Method of manufacturing dioctyl phthalate (DOP)
Dioctyl phthalate (DOP) is a widely used plasticizer, mainly used in the processing of plastics such as polyvinyl chloride (PVC). The following is the manufacturing method of DOP.
I. Raw material preparation
The main raw materials for producing DOP are phthalic acid and octanol. Phthalic acid can be obtained from phthalic anhydride or o-xylene oxidation method, while octanol can be obtained from petrochemical raw material ethylene.
Two, esterification reaction
Phthalic acid and octanol will be added into the esterification reactor according to a certain molar ratio, and sulfuric acid is generally used as a catalyst to carry out the esterification reaction. The temperature and pH should be controlled during the reaction to ensure the smooth progress of the reaction. After the reaction is completed, the crude product of DOP is obtained.
III. Neutralization and washing
The crude product contains catalyst sulfuric acid, which needs to be neutralized with alkaline solution to remove the acid. Then it is washed with water to neutralization to get the slurry of DOP.
IV.Dehydration
The water in the slurry liquid needs to be removed by vacuum dehydration or centrifugal dehydration to obtain DOP products with lower water content.
V. Distillation and purification
In order to obtain DOP with higher purity, the dehydrated product needs to be distilled and purified. Generally, vacuum distillation is used to obtain DOP with purity above 99%.
VI.Packaging and Storage
Purified DOP is packed into special storage containers and kept in sealed condition to prevent light and high temperature.
The above is the basic manufacturing method of DOP, the specific production process also needs to be adjusted and optimized according to the actual situation, in order to ensure the smooth progress of production and product quality. At the same time, the production process also needs to pay attention to safety and environmental protection, and comply with relevant laws and regulations. In general, the manufacture of DOP requires certain technology and equipment, so it is necessary to strictly control each link in the actual production process to ensure product quality and production safety.
