Produção de biossurfactante por Bacillus subtilis com elevada eficiência na mobilização de óleo pesado

• Autor(a) principal: Batista, Fabiane de Mesquita
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5309
• topic: Óleo pesado; MEOR; Bacillus subtilis; Anaerobiose; Superfície de resposta; Biossurfactante; Núcleo poroso de areia; Heavy oil; MEOR; Bacillus subtilis; Anaerobiosis; Biosurfactant; Surface of response; Sand-pack columms; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::MICROBIOLOGIA APLICADA

The heavy oil (10 20ºAPI) is more than half of world oil reserves, there are predictions that in 2025 are the main source of oil in the world. The difficulties in exploration this kind of oil are associated with unfavorable characteristics such as density and viscosity (100 to 10.000 cP). With the need to improve the utilization of reservoir - in view of the relatively low levels of efficiency of traditional techniques - it has expanded the research to develop new techniques for recovery, especially Microbialy Enhanced Oil Recovery (MEOR). In the recovery of oil contained in sand-pack columns, two dimensionless variables are reported as important: the capillary number and ratio of viscosity. As the increases capillary number, the residual oil decreases. This can be achieved by reducing the interfacial tension between the fluid of residual oil. Several authors have reported the tensions interfaciais ultra between biosurfactant and hydrocarbons, including heavy oil. In the present work, tested the hypothesis that the biosurfactant produced on condition of reservoir, by two isolates of Bacillus subtilis from the collection of culture of the Laboratório de Biotecnologia e Biodiversidade para o Meio Ambiente (LBBMA / DMB / UFV), are capable to remove heavy oil in sand-pack columns. Initially, the isolates of Bacillus subtilis LBBMA 155 and Bacillus subtilis subsp. spizizenii LBBMA 258 were evaluated as to the growth and biosurfactant production in response to temperature and salinity. A central composite rotatable design (CCRD) was used, with temperature and salinity being independent variable. The results were analyzed using Response Surface Methodology (RSM) and showed that the those isolates were able of growth and biosurfactant production of under anaerobic conditions. The growth was influenced by temperature and biosurfactant production was influenced by temperature and salinity. After that, the biosurfactant produced by those isolates, alone or mixed, were analyzed as the ability to remove heavy oil trapped in sand-pack columms. The injection of three volumes of porous extract biossurfactante (EB) produced by Bacillus subtilis LBBMA 155 and Bacillus subtilis subsp. spizizenii LBBMA 258 removed 13.55% and 17.42%, respectively, from residual oil (14 ºAPI). The mixed of extracts from biosurfactant produced by those two isolates showed intermediate values of DMC and recovery of residual oil reported for each. Summarize, the extracts from biosurfactant (EB) produced under anaerobic conditions by Bacillus subtilis LBBMA 155 e Bacillus subtilis subsp. spizizenii LBBM 258 are effective in recovery heavy oil nuclei of the sand-pack columms and have potencial for use Microbialy Enhanced Oil Recovery.