Table 3 Green corrosion inhibitors for preventing corrosion in hydrochloric acid solution sorted based on the lowest corrosion rate obtained from polarisation parameters.
From: A review of plant extracts as green corrosion inhibitors for CO2 corrosion of carbon steel
Plant extract | Steel specimen | Inhibitor concentration (at max. IE%) | Testing temperature (°C) | Uninhibited corrosion rate (mm y−1) | Inhibited corrosion rate (mm y−1) | Testing solution |
|---|---|---|---|---|---|---|
Sunflower seed hull | MS | 400 ppm | 25 | 3.509 | 0.054 | 1.0 M HCl |
Maple | A1010 LCS | 0.4 g/L (400 ppm) | 25 | 1.836 | 0.116 | 1.0 M HCl |
Cocoa bark | A1020 LCS | 1.112 g/L (1112 ppm) | 30 | 1.162 | 0.128 | 18.23 g/L HCl (0.5 M HCl) |
Griffonia simplicifolia seed | MS | 1000 ppm | 30 | 11.263 | 0.163 | 1.0 M HCl |
Maple | A1010 LCS | 0.4 g/L (400 ppm) | 25 | 1.140 | 0.163 | 1.0 M HCl |
Pisum sativum peel | MS | 0.4 g/L (400 ppm) | 30 | 2.754 | 0.349 | 1.0 M HCl |
Gentiana olivieri | MS | 800 mg/L (800 ppm) | 20 | 3.509 | 0.349 | 0.5 M HCl |
Longan peel | MS | 600 mg/L (600 ppm) | 25 | 4.934 | 0.349 | 0.5 M HCl |
Aquilaria subintegra leaf | MS | 1500 ppm | 30 | 3.277 | 0.372 | 1.0 M HCl |
Ginkgo biloba leaf | X70 | 200 mg/L (200 ppm) | 30 | 4.047 | 0.403 | 1.0 M HCl |
Glycyrrhiza glabra leaf | MS | 800 ppm | 25 | 3.026 | 0.467 | 1.0 M HCl |
Griffonia simplicifolia seed | J55 | 1000 ppm | 30 | 7.145 | 0.482 | 1.0 M HCl |
Griffonia simplicifolia seed | X80 | 1000 ppm | 30 | 8.061 | 0.578 | 1.0 M HCl |
Phyllanthus amarus leaf | MS | 4 v/v % (40,000 ppm) | 30 | 12.270 | 0.593 | 1.0 M HCl |
Pennisetum purpureum grass | MS | 5.0 g/L + 0.1 mol/L KI (5000 ppm + 16,600 ppm KI) | 30 | 16.153 | 0.634 | 3.5% HCl (1.0 M HCl) |
Ginkgo biloba leaf | X70 | 200 mg/L (200 ppm) | 30 | 8.399 | 0.727 | 1.0 M HCl |
Plantago ovata | A1020 LCS | 1000 ppm | 30 | 14.042 | 1.050 | 1.0 M HCl |
Ginkgo biloba leaf | X70 | 200 mg/L (200 ppm) | 30 | 14.432 | 1.125 | 1.0 M HCl |
Phyllanthus amarus leaf | MS | 4 v/v % (40,000 ppm) | 30 | 40.111 | 1.871 | 1.0 M HCl |
Phyllanthus amarus leaf | MS | 4 v/v % (40,000 ppm) | 30 | 42.052 | 14.908 | 1.0 M HCl |
