Experimental and computational approach on the development of a new Green corrosion inhibitor formulation for N80 steel in 20% formic acid.

Organic acids are employed as scale dissolvers in the oil & gas industry during production to stimulate oil recovery by pumping in the formations. Corrosion of metallic surfaces in organic acid solutions poses a significant issue in the oil and gas sector. In recent years, considering the stringent environmental regulations, there has been a growing research interest in environmentally safe inhibitors. This paper explores the synthesis of 2-(3-(carboxymethyl)-1H-imidazol-3-ium-1-yl) acetate (IZ) and its first-time application for corrosion mitigation of N80 steel in 20% formic acid. A detailed experimental study involving gravimetric, electrochemical, and surface analytical techniques is reported herein. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) analyses suggest a rise of impedance with IZ and a mixed-type inhibition behavior, respectively. The inhibition efficiency (IE) is 99.54% at 200 mg/L at 308 K, reaching 99.4% at 363 K with the introduction of KI as a synergistic agent. Computational studies revealed that the inhibitor IZ gets protonated in the experimental environment. The protonated form shows a tendency to receive electrons from the metal surface and shows a greater energy of adsorption compared to that of the neutral form.

Chitosan-cinnamaldehyde Schiff base: A bioinspired macromolecule as corrosion inhibitor for oil and gas industry.

A Schiff base of chitosan with cinnamaldehyde (Cinn-Cht) was synthesized in a single step using microwave irradiation and characterized using spectroscopic techniques. The synthesized Schiff base was used for the mitigation of carbon steel corrosion in 15% HCl. The corrosion evaluation was performed using weight loss tests, electrochemical impedance measurements, and polarization studies. The corrosion inhibition efficiency increased with inhibitor dosage and achieved a high value of 85.16% at 400 mgL-1. The inhibitor adsorption followed the Langmuir isotherm and displayed a mixed physical and chemical adsorption behavior. To further improve the corrosion inhibition efficiency, potassium iodide (KI) was incorporated in the corrosive solution, which increased the inhibition efficiency further to 92.45% at a concentration of 10 mM. Surface studies carried out via SEM analyses indicated the inhibitor adsorption and protective film formation on the steel surface. The computational studies carried out via DFT revealed that mainly the protonated form of inhibitor adsorbs on the metal surface. Monte Carlo simulation studies also showed that the protonated form of the inhibitor molecule exhibited higher adsorption energy than the neutral inhibitor.

Microwave-assisted synthesis of a new Piperonal-Chitosan Schiff base as a bio-inspired corrosion inhibitor for oil-well acidizing.

A new Schiff base of chitosan, namely Piperonal-chitosan (Pip-Cht), was synthesized for the first time, using a microwave irradiation method and characterized using spectroscopic techniques. The corrosion inhibition behavior of the new Schiff base was evaluated on carbon steel in 15% HCl medium via gravimetric and electrochemical techniques. This is the first work on the application of chemically functionalized chitosan as a corrosion inhibitor in the oil-well acidizing environment. The Pip-Cht inhibitor exhibited a high corrosion inhibition efficiency of 85.16% at a moderate dose of 600 mg L-1. Further, the addition of potassium iodide as a synergistic agent to the corrosive electrolyte produced a significant improvement in the inhibition efficiency to 91.15% at a low dosage of 10 mM of KI. At a higher temperature of 65 °C, the combination of both the inhibitor and KI yielded a high inhibition efficiency. The results of the gravimetric and electrochemical experiments were corroborated using AFM and SEM studies. The DFT calculations indicated that corrosion inhibition behavior of the Schiff base mainly occurs in the protonated form.

Bis(2-aminoethyl)amine-modified graphene oxide nanoemulsion for carbon steel protection in 15% HCl: Effect of temperature and synergism with iodide ions.

