Theoretical Study and Adsorption Behavior of Urea on Mild Steel in Automotive Gas Oil (AGO) Medium (original) (raw)
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Study the Effect of Urea as Inhibitor for Corrosion in Mild Steel in 2204-Tank
The effect of urea as a corrosion inhibitor on mild steel in the present of water taken from the 2204-tank located in Al-Shaiba Crude Oil Refinery in Basrah was investigated by using potentiodynamic measurement. It is found that the inhibition efficiency (IE) and coverage ratio of urea at 1.5 g/L increase by increasing the concentration of urea until reach 99.46% and 0.994, respectively. The corrosion rate is reduced with increasing the concentration of inhibitor until 1.5g/L; however, after that the corrosion rate increases. Urea inhibitor acts as a cathodic inhibitor.
2020
Received 3 March 2020; Accepted 20 March, 2020 The corrosion inhibition of mild steel in, 0.5M HCl solution by 1((2-arbamoylguanidino) (furan-2-ylmethyl) urea (CFU) was investigated using weight loss experiment at different temperature (30oC, 40oC, 50oC). The CFU was synthesized and characterized using FTIR and 1HNMR. The finding indicates that CFU acts as an effective corrosion inhibitor for mild steel in hydrochloric acid solution. The inhibition efficiency and surface coverage of mild steel increased with increasing concentration of CFU, but reduced as temperature increases. Langmuir adsorption isotherm and freundlick adsorption isotherm were used to deduce that the adsorption mechanism was physical adsorption. The estimation of the adsorption also determined the free Gift’s energy at the range of -12KJmol-1 to -14KJmol-1, which implies that the reaction was spontaneous. The inhibitive ability of CFU was attributed to the presence of oxygen, nitrogen and aromatic furan in its str...
Scientific African, 2021
Polyesteramide urethane was synthesized from Cucurbita maxima seed oil and characterized via Thermogravimetric analysis, Fourier Transformed Infrared spectroscopy, and Differential Scanning Calorimetry. The inhibiting effect of the synthesized polyesteramide urethane (CPEAU) on mild steel in 1.0 Molar concentrations of HCl was investigated through electrochemical and weight loss measurements. The temperature effect on the corrosion performance of the mild steel with or without CPEAU was studied in the range of 303-333 K. It was found that an increase in temperature led to a decrease in inhibition efficiency. The adsorption of CPEAU molecules on mild steel was spontaneous and the isotherm model which the adsorption obeyed was Langmuir's. It was observed that, the value of activation energy for the uninhibited test solution (35.82 kJ/mol) was discovered to be less than those obtained for the inhibited test solutions at different temperatures (49.91 kJ/mol, 50.49 kJ/mol, 53.78 kJ/mol, 62.78 kJ/mol and 69.89 kJ/mol), that signifying electrostatic interaction (physisorption mechanism) of CPEAU on mild steel. Potentiodynamic polarization investigation signified a mixed-type inhibition mechanism of CPEAU at a lower concentration with predominant cathodic effects at a higher concentration. Quantum chemical descriptors revealed the carboxylic group on CPEAU molecule as the active adsorptive sites through which adsorption occurred on the mild steel surface, and a molecular dynamics simulation showed the adsorption and binding energies of the inhibitor. The experimental and computational results were in good agreement.
Quantum chemical calculations based on density functional theory (DFT) methods were performed on indigo blue (IB), methylene blue (MB), and crystal violet (CV) molecules as inhibitors for iron corrosion in acid media. DFT calculations were performed on the molecular structures to describe electronic parameters which are associated with inhibition efficiency such as the Homo values −4.981 eV, −4.518 eV, and −3.872 eV which increased in the order IB > MB > CV while LUMO values were −3.73 eV, −3.63 eV, and −2.87 eV for IB, MB, and CV, respectively. Quench molecular dynamics simulations performed at metal/vacuum interface were applied to find the equilibrium adsorption configurations and calculate the minima interaction energy between inhibitor molecules and iron surface Fe(110). The theoretical order of inhibition efficiency of these dye molecules had a linear relationship with experimentally observed inhibition efficiency on iron corrosion in acid media. The electronic structures as well as reactivity elucidate parameters which could be practical in designing novel high-efficiency, cheap, and eco-friendly inhibitors by quantitative structure-activity relationship (QSAR) method.
