Banca de DEFESA: JÉSSICA MARIA DAMIÃO DE ARRUDA CÂMARA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA MARIA DAMIÃO DE ARRUDA CÂMARA
DATA : 22/07/2019
HORA: 13:00
LOCAL: AUDITÓRIO NUPEG
TÍTULO:
Kinetic Study of the rhamnolipid production by Pseudomonas aeruginosa and its application in enhanced oil recovery.

PALAVRAS-CHAVES:

Ramnolipídeo. Pseudomonas aeruginosa. Optimization. Production kinetics. Microbial Enhanced Oil Revovery (MEOR).  


PÁGINAS: 138
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:
The biosurfactants displays an alternative to the use of synthetic surfactants, especially when considering their advantages of less toxicity, greater biodegradability and stability. Among these biosurfactants, the rhamnolipid, produced by Pseudomonas aeruginosa, has been presenting itself as one of the most notable biosurfactants as a result of its high performance and applicability in advanced petroleum recovery. However, the large scale application of rhamnolipids has been a challenge to companies since the costs of production are high, due to, mainly, the downstream purification process. Therefore, in this study the production of  rhamnolipid by a strain of Pseudomonas aeruginosa was investigated and optimized. The Plackett-Burman design was used to select the variables that affect significantly the production yield of the biosurfactant and the Central Composite design was used to optimize the rhamnolipid production. Afterwards, the kinetic modeling was performed, in which four non-structural models were tested, and the parameters were optimized through the genetic algorithm and the numeric discretization by the Runge-Kutta method. The biosurfactant produced was characterized and evaluated regarding its capacity of being used in the Microbial Enhanced Oil Recovery (MEOR), finally, the influence of the purification stage was investigated in the rhamnolipidability to increase oil production after the convencional recovery process. The results indicated that the optimal values of temperature, pH, carbon/nitrogen rate, glycerol concentration and time (variables selected through the statistical experimental design) are, respectively, 30.17°C, 7.37, 32.35, 9.36% (v/v) and 10.26 days. The biosurfactant produced also presented a excellent emulsification rate, approximately 67% for the n-hexane and 69% for the petroleum, and a capacity of reducing the water superficial tension from 72 to 35.26 mN/m in a c.m.c of 127 mg/L. Furthermore, the rhamnolipid also presented a good stability to wide ranges of pH and salinity. Such characteristics configured the rhamnolipid as a good candidate to the application in MEOR. The kinetic parameters, of four non-structural models, for the experimental data of four rhamnolipid production curves were optimized by the genetic algorithm method and the main result demonstrated that the Monod model is the best predicting the data, with values of  µmáx equal to 0.06 h-1, KS equal to 50.8 g/L, YX/S equal to 0.43 g/g and YP/X equal to 0.017 g/g. At last, with the tests of advanced recovery, it was demonstrated that the rhamnolipid can efficiently recover the oil, obtaining the best result for a biosurfactant concentration 100% above the c.m.c and petroleum with a API Gravity of 21.90, which was able to achieve a total recovery of 50.45±0.79%, of which 11.91±0.39% corresponds to the MEOR. Moreover, it was evidenced that the biodegradability of the rhamnolipid did not represent a desavantage and that bigger investments in purification processes for the biosurfactant would be dispensable, since the biosurfactant was able to maintain its ability of increasing the oil recovered factor, even after two months of production. Also, the non-purificated rhamnolipid presented higher recovery factors when compared with the purificated, for all three types of oils studied.


MEMBROS DA BANCA:
Interno - 347289 - AFONSO AVELINO DANTAS NETO
Externa à Instituição - ANITA MARIA DE LIMA - UFS
Presidente - 1308273 - EDUARDO LINS DE BARROS NETO
Externo à Instituição - FRANCISCO KLEBSON GOMES DOS SANTOS - UFERSA
Externa ao Programa - 2668814 - MAGNA ANGELICA DOS SANTOS BEZERRA SOUSA
Notícia cadastrada em: 10/07/2019 15:12
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