein the hydrocarbon is paraffinic, olefinic, or aromatic.
Brazilian Journal of Chemical Engineering, Dec 1, 2000
Gas-liquid solubility of hydrogen in methanol and ethanol systems with electrolytes was studied i... more Gas-liquid solubility of hydrogen in methanol and ethanol systems with electrolytes was studied in the temperature range from 305.15 K to 498.15 K and pressures from 4 to 10 MPa. The experimental method used was the Total Pressure Method, which eliminates sampling and analysis of the phases, determining their composition at equilibrium using the following experimental data: moles of solute and solvent in the system; pressure, temperature and volume of the system at equilibrium; together with thermodynamic equations for fluid-phase equilibria. The salts used were lithium chloride and potassium acetate. The solubility of hydrogen increases with increasing temperature and pressure and the presence of salts causes a decrease in the solubility of hydrogen, when compared with the results of systems without salts, characterizing a "salting-out" effect, which is greater in conditions of lower temperature and pressure, specially for potassium acetate.
The Journal of Chemical Thermodynamics, Feb 1, 2017
Abstract In this work, density and speed of sound of binary mixtures of {n-butylammonium butanoat... more Abstract In this work, density and speed of sound of binary mixtures of {n-butylammonium butanoate ionic liquid (N4Bu) + alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol)} have been measured as a function of composition at T = (293.15–313.15) K and atmospheric pressure. The results were used to calculate the excess molar volume, V m E , and deviation in isentropic compressibility, Δ κ S , and correlated to the Redlich-Kister polynomial equation. N4Bu was synthesized by the method of acid-base neutralization reaction using n-butylamine and butanoic acid, and characterized using 1H NMR, 13C NMR and FTIR spectroscopy techniques. For all systems studied, the values of excess molar volumes and deviations in isentropic compressibility were negative over the entire composition range. The results obtained were discussed in terms of structural effects and intermolecular interactions between like and unlike molecules.
Revista dos Trabalhos de Iniciação Científica da Unicamp, Dec 4, 2018
Resumo Este projeto avaliou o desempenho termodinâmico de um ciclo de refrigeração em cascata, op... more Resumo Este projeto avaliou o desempenho termodinâmico de um ciclo de refrigeração em cascata, operando com diferentes configurações e refrigerantes naturais. Realizou-se a otimização do sistema, com o intuito de obter o valor máximo do coefiiente de desempenho do ciclo.
Industrial & Engineering Chemistry Research, Nov 27, 2020
A 2D steady-state phenomenological model used for sizing a multitubular catalytic reactor for wat... more A 2D steady-state phenomenological model used for sizing a multitubular catalytic reactor for water-gas shift reaction is presented. The model contemplates momentum, mass, and energy balances. In addition, the thermodynamic behavior is described by the Peng−Robinson−Stryjek−Vera equation of state. After the model validation, a set of equations was used in an optimization procedure to find the optimal reactor's dimensions and operational conditions, minimizing both capital and operating expenses. The results were compared with data from the literature, and the water-gas shift reaction has proven disadvantageous at a low temperature, with heat exchange, because this considerably increases the required catalyst amount. The multitubular reactor has shown to be appropriate in the studied temperature range (430−520 K) only for a more active catalyst or for a more exothermic reaction.
The Journal of Chemical Thermodynamics, Oct 1, 2023
An apparatus is newly designed and constructed for investigation of high-pressure vapor-liquid eq... more An apparatus is newly designed and constructed for investigation of high-pressure vapor-liquid equilibrium in the temperature range-50°C to 50°C at pressures up to 100 atm. The visual type of static apparatus is distinguished by the inclusion of a specially designed sampling device for liquid phase to reduce experimental error during the sampling, and of a magnetically driven agitator by which the vapor phase is dispersed into the liquid phase within the cell. Using this apparatus, the binary vapor-liquid equilibrium data for the ethylene-propylene system at-10.08°, 0.07°, 10.07°and 20.14°C, and ethylene-1-butene at-0.01°, 10.01°and 20.20°C are measured. The data obtained are correlated by using three equations of state. The predicted results are in good agreement with the experimental data except in the region close to the critical point.
Uploads
Papers by Jose Dangelo