Glacial acetic acid preparation method detailed explanation

Glacial acetic acid (also known as anhydrous acetic acid) is an important chemical raw material in the chemical industry and is widely used in the production of plastics, fibers, synthetic resins and pharmaceuticals. This article will detail the different answers to the question "the preparation method of glacial acetic acid is" to help you understand the production process of this common chemical.

What is glacial acetic acid?

Glacial acetic acid, whose chemical formula is CHLover COOH, is a colorless liquid with a strong sour taste. It is a strong acid that is miscible with water and alcohols. Glacial acetic acid is mainly used in the synthesis of acetate compounds, acetate fiber and the synthesis of acetic acid derivatives. In industrial production, glacial acetic acid is obtained through several different preparation methods. We will analyze these methods one by one.

Traditional glacial acetic acid preparation method: ethylene method

One of the traditional answers to the question "the preparation method of glacial acetic acid" is to produce it by the ethylene method. The ethylene method mainly relies on the reaction of ethylene (C? H? H?) with oxygen in the presence of a catalyst to produce acetic acid. The reaction formula for this process is:

[ C2H4 O2 → CH3COOH ]

this process is usually carried out under high temperature and high pressure conditions, and the catalyst used is generally a noble metal catalyst such as palladium (Pd) or rhodium (Rh). The acetic acid obtained by the reaction is further dehydrated by a water absorbing agent to obtain anhydrous glacial acetic acid.

Ethylene Method Advantages and Limitations

The main advantage of the ethylene method is that the reaction conditions are relatively stable, the reaction rate is fast, and a large amount of glacial acetic acid can be produced. However, the disadvantages of the ethylene method cannot be ignored. Ethylene is a by-product of petrochemicals, and its price fluctuates greatly with the price of crude oil; the service life of the catalyst is limited and it needs to be replaced regularly, which increases the production cost.

Modern glacial acetic acid preparation method: methanol method

In addition to the ethylene process, the methanol process has become the mainstream technology for the production of glacial acetic acid in recent years. The basic principle of the methanol method is to react methanol (CHalphaOH) with carbon monoxide (CO) to produce acetic acid. The reaction formula is as follows:

[ CH3OH CO → CH3COOH ]

this process is usually carried out in a high-temperature, high-pressure environment using palladium or rhodium as a catalyst. Compared with the ethylene method, the methanol method has a wider range of raw material sources, especially suitable for methanol as a low-cost chemical raw material areas.

Methanol Method Advantages and Limitations

The biggest advantage of the methanol method is that the source of raw materials is abundant, and it can use natural gas, coal and other resources to produce methanol, thus providing a more stable supply for the production of glacial acetic acid. The use efficiency of the catalyst in the methanol process is high, which reduces the frequency of catalyst replacement.

The methanol method also has some limitations. The reaction process requires a high temperature and high pressure environment, so it requires a large energy input; some by-products may be produced during the reaction process, which require further separation and treatment, increasing the complexity of production.

Green environmental protection preparation method: biological fermentation method

With the improvement of environmental awareness, biological fermentation has gradually become a promising preparation method. The biological fermentation method is to use specific microorganisms to ferment ethanol to produce acetic acid, and then extract glacial acetic acid by distillation and other means. This method is not only environmentally friendly, but also rich in raw materials.

Biological Fermentation: Advantages and Limitations

The biggest advantage of biological fermentation is its environmental friendliness and low raw material cost. Because the operating conditions of this method are relatively mild, and the environmental pollution is less, it has a high potential for green development. The production speed of biological fermentation is slow and the yield is low, so it is difficult to meet the needs of large-scale industrial production.

Conclusion: Glacial acetic acid preparation method selection

To sum up, the answer to the question "the preparation method of glacial acetic acid is" depends on the specific production needs, raw material costs and environmental protection requirements. The traditional ethylene method is suitable for plants with high yield requirements, while the methanol method has obvious advantages in raw material diversity and stability. With the progress of technology, biological fermentation is expected to become a green and sustainable production method, but it still faces the challenge of large-scale production. In actual production, enterprises need to choose the appropriate preparation method according to the specific situation to maximize economic and environmental benefits.

I hope that through the introduction of this article, you have a clearer understanding of the preparation method of glacial acetic acid.