Enhanced corrosion inhibition of mild steel in CO2-saturated solutions containing some novel green surfactants based on cottonseed oil

Abstract

Some novel green surfactants based on cottonseed oil were synthesized and tested as inhibitors for the corrosion of mild steel in CO 2 -saturated 1% NaCl solution by potentiodynamic polarization and linear polarization resistance corrosion rate measurements at 50°C. Their critical micelle concentrations at equilibrium in water at 25°C were also determined. Inhibition efficiency increased with increase in the concentration of the studied surfactants, reached the maximum (99.34%) at 100 ppm. The Tafel polarization results indicate that the inhibitors act as mixed inhibitors. The adsorption of the inhibitors on the steel surface obeys Langmuir isotherms. The thermodynamic parameters of adsorption revealed a strong interaction between the inhibitors and the corroding mild steel surface.

A Review of Recent Advances in the Inhibition of Sweet Corrosion

“…The vast majority of these studies investigated extracts obtained from various parts of plants, including roots, [31a] bark, [101] leaves, [30c,31b,78–79,90,112‐113] seeds, [30d,79e] and fruits (including the peel of certain fruits) [30c,71c,79b,88a–c,143] as CIs for steel in a CO 2 environment (Table S9 in Supplementary Material). It was also reported that natural products are used to either synthesize [37,104–105,107c,118b,119‐120,131a‐c,e,144] or modify other compounds [128c,f,131d] that have been tested as CIs in a CO 2 environment (Table S10 in Supplementary Material). In addition, the corrosion inhibition effectiveness of extracellular polymeric substances extracted from waste activated sludge [77] and berberine extracted from Coptis chinensis [67c] was evaluated for CS immersed in CO 2 ‐saturated 3.64 wt.% NaCl solution and for L360 steel immersed in CO 2 ‐saturated 3.5 wt.% NaCl solution, respectively.…”

Adsorption and corrosion inhibiting behavior of Passiflora foetida leaf extract on mild steel corrosion

“…Generally the values of ΔG ads up to -20 KJ/mol signify physisorption, which is consistent with electrostatic interaction between charged molecules and a charged metal. The values around -40 KJ/mol or higher involve charge sharing or transfer from the inhibitor molecules to the metal surface to form a co-ordinate type of bond [38][39][40][41]. In this study, the calculated values of ΔG ads are around -30 KJ/mol, indicating that the adsorption of mechanism of PFLE on mild steel in 1 M hydrochloric acid solution at the studied temperatures is both physisorption and chemisorption [41][42][43].…”

“…It has been found that values of ΔH ads are negative, suggesting that the adsorption of inhibitor is an exothermic process, which means lower inhibition efficiency at high temperature. This indicated the gradual desorption of inhibitors from the surface of mild steel [40]. All values of 0 ads S  are negative.…”

“…All values of 0 ads S  are negative. This behavior might be explained as follows: before the adsorption of inhibitor molecules onto the mild steel surface, inhibitor molecules might freely move in the bulk solution (inhibitor molecules were chaotic), but with the process of adsorption inhibitor molecules were orderly adsorbed onto the steel surface, as a result a decrease in entropy is observed [40,44].…”

Some surfactants based on the vegetable oils as CO2 corrosion inhibitors for mild steel in oilfield formation water

“…It has been acknowledged that CO 2 corrosion is one of major corrosion types resulting in oil well failure [1]. Due to the complexity of environment in oil well, CO 2 corrosion is dependent on various environmental conditions like temperature, CO 2 partial pressure, flow conditions and protective corrosion scales [2][3][4][5][6][7]. Corrosion inhibitors are the most effective and flexible mean of corrosion control in oil and gas production systems, but the selection and application of inhibitors are actually complicated because of the variable corrosive environments in these systems [8].…”