Jurnal Teori dan Aplikasi Fisika, 2022
Steel is a material that has low resistance to corrosion when interacting with a corrosive environment. The application of natural extracts as green inhibitors is able to provide good performance in inhibiting corrosion of steel with high inhibition efficiency. Natural extracts that are effective and efficient as corrosion inhibitors on steel are those which in their compound structure contain heteroatom groups (such as O, N, S, P) and aromatic rings. This work provides an important comparative overview for the development of green inhibitor natural extracts in steel. The results of theoretical studies based on quantum mechanics with the DFT method at the atomic level based on molecular orbitals, chemical quantum parameters, and adsorption characteristics show results that are in accordance with experimental studies. The frontier molecular orbital (FMO) plot shows the distribution of electron density in the HOMO-LUMO region as a predictor of the active site of the inhibitor molecule interacting with the steel surface. Quantum chemical parameters such as ionization potential (I), electron affinity (A), absolute electronegativity (χ), hardness (η), softness (σ), fraction of electrons transferred (ΔN), electrophilicity (ɷ), and electron backdonation (ΔEback-donation) was calculated to obtain a correlation between the electronic properties of the inhibitor molecule and the corrosion inhibition potential. The results of the calculation of the quantum chemical parameters show the reactivity of the inhibitor molecule which has a very good potential to interact and bind strongly to the steel surface. This has the potential to make the inhibitor molecule have a high inhibition efficiency. Chemical adsorption and/or physical adsorption by forming complex compounds between inhibitor molecules and the steel surface are corrosion inhibition mechanisms to protect steel from a corrosive environment.The development of future studies should be able to display the mechanism of interaction and inhibition of inhibitor molecules in more detail and systematically at the atomic level on several metal surfaces such as Fe, Al, Cu, and others.
Materials International, 2025
Present-day theoretical computation methods are quite effective at anticipating how corrosion inhibitors would behave on metal surfaces, conserving time and resources on laboratory testing. The present study aims to predict the inhibitory effectiveness of certain furan derivatives on surfaces of Fe (110) and Sn (111) in acidic media. To compare their fundamental attributes against corrosion as well as their behavior on iron (Fe) and tin (Sn) surfaces in an acid medium, six urea derivatives have been chosen for this purpose: Imidazolidin-2-one (Cpd A), 4-methylimidazolidine-2-one (Cpd B), Tetrahyropyrimidin-2(1H)-one (Cpd C), 1,3-dimethylimidazolidin-2-one (Cpd D), 1,1-diethylurea (Cpd E), 1,3-dimethylurea (Cpd F). The anti-corrosive characteristics of Cpds A - F were generally explored using Density Functional Theory and Monte Carlo simulations. The results indicate that the compounds had low energy gaps, the highest occupied molecular orbital energy, global hardness, as well as ionization energy and high Electron affinity, ELUMO, global softness, and number of transferred electrons, which explained their corrosion inhibition potentials. Electrostatic potential (ESP) and Fukui indices identified the reactive sites with the ability to accept and donate electrons via back-donation to the metal's d-orbital. The Monte Carlo simulation demonstrated a favorable contact between the Fe (110) and Sn (111) surfaces and inhibitory molecules in the acidic medium. In the industrial sectors, these compounds may be secured as corrosion protectors.
