Navegando por Autor "Nascimento, Jailton Ferreira do"
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Artigo Density and electrical conductivity for aqueous mixtures of monoethylene glycol and sodium chloride: experimental data and data-driven modeling for composition determination(ACS Publications, 2021-04-09) Chiavone Filho, Osvaldo; Moura Neto, Mário Hermes de; Monteiro, Mateus Fernandes; Ferreira, Fedra A. V.; Silva, Dannielle Janainne; Figueiredo, Camila S.; Ciambelli, João Rafael Perroni; Pereira, Leonardo S.; Nascimento, Jailton Ferreira doMonoethylene glycol (MEG) is a gas hydrate inhibitor widely applied for natural gas flow assurance. A series of density and electrical conductivity measurements of water + MEG + NaCl mixtures are reported, allowing the supervision of the MEG regeneration unit. Density (509 data points) and electrical conductivity (212 data points) measurements were performed in wide ranges of temperature, T = 278.15−363.15 K, and concentration of solvents and NaCl up to almost saturation. The theory of solutions was applied for density description using excess volume, which was correlated with the Redlich−Kister equation. The resulting absolute and relative mean deviations are 0.00127 g·cm−3 and 0.12%, indicating accurate representation. A semi- empirical correlation with 15 adjustable parameters was considered for electrical conductivity of water + MEG + NaCl mixtures. The obtained absolute and relative mean deviations are 1.49 mS·cm−1 and 5.70%. The properties functions presented an approximately orthogonal behavior to each other, allowing the determination of mixture composition from experimental density and electrical conductivity data. The Matlab environment was found to be robust in solving the nonlinear system of two equations with constraints. The proposed methodology was extensively tested, and deviations less than 0.0060 and 0.0011 in solvents and NaCl mass fractions were obtained, respectively, demonstrating the required accuracy for industrial applicationArtigo Electrosynthesis via plasma electrochemistry: generalist dynamical model to explain hydrogen production induced by a discharge over water(ACS Publications, 2019) Chiavone Filho, Osvaldo; Lima, Andressa Mota; Nascimento, Jailton Ferreira do; Nascimento, Claudio Augusto OllerElectrosynthesis via electrochemical plasma, a discharge over the surface of liquid water (or plasma cathode), may offer an unprecedented route of synthesis for chemicals and (wind) solar fuels. Describing the physical chemical events underneath plasma/liquid interface (PLI) on a theoretical basis is crucial for enabling a rational designing of chemical synthesis. To address this problem, this work proposes a generalist dynamical model for the nanoreactor, a fraction of nanoliters localized beneath the PLI that features substantially high concentration of hydrated electrons (eaq−), and it screens chemical reaction networks (CRN) related to the synthesis of hydrogen, a model electrosynthesis process. The computational results elucidate two major routes for hydrogen production: (a) in very alkaline media, the water reduction via self-recombination of eaq− [2eaq− + 2H2O → H2 + 2OH−] consumes the majority of eaq−, whereas (b) in very acid media, eaq− is majorly scavenger by the ion Haq+, generating an abnormally high concentration of the radical H•, a precursor for gaseous hydrogen. Additionally, two scenarios are disadvantageous for synthesizing H2. Side reactions with aqueous oxygen and aqueous radical • OH leads to substantial production of O2 − and OH−, respectively. Without loss of generality, the dynamical model proposed in this work is a powerful theoretical frame for understanding and predicting a variety of plasma-induced CRNs, assisting to advance the emerging field of plasma electrochemistryArtigo Isobaric vapor−liquid equilibrium measurements and modeling of water + monoethylene glycol + NaCl mixtures(ACS Publications, 2020-09-10) Chiavone Filho, Osvaldo; Moura Neto, Mário Hermes de; Monteiro, Mateus Fernandes; Mota, André Luis Novais; Silva, Dannielle Janainne; Nascimento, Jailton Ferreira do; Pereira, Leonardo S.Vapor−liquid equilibrium (VLE) data for aqueous systems in the presence of electrolytes have many industrial applications. VLE data for water + monoethylene glycol (MEG) mixtures in the presence