Union Carbide Tetra Process

Union Carbide Tetra Process tetraethylene glycol [112-60-7] 29... 

Removal of Aromatic Compounds. Because of the demand for high-purity aromatic compounds for petrochemical feedstocks, several processes have been developed for BTX (benzene, toluene, and xylenes) recovery from distillate streams. In these processes, aromatic compounds are separated from nonaromatic compounds by liquid—liquid extraction using polar solvents. The three major processes in use are the UOP—Dow UDEX process (di- or triethylene glycol solvent), the UOP sulfolane process (tetrahydrothiophene 1,1-dioxide), and the Union Carbide TETRA process (tetraethylene glycol). 

Eig. 5. Union Carbide Corp. Tetra extraction process (36). 

These solvents are characterized by a high affinity for aromatics, good thermal stability, and rapid phase separation. The Tetra extraction process by Union Carbide (Figure 2-2) uses tetraethylene glycol as a solvent. The feed (reformate), which contains a mixture of aromatics, paraffins. 

Tetra [Tetraethylene glycol] Also called Tetia-extraction. A process for removing aromatic hydrocarbons from petroleum fractions by liquid-liquid extraction using tetraethylene glycol. Developed by Union Carbide Corporation as an improvement on the Udex process. In 1981, 30 Udex-type units had been converted to this process. Now licensed by UOP. 

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