Determination and improvement of the operability index for a toluene hidrodealkylation process

V diplomskem delu je prikazana študija indeksa operabilnosti, za katero menimo, da lahko postane integralni del metod uporabljenih za načrtovanje učinkovitejših procesov. Cilj dela je bil, določiti indeks operabilnosti (OCI) za vsako enoto posebej in tudi za celoten proces z namenom izboljšanja OCI. Na osnovi računalniških simulacij procesa hidrodealkilacije toluena (HDA) smo pridobili obratovalne parametre procesa pri velikem razponu vhodnih parametrov. Te smo nato grafično analizirali v programu Microsoft Excel in določili indeks operabilnosti. Z občutljivostno analizo procesa, pri kateri smo opazovali spremembo koncentracije benzena na iztoku v odvisnosti od dolžine reaktorja in števila destilacijskih stopenj, smo izbrali nov tip reaktorja in separatorja z namenom izboljšanja OCI. Rezultati so pokazali, da smo s spremembo reaktorja izboljšali OCI. Sprememba separatorja pa ni imela vpliva na OCI. Iz tega smo razbrali, da bi za postavitev procesa HDA izbrali drugi reaktor in cenejšo verzijo separatorja, saj slednji nima vpliva na OCI.The thesis presents a study of the Operability Index (OCI) and shows how we believe it can be used to improve different types of processes in many industries. Our goal was to determine the OCI separately for each process unit as well as for the entire process. The final goal was to improve the OCI. The case study process (hydrodealkylation of toluene, HDA) was simulated in Aspen Plus. The data obtained were analyzed graphically in MS Excel and the operability index was determined. The search for possible improvements was based on sensitivity analysis. We looked for changes in benzene concentration in the process output while varying the reactor length and the number of distillation stages. Based on the results, we chose a different reactor and distillation column, which resulted in a better OCI The results show that changed reactor lead to improved OCI. Selection of different separator did not affect OCI. Based on this results we would choose the second reactor and a cheaper separator to set up HDA process, as the latter has no effect on OCI