Extractive desulfurization of dibenzothiophene using phosphonium-based ionic liquid: Modeling of batch extraction experimental data and simulation of continuous extraction process

The combination of n-heptane + dibenzothiophene (DBT), a model diesel fuel (MDF), was used to demonstrate the desulfurization capacity of trihexyl tetradecyl phosphonium chloride ionic liquid (CYPHOS101-IL) by extractive desulfurization (EDS) process. Maximum of 81.4% DBT removal capacity was observed for a mass ratio (IL/MDF) of 1:3. Furthermore, the reusability of used IL for the removal of DBT from fresh MDF was tested without any regeneration and it was found that the used ionic liquid can be used up to 5 cycles for DBT removal, though the extraction efficiency decreases marginally. The batch extractive experimental data were well correlated with the theoretical values obtained from NRTL model using ASPEN PLUS. The binary interaction parameters for DBT and IL were obtained and used further to simulate the continuous extraction process by using extractor sub routine of the ASPEN PLUS simulator.