Acid Corrosion Inhibitor for Citric Acid and EDTA

Acids in any case are corrosive and degrades metallic surfaces over time. Almost all the acids bear oxidizing property and reduce metallic ions whenever they take part in a reaction. The presence of free hydrogen ions in acids make way for the redox reaction to occur, resulting in the corrosion of metals. The corrosive property of an acid can be determined by the level of damage it causes to the metal surfaces upon contact. Generally, chemicals with lower pH values or higher pH values are corrosive in nature.

Citric acid, Acetic Acid, EDTA are all presumed to be in the category of weak organic acids having higher pH value, in the world of chemicals but still shows some corrosive property on steel, brass, copper and other soft metals.

pH refers to the power or rather potential of hydrogen. It is used for quantification of acidity or alkalinity of a chemical in terms of concentration of Hydrogen Ion (H+).

Citric Acid, when reacts with these soft metal ions form a series of reactions where the metal loses its electrons, getting oxidized in the way. The H+ ions of citric acid get reduced to be liberated as hydrogen. These metal ions’ oxidation is the prime reason for the metallic corrosion. Similarly, in case of EDTA, at higher temperatures roughly in the range of 60-150°C, corrosive property of the same is observed. EDTA is a vital chemical used in boiler and heat transfer system (Read: metallic structure) as a chelating agent. In Heat Transfer System (HTS), the temperature can sometimes rise up to highest level as well as can drop to the lowest level. EDTA demonstrates reduction properties at higher temperatures even if there is no presence of oxygen, ultimately resulting in corrosion of HTS surface. The rate of corrosion may be low or high but it has a cut down effect on the efficiency of the system irrespective of the conditions.

Citric acid and EDTA are mostly used in applications of acid cleaning, as an agent to remove unwanted dirt build ups, spots, mild stains etc. These acids find its place among the top acid cleaners and are popular chelating agents owing to its organic nature, its high pH and relatively having less corrosive properties on base metals and it’s the only reason why organic acid cleaners are replacing mineral acids. Nonetheless, acids are oxidizing in nature and will lead to corrosion of metals, may be slowly but it will. Since these weak acids are used in cleaning applications, its necessary that these metal surface be protected from their slow corrosive activities. Acid inhibitors can be used or applied over these metal surfaces during cleaning applications. What these inhibitors will do is, it will form an inhibiting layer over the application surface which in turn will make the surface inert against any type of oxidizing reaction.

Range of acid corrosion inhibitors manufactured by Chemtex Speciality Limited meets the standard industry requirements, and ensuring smooth functioning of the application system. A blend of unique low foaming corrosion inhibiting chemical compounds that prevent corrosive action of citric acid, bisulphate solution and EDTA and conditionally for HCl, thereof on the metal surface during cleaning and descaling operations on steel, brass and copper alloys of medium and high pressure boiler internals against the pickling agents, its assured benefits are :

• Modifies metal surface preventing corrosion
• Excellent wetting properties for better cleaning
• Enhances cleaning efficiency
• With regular usage, metal wastage is reduced
• Saves money and labor
• Prevents exorbitant maintenance costs

Know more at www.chemtexltd.com

The name Chemtex depicts Chemical Technology Experts. The early 1970s saw the foundation of Chemtex. And in the following decades, it expanded with its variety of indigenous chemicals and industries catered.