A kind of preparation method of medicinal glacial acetic acid

Abstract

The invention discloses a preparation method of medicinal glacial acetic acid. The preparation method is characterized by comprising the following steps: (1) carrying out oxidization treatment: adding excessive hydrogen peroxide into a raw material industrial acetic acid to obtain an oxidized product; (2) carrying out molecular sieve absorption: enabling the oxidized product to pass through a ZSM-5 molecular sieve to obtain an impurity-removed product; (3) carrying out azeotropic distillation: adding an azeotropic agent into the impurity-removed product and putting a mixture into a rectifying tower and carrying out the azeotropic distillation, wherein the azeotropic agent is one of ethyl acetate, isopropyl acetate and butyl acetate; controlling tower top temperature to be 64 DEG C to 80 DEG C and collecting a kettle bottom product to obtain primary-grade glacial acetic acid; (4) absorbing water by copper sulfate: introducing the primary-grade glacial acetic acid into a copper sulfate absorption device and collecting a flowing-out product from the copper sulfate absorption device to obtain a product. The preparation method of the medicinal glacial acetic acid, disclosed by the invention, has the advantages of simple preparation method, energy saving and environmental friendliness; the medicinal glacial acetic acid is directly prepared from the industrial acetic acid and automatic control is realized; the obtained medicinal glacial acetic acid has high purity and meets the requirements of Chinese Pharmacopoeia.

Description

technical field [0001] The invention relates to a preparation method of medicinal glacial acetic acid. Background technique [0002] The liquid-phase carbonylation reaction of methanol is a kind of acetic acid production method widely used in industry, usually adopts rhodium or iridium as catalyst, and halogen compounds such as methyl iodide or hydrogen iodide are used as promoters, and the produced acetic acid contains formic acid, Impurities such as organic iodides, metal iodides, unsaturated compounds and carbonyl compounds. In order to obtain higher purity acetic acid, the industry generally adopts rectification method to purify acetic acid. Since the boiling point of acetic acid is close to that of water and formic acid, and water has low volatility relative to acetic acid, the rectification tower needs high trays. Number, the top of the tower needs to be provided with a larger reflux ratio, or it needs to be rectified multiple times step by step, so that the acetic ac...

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Problems solved by technology

In order to obtain higher purity acetic acid, the industry generally adopts rectification method to purify acetic acid. Since the boiling point of acetic acid is close to that of water and formic acid, and water has low volatility relative to acetic acid, the rectification tower needs high trays. The number and the top of the tower need to be set with a larger reflux ratio, or multiple rectification steps are required, so that the acetic acid obtained after purification is not only low in purity, but also requires large-scale equipment, consumes a lot of energy, and reduces production efficiency

[0003] However, medicinal glacial acetic acid not only has high requirements on the purity of acetic acid, but also has relatively strict requirements on the content of potassium permanganate reducing substances and heavy metals, which cannot be met by conventional purification methods.

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