There has been an increased need to search for corrosion inhibitors that are safe and effective in various applications while minimizing their impact on the environment. This is especially true in the case of organic inhibitors that often have harmful side effects such as toxicity and bioaccumulation.
Green corrosion inhibitors are becoming increasingly popular amongst industrial professionals because of their ability to impart superior corrosion resistance while having a minimum impact on the environment. In recent years, plant based products such as tannins, alkaloids, amino acids and organic dyes have shown promising corrosion inhibition properties.
Some of the main features of these corrosion inhibitors include their high adsorption ability, low cost and toxicity, biodegradability and sustainability as well as being available and renewable. They have been used in numerous fields, including metallurgical, chemical, and oil and gas industries as well as in surface treatment for cultural heritage.
They are classified as anodic, cathodic and mixed types depending on the mode of action they take in suppressing the corrosion process. Typical anodic inhibitors work by forming a layer of oxide on the metal surface which prevents the diffusion of corrosive species onto the metal surface and therefore reduces its potential to corrode. Examples of anodic inhibitors include chromates, molybdates and nitrates.
The effectiveness of a corrosion inhibitor is determined by the relationship between the concentration of the inhibitor and the corrosion rate of the metal. This is a quantitative equation that involves the concentration of the corrosive agent and the water’s chemical properties, such as pH, temperature and flow velocity.
It has been found that anodic corrosion rates can be decreased with the application of a large amount of a corrosion inhibitor in water or other fluids. This decrease in corrosion rates is largely due to a reduction in the velocities of the anodic and cathodic electrode reactions.
There are several other aspects that need to be considered when choosing the right inhibitor for a specific application. Aside from efficiency, factors such as toxicity, safety to the environment and its species, cost, availability and ease of use also need to be considered.
In addition, a wide range of environmentally friendly corrosion inhibitors have been discovered. These compounds are derived from natural sources such as plant extracts, minerals, and amino acids. Some of the most promising green inhibitors are extracted from algae, mushrooms and other fungi.
These compounds are very cheap and readily available, so they have become an excellent choice for many applications. They also have the advantage of being biodegradable and can be easily composted or bio-reclaimed, thus minimizing the potential of contamination by these chemicals into the environment.
They are a useful tool in controlling the corrosion of metals and are important for securing pipes that are used in fuel and heating systems. These inhibitors can be dissolved in water and applied to the exposed surfaces of metals.
In addition, they can be incorporated into the materials used for the production of pipelines, tanks, pumps and other vessels that may be exposed to severe environments such as seawater. These are a cost-effective and eco-friendly way to prevent rusting, corrosion and other forms of damage to metals in such harsh conditions.