Phenol ketone products

Plastic rubber

Current Location： Home > News > Chemical Knowledge > OX (o-xylene) production and manufacturing methods and processes

[Chemical Knowledge]：OX (o-xylene) production and manufacturing methods and processes

Read： 974 Time：20months ago Source：Transform the World with Simplicity

O-xylene (OX) is an important chemical raw material, which is widely used in the production of phthalic anhydride, polyester fiber, unsaturated polyester resin and other fields. The following are several common ortho-xylene manufacturing methods:

1. toluene disproportionation method
toluene disproportionation method is a commonly used method of producing ortho-xylene, the method is in the role of acidic catalyst, the toluene disproportionation reaction to produce benzene and xylene, and then through the separation of ortho-xylene. Common acidic catalysts include alumina, aluminosilicates, aluminum phosphates, and the like. The reaction temperature of this method is relatively high, and it needs to be carried out at 350-450°C. At the same time, factors such as the pressure and space velocity of the reactor need to be controlled to ensure the progress of the reaction and the selectivity of the product. The advantages of toluene disproportionation method are that the raw materials are easily available and the operation is simple, but the selectivity of o-xylene is low, and it needs to be purified by distillation and other separation methods.

2. o-xylene selective oxidation
o-xylene selective oxidation method is a direct oxidation of o-xylene to produce phthalic anhydride method, the reaction principle is under the action of a catalyst, the o-xylene and air or oxygen oxidation reaction, the formation of phthalic anhydride and water. Commonly used catalysts for this method include vanadium-based, titanium-based, zirconium-based and other metal oxide catalysts. The reaction temperature is generally between 350 and 450 ° C. and the reaction pressure is between 0.1 and 1.0MPa. The advantage of this method is that the phthalic anhydride product can be directly obtained, avoiding the steps of separation and purification, but the activity and selectivity of the catalyst have a greater impact on the reaction, and the catalyst needs to be replaced regularly.

3. Aromatic conversion method
Aromatic conversion method is a method to produce o-xylene through aromatic conversion reaction. The method converts aromatic hydrocarbons (such as ethylbenzene, propylbenzene, etc.) into o-xylene and other products under the action of high temperature, high pressure and catalyst. Commonly used catalysts include molecular sieves, alumina, aluminum phosphate, and the like. The reaction temperature is generally between 400 and 600 ° C., and the reaction pressure is between 2 and 10MPa. The advantage of this method is that low-value aromatic compounds can be used to produce high-value o-xylene, but the reaction conditions and catalyst requirements are higher, and the reaction conditions and catalyst activity need to be strictly controlled.

No matter which method is used to manufacture o-xylene, it is necessary to strictly abide by safety production regulations to ensure the normal operation of the reactor and the health and safety of employees. At the same time, it is also necessary to pay attention to environmental protection issues and take effective waste gas and wastewater treatment measures to reduce environmental pollution.

Previous： Manufacturing method and process flow of PX (paraxylene)

Next： Production and manufacturing method and process of chloroacetic acid (sulfur method)

News Categories