Anhydrous citric acid is an important weak organic acid. It has the advantages of mild acidity, strong chelating ability, and easy biodegradability, and has become a “multifunctional raw material” in industrial production and people’s lives, with its functions covering many key links such as cleaning, process control and water treatment.
Its core functions are primarily acidity regulation and descaling. Its acidity is mild yet potent, quickly neutralizing alkaline scale (such as calcium carbonate and magnesium hydroxide) in boilers and pipelines to form soluble citrate, thus achieving highly efficient descaling. Simultaneously, its corrosiveness to metal equipment is far lower than that of inorganic acids, making it particularly suitable for in-situ cleaning (CIP) systems in the food and beverage industry. After cleaning tanks and pipelines, residues are easily rinsed off, meeting food safety standards. Secondly, it can chelate metal ions. The hydroxyl and carboxyl groups in its molecule can firmly “capture” metal ions such as calcium, magnesium, and iron, forming stable complexes. In industrial circulating water systems, this prevents scale formation and slows equipment corrosion; in electroplating solutions, it stabilizes metal ion concentration, ensuring a uniform and bright coating; in textile printing and dyeing, it eliminates the interference of metal ions on dye color. Furthermore, it can form a pH buffer system with sodium citrate, stabilizing the solution’s pH within the critical range of 3-6, providing a stable environment for pH-sensitive processes such as electroplating and bio-fermentation.
Its applications are widespread across multiple industries: in industrial cleaning, it is a core component of chemical cleaning agents for boilers, heat exchangers, and reverse osmosis membranes; in the water treatment industry, it serves as an environmentally friendly scale inhibitor, replacing phosphorus-based agents for scale inhibition in circulating water, and can also adjust the pH of wastewater and assist in the removal of heavy metal ions; in electroplating and metal processing, it is used to formulate plating solutions and metal pickling, improving surface treatment quality; in the textile and leather industry, it adjusts pH in bleaching and tanning processes, enhancing fabric feel and leather softness; in the food and pharmaceutical fields, it is used as a legal additive to adjust the acidity and flavor of beverages and jams, or for pH control in effervescent tablets and oral liquids. Its safe, efficient, and multifunctional characteristics make anhydrous citric acid irreplaceable in various fields.
