Xylene is a widely used raw material for the production of chemicals, especially in the field of solvents with important applications. The following are the manufacturing methods of xylene:
1. Catalytic reforming method
Catalytic reforming method is a commonly used method for manufacturing xylene. This method uses naphtha or straight-run gasoline as feedstock, and in the presence of a catalyst, a high-temperature reforming reaction is carried out to produce aromatic hydrocarbons, including xylene. High purity xylene can be obtained from the reaction products by separation and purification. Catalytic reforming method has the advantages of easy availability of raw materials, large production scale, high product quality and so on, so it is more widely used in the production of xylene.
2. Methylation method
Methylation method is a method to produce xylene by methylation reaction using toluene as raw material. In this method, toluene reacts with methylation reagents such as methanol or formaldehyde in the presence of an acidic catalyst to produce xylene and water. Xylene can be obtained from the reaction product by separation and purification. The methylation method has the advantages of easy availability of raw materials, mild reaction conditions, high selectivity, etc. However, problems such as decreased catalyst activity and equipment corrosion need to be solved.
3. Disproportionation
Disproportionation is a method of generating xylene by disproportionating toluene in the presence of an acidic catalyst. In this method, toluene is mixed with an appropriate amount of hydrogen and then disproportionation reaction occurs under high temperature and pressure by the action of a catalyst to produce xylene and benzene. Xylene can be obtained from the reaction products by separation and purification. The disproportionation method has the advantages of easy availability of raw materials, mild reaction conditions, and high selectivity, but requires improved catalyst activity and stability.
The above are the three main manufacturing methods of xylene, and different methods have different advantages, disadvantages and scope of application. In the actual production, the suitable manufacturing method can be selected according to the specific raw material source, production scale and product requirements and other factors. Meanwhile, in order to improve the production efficiency and product quality of xylene, it is also necessary to strengthen the optimization of the production process and equipment maintenance and other aspects.
In conclusion, as an important raw material for chemical production, xylene has a wide range of applications in the solvent field. High purity xylene can be obtained through different manufacturing methods, providing important support for the development of chemical industry.
