ИСТИНА

One of the most up-to-date industrial problems, especially in the oil and gas extraction and processing industry, in developed countries of the world is corrosion process. As a result of this process, when the direct and indirect losses occur, the risk of explosion and fire increases and as a consequence, raw materials, ready-made and combustion products are poured into the surroundings to create environmental stress. Therefore, investigation of the corrosion processes and to find solutions for them is one of the important issues of the industry. One of the simplest and most effective ways for solving this problem is the using of corrosion inhibitors. Novel environmental friendly surfactants were synthesized based on some vegetable oils. The structures of surfactants were characterized by physical-chemical spectroscopic methods. The surface activity of the synthesized surfactants solutions was determined using surface and interfacial tension measurements at 25oC. Some of physical and chemical properties of the prepared compounds such as solubility, acid and iodine numbers have been studied. Surface active properties (interfacial tension) of the obtained surfactants were investigated by the stalogmometric method and critical micelle concentration (CMC), maximum surface excess (Γmax), minimum surface area (Amin), free energies of micellization ( ), and adsorption( ) were calculated. The efficiency of carbon steel corrosion inhibition in CO2- saturated brine shown by the synthesized surfactants was studied using extrapolation of cathodic and anodic Tafel lines and electrochemical impedance spectroscopy at 50 oC. Adsorption of inhibitors was found to obey Langmuir isotherm and was chemisorption. Thermodynamic adsorption parameters (Kads, ∆G0ads) of studied inhibitors were calculated using the Langmuir adsorption isotherm. By using a bioluminescence ATP assay, we have determined the minimal concentrations of surfactants suppressing most common microbial corrosion inducers: Desulfovibrio vulgaris, Pseudomonas putida, Rhodococcus ruber. The experimental results showed that the synthesized surfactants are good corrosion inhibitors reagents and the inhibition efficiency increased with increasing of surfactant concentration. Analysis of data obtained from bioluminescence method showed that various corrosion inhibitors have biocide influence on the different microorganisms in non-equal dozes. From the results of petroleum-collecting and petroleum-dispersing ability studies of the synthesized surfactants, we found that synthesized compounds have good petro-collecting or dispersing effects.