The physicochemical properties and preparation method of hydroxysuccinic acid

Hydroxysuccinic acid

[Structural formula]

[Physical and chemical properties] Hydroxysuccinic acid, also known as malic acid

As a sour agent, malic acid is widely used in the beverage and food industries.

[Preparation]

(1) Catalytic oxidation of benzene to obtain maleic acid and fumaric acid , which are then hydrated under high temperature and high pressure

Although malic acid can be extracted from the fruits of natural plants such as apples and can also be prepared by fermentation, from an economic point of view, the most competitive method is to hydrate maleic acid or fumaric acid to produce malic acid

There is still a small amount of unreacted maleic acid, and then after a series of separation and refining, malic acid is obtained

EP0515345 introduces an improved method, in the presence of sodium ions or calcium ions, maleic acid, fumaric acid or their mixtures are hydrated at a temperature of 160～220℃, and a pressure of 10～15kgf/cm ² (1kgf/cm ² = 98.

(2) Chinese patent 98111387.

Take 750 mL of the decolorized maleic acid solution with a mass concentration of 49%, react for 4 hours at a temperature of 160°C and a pressure of 0.

The process has no catalytic reaction, the yield of fumaric acid is 40%-50%, and the yield of malic acid is 20%-50%.

(3) Chinese patent CN1560016A introduces another preparation method of hydroxysuccinic acid

The malic acid synthesis solution is subjected to anion exchange to remove maleic acid according to the traditional method, activated carbon to adsorb and remove fumaric acid and pigments, and cation exchange to remove cations to obtain a malic acid purification solution, which is concentrated and crystallized to obtain high-quality malic acid

[Technical Index]

[Application] In an aqueous solution with appropriate pH value, malic acid can form a complex or chelate with metal ions.

Malic acid can be used alone with other organic acids