Production of plasticizers can be shortly divided in few steps:

• Esterification

Esterification is  an equilibrium chemical reaction which is caried out as a batch process in the reactor containing an agitator and other equipment – particularly for water separation and removal which is  formed during chemical reaction.

First phthalic anhydride and the 2-ethyhexanol are mixed in the reactor in order to form the monoester - mono-2-ethylhexylphtalate. The reaction takes place at about 150°C. Further the reaction mixture is heated to 170 - 180°C.  At this point the catalyst tetrabutyl-titanate  is added. Before the addition care must be taken to separate all the water formed in chemical reaction from the system. The evolution of reaction takes place and water formed must be continously carefully separated in the alcohol water separator. The temperature in the reactor is further increased up to 220-235°C to terminate the esterification. The Raw DOP is obtained.

• Distillation and Neutralization

Raw DOP is transferred to the distillation section which consists  of an reactor equipped with the stirrer, vapors condenser, cooler and alcohol water separator.

The alcohol is distilled first under mild vacuum distillation and at the end with vacuum distillation and steam stripping. At about 170-180°C  sodium carbonate is introduced to neutralize the traces of the monoester. The hydrolysis of the tetrabutyltitanate is performed in next step by adding small amounts of water. After the hydrolysis filter aid  (diatomite earth)  is added and DOP is dried under vacuum  and a light flow of nitrogen.

• Filtration

In this phase, solids formed or aded (diatomite earth) during neutralization and hydrolysis of the catalyst are removed by filtration.Other types of plasticizers are produced on the same equipment using different raw materials.