How to prepare sulfuric acid: chemical industry key process and technology

As an important chemical raw material, sulfuric acid (H₂ SO?) is widely used in many industries such as chemical industry, metallurgy, petroleum processing, and medicine. "How to prepare sulfuric acid" has become an important industrial problem. In this paper, the main methods, technological processes and applications of preparing sulfuric acid will be analyzed in detail.

1. Sulfuric acid main preparation method

There are two main methods for the preparation of sulfuric acid: contact method and lead chamber method. In modern industry, the contact method is the most common mode of production, which has higher production efficiency and lower environmental pollution. We will introduce these two methods separately.

contact method

The contact method is currently the most commonly used method for the preparation of sulfuric acid in the world. The basic principle is to react sulfur dioxide (SO) with oxygen in the air under the action of a catalyst to generate sulfur trioxide (SO), and then dissolve SO in water to generate sulfuric acid. Specific steps include:

1. Sulfur dioxide preparation: sulfur-containing raw materials (such as sulfur ore, oil, etc.) by incineration and other means to generate sulfur dioxide.
2. Sulfur dioxide oxidation: through the catalyst (such as vanadium pentoxide) so that sulfur dioxide and oxygen reaction to produce sulfur trioxide.
3. Sulfur trioxide dissolution: sulfur trioxide and water vapor reaction, and finally get concentrated sulfuric acid.

This method is economical because it uses a high-efficiency catalyst and can carry out the reaction at a lower temperature and pressure.

lead chamber method

The lead chamber method is an earlier sulfuric acid production process. Although it is gradually replaced by the contact method, it is still used in some special applications. The basic principle of this method is to generate sulfur dioxide through the process of oxidizing sulfur, and then use the special design of the lead chamber to cool and deposit sulfuric acid, and finally generate sulfuric acid. The advantage of this method is that the process is simple and suitable for the production environment where the demand for sulfuric acid is small.

2. Sulfuric acid production in the important control factors

In the production process of sulfuric acid, in addition to selecting the appropriate preparation method, many factors need to be paid attention to to ensure the stability of the production process and the quality of sulfuric acid.

Temperature control

In the contact process, the reaction temperature is a key factor in determining the conversion of sulfur dioxide and the quality of the product. Too high or too low temperature will affect the reaction efficiency, so it is necessary to accurately control the reaction temperature. In general, during the contact reaction, the temperature is maintained between 450 and 500 ° C. in order to ensure the reaction rate and the activity of the catalyst.

Catalyst Selection

The catalyst used in the contact process, such as vanadium pentoxide, has a decisive effect on the reaction rate and the reaction effect. The quality and activity of the catalyst are directly related to the efficiency and cost of sulfuric acid production, so it is very important to choose the right catalyst. The life and regeneration of the catalyst is also a key point to improve the efficiency of sulfuric acid production.

Reaction gas purification

In the process of sulfuric acid production, the waste gas produced may contain harmful gases, such as sulfur dioxide, nitrogen oxides, etc. These waste gases must be purified before they can be discharged into the environment. Common purification methods include the use of scrubbers, desulfurization towers and other equipment to convert harmful gases into harmless substances to meet environmental requirements.

3. Sulfuric acid application and importance

Sulfuric acid has an important application in modern industry, mainly used in the following aspects:

fertilizer production

Sulfuric acid is one of the important raw materials for the production of phosphate fertilizer and nitrogen fertilizer. In the production of phosphate fertilizer, sulfuric acid reacts with phosphate rock to form phosphoric acid, which is further used to prepare various phosphate fertilizers. The demand for sulfuric acid occupies an important position in agriculture.

metal smelting

Sulfuric acid also plays an important role in metal smelting, especially in the extraction process of copper, lead, zinc and other metals. By reacting sulfuric acid with metal ore, metal elements can be effectively extracted and smelting efficiency can be improved.

Petroleum Refining

In the process of petroleum refining, sulfuric acid is widely used as catalyst and reaction medium in petroleum cracking and desulfurization process. By using sulfuric acid, impurities in petroleum can be effectively removed and the quality of petroleum products can be improved.

4. How to prepare sulfuric acid: summary

The preparation of sulfuric acid is not only a simple operation of chemical reaction, but also involves many technologies such as catalyst selection, temperature control and exhaust gas treatment. Whether the contact method or the lead chamber method is used, scientific and reasonable process design and equipment configuration are very important. When choosing a suitable production method, we should not only consider the production efficiency, but also pay attention to environmental protection and resource utilization.

As a basic chemical raw material, sulfuric acid is widely used in agriculture, metallurgy, petroleum and other industries, and its production process and technical level directly affect the development of related industries. Therefore, the problem of "how to prepare sulfuric acid" is not only related to the development of chemical industry, but also related to the sustainable development of social economy.