Physica E-low-dimensional Systems & Nanostructures, 2015
The detection of uranium is very important, especially in water and, more importantly, in the form of uranyl ion (UO 2) 2+ , which is one of its most abundant moieties. Here, we report analyses and simulations of uranyl in water using ab initio modified force fields for water with improved parameters and charges of uranyl. We use a TIP4P model, which allows us to obtain accurate water properties such as the boiling point and the second and third shells of water molecules in the radial distribution function thanks to a fictitious charge that corrects the 3-point models by reproducing the exact dipole moment of the water molecule. We also introduced non-bonded interaction parameters for the water-uranyl intermolecular force field. Special care was taken in testing the effect of a range of uranyl charges on the structure of uranylwater complexes. Atomic charges of the solvated ion in water were obtained using density functional theory (DFT) calculations taking into account the presence of nitrate ions in the solution, forming a neutral ensemble. DFT-based force fields were calculated in such a way that water properties, such as the boiling point or the pair distribution function stand. Finally, molecular dynamics simulations of a water box containing uranyl cations and nitrate anions are performed at room temperature. The three peaks in the oxygen-oxygen radial distribution function for water were found to be kept in the presence of uranyl thanks to the improvement of interaction parameters and charges. Also, we found three shells of water molecules surrounding the uranyl ion instead of two as was previously thought.
Journal of electrochemical science and technology, 2019
The corrosion inhibiting mechanism of Vietnam orange peel essential oil (OPEO) for mild steel in 1 N HCl solution was investigated elaborately. Corrosion inhibition ability of OPEO was characterized by electrochemical polarization, electrochemical impedance spectroscopy (EIS), and weight loss method. In the corrosive solution, OPEO worked as a mixed inhibitor and the inhibition efficiency of OPEO increased with the increase of its concentration. High inhibition efficiencies over 90% were achieved for the concentration of 3 4 g/L OPEO, comparable to that of 3.5 g/L urotropine (URO), a commercial corrosion inhibitor for acid media used in industry. By using adsorption isotherm models (Langmuir, Temkin and Frumkin), thermodynamic parameters of adsorption were calculated. The obtained results indicated physical adsorption mechanism of OPEO on the steel surface. The components responsible for the corrosion inhibition activity of OPEO were not only D-limonene, but also other compounds, wh...
Evaluation of Performance of Corrosion Inhibitors Using Adsorption Isotherm Models: An Overview
Chemical Science International Journal, 2017
Adsorption isotherm models are an important tool for describing interaction of corrosion inhibitors with metal surfaces which they are aimed to protect. In this paper, key adsorption isotherms used in corrosion inhibition studies have been reviewed. We have examined how some deductions on the nature of metal-corrosion inhibitor interactions are obtained from certain parameters and interpreted to characterize the adsorption of the corrosion inhibitors and their mechanisms of inhibition. More attention is paid to their applications and the useful information that may be derived from them than on their background and derivation. Efforts have also been made to identify some limitations (where applicable) and/or discrepancies in usage of some models in reporting experimental findings. Informed by some inconsistencies observed from some literature reports, critical suggestions on appropriate approaches to collection and processing of data for fitting into these isotherms have been made. This paper will be a beneficial secondary source of information to readers and invaluable reference material to experts and future researchers in the subject area.
World Scientific News , 2017
Ethanollic extract of Phyllanthus amarus (EEPA) was tested as corrosion inhibitor for mild steel in 2 M HCl solution using gravimetric and gasometric methods at 303, 313, 323 K and 333 K. The results revealed that the corrosion rate increases with temperature and time. Addition of the concentration of ethanollic extract of Phyllanthus amarus to the corroding environment lowered the corrosion rate of mild steel and increased inhibition efficiency (IE %) of ethanollic extract. Inhibition efficiency was found to decreased with temperature. Fitting of the experimental data to the Arrhenius and Transition state equations revealed that the Organic constituents of the extract were physically adsorbed on the corroding surface of the steel and adsorption of ethanollic extract of Phyllanthus amarus (EEPA) on mild steel surface was found to obey the Langmuir adsorption isotherm and Freundlich adsorption isotherm and sign of the Gibb's fee energy of the adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface. Positive values obtained for enthalpy change indicated that the adsorption of inhibitor is endothermic.