Manufacturing method of m-xylene
Meso-xylene (m-xylene) is an important raw material for chemical production, widely used in plastics, resins, dyestuffs, pharmaceuticals and other fields. This article will introduce the manufacturing method of m-xylene, including raw material selection, reaction principle, process flow, equipment selection and other aspects.
I. Raw material selection
The raw material for the manufacture of m-xylene mainly adopts mixed xylene, which contains isomers such as m-xylene, o-xylene and p-xylene. In order to obtain high purity m-xylene, it is necessary to select mixed xylenes with high purity as the raw material, and the purity is generally required to be above 98%.
II. Reaction Principle
The manufacture of m-xylene mainly adopts the adsorption separation method, which is based on the principle of utilizing the adsorbent's different adsorption capacity for different isomers to separate out the m-xylene in mixed xylenes. Commonly used adsorbents are molecular sieve, silica gel and so on.
3. Process flow
The manufacturing process of m-xylene mainly consists of the following steps:
1. Raw material pretreatment: the mixed xylenes will be pretreated with dehydration, desulfurization and so on to ensure the quality of raw materials.
2. Adsorption and Separation: The pretreated mixed xylene is passed into the adsorption tower, and the selective adsorption of m-xylene by the adsorbent is utilized to separate m-xylene from other isomers.
3. Desorption and regeneration: Desorption and regeneration of the adsorbent to restore the activity of the adsorbent for recycling.
4. Product refining: Refine the separated m-xylene to remove the impurities and get the high-purity m-xylene product.
4. Equipment Selection
The following equipment is needed for the manufacture of m-xylene:
1. Adsorption Tower: Used for adsorption and separation of m-xylene in mixed xylene.
2. Desorption tower: for desorption and regeneration of adsorbent.
3. Refining tower: for refining m-xylene and removing impurities from it.
4. Pumps, valves, pipelines and other auxiliary equipment: used for conveying and controlling materials.
V. Operation points
In the process of manufacturing m-xylene, the following operation points need to be noted:
1. Control the quality and purity of raw materials to ensure the quality and yield of the product.
2. Control the type and particle size of adsorbent to improve the effect of adsorption and separation.
3. Control the operating temperature and pressure of the adsorption tower to ensure the effect of adsorption and separation and the operational stability of the equipment.
4. Regularly carry out regeneration and replacement of adsorbent to maintain the activity and separation effect of adsorbent.
VI. Safety and environmental protection measures
In carrying out the manufacturing process of m-xylene, the following safety and environmental protection measures need to be taken:
1. Strengthen the management of storage and transportation of raw materials and products to avoid leakage and fire accidents.
2. Strengthen the maintenance and upkeep of the production equipment to ensure the safe and stable operation of the equipment.
3. Strengthen the management and emission control of production waste gas to reduce the pollution to the environment.
VII. Conclusion
m-xylene, as an important raw material for chemical production, is mainly manufactured by adsorption separation method. In carrying out the manufacturing process, it is necessary to pay attention to the selection of raw materials, reaction principle, process flow, equipment selection, etc., and at the same time, strengthen the operation points and the management of safety and environmental protection measures, in order to ensure the quality and yield of the product, and to improve the economic and social benefits of the enterprise.
