10 research outputs found
Corrosion inhibition effect of a benzimidazole derivative on heat exchanger tubing materials during acid cleaning of multistage flash desalination plants
A benzimidazole derivative, 2-(2-bromophenyl)-1-methyl-1Hbenzimidazole
(2BPB) has been studied as a corrosion inhibitor for
Cu-Ni 70/30 and 90/10 alloys in 1 mol/dm3 HCl solution at low and
high temperatures using the weight loss, electrochemical
(potentiodynamic polarization (PDP), electrochemical impedance
spectroscopy (EIS), & cyclic voltammetry (CV)), and surface
characterization (scanning electron microscopy (SEM) & Fouriertransform
infrared spectroscopy (FTIR)) techniques. The effect of
immersion time (up to 72 h) and addition of iodide ions on the
inhibition efficiency of 2BPB have also been investigated. At low
temperature, 1.0 g/L 2BPB inhibits Cu-Ni 70/30 and 90/10 alloys by
88.9 ± 4.8% and 57.5 ± 1.3%, respectively. The performance of 2BPB
improves with increase in immersion time and addition of iodide ions
but slightly depreciates with rise in temperature. 2BPB acts as a mixed
type corrosion inhibitor and adsorbs on the alloys surfaces through
physical adsorption mechanism. SEM and FTIR results confirm the
adsorption of 2BPB on the alloys surfaces. 2BPB is a potential low
toxic candidate for the formulation of acid corrosion inhibitor for Cu-Ni
alloys
Development of a green corrosion inhibitor for use in acid cleaning of MSF desalination plan
A green and cost-effective inhibitor based on Date palm leaves extract was formulated for use during acid
cleaning of thermal desalination plants. The inhibitor formulation designated as F1 was tested against the
corrosion of ferrous-based alloys namely: carbon steel, Ni-resist, and 316L stainless steel in 2% HCl solution at
40 °C under static and hydrodynamic conditions. Weight loss and electrochemical methods complemented with
scanning electron microscopy were used in the study. Experiments were performed for 6, 24, and 72 h and the
performance of F1 was compared with that of a commercial acid corrosion inhibitor. F1 exhibited excellent
corrosion inhibition performance. Under static and dynamic conditions, 0.4% of F1 provided excellent corrosion
inhibition up to 72 h and comparable to the commercial inhibitor performance. The inhibitors (F1 and the
commercial one) exhibited a behavior typical of a mixed type corrosion inhibitor in the studied environment
according to the potentiodynamic polarization. Results from cyclic potentiodynamic polarization experiments
excluded pitting corrosion risk on the 316L stainless steel in the studied medium. Results from all applied
techniques are in good agreement
Adsorption and corrosion inhibition characteristics of 2–(chloromethyl) benzimidazole for C1018 carbon steel in a typical sweet corrosion environment: Effect of chloride ion concentration and temperature
Benzimidazole derivatives are emerging as promising corrosion inhibitors for oil and gas application because
they exhibit high efficiency and very good environmental profile. Although long alkyl and phenyl chains enhance
their efficiency, they also increase their toxicity. Finding benzimidazole derivatives devoid of long hydrocarbon
chains and with lower toxicity has become a priority. 2–(chloromethyl)benzimidazole (CMB), with log Po/w =
2.2, has been investigated as a promising low-toxic sweet corrosion inhibitor for C1018 carbon steel in
CO2–saturated NaCl solution under static condition using experimental and theoretical approaches. At 25 ◦C,
Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization
(PDP) techniques confirm that CMB is an anodic-type sweet corrosion inhibitor which is able to form a protective
layer on the steel surface and provide inhibition efficiency of 97.54% at 10 ppm. The efficiency increased to
98.40% and 98.58% upon increasing the temperature to 40 â—¦C and 60 â—¦C, respectively but decreased to 96.32%
and 94.76% as the salt concentration was raised to 5.0% and 7.0% NaCl, respectively. The latter was attributed
to the antagonistic competition between Cl– ions and CMB for anodic adsorption. The CMB–steel interaction is
facilitated by the free electrons around N heteroatoms and C = C bonds, based on FTIR analysis and computational calculations. This eventually ameliorates the surface degradation of the steel during the sweet
corrosion at 25 and 60 â—¦C. CMB performance is highly comparable with reported sweet corrosion inhibitors with
higher toxicity values
Pterocarpus santalinoides leaves extract as a sustainable and potent inhibitor for low carbon steel in a simulated pickling medium
The crude extract of Pterocarpus santalinoides leaves (PSLE) extracted using water, ethanol, and methanol as the
extraction solvent has been studied as inhibitor for low carbon steel in 1 moL/dm3 HCl solution using electrochemical
approaches at 25 �C and 60 �C. The results obtained reveal that, PSLE extract has the capacity to
effectively suppress the dissolution of the studied substrate. The inhibition performance of PSLE is a function of
concentration, temperature, and extraction solvent. Corrosion inhibition is in the order: ethanolic extract >
methanolic extract > aqueous extract. With 0.7 g/L PSLE, inhibition efficiency of >90% has been obtained at 60
�C. Based on calculated values of adsorption parameters and UV–vis results, it is proposed that PSLE molecules
chemically interacted with the substrate surface. PSLE extract suppressed both the rate of cathodic and anodic
reactions according to the PDP results. However, aqueous PSLE extract inhibited anodic corrosion reactions
predominantly while ethanolic and methanolic extracts mainly inhibited the cathodic corrosion reactions. Surface
characterization studies via SEM, EDAX, and AFM provide experimental evidence to the claim of interaction
and presence of PSLE molecules on the studied substrate surface
Investigation into the adsorption and inhibition properties of sodium octanoate against CO2 corrosion of C1018 carbon steel under static and hydrodynamic conditions
Sodium octanoate (Na-oct), a simple, naturally-abundant, cheap and low-toxic organic molecule has been investigated for its adsorption and inhibition properties against the CO2 corrosion of C1018 carbon steel in 3.5 % NaCl under static (0 rpm) and hydrodynamic conditions (1000 rpm). At open circuit potential (OCP) under static condition, a Langmuir-type adsorption of Na-oct modified the dielectric property of the steel-solution interface by lowering double layer capacitance and increasing resistance to charge transfer, based on electrochemical impedance spectroscopy (EIS) analysis. Under this condition, potentiodynamic polarization (PDP) analysis showed that Na-oct adsorbed more preferentially on anodic sites of steel surface and impacted ∼96 % inhibition efficiency. Hydrodynamic condition at 1000 rpm caused a Langmuir and Temkin adsorption mechanism and diminished the Na-oct efficiency to ∼86 %. FTIR characterization revealed that the inhibitor adsorption was enabled by its COO– functional group. Computational modeling, using DFT and MDS, confirmed the experimental findings