**4. Simulation setup**

ASPEN Plus® radfrac with the Rate-Sep package enables the use of the rate-based model to evaluate the effect of the solvent on the mass transfer efficiency in the ED process. This model needs physical and transport properties of both pure component and ternary mixture which were taken elsewhere [27, 37, 44]. Column internals are other parameters that have to be defined. Sieve trays and Mellapak® 250Y are the selected internals for this study. **Table 2** summarized the features of these internals. These internals will be used to analyze the separation of water-ethanol.

It is worth to mention that, vapor flow regimes inside the ED column could also affect mass transfer efficiency. However, to avoid this effect, these flow regimes were set constant at a value of flooding of 70%.


**Table 2.** Used column internal characteristics in the simulations for 100 kg/h of mixture and 50% wt ethanol as a base flow and feeding concentration respectively [35].

**Figure 2.** Scheme of the extractive distillation pilot plant at Eindhoven University of Technology [38].

Solvent Reboiler duty [kW]<sup>a</sup> Distillate rate

Mass Transfer in Extractive Distillation when Using Ionic Liquids as Solvents

http://dx.doi.org/10.5772/intechopen.76544

113

NMP 50% 0.3 [emim][TCB] 50% 0.3

[kg h−1]

**Variable Value** Feed flow rate [kg h−1] 2 Toluene concentration at feed [wt%] 70 Feed temperature [°C] 90 Solvent temperature [°C] 100 Solvent-to-feed ratio (mass) 5

a

100% = 2.04 [kW].

**Table 3.** Operating conditions [38].