of sodium chloride at low pressures are important to describe the effects of composition, temperature, and pressure on a MEG (gas hydrate inhibitor) regeneration unit. A modified version of the Othmer ebulliometer was applied to measure reliable VLE data for water + MEG + NaCl at 101.325, 65, and 35 kPa. Binary systems (water + MEG and MEG + NaCl) were also experimentally studied. Vapor pressures for water and MEG were determined and compared with the selected literature data via Antoine correlation. The electrolyte nonrandom two-liquid and universal quasi-chemical activity coefficient models were successfully parameterized to describe the VLE behavior for water + MEG + NaCl systems. Thermodynamic consistence of the data sets was also checked. Interaction parameter estimation followed a systematic strategy: (1) water−MEG, (2) water−NaCl, and finally (3) MEG−NaCl with the experimental data of MEG + NaCl and ternary data. MEG + NaCl solutions presented an inverted colligative property, that is, the addition of salt decreases the boiling point. VLE data indicated that water separation is less efficient due to the addition of salt. The parameterized models allow an evaluation of the MEG regeneration process as a function of temperature, pressure, and compositionArtigo Salt solubility and saturated electrical conductivity data for water + monoethylene glycol + NaCl in a wide temperature range(ACS publications, 2021-03-08) Chiavone Filho, Osvaldo; Monteiro, Mateus Fernandes; Moura Neto, Mário Hermes de; Mota, André Luis Novais; Figueiredo, Camila S.; Ciambelli, João Rafael Perroni; Nascimento, Jailton Ferreira do; Pereira, Leonardo S.Monoethylene glycol (MEG) is used to prevent hydrate formation in subsea pipelines of natural gas production. MEG is recovered at an offshore regeneration unit. Sodium chloride is the predominant salt in the water−MEG streams. Thus, knowledge of NaCl solubilities in the process conditions is relevant for the design and operation of a MEG regeneration unit. Six isotherms of NaCl solubility were measured (76 data points) from T = (293.15 to 403.15) K in the whole solvent concentration range. The analytical method for salt solubility was based on the reproducibility of the concentration of two successive samples. Density measurements were accurately applied for these analyses. The temperature dependence on NaCl solubility is relatively weak. A reverse behavior with increasing temperature was observed for MEG contents higher than 90 wt %. Salt solubilities were successfully correlated with Redlich−Kister expansion (AADwNaCl = 0.0006 and ΔwNaCl = 0.47%). Electrical conductivity of NaCl - saturated solutions were measured (44 data points) at T = (293.15 to 363.15) K and correlated with a semiempirical model. A large difference in electrical conductivity for the two solvents was observed. The correlation adequately represented the data set (AADκ = 5.67 mS·cm−1 and Δκ = 5.94%). NaCl solubilities and electrical conductivities were accurately determined and are useful for the MEG regeneration processArtigo Strontium carbonate solubility data in aqueous mixtures of monoethyleneglycol under a carbon dioxide atmosphere(Brazilian Society of Chemical Engineering, 2018) Chiavone Filho, Osvaldo; Andrade, Deborah Cordeiro de; Maniçoba, Naíra Sinara de Almeida; Santana, Rony Oliveira de; Ferreira, Fedra A.V.; Figueiredo, Camila S.; Nascimento, Jailton Ferreira do; Pereira, Leonardo S.In order to inhibit natural gas hydrate formation, monoethyleneglycol (MEG) is usually injected into producing well heads. The MEG regeneration process is continuously performed at the platform. Scaling problems usually occur due to the presence of chlorides and carbonates. This work presents salt solubility data for the aqueous system with strontium carbonate, MEG and carbon dioxide. A specific analytical method was developed. Thus, experimental data for strontium carbonate (SrCO3) solubility at various carbon dioxide pressures are reported. Solubilities of SrCO3 in water were measured from 760 to 1610 mmHg at 278.15. 288.15. 298.15 and 323.15 K. For the mixed solvent (ms) conditions, solubilities were measured at 298.15 K and four isobars, i.e., 760, 1210, 1410 and 1520 mmHg. Experimental data were correlated and demonstrated to be accurate for thermodynamic modeling and process simulation