How to deal with the common by-products (such as propylene glycol, chloride) in the production of propylene oxide?

Propylene oxide is an important basic chemical raw material, which is widely used in the manufacture of polyurethane, epoxy resin and other fields. In the production process of propylene oxide, some by-products, such as propylene glycol and chloride, will inevitably be produced. If these by-products are not properly treated, they will not only cause pollution to the environment, but may also affect the safety and efficiency of the production process. This paper will discuss in detail the treatment of by-products in the production of propylene oxide and its significance.

1. Propylene oxide production of common by-products

The main production methods of propylene oxide include chlorination and oxidation. Among them, the chlorination method is still the mainstream process due to the mild reaction conditions and mature process. A large number of by-products are produced in the process of producing propylene oxide by chlorination, mainly including propylene glycol and chloride. Propylene glycol is a colorless liquid with good solubility and moisture retention, and is usually isolated as a by-product. Chlorides mainly include hydrogen chloride and organic chlorides. If these substances are discharged directly without treatment, they will pose a serious threat to the environment and human health.

2. By-product treatment techniques and methods

For the treatment of by-products in the production of propylene oxide, the following methods are mainly used at present:

(1) Fractional separation of propylene glycol

Propylene glycol, as an important by-product in the production of propylene oxide, can be separated and purified by fractionation. Fractional distillation is a separation technique based on the difference in boiling points of substances and is suitable for the treatment of low-boiling by-products. In the fractionation process, propylene glycol is separated from other impurities, and finally a high purity propylene glycol product is obtained. This part of propylene glycol can be sold as a by-product for the production of antifreeze, plasticizers and other fields, so as to realize the recycling of resources.

(2) Chemical oxidation treatment of chloride

The treatment of chlorides is relatively complex, especially the treatment of organic chlorides is difficult. At present, chemical oxidation is a commonly used technical means, which can convert organic chlorides into non-toxic or low-toxic substances. For example, the oxidation of organic chlorides with hydrogen peroxide or other oxidizing agents can produce the corresponding carboxylic acids or carbon dioxide, thereby reducing the harm to the environment. The decomposition efficiency of chloride can be further improved by catalytic oxidation technology.

(3) Recycling technology

Some by-products in the propylene oxide production process have high recovery value. For example, propylene glycol can be reused as a solvent or antifreeze, while the chlorine element in chlorides can be recycled through chemical reactions to produce other chlorinated products. Through recycling technology, not only can reduce the waste of resources, but also reduce the production cost of enterprises.

3. By-product treatment significance

The treatment of by-products in the production of propylene oxide is not only related to the economic benefits of enterprises, but also of great significance to environmental protection and production safety. Proper disposal of by-products can reduce the emission of pollutants and reduce the burden on the environment. Rational use of by-products can improve the utilization rate of resources and promote the development of green chemical industry. Through the treatment of by-products, it can avoid its interference to the production equipment and process, to ensure the smooth progress of production.

4. Future development direction

With the continuous improvement of environmental protection requirements and the enhancement of resource utilization awareness, the treatment technology of by-products in the production of propylene oxide will be further optimized and innovated. In the future, more efficient and environmentally friendly treatment methods can be explored, such as biodegradation technology, membrane separation technology, etc. The development of high value-added applications of by-products is also the focus of future research.

Summary

The by-products produced in the production of propylene oxide, such as propylene glycol and chloride, will have a serious impact on the environment and production safety if they are not properly treated. By fractionation, chemical oxidation and other technical means, these by-products can be effectively treated and recycled. This not only helps to reduce environmental pollution, but also improves the efficiency of resource utilization and promotes the sustainable development of the propylene oxide industry. In the future, with the progress of technology and the increase of environmental protection demand, the treatment of propylene oxide by-products will develop in a more efficient and environmentally friendly direction.