Modeling of extraction separation of aliphatic and aromatic hydrocarbons usimg tetraethylene glycol - water mixtures

Cilj ovog rada je modelirati ekstrakcijsko razdvajanje aromata i alifata s polarnim otapalom, smjesom tetraetilenglikola i vode. Iz literature su uzeti potrebni eksperimentalni podatci o ravnoteži kapljevina-kapljevina za osam različitih sustava u temperaturnom području od 60 °C do 140 °C. Pri modeliranju modelima koeficijenta aktivnosti NRTL i UNIQUAC primijenio se pseudo-trokomponentni pristup. Parametri modela određeni su regresijskom analizom, a dobiveni skupovi parametara provjereni su testom termodinamičke konzistentnosti. Rezultati pokazuju da se pseudo-trokomponentni pristup može uspješno primijeniti na modeliranje takvih sustava te je iz dobivenih parametara modela moguće proračunavati ravnotežne sastave faza i predviđati fazno ponašanje tih sustava. Ravnotežni sastavi faza izračunati su i prediktivnim modelom UNIFAC radi usporedbe s korelativnim modelima. Dobiveni rezultati slični su onima kao kod modela UNIQUAC i NRTL iako je postignuto nešto lošije slaganje eksperimenta i modela. In this thesis, extraction separation of aromatic and aliphatic compounds with a polar solvent, a mixture of tetraethlyene glycol and water, is modeled. Liquid-liquid equilibrium (LLE) experimental data were taken from literature for eight different systems in the temperature range from 60 °C to 140 °C. The pseudo-three-component approach was used along with NRTL and UNIQUAC activity coefficient models. The model parameters were determined with regression analysis and thus obtained parameter sets were checked for thermodynamic consistency. The results show that the pseudo-three-component approach can be successfully used for LLE calculations in such systems using regressed NRTL and UNIQUAC parameters. UNIFAC calculations of tie lines were also done to compare the results with those of the correlative models. UNIFAC results were similar to those obtained by NRTL and UNIQUAC although with somewhat worse fit between experiment and model.