HYPOTHESIS: There is a scarcity of available literature studies on the inhibition of aqueous corrosion using graphene and graphene oxide (GO) due to their poor aqueous solubility. The abundance of oxygen-containing functional groups on the surface of GO offers promising aspects for its chemical modification. Accordingly, we herein report the application of bis(2-aminoethyl)amine-modified graphene oxide (B2AA-GO) as a corrosion inhibitor for carbon steel in industrial oil-well acidizing conditions. EXPERIMENTS: B2AA was used to modify the graphene oxide (GO) chemically and characterized using FTIR, SEM, and TEM. The corrosion evaluations were undertaken in 15% HCl using weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization techniques supported by a thorough surface analysis using water contact angle measurements, FTIR, and atomic force microscopy. FINDINGS: It observed that the B2AA-GO acted by adsorption on the metal surface and exhibited a mixed type of nature with cathodic prevalence. The results showed that the chemically modified GO exhibits excellent inhibition behavior showing 90.27% corrosion inhibition efficiency up to 65 °C. Furthermore, iodide ions were introduced to improve the inhibition efficiency of the GO via synergistic action and inhibition efficiency of 96.77% was obtained at 65 °C. The obtained results show that the chemically modified GO is a promising corrosion inhibitor in the acidizing environment.

The synergistic influence of polyethyleneimine-grafted graphene oxide and iodide for the protection of steel in acidizing conditions.

Herein, graphene oxide (GO) was chemically functionalized with polyethyleneimine (PEI) in a single step to obtain PEI-GO, which was characterized via FTIR spectroscopy, SEM, and TEM. Additionally, for the first time, PEI-GO was employed for the corrosion mitigation of carbon steel in a solution of 15% HCl. The corrosion performance of the inhibitor was evaluated by utilizing weight loss tests, electrochemical measurements with impedance analysis, electrochemical frequency modulation, and potentiodynamic polarization studies. Thorough surface analysis was performed using 3D profilometry and static water contact angle measurements. PEI-GO was adsorbed on the steel surface and showed mixed-type corrosion inhibition behavior with the prevalence of cathodic characteristics. Additionally, potassium iodide was incorporated in the acid solution as a synergistic agent to enhance the corrosion inhibition behavior of PEI-GO. The obtained results showed that PEI-GO alone provided a high corrosion inhibition efficiency of 88.24% at a temperature of 65 °C and in the presence of KI, it showed an I.E. of 95.77% due to their synergistic effect. These interesting results demonstrate that PEI-GO can act as a potential corrosion inhibitor in acidizing conditions. The DFT-based computational studies showed that the inhibitor functioned in both its neutral and protonated forms.

Chitosan Schiff base: an environmentally benign biological macromolecule as a new corrosion inhibitor for oil & gas industries.

An eco-friendly Schiff base, namely Salicylaldeyde-Chitosan Schiff Base (SCSB), was synthesized by the reaction of chitosan and salicylaldehyde. In 3.5% NaCl saturated with carbon dioxide at 65 °C corrosion inhibition effect was analyzed using weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) methods. The PDP results revealed that SCSB acts as a mixed type inhibitor and reduces the corrosion process effectively at 150 mg L-1 concentration with an inhibition efficiency of 95.2% and corrosion rate of 0.444 mm/y. EIS measurements suggest that the corrosion inhibition process is kinetically controlled. Langmuir adsorption model is the best fit among the other tested isotherms. The surface analysis was carried out using scanning electron microscopy (SEM), atomic force microscopy (AFM), scanning Kelvin probe (SKP), and X-ray photoelectron spectroscopy (XPS) to corroborate the formation of inhibitor film on the metal surface. Computational studies showed the effective adsorption of the protonated form of inhibitor.

Comprehensive investigation of steel corrosion inhibition at macro/micro level by ecofriendly green corrosion inhibitor in 15% HCl medium.

