Iranian Journal of Oil and Gas Science and Technology

Abstract The effect of using Conocarpus extract as a green inhibitor on the corrosion behavior of mild steel in a 1 M HCL environment is investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The impedance tests show that the polarization resistance increases from 29 for the blank solution to 299 for the solution containing 2500 ppm of Conocarpus extract. The polarization test results show that at room temperature, the corrosion current density for the blank solution decreases from 3.5 × 10^–4 to 2.6× 10^–5 for the solution containing 2500 ppm of Conocarpus extract, and the potential is shifted to negative values. The polarization test is performed at three temperatures of 25, 55, and 85 °C. The results show that the efficiency of 1925 ppm decreases from 93% at room temperature to 86% at 85 °C. The high-temperature efficiency does not decline significantly, indicating the effectiveness of Conocarpus extract at high temperatures. The FTIR tests also prove that the corrosion inhibitory effect of Conocarpus extract is due to the presence of heteroatoms such as N, S, and O. The adsorption isotherm results show that the adsorption of the extract as a single layer on the surface is consistent with the Langmuir isotherm.

Abstract Different amounts of nanoclay were incorporated into the acrylic resin matrix at 0, 1, 3, and 5 wt.% loadings. The coatings were applied on low carbon steel plates. Optical microscopy, sedimentation test, transmission electron microscopy, and X-ray diffraction were employed to investigate the dispersion of nanoclay in matrix. The corrosion resistance of coatings was evaluated by electrochemical impedance spectroscopy, polarization measurement, and salt spray test. In addition, pull-off and cross-cut tests were used for the assessment of coating adhesion to the substrate. The results indicated that the anti-corrosive properties of the acrylic resin were obviously increased by the addition of nanoclay. The nanocomposite coatings containing 3 wt.% clay showed the best corrosion resistance. Finally, the nanocomposites containing 1 and 3 wt.% showed the highest adhesion to the substrate.

Abstract In this study, nanocomposite coatings based on polyurethane cerium nitrate montmorillonite (MMT) were prepared, applied on carbon steel substrates, and investigated. The nanocomposite coatings were successfully prepared by the effective dispersing of nanoparticles in polyurethane resin by mechanical and sonication processes. The state of dispersion, dissolution, and incorporation were characterized by optical microscopy, sedimentation tests, and transmission electron microscopy. The structure and properties of the nanocomposite coatings were investigated by X-ray diffraction and anticorrosive properties of the nanocomposites were studied by Tafel polarization measurements. The experimental results showed that the PU/MMT/Cerium nitrate nanocomposite coatings were superior to the neat PU in corrosion protection. In addition, it was observed that the corrosion protection of the nanocomposite coatings was improved as the clay and cerium nitrate loadings were increased to 4 wt.% to 2 wt.% respectively.

Abstract In this study, the corrosion resistance of a bituminous coating reinforced with different ratios of nanoclay pigment was studied. To make nanocomposite coatings, 2, 3, and 4 wt.% of clay (Cloisite Na+) were incorporated into water emulsified bitumen. The coatings were applied to steel 37. Optical microscopy and X-ray diffraction (XRD) were used to characterize the nanocomposite structure. In order to investigate the anticorrosion behavior of the coatings, electrochemical impedance spectroscopy (EIS) and direct current polarization techniques were used. The results show that the coatings containing nanoclay have better performance compared to the neat bitumen. Moreover, it was revealed that the corrosion resistance of the nanocomposite increased as the clay loading increased up to 4 wt.%.

Abstract In this paper, the effect of cationic and anionic ion sizes on the charge storage capability of graphene nanosheets is investigated. The electrochemical properties of the produced electrode are studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in 3M NaCl, NaOH, and KOH electrolytes. Scanning electron microscopy (SEM) is used to characterize the microstructure and nature of the prepared electrode. The SEM images and X-ray diffraction (XRD) patterns confirm the layered structure (12 nm thickness) of the used graphene with an interlayer distance of 3.36 Å. The electrochemical results and the ratio of  confirm good charge storage and charge delivering capability of the prepared electrode in the 3M NaCl electrolyte. Charge/discharge cycling tests show a good reversibility and confirm that the solution resistance will increase after 500 cycles. In this paper, the effect of cationic and anionic ion sizes on the charge storage capability of graphene nanosheets, is investigated. Electrochemical properties of produced electrode are studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, in 3M NaCl, NaOH and KOH electrolytes. Scanning electron microscopy (SEM) is used to characterize the microstructure and nature of prepared electrode. SEM images and XRD patterns confirm the layered structure (12 nm thickness) of the used graphene with an interlayer distance of 3.36 (Å). The electrochemical results and the ratio of q*_O/q*_T confirm a good charge storage and charge delivering capability of prepared electrode in 3M NaCl electrolyte. Charge/discharge cycling test shows a good reversibility and confirms that solution resistance will increase after 500 cycles.

Abstract Arguably, the natural gas transmission pipeline infrastructure in Iran represents one of the largest and most complex mechanical systems in the world. The optimization of large gas trunk lines known as IGAT results in reduced fuel consumption or higher capability and improves pipeline operation. In the current study, a single-objective optimization was conducted for Khormoj compressor station on the Iranian gas trunk line V (IGAT5). The system consists of over 504 kilometers of 56-inch pipeline from South Pars to Aghajari. This system passes through a tortuous terrain with changes in elevation which makes the optimization process even more challenging. Genetic algorithm (GA) was used in this optimization along with detailed models of the performance characteristics of compressors. The results show that in stations having the same compressor in parallel the minimum power (energy) consumption is reached when split flow in all the compressors is the same.