Banca de QUALIFICAÇÃO: VALDIVINO FRANCISCO DOS SANTOS BORGES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : VALDIVINO FRANCISCO DOS SANTOS BORGES
DATE: 30/06/2023
TIME: 09:00
LOCAL: videoconferência
TITLE:

Study of the adsorption of anionic surfactants in carbonate rocks and sandstones: characterizations, experimental planning and effectiveness of the parameters.

KEY WORDS:

surfactants; sandstone; limestone; adsorption; equilibrium isotherms

PAGES: 110
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química de Interfaces
SUMMARY:

There is a constant search for methods and techniques that provide an increase in the production of oil fields, since oil exploration using only natural energy results in a relatively low yield, reaching around 35% of the reservoir capacity. For this reason, several alternative and complementary methods have been developed, among them the injection of surfactants stands out. Advanced surfactant oil recovery includes surfactant injection and stimulation. The main functions of this method are to reduce the water/oil interfacial tension and change the wettability of the reservoir rock, which most of the time shows to be oil-wet, making it water-wettable. This property of surfactants is due to their amphiphilic nature, which has two well-defined regions with distinct affinities to different and immiscible solvents. In this study, the adsorption of anionic surfactants on carbonate and sandstone materials was investigated. The finite bath method was performed to evaluate the adsorption efficiency of each surfactant, varying parameters such as temperature, contact time, and concentration. Saponified anionic surfactants were chosen from vegetable oils because they are much more economically and sustainably viable. They are saponified coconut oil (SCO), saponified babassu coconut oil (SBCO), and saponified castor bean oil (SCBO), in addition to the commercial sodium dodecyl sulfate (SDS). It was found that the adsorption of SCO, SBCO, and SCBO was effective in limestone and negligible in sandstone, while SDS showed low adsorption efficiency in both rocks. The experimental data were analyzed by equilibrium isotherm, kinetic and thermodynamic models. The isotherm data were well described by the Sips isotherm model for the surfactants: SCO, SBCO, and SCBO. Kinetic data were done using first and pseudo-second- order models. The results indicated that the adsorption fit well with the pseudo-second-order kinetic model. The Langmuir model simulated the OCS adsorption isotherms better than the Freundlich model at three different temperatures of 298, 313, and 333K. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) calculated from the temperature-dependent adsorption isotherms indicated that the adsorption process of OCS on limestone was spontaneous and endothermic. The adsorbents were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermal analysis (TG/DTG), X-Ray Diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy (SEM), granulometric, and Zeta Potential analysis. The results showed that both non-polar and electrostatic interactions contributed to the adsorption of these surfactants in each type of rock.

COMMITTEE MEMBERS:
Externo ao Programa - 1753094 - ALCIDES DE OLIVEIRA WANDERLEY NETO - nullInterno - 1198847 - JOSE LUIS CARDOZO FONSECA
Presidente - 2087667 - TIAGO PINHEIRO BRAGA
Externa ao Programa - 1531209 - VANESSA CRISTINA SANTANNA - null