HYPOTHESIS: In the present time, there is enormous need for environmentally friendly and effective corrosion inhibitor for the acidizing process. During acidization 15% hydrochloric acid is used, which causes corrosion of N80 steel. EXPERIMENTS: The present study aims at the synthesis of environmentally benign corrosion inhibitor, namely 2-amino-4-(5-hydroxy-3-methyl-1H-pyrazole-4-yl)-4H-chromene-3-carbonitrile (PCP), and corrosion inhibition evaluation for N80 steel in 15% HCl. The inhibition potential of PCP was examined by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), density functional theory (DFT), and molecular dynamics simulation (MSD). The surface morphology of N80 steel samples was characterized by atomic force microscopy (AFM), contact angle measurement, UV-vis spectroscopy, and scanning electron microscopy (SEM). FINDINGS: The EIS measurements disclosed that PCP inhibits corrosion via kinetic controlled process. PDP results confirmed that PCP is a mixed type inhibitor and reduces the corrosion process effectively at 400 mg/L concentration with 98.4% efficiency. The adsorption of PCP followed Langmuir isotherm. Surface analysis by SEM, AFM, contact angle measurement, and UV-vis spectroscopy supports PCP adsorption over the N80 steel surface. The DFT study explores the adsorption and reactive regions of the PCP molecules. The MSD reveals that the diffusion co-efficient of the corrosive species in inhibited solution is less as compared to uninhibited.

Thiosemicarbazide and thiocarbohydrazide functionalized chitosan as ecofriendly corrosion inhibitors for carbon steel in hydrochloric acid solution.

Organically functionalized chitosan macromolecules namely Chitosan-Thiosemicarbazide (CS-TS) and Chitosan-Thiocarbohydrazide (CS-TCH) were synthesized and evaluated as new corrosion inhibitors for mild steel corrosion in 1M HCl. The FTIR and 1H NMR studies confirmed the formation of the derivatives. The corrosion tests were performed using weight loss method, electrochemical measurements, surface morphology (AFM), quantum chemical investigation and molecular dynamics simulation methods. The maximum efficiency of 92% was obtained at a concentration as low as 200mgL-1. The inhibitors were found to obey Langmuir adsorption isotherm and exhibited both physical and chemical adsorption. Electrochemical impedance spectroscopy (EIS) results showed an increase in polarization resistance which supported the adsorption of inhibitors on the mild steel surface. Tafel data showed a mixed type behavior with cathodic predominance. The data of quantum chemical calculations and molecular dynamics simulation supported the experimental findings.

An impending inhibitor useful for the oil and gas production industry: Weight loss, electrochemical, surface and quantum chemical calculation.

The influence of a Schiff base namely N,N'-(pyridine-2,6-diyl)bis(1-(4-methoxyphenyl) methanimine) (PM) on the corrosion of J55 and N80 steel in 3.5 wt.% NaCl solution saturated with CO2 was evaluated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), contact angle, scanning electron microscopy (SEM), atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM). Potentiodynamic polarization results suggested that the inhibitor acted as a mixed type inhibitor by reducing both anodic and cathodic reactions. The adsorption of PM on the J55 and N80 steel surface obeyed the Langmuir adsorption isotherm. XRD, contact angle, SEM, AFM and SECM studies revealed that the surface of the metal was quite unaffected after the addition of inhibitor. Quantum chemical calculations and molecular dynamic simulation support the experimental results well.

Theoretical, thermodynamic and electrochemical analysis of biotin drug as an impending corrosion inhibitor for mild steel in 15% hydrochloric acid.

The corrosion mitigation efficiency of biotin drug for mild steel in 15% hydrochloric acid was thoroughly investigated by weight loss and electrochemical methods. The surface morphology was studied by the contact angle, scanning electrochemical microscopy, atomic force microscopy and scanning electron microscopy methods. Quantum chemical calculation and Fukui analysis were done to correlate the experimental and theoretical data. The influence of the concentration of inhibitor, immersion time, temperature, activation energy, enthalpy and entropy has been reported. The mitigation efficiency of biotin obtained by all methods was in good correlation with each other. Polarization studies revealed that biotin acted as a mixed inhibitor. The adsorption of biotin was found to obey the Langmuir adsorption isotherm. Surface studies showed the hydrophobic nature of the steel with inhibitor and vindicated the formation of a film on the metal surface that reduced the corrosion rate.