DMT Production Process
In our DMT-process of Huels a mixture of P-xylene and pT-Ester is oxidized with air in liquid phase to p-toluic acid and terephthalic acid monomethyl ester, respectively ,using Cobalt Manganese catalyst. The acid and ester mixture which is called oxidate is then esterified with methanol to the corresponding methyl ester (raw ester).a
Raw ester is separated by distillation into the following fractions- pT-ester fraction - DMT-fraction - and residue pT-ester is recycled to the oxidation stage, DMT fraction is purified by crystallization. Finally, the catalysts namely cobalt and manganese are extracted by waste water from the residue which is then to the corresponding by product
Some amount of DMT product are dispatched to the solid unit in order to convert and become prepared for exporting to other countries this product is used mainly to produce polyester resins, fibres ,and films , plasticizers such as DOTP , ,.PBT and etc
The byproducts of above process are BME and Residue:
a. BME is uses as a solvent in different industries and also utilizes in producing sodium Benzoate in food industry
b. Residue is one of the main product in the rubber industries and carbon black production process
DOTP Production Process
Dioctyl Terephtalate , commonly abbreviated DOTP, is an organic compound with the formula C24 H38 O4
This product is a non toxic plasticizer applicable to future good compatibility with polymeric materials such as PVC industries in order to produce medical equipments, toys,Artificial leather and etc,.DOTP plasticizer as an environmentally friendly product has caused widespread .concern in the industry of plasticizers
Esters of DOTP can be synthesized mainly by reacting Dimethyl Terephtalate and 2-ethyl Hexanol under pressurized condition in the presence of TIPT catalyst .In the next stage , methanol which is produced from the above reaction and the excess value of 2-ethyl Hexanol are removed by vaccum distillation in two steps. The obtained product is purified by filteration in the final stage.
