Liquid-Liquid Equilibria in Aspen Plus® v8.8 CHEN 354 Texas A&M University

N-Methylformamide(1) + Hexadecane (2) Environmental regulations that aim to improve air quality require reducing sulfur from diesel vehicle emissions Hydrodesulfurization (HDS) is a typical process in industry that removes sulfur by converting sulfur compounds to hydrogen sulfide Heterocyclic nitrogen compounds act as inhibitors of HDS N-methylformamide (NMF) can be used as a solvent for extracting nitrogen compounds from diesel oil A mixture containing NMF – diesel (represented here as hexadecane) may split into two liquid phases and the NMF-rich phase will dissolve the undesired compounds

Hexadecane- rich phase x1 Data* @ p = 1 atm T/K NMF- rich phase x1 Hexadecane- rich phase x1 293.15 0.9993 0.0009 298.15 0.999 0.0011 303.15 0.9984 0.0021 308.15 0.9985 0.0026 313.15 0.9988 0.0027 318.15 0.9987 0.0029 Find binary parameters for the LLE of NMF – hexadecane using UNIQUAC and NRTL *Source: Hwang, In-Chan, et al. "Binary Liquid− Liquid Equilibrium (LLE) for N-Methylformamide (NMF)+ Hexadecane between (288.15 and 318.15) K and Ternary LLE for Systems of NMF+ Heterocyclic Nitrogen Compounds+ Hexadecane at 298.15 K." Journal of Chemical & Engineering Data 54.1 (2008): 78-82.

Open Aspen Plus® and add the components N- methylformamide (1) – hexadecane (2)

Select UNIQUAC as the method to model the system

Input the data (Txx) provided in the table as shown below

Click on regression, create a new regression and select UNIQUAC as method. Since a range of temperatures are involved, two interaction parameters for each binary pair (ij and ji) will be used. Click the run button and click OK

The two sets of binary parameters are estimated by the UNIFAC method The two sets of binary parameters are estimated by the UNIFAC method. Similarly, it was also calculated using NRTL. UNIQUAC NRTL What can be concluded about the parameters calculated by the two different methods?

Click plots > Txx UNIQUAC NRTL What can be concluded about the diagrams calculated by the two different methods?

Click on Analysis> Binary to study the VLLE of this mixture Click on Analysis> Binary to study the VLLE of this mixture. Scroll down and click run analysis

VLLE diagrams UNIQUAC NRTL