Banca de DEFESA: MÁRIO HERMES DE MOURA NETO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MÁRIO HERMES DE MOURA NETO
DATE: 17/06/2021
TIME: 14:00
LOCAL: meet.google.com/cwd-eycu-dof
TITLE:

Experimental Data and Computational Method for the Determination of Composition in the Monoethylene Glycol Regeneration Process

KEY WORDS:

Hydrate inhibitor; Thermodynamic of electrolytes; Matlab; Density; Electrical conductivity; Vapor-liquid equilibria.

 

PAGES: 100
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Operações Industriais e Equipamentos para Engenharia Química
SPECIALTY: Operações de Separação e Mistura
SUMMARY:

Gas hydrates are crystalline solids formed by the combination of small gas molecules (e.g. CO₂ and methane) and water. These solids may form in Natural Gas production lines, causing great damage, such as partial or total obstruction of the production flow and rupture of the pipelines. Monoethylene glycol (MEG) is a thermodynamic gas hydrate inhibitor widely applied for natural gas flow assurance. To ensure financial and environmental feasibility the MEG needs to be regenerated and reused. A series of density and electrical conductivity measurements of water+MEG+NaCl mixtures was reported allowing indirect supervision of the MEG regeneration unit (MRU). Density (610 data points) and electrical conductivity (250 data points) measurements were performed from 278.15 to 363.15 K, the complete concentration range of solvents and NaCl up to almost saturation. The solution theory was applied for density modeling purpose, using the excess volume ( ). The  was correlated with the aid of the Redlich–Kister equation. A semiempirical correlation with five adjustable parameters was applied for electrical conductivities of water+NaCl and MEG+NaCl binary mixtures. To describe the ternary system, a quadratic mixing rule with a correction parameter accounted for the solvent composition. Accurate thermodynamic correlations for density (ρ) and electrical conductivity (κ) as function of water, MEG and, NaCl concentrations and temperature were obtained. These functions allowed the determination of VLE data for water+MEG mixtures in the presence of NaCl at low pressures, which are important to describe the effects of composition, temperature, and pressure in the MRU. 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. The Electrolyte Nonrandom Two-Liquid and Universal Quasi-Chemical Activity Coefficient models were parameterized to describe the VLE behavior of water+MEG+NaCl. MEG+NaCl solutions presented an inverted colligative property, i.e., the addition of salt decreases the boiling point. VLE data indicated that water separation is less efficient due to the addition of salt. The ρ and κ functions also presented an approximately orthogonal behavior to each other, allowing the determination of mixture composition. The Matlab environment was considered to solve the nonlinear system of two equations with constraints. The fmincon built–in function was found robust for composition determination from the experimental density and electrical conductivity data. The proposed methodology was extensively tested (860 data points) and deviations less than 0.0060 and 0.0011 in solvents and NaCl mass fractions were obtained, demonstrating the required accuracy.

BANKING MEMBERS:
Presidente - 1149554 - OSVALDO CHIAVONE FILHO
Interna - 000.000.000-00 - FEDRA ALEXANDRA DE SOUSA VAQUERO MARADO FERREIRA - UFRN
Interno - 1547970 - JACKSON ARAUJO DE OLIVEIRA
Externo à Instituição - ALESSANDRO ALISSON DE LEMOS ARAÚJO - UFERSA