# Review on Corrosion Inhibitors for Oil and Gas Corrosion Issues
## 4 Green-Based Corrosion Inhibitors
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Details** & **Gap** & **Reference/Year** \\ \hline (a) Sunflower seed hull (flower) & Limitation: Constant & [89]/2018 \\ (b) Experiments: FT-IR, UV-vis & immersion time (24 h) used & \\ (c) Parameters: Inhibitor concentration (50, 100, 200, 300, 400 ppm) & throughout experiment & \\ and temperatures (25, 40, 50, 60 \({}^{\circ}\)C) & Remark: & \\ (d) Result: 400 ppm gave 98.46\% IE at 60 \({}^{\circ}\)C & Vary the immersion time from & \\  & 3 up to 30 days & \\ \hline (a) _Gongronena latifolium_ (utazi, herb) & Limitation: Immersion time & [90]/2018 \\ (b) Experiments: Gasometric method & was not stated in this article, & \\ (c) Parameters: Inhibitor concentration (50, 100, 250, 500, 1000 ppm) & and only one major & \\ and temperature (30, 40, 50, 60 \({}^{\circ}\)C) & experiment was carried out & \\ (d) Results & Remark: & \\ i. EECL: 1000 ppm gave 93.7\% IE at 30 \({}^{\circ}\)C & Immersion time should be & \\ ii. SEGL: 1000 ppm gave 96.5\% IE at 50 \({}^{\circ}\)C & tested from 3 up to 30 days & \\ \hline (a) _Zizyphus lotuse_ (lotus) & Limitation: Constant & [91]/2018 \\ (b) Active ingredients: Vitamin C (ascorbic acid), linoleic acid, & immersion time (24 h) used & [91]/2018 \\ oleanolytic acid, flavonoid compound, triterpeneonic acid, jujuboside & throughout experiment & \\ (c) Experiments: Electrochemical methods, potentiodynamic & Remark: & \\ polarization, SEM and EDS analysis & Vary the immersion time from & \\ (d) Parameters: Concentration of inhibitors (0.05–2 g L\({}^{-1}\)) and & 3 up to 30 days & \\ Temperatures (25, 35, 45, 55 \({}^{\circ}\)C) & & \\ (e) Results: & \\ i. Concentration effect: 1000 ppm gave 93\% IE & & \\ ii. Temperature effect at 1000 ppm: 25 \({}^{\circ}\)C; 93.16\% IE & & \\ (a) _Xanthin strumarium_ (cocklebur) leaf extract & Limitation: Constant & [92]/2018 \\ (b) Experiments: SEM, FTIR, weight loss & immersion time (24 h) used & \\ (c) Parameters: Inhibitor concentration (200, 400, 600, 800, 1000 ppm) and temperature (30, 40, 50, 60 \({}^{\circ}\)C) & & \\ (d) Results: 1000 ppm gave 94.82\% IE at 60 \({}^{\circ}\)C & Vary the immersion time from & \\  & 3 up to 30 days & \\ \hline (a) _Cuscuta reflexua_ (morning glory family, fruit extract) & Limitation: Constant & [93]/2018 \\ (b) Experiments: Weight loss, electrochemical measurement, & immersion time (24 h) used & \\ UV-visible spectroscopy, FT-IR spectroscopy, surface analyses, & throughout experiment & \\ quantum chemical studies & Remark: & \\ (c) Parameter: Inhibitor concentration (100, 200, 300, 400, 500 ppm) & Vary the immersion time from & \\ (d) Results: 500 ppm gave 95.47\% IE & 3 up to 30 days & \\ \hline (a) _Taraxacuum officinal_ (dandelion, flower) & Limitation: Constant & [94]/2018 \\ (b) Experiments: Weight loss, Thermometric measurements, & immersion time (24 h) used & \\ Electrochemical measurements, Gravimetric & throughout experiment & \\ (c) Parameters: Type of crude (saponins—STOL; & Remark: & \\ flavonoids—FETOL; alkaloids—AETOL) and inhibitor & Vary the immersion time from & \\ concentration (10, 30, 70, 150, 300 ppm) and temperature (25, 40, 60 \({}^{\circ}\)C) & & \\ (d) Results & & \\ i. Gravimetric & & \\ AETOL & & \\
300 ppm; 99.3\% IE & & \\ ii. Thermometric & & \\ AETOL & & \\
300 ppm; 25 \({}^{\circ}\)C; 98.2\% IE & & \\ iii. EIS & & \\ AETOL; 79.0\% IE & & \\ \hline (a) _Tridax procumbens_ (daisy flower) and Chromolaena odorata & Limitation: Constant & [95]/2018 \\ (Christmas bush-leaf) & temperature (40 \({}^{\circ}\)C) and & immersion time & \\ (b) Experiments: EIS and adsorption isotherm & & \\ (c) Parameters: Inhibitor concentration (100, 200, 300, 400 ppm) & Remark: Vary the temperature & \\  & from 25 up to 90 \({}^{\circ}\)C and the & immersion time from 3 up to \\  & 30 days & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: \(Cont.\)