Analyzing The Source And Production Process of Bromine Flame Retardants

Analyzing The Source And Production Process of Bromine Flame Retardants

Overview

Bromine flame retardants, as a class of important chemical additives, easy to use, can be added directly in the post-treatment of textiles (polyester, viscose fiber, blended, cotton, polyester products), at room temperature to complete the whole process of finishing, and compared with the conventional products of polybrominated diphenyl ethers, in the polymer thermal cracking or combustion, there is no toxic dibenzodihydrodimethylene and polybrominated dibenzofuran produced. They also have a wide range of applications in the fields of plastics, textiles, electronic and electrical equipment and construction materials. Their main role is to release hydrogen bromide or other bromine compounds when the material is heated, capture free radicals, interrupt the chain reaction in the combustion process, thus improving the flame retardant properties of the material.

Representative products of bromine flame retardants include: brominated polystyrene, tetrabromobisphenol A, decabromodiphenylethane, brominated polystyrene, bromotriazine, methyl octabromo ether, hexabromocyclododecane and so on. The downstream is widely used in the production of electrical and electronic flame-retardant parts, the production of related building parts in the construction field, the production of flame-retardant plastic parts in the field of transportation, as well as the production of flame-retardant plastic parts in the construction of power grids, the scope of application is very wide.

Source of bromine flame retardants

The upstream raw materials of bromine flame retardants mainly include inorganic salts, such as potassium bromide, sodium bromide, etc., as well as organic bromides. These raw materials through a specific chemical reaction, can be synthesized with a specific structure of the bromine flame retardant. The source of bromine is mainly brine and underground brine, and bromine is extracted through bromine vaporization process or bromine blowing process.

Production process

The production of bromine flame retardants mainly includes three stages: bromine extraction, bromine flame retardant synthesis, product purification and packaging.

1. Bromine extraction: 

Bromine is extracted from brine and underground brine through bromine vaporization process or bromine blowing process. The evaporation process is to extract bromine by evaporation using the mother liquor of potassium production; the blowing process is to extract bromine with the help of air blowing out method using the low and medium brine and underground brine which are not made into salt.

1.1 Steaming bromine process: 

Since chlorine is used for oxidation in the production of industrial bromine, and its chlorine ratio is generally about 115%, the crude bromine distilled must be refined and de-chlorinated in order to reach the industrial bromine industry standard. At present, the refining method of crude bromine in the process of domestic production of industrial bromine is that the bromine vapor distilled from the distillation tower enters into the distillation tower equipped with a condenser, and based on the nature of chlorine, which has a lower boiling point than that of bromine, free chlorine is evaporated and discharged from the system by means of distillation.

The process is mature, simple to operate, high efficiency and low cost, but requires a bromine content of 3g/L or more brine as raw material. The raw materials of chemical plants using water vapor distillation method of bromine are the mother liquor after precipitation of carnallite in the process of producing potassium chloride, and the bromine content of bitter brine after salt production in coastal areas is generally 2.5g/L~3g/L. Due to the low bromine content, a large amount of steam needs to be consumed, which results in the increase of production cost.

1.2 Bromine blowing process: 

The process of air blowing out acid bromine, is brine from the centrifugal pump pumped into the pipeline, adding distillation waste liquid for acidification, adjust the pH value to the required range. Then pass into the chlorine gas for oxidation, further reaction by the static mixer sent to the blowing tower, top to bottom spray, the tower is filled with filler, the fan from the lower part of the tower blowing air, gas-liquid exchange on the surface of the filler, free bromine is taken away by the inert gas, the waste liquid is discharged from the bottom of the tower. Sulfur dioxide gas plus fresh water sprayed at the top of the tower for downstream absorption of bromine-containing air. The bromine content of the absorption solution reaches 70kg/m~80kg/m, and then the second chlorination is carried out, and the finished bromine product is distilled. Air-blowing acid absorption process has been fully mature, its rapid reaction, complete absorption, simple process, less equipment, high concentration of bromine in the absorption solution, steam consumption can be as low as 2t/t or less, so the vast majority of domestic enterprises use this process to produce bromine.

2. Synthesis of bromine flame retardants: 

Accurately measure the bromine source and the corresponding organic or inorganic compounds, and then carry out the substitution reaction or addition reaction under specific temperature and pressure to obtain bromine flame retardants.

3. Product purification and packaging: 

The synthesized bromine flame retardant is subjected to post-treatment steps such as filtration, washing and drying to remove by-products and impurities. Finally, it is packaged according to the specifications and ready to enter the market.

Fourth, the application of bromine flame retardants

Bromine flame retardants are mainly used in plastic products, textile industry, electronic and electrical products and construction materials. In plastic products, it can enhance the flame retardancy of polycarbonate, polypropylene, polyurethane, etc.; in textile industry, it can give fabrics flame retardant properties; in electrical and electronic products, it can improve the safety of wires, circuit boards, etc.; in building materials, it can be used for fireproofing material production.

China Brominated Flame Retardant Industry Chain Diagram

4. Environmental and health considerations

Although brominated flame retardants have been shown to be effective in improving the flame retardancy of materials, they may have environmental and health impacts. Some brominated flame retardants may decompose and release toxic substances, such as polybrominated diphenyl ethers (PBDEs), which are bioaccumulative and potentially neurotoxic.Therefore, the development of environmentally friendly and non-brominated flame retardants has become an important research direction.

Conclusion

Summary: Market Prospects and Challenges of Brominated Flame Retardants

Although brominated flame retardants occupy an important position in the Chinese flame retardant market and their market share is expected to continue to expand, the market trend is gradually favoring the choice of non-halogenated flame retardants. Behind this shift is a growing concern for environmental protection and human health, driving the industry toward greener, more sustainable flame retardant solutions. At the same time, with the requirements of industrial upgrading and new product iteration, energy-intensive and highly polluting brominated flame retardant products will be under pressure to be phased out or upgraded, especially those that pose potential threats to human health.

Prospect: technological innovation and market adaptation

In the face of market changes, technological innovation has become the key word in the brominated flame retardant industry. In order to maintain competitiveness, manufacturers need to develop a new generation of brominated flame retardants that not only meet environmental requirements, but also have excellent flame retardant properties. Demand for brominated flame retardants in key areas such as electrical and electronics, power grid construction and building energy efficiency is expected to maintain steady growth, bringing new growth points to the industry. However, the future growth of brominated flame retardants also depends on their continued optimization in terms of performance, cost-effectiveness and environmental impact.It is only through continuous technological innovation and market adaptation that brominated flame retardants will be able to maintain their important position in the global flame retardant market.