# Review on Corrosion Inhibitors for Oil and Gas Corrosion Issues
## 4 Green-Based Corrosion Inhibitors
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**Details** & **Gap** & **Reference/Year** \\ \hline (a) Borage flower & Limitation: Constant temperature (25 °C) & [83]/2019 \\ (b) Experiments: Weight loss, EIS, surface analysis (c) Parameters: Concentration (200, 400, 600, 800 ppm) and immersion time (0.5, 2.5, 5.0 h) & Remark: Vary the temperature from 25 up to 90 ° \\ (d) Results: 800 ppm; 2.5 h; 91\% IE & & \\ \hline (a) Rice straw extract & Limitation: Constant temperature (25 °C) used throughout 42 days & [84]/2019 \\ (b) Experiments: Weight loss, surface and morphology analysis, and electrochemical test & Remark: Vary the temperature from 25 up to 90 °C & \\ (c) Parameters: Immersion time (7, 14, 21, 28, 35, 42 days) at room temperature (25 °C) & & Remark: Vary the temperature from 25 up to 90 °C \\ (d) Results: Immersion time of 7 to 14 days and 85\% IE & & \\ \hline (a) _Glycyrhizing alpha_ (Pa and bean family) leaves (b) Experiments: EIS, surface characterization (c) Parameters: Concentration of inhibitor (200, 400, 600, 800 ppm) & Limitation:Constant immersion time (24 h) used throughout experiment & [85]/2018 \\ (d) Results: 800 ppm gave 88\% IE & Remark: Vary the immersion time from 3 up to 30 days & \\ \hline (a) Lemon balm extracts (b) Experiments: Characterization technique (LBE, EIS, surface analysis) (c) Parameters: Inhibitor concentration (200, 400, 600, 800 ppm) and immersion time (0.5, 2, 4, 6, 12, 24 h) & & \\ (d) Result: 800 ppm with immersion time of 24 h and 94.6\% IE & & \\ \hline (a) _Ficus religios_ (leaf, bodhi tree) (b) Experiments: EIS, gravimetric measurements, quantum chemical study, SEM (c) Parameters: Temperature (25, 35, 45 °C), inhibitor concentration (100–500 ppm) (d) Results: 50 ppm gave 88.29\% IE at 25 °C & & [86]/2018 \\ (a) _Myristic fragments_ (nutmeg fruit) (b) Experiments: Weight loss, UV-vis spectroscopy, FT-IR spectroscopy, NMR analysis, quantum chemical studies, SEM (c) Parameter: Inhibitor concentration (100, 200, 300, 400, 500 ppm) & Limitation: Constant immersion time (24 h) used throughout experiment & [86]/2018 \\ D) Results: 500 ppm gave 87.81\% IE & & \\ \hline (a) _Ficus religios_ (leaf, bodhi tree) (b) Experiments: EIS, gravimetric measurements, quantum chemical study, SEM (c) Parameters: Temperature (25, 35, 45 °C), inhibitor concentration (100–500 ppm) (d) Results: 50 ppm gave 88.29\% IE at 25 °C & & \\ \hline (a) _F Myristic fragments_ (nutmeg fruit) (b) Experiments: Weight loss, UV-vis spectroscopy, FT-IR spectroscopy, NMR analysis, quantum chemical studies, SEM (c) Parameter: Inhibitor concentration (100, 200, 300, 400, 500 ppm) & Limitation: Constant temperature (25 °C) and immersion time (24 h) & [88]/2018 \\ D) Results: 500 ppm gave 87.81\% IE & Remark: Vary the temperature from 25 up to 90 °C and extend the immersion time from 3 up to 30 days & Remark: Vary the temperature from 25 up to 90 °C and extend the immersion time from 3 up to 30 days & [88]/2018 \\ \hline \hline \end{tabular}
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Table 1: Summary of research gaps for plant-based green corrosion inhibitors from 2010 to 2019. -Note: EIS-Electrochemical impedance spectroscopy; IE- inhibition efficiency; FTIR- fourier transformed spectroscopy _Appl. Sci._**2020**, _10_, 3389