subject: Ethylene And Propylene Glycol Corrosion Inhibitors [print this page] It"s hard enough to describe the repeated failure of chillers in the food & beverage industry. It"s nothing but corrosion. It is the main culprit behind the whole story. In order to increase the efficacy of chiller systems we started using Mono Ethylene Glycol or Propylene Glycol instead of water in the chillers. But uninhibited Glycol may cause severe corrosion and hence may damage the chilling system too. Use of standard Uninhibited Ethylene Glycol and Propylene Glycol may lead to galvanic corrosion and failure of the system.
The threat of corrosion is increased by the use of standard but uninhibited Ethylene Glycol and Propylene Glycol due to the lack of corrosion inhibitors. Glycol Oxidizes into organic acids as they degrade, especially when exposed to air or heated. In turn, these acids lower the total solution"s pH level. In this acidic medium, the solution of Mono Ethylene Glycol or Propylene Glycol is more corrosive even than pure and plain water, when no corrosion inhibitors are added to the solution to buffer these acids and protect the system metal.
To fight with this corrosion related problems one can use Inhibited Mono Ethylene Glycol or Inhibited Propylene Glycol whenever and wherever necessary. These inhibited glycols are perfect blends of standard glycol and their corrosion inhibitor packages. They act as a buffer to those organic acids, prevent low pH attack on the system metal, maintain alkalinity of the solution and also passivate the metal surface to protect them from corrosion. Chemtex"s R&D team is rich enough in terms of technology to develop these anti- corrosive vaccines for system metal named Inhibited Ethylene Glycol and Inhibited Propylene Glycol.
Corrosion inhibitors are specially formulated chemical additive for Propylene Glycol to protect system metals from corrosion. It is a multi-metal corrosion inhibitor and prevents corrosion in multi-ways.
They modify metal surface by absorption and making it less susceptible to corrosion. It buffers the organic acids formed as a result of glycol oxidation and prevents further formation of acids. They are compatible and fully functional in glycol-water & glycol-ethanol (rectified spirit) mixtures and improves heat transferability.
Propylene Glycol oxidizes when exposed to air and heat. When this occurs, five organic acids viz., Glycolic, Glyoxalic, Formic, Carbonic and Oxalic Acid are formed. If not properly inhibited, this fluid gets very corrosive. These organic acids then chemically attacks and corrodes the system metal, causing pitting, pinhole and stress cracking corrosion.
Corrosion inhibitors are added to Propylene Glycol to act as buffer, preventing low pH attack on the system metal. It also passivates the metal surface to protect them from corrosion.
Benefits:-
Extends system metal life
Saves power and increases heat transfer efficiency
Increases life of Glycol by avoiding degradation
Does not affect Freeze protection properties
Does not form sludge deposit in the system
Avoids leakage and minimizes maintenance jobs
Avoids chances of Beverage, Brewery and Dairy batch losses due to PHE leakage
