Quantitative Evaluation of the Efficiency of Water-in-Crude-Oil Emulsion Dehydration by Electrocoalescence in Pilot-Plant and Full-Scale Units

Bioconversion of Glycerol into Lactic Acid by a New Bacterial Strain from the Brazilian Cerrado Soil

A lactic-acid-producing strain was isolated from the Brazilian Cerrado soil (Brazilian savanna). Glycerol, a byproduct of the biodiesel industry, can be converted into various chemical intermediates of industrial value by biotechnological routes. Klebsiella pneumoniae can metabolize glycerol in environments with or without oxygen and bioconvert it into several chemicals with high value-added, such as lactic acid, 3-hydroxypropionic acid and 1,3 propanediol. The wild-type bacterial strain (2GPP) isolated from a soil sample from the Brazilian Cerrado was determined to be a K. pneumoniae complex that was capable of successfully metabolizing glycerol. Fermentations were performed with different temperatures, pH, and inoculum concentrations to evaluate the best lactic acid production. At first, 1,3-propanediol and L-(+)-lactic acid were produced in mini reactors. A lactic acid production of 3.8 g·L−1 and a decrease in 1,3-propanediol output were observed. Thus, by adjusting process variables such as pH and temperature during fermentation, it was possible to maximize the production of lactic acid and decrease the formation of 1,3-propanediol by utilizing experimental design strategies.

Contactless Method for Electrocoalescence of Water in Oil

This paper discusses an experimental approach to study the effects of a contactless method on electrocoalescence of water-in-oil mixture/emulsion. A positive corona discharge is utilized using a sharp conductive needle without direct contact with the mixture/solution to avoid potential corrosion of the electrode. This creates a nonuniform electric field, which is further used for the coalescence of water droplets in the range of micro to macro in oil. Two approaches are employed in this study: qualitative analysis conducted by visually studying coalescence patterns in videos captured with a high-speed camera and a quantitative analysis based on calculations obtained from dynamic light scattering measurements. From the behavior of the water droplets under the electric field, it is observed that dipole-dipole interaction, migratory coalescence/electrophoresis, and dielectrophoresis have major roles in promoting the coalescence events. The effects of oil viscosity and power consumption on the coalescence rate are also investigated, suggesting an optimal oil-water separation process. The results of this study pave a path for developing a safe, contactless, rapid, and low-power-consuming separation process, potentially suitable for an offsite application.