Selection of property methods for distillation systems
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To simulate a distillation column, the components are hydrocarbons and methanol. Hydrocarbons have very small dipole moments, while methanol has a large dipole moment. Using the P-R equation yields a better fit in the absence of methanol. After adding methanol, can the P-R equation still be used to accurately predict the components? Please help! !
Then try SRK, or activity coefficient equations such as NRTL-SRK
For SRK, the activity coefficient method can be used normally, but for hydrocarbon systems, the fitting is not very good
What is your hydrocarbon system? Based on my experience, the SRK equation is an EOS equation that can achieve good simulation results for most hydrocarbons in most cases. If the liquid-phase activity coefficient also uses NRTL, there should be no major problems. You say that the simulation is inaccurate – is there any concrete data to support this?
In our process of low-temperature separation after natural gas compression, methanol is also added as a hydrate inhibitor; using the P-R model directly is no problem. When distilling methanol from a methanol-water system to recover it, the Wilson model is used.
The accuracy of the P-R equation is fairly good.
Mm-hmm, since I started using Plus, I’ve basically not used any other property methods. It seems like PR is a panacea. . .