Hello all,
I recently moved from systems engineering to process simulations. Please help me with the following basic questions.
Have a feed comprising (I-butene - 54%, Isoprene, 6%, tert-butyl alcohol 8%, Pyran <1%, C5Ohs < 1% and traces of formaldehyde (<1%) with remaining water -30%). Need to recover all the products > 99%.
Question - As water present in significant amount - whats the optimum method to remove this first. Noted formaldehyde is highly miscible with water and I need to have nearly 99% recovery. (Commercial formaldehyde as product - 37 wt %).
I understand property package defines the interaction parameters, viscosity, enthalpy, entropy calculations etc.
The feed was preheated to XX C in exchanger and directed to a flash drum where vapors in overhead, liquid and water in bottoms.
I tried following of few options:
Option A - Using SRK. Pure water gets separated in bottom of flash drum while remaining vapor and liquid streams obtained as per equilibrium conditions of flash drum. Formaldehyde (that is highly miscible with water goes into vapor stream). The other liquid stream can be fed to a column for further separation.
Option B - Using NRTL (K-Value VLE-NRTL and no other changes for property estimations in thermo package).
There is NO water separation from bottoms, and only vapor and liquid.
Option C - Using NRTL (K-Value VLE-NRTL and K-Value LLE-NRTL).
There is small flow in liquid and MOST of the components in water separated from bottoms
I am wondeirng
1 - how do I know which property package to use
2. how do i separate water (>30% wt in feed)
3. basis to use other thermodynamic properties e.g. Liquid / vapor enthalpy, liquid / vapor entropy, liquid / vapor density etc.
Thanks in advance for your replies.