How to produce acetic acid: from traditional methods to modern technology of comprehensive analysis

Acetic acid is a very important chemical raw material in the chemical industry, which is widely used in food, medicine, textiles, plastics and chemical synthesis. It is one of the production bases of ethylene, vinyl acetate and other chemicals, so the production technology of acetic acid has always been the focus of research in the chemical industry. How to produce acetic acid? This article will be from the traditional synthesis methods to modern efficient production technology, a comprehensive analysis of the production process of acetic acid.

1. Acetic acid production method overview

There are two main methods for the production of acetic acid: the traditional wood dry distillation method and the modern ethylene method. With the development of chemical technology, the ethylene method has gradually replaced the wood dry distillation method and become the mainstream process for the production of acetic acid.

Traditional method: wood dry distillation method

Early production of acetic acid using wood dry distillation method, the use of wood at high temperature decomposition of acetic acid containing gas. Although this method has been applied in the early stage of industry, the yield is low and the operation is complicated. With the emergence of other efficient methods, this traditional method is gradually eliminated.

2. Ethylene method: modern acetic acid mainstream production process

In the modern chemical industry, the most commonly used acetic acid production method is the ethylene method. This method mainly generates acetic acid through the reaction of ethylene and oxygen, which has the characteristics of high yield and simple process.

ethylene oxidation method

The core process of the ethylene method is the ethylene oxidation reaction, in which ethylene (C₂ Halready) reacts with oxygen (O₂) under the action of a catalyst to produce acetic acid. The chemical equation for this reaction is as follows:

[C2H4 O2 \rightarrow CH3COOH]

the process is mainly divided into two stages: ethylene and oxygen under the action of catalyst to produce vinyl acetate; then, through the hydrogenation reduction reaction to obtain acetic acid. The ethylene method not only improves the yield, but also reduces the dependence on raw materials, making it the most commonly used acetic acid production process.

The Ethylene Advantage

1. Efficiency: The ethylene method can produce a large amount of acetic acid in a short reaction time, and the yield is high.
2. Low cost: Because ethylene is extracted from petroleum or natural gas, the raw material source is stable and the cost is relatively low.
3. Environmentally friendly: using modern catalyst technology, ethylene by-products are less, and exhaust emissions are effectively controlled.

3. Acetic acid production process

To understand how to produce acetic acid, in addition to know the production method, but also need to understand the specific process. Taking the ethylene method as an example, the production process of acetic acid can be roughly divided into the following main steps:

Reaction stage

Ethylene and oxygen enter the reactor first, and the catalyst (such as molybdenum or ruthenium catalyst) promotes the reaction of ethylene and oxygen at a certain temperature and pressure to generate vinyl acetate. The reaction is typically carried out at elevated temperatures to increase the reaction rate and yield.

generate acetic acid

Next, vinyl acetate is subjected to a hydrogenation reduction reaction to generate acetic acid. The process requires the use of hydrogen and is catalyzed by a specific catalyst, such as a copper-based catalyst.

Distillation and separation

After cooling, the reaction product enters the separation column for rectification. The distillation tower separates and purifies acetic acid from other by-products (such as water, ethylene, etc.) through the boiling point difference of different components, and finally obtains high purity acetic acid.

4. Emerging technologies: methanol method and biological method

In addition to the traditional ethylene method, methanol method and biological method have gradually received attention in recent years, and have been applied to acetic acid production by some advanced chemical enterprises.

methanol method

The methanol method mainly synthesizes acetic acid by methanol (CHYOH) and carbon monoxide (CO) under the action of a catalyst. The production process of this method is relatively simple, but requires a stable supply of methanol.

biological law

Biological method is the use of microbial fermentation of organic matter (such as glucose, lignin, etc.) into acetic acid. Although biological methods still have challenges in terms of efficiency and cost, they are gradually being applied as a sustainable production method.

5. Summary: How to choose the right acetic acid production method?

The problem of how to produce acetic acid actually depends on many factors such as production scale, raw material cost, and environmental protection requirements. Ethylene is still the mainstream process due to its high efficiency and low cost. Methanol and biological laws show their unique advantages in certain situations, especially in environmental protection and sustainable development.

Regardless of the method chosen, the production of acetic acid requires a high degree of technical support and precise process control. With the development of technology, the future acetic acid production process will be more efficient and environmentally friendly to meet the growing market demand for acetic acid.