Produção de biossurfactantes e recuperação de óleo pesado em meios porosos não-consolidados

• Ano de defesa: 2009
• Autor(a) principal: Parreira, Adriano Guimarães
• Orientador(a): Tótola, Marcos Rogério
• Banca de defesa: Santos, Vera Lúcia dos , Moraes, Célia Alencar de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Microbiologia Agrícola
• Departamento: Associações micorrízicas; Bactérias láticas e probióticos; Biologia molecular de fungos de interesse
• País: BR
• Palavras-chave em Português: Petróleo; Surfactina; MEOR; Óleo pesado
• Palavras-chave em Inglês: Heavy Oil; Surfactin; Microbial Enhanced Oil Recovery; Heavy oil
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::MICROBIOLOGIA APLICADA
• Link de acesso: http://locus.ufv.br/handle/123456789/1547

The world reserves of heavy oil, characterized by high density and viscosity, are estimated to be more than 50% larger than those of light oil, hence the need to develop new techniques for their recovery. These characteristics highlight the need to develop new techniques that allow for their recovery. In this context the application of Microbial Enhanced Oil Recovery process is revealed as a feasible and promising strategy. This study aimed to select isolates of Bacillus able to produce surfactants in the conditions of the oil reserves and to recovery heavy oil of unconsolidated porous media inoculated with them. We isolated B. subtilis subspecie spizizenii, LBBMA 4914 and B. subtilis LBBMA 4951, with desirable characteristics for application in Microbial Enhanced Oil Recovery. These isolates are able to produce surfactants when cultivated under anaerobic conditions, in 34 °C and mineral medium containing glucose to 2.0% (w/v) and NaCl to 5.0% (w/v). Isolates LBBMA 4914 and LBBMA 4951 in the form of endospores and mixed cultures have high transport efficiency of its cells in sand packed columns 70% and capacity of surfactin production inside the porous media to 26.3 mg L-1. The mixed cultures inoculated in porous media produced surfactants with DMC values of 8, reduced the surface tension to 29.4 mN m-1 and reduced interfacial tensions on n-hexadecane to 2.5 mN m-1. The injection of the strains in mixed cultures and suspended in mineral medium containing 2.0% (w/v) glucose and 5.0% (w/v) NaCl provided 12.9% of heavy oil recovery of unconsolidated porous media. The injection of production water how inoculate enabled the recovery of 10.3% of heavy oil, that surpassed those obtained with the injection of LBBMA 4914 and LBBMA 4951 in the form of pure cultures. There were changes in the hydrocarbon composition of oil samples recovered from columns subjected to treatment with a mixed culture, indicating possible biotransformation of the heavy oil by the selected strains of B. subtilis. The ability of B. subtilis subsp. spizizenii LBBMA 4914 and B. subtilis LBBMA 4951 to produce surfactants and promote the heavy oil recovery from porous media qualify them to apply in strategies of enhanced oil recovery in-situ, however, conditions that favor their production of surfactant need to be addressed.