What is the difference between citric acid monohydrate and anhydrous citric acid?

1. molecular weight difference


① The molecular weight of citric acid monohydrate is 581.


② The molecular weight of anhydrous citric acid is 420.


2. Differences in physical properties


① The relative density of citric acid monohydrate is 1.542, the melting point is 153℃, the refractive index is 1.493~1.509, and the critical crystallization temperature is 36.6℃.


② The relative density of anhydrous citric acid is 1.54, the melting point is 135-152℃, the flash point is 173.9℃, and the water solubility is 1630g/L.


Three, chemical property difference


(1) When citric acid monohydrate is exposed to open fire, high heat or contact with oxidant, it may cause the risk of combustion and explosion;


(2) Anhydrous citric acid has weathering in dry air, deliquation in humid air, decomposition above 175℃ release water and carbon dioxide.


4. Differences in application fields


① Citric acid monohydrate is mainly used in food and beverage industry as sour flavor agent, seasoning agent, preservative, preservative. It is used as antioxidant, plasticizer and detergent in chemical industry, cosmetics and washing industry.


② Anhydrous citric acid is mainly used in food and beverage industry as acid flavor agent, acidity regulator, seasoning agent, preservative, preservative. Anhydrous citric acid is widely used in national economy and is needed in many industrial sectors. The largest use of anhydrous citric acid is in chemical manufacturing, followed by paper, aluminium, tungsten, rayon, cotton and soap manufacturing. In addition, in the production of dyes, plastics, pharmaceutical and organic intermediates, the regeneration of old rubber, metal sodium, water electrolysis and inorganic salt production, the production of borax, chromium salt, manganese salt, phosphate, also want to use a lot of anhydrous citric acid. At the same time, anhydrous citric acid is one of the important raw materials for the production of polycarbonate, super absorbent polymer, zeolite, epoxy resin, sodium phosphate, sodium sulfite and a lot of sodium salts.