Preventing Corrosion with Plant-Based Extracts


A team of researchers recently reviewed several plant-based extracts as an environmentally friendly corrosion inhibitor for carbon steel in the oil and gas industry.

The study, authored by Basit Raza Fazal, Thomas Becker, Brian Kinsella and Katerina Lepkova, was recently published in the journal NPJ Materials Degradation.

Green Inhibitor Research

According to the study, because of its mechanical properties and low cost, carbon steel is the preferred material for pipeline construction. However, because of higher costs, it is not typically possible to replace carbon steel with corrosion resistant alloys and is highly susceptible to corrosion.

The team notes that the presence of carbon dioxide, hydrogen sulfide and organic acids, such as acetic acid, propionic acid and formic acid, is one of the leading causes of localized or pitting corrosion in oil and gas production.

With an increased focus on creating and using low-cost, biodegradable and environmentally inhibitor formulations, researchers analyzed plant extract-based green corrosion inhibitors that have been investigated to mitigate CO2 corrosion. Additionally, they reviewed extracts’ efficiency to prevent strong acid corrosion by HCl and H2SO4 since both are expected to also prevent weak acid corrosion from CO2.

Researchers looked at phytochemicals, or non-nutritive components that give a plant its smell, taste and color. Additionally, they can be extracted from various parts of a plant, including its fruit, leaves, bark roots, seeds or peels. The molecular structure of some of these phytochemicals resembled those of conventional synthetic organic corrosion inhibitors.

To study the plant extract and its corrosion prevention properties, researchers used various analysis techniques, including weight loss measurements and electrochemical techniques. Concentrated plant extracts were then diluted to prepare inhibitor solutions for tests.

In the review, the team looked at advances in research on plant extracts used as CO2-saturated corrosion inhibitors, such as:

  • Cashew nut;
  • Tridax procumbens and chromolaena odorata;
  • Kuding leaf;
  • Olive leaf;
  • Jatropha curcas oil;
  • Sida acuta;
  • Coptis chinensis and berberine;
  • Licorice extract;
  • Tobacco leaf;
  • Pomelo peel;
  • Calotropis procera leaf;
  • Corn oil;
  • Dimocarpus longan peel;
  • Gingko biloba; and
  • Momordica charantia seed.

Additionally, the researchers reviewed green inhibitors for carbon steel in acidic media, including sunflower seed hull, cocoa bark and maple leaf, among others.

Effective techniques to determine the most active ingredients in the plant extracts included conducting phytochemical screening and running molecular dynamic and quantum chemical simulations. It was also observed that most of the commercial inhibitor formulations were made up of a variety of chemical substances.

Since oil and gas are generated at high pressures and temperatures with corrosive gases like CO2, more rigorous lab testing at high temperatures, high pressure and shear test were required for field applications. In many of the studies, only  water-based electrolytes were tested for plant-extract-based inhibitors.

Based on the review, the team states that while a majority of plant-extract-based inhibitors provide adequate levels of protection, there is still a need to optimize the formulations. They suggest conducting phytochemical screening and performing quantum chemical and molecular dynamic simulations to identify the most active ingredient of the various phytochemicals present in a plant extract.

Additionally, the next step would be to study the synergism between active molecules to create an overall “superior” formulation, as most commercial inhibitor formulations are a blend of different chemical compounds.

“In short, there is an urgent need of suitable green inhibitors given the extensive use of mild steel and the resulting economical loss in the form of corrosion,” wrote the authors. “The development of an adequate and commercial plant-extract-based green inhibitor suitable for trialing in oil and gas fields appears to be a practically beneficial research area with great potential for innovation in inhibitor formulations.”


Tagged categories: Asia Pacific; Bio-based materials; Carbon dioxide; Carbon Steel; Coating Materials; Corrosion; Corrosion inhibitors; Corrosion protection; EMEA (Europe, Middle East and Africa); Environmental Controls; Environmentally friendly; Green chemistry; Green coatings; Latin America; North America; Oil and Gas; Pipeline; Pipelines; Plant-based coatings; Program/Project Management; Research; Research and development; Z-Continents

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