Obtención de un biosurfactante para el recobro mejorado de petróleo

Resumen: En este proyecto de investigación se obtiene un biosurfactante y se evalúa su uso en recobro mejorado de petróleo. El biosurfactante se produjo a partir de la fermentación de biomasas residuales utilizando bacterias de Lactobacillus fermentum, aisladas de suero láctico de diferentes regiones de Colombia. A partir de un estudio preliminar, en el cual se examinaron 18 cepas para detectar bacterias productoras de biosurfactante, se seleccionaron tres de estos microorganismos (LAC05, LAC10 y LAC12) para llevar a cabo el proceso de obtención del biosurfactante. Los experimentos se realizaron a 37°C, la cual fue seleccionada entre cinco temperaturas (31, 34, 37 y 40°C), como la óptima para crecimiento de las bacterias ácido lácticas. Para optimizar la producción del biosurfactante se utilizó un esquema factorial (3x2x4) aleatorizado con tres replicas correspondiente a tres cepas microbianas, dos fuentes de carbón (melaza y suero) y cuatro formulaciones de medios de cultivo, en los cuales se variaron las concentraciones de nitrógeno, hierro y fosforo. La tensión superficial de los medios de cultivo se seleccionó como variable respuesta del diseño de experimentos. La combinación de variables que permitió minimizar la tensión superficial del medio de cultivo se obtuvo con la bacteria LAC12, la melaza y el medio M2. Al biosurfactante obtenido se le determinó su concentración crítica micelar y su balance lipofílico-hidrofílico (HLB). Adicionalmente, el biosurfactante se caracterizó por medio de Espectroscopía Infrarroja por transformada de Fourier (FTIR) y Cromatografía Líquida de Alta Eficacia (HPLC: High Performance Liquid Chromatography). La factibilidad técnica del biosurfactante para ser usado en procesos de recobro mejorado de petróleo se evaluó mediante el montaje de una prueba de desplazamiento usando un empaque de arena. El biosurfactante obtenido demostró ser efectivo en el recobro de petróleo ya que aumentó en un 18% la producción de petróleo en comparación con el petróleo recuperado con una inyección convencional de agua.Abstract: In this research project, a biosurfactant is produced and its use in enhanced oil recovery is evaluated. The biosurfactant was produced from the fermentation of residual biomasses using Lactobacillus fermentum bacteria, isolated from whey coming from different regions of Colombia. From a preliminary study, in which 19 strains were examined in order to detect biosurfactant producing bacteria, three of these microorganisms (LAC05, LAC10 y LAC12) were selected for carrying out the biosurfactant production process. All experiments were performed at 37°C. This temperature was selected among five values (31, 34, 37 y 40°C), as the optimum temperature for maximizing the growing of the lactic acid bacteria. Biosurfactant production was optimized by means of a (3x2x4) randomized factorial scheme with three replicates. The factors taken into account were three strains, two carbon sources (molasses and whey) and four culture media formulations in which the concentrations of iron, nitrogen and phosphorus were varied. Superficial tension of the culture media was selected as response variable. Minimization of the superficial tension of the culture media was achieved when the LAC12 bacterium, the molasses and the culture medium M2 were combined. Key biosurfactante properties such as its Critical Micelle Concentration (CMC) and its Hydrophilic-Lipophilic Balance (HLB) were determined. Additionally, the biosurfactante was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography (HPLC). The technical feasibility of application of the biosurfactant in enhanced oil recovery processes was evaluated by means of a displacement test using a sand pack. Biosurfactant was effective in enhanced oil recovery due to is increasing recovery factor in 18%.Maestrí

Production of fuel additives by direct conversion of softwood bark using a cheap metal salt

Levulinates could be used as oxygenated fuel additives or as blending components in biodiesel. In this work, a metallic salt was used for the direct conversion of biomass, ie. (softwood bark), to produce methyl levulinate (ML) and levulinic acid (LA). The experimental data were analyzed through using a response surface methodology (RSM) as well as a central composite design (CCD). Three dependent responses (ML yield, LA yield, and residue production) were studied to determine the optimum combination of the four factors. The total yield of levulinates was 62% at the optimum process parameters, including catalyst concentration (0.067 mol/L), reaction time (5.67 h), and softwood bark concentration (2.5 wt%) at 200 °C. Finally, the results showed that Al2(SO4)3 allowed the production of levulinates probably in light of its good BrØnsted/Lewis acidity while also allowing t to decrease the corrosion inside the reactor (as compared to homogeneous acids such as H2SO4). This shows that the use of these metal salts for this specific application could positively affect the production costs of levulinates (either CAPEX or OPEX) at larger scale

A simple process for the production of fuel additives using residual lignocellulosic biomass

International audienceIn this work, the direct production of levulinates from cheap residual lignocellulosic biomass was performed using an affordable homogeneous catalyst. A central composite design (CCD) using the response surface methodology (RSM) was applied to analyze the effects of the four selected factors (acid concentration, temperature, α-cellulose content, and reaction time) on the production of levulinates (levulinic acid derivatives). This optimization led to a total production of levulinates of 78 wt%, 72.5 wt%, 83 wt%, and 73 wt% using α-cellulose, poplar, sorghum, and softwood bark, respectively