In this simulation, we took special care not to harm any chemical compounds.
But, to protect their identities, we replaced their names.
Ok, practically, COMP1 to COMP13 are the usual suspect from Methane to Nonane with some gases like maybe CO2 or others.
The PETRO_1 to PETRO_11 are petro cuts. H20 is left because it is really obvious.
If you see - as fraction for a phase, this is because the fraction is lower than 1.0E-35.
The flash can find theoritical fractions way below that.
This not that important for a standard flash, if your fraction is 1.0E-15 or 1.0E-45, you do not really care, but this is important when you are looking at phase boundaries.
Anyway, this is a beautiful flash problem. If you look at the two liquid phases, they are nearly identical. I am really proud that my flash code is able to solve such a hard problem and not lose the second liquid.
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P(Pa) 31455470.00 P(bar) 314.55
T(K) 299.82 T(cel) 26.67
MODEL 1 1 1 1
Z 1.374942 1.262459 0.969510 0.300845
STATE LIQUID LIQUID VAPOR LIQUID
NATURE HYDROCAR HYDROCAR HYDROCAR AQUEOUS
BETA 0.017572 0.007757 0.469552 0.505119 FEED
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PETRO_1a 0.088650 0.076813 0.020270 - 0.011672
PETRO_2 0.002647 0.002358 0.000830 1.92E-35 0.000455
PETRO_3 0.003136 0.002713 0.000731 - 0.000420
PETRO_4 0.002137 0.001806 0.000393 - 0.000236
PETRO_6 0.003024 0.002497 0.000441 - 0.000280
PETRO_7 0.003148 0.002452 0.000270 - 0.000201
PETRO_8 0.003845 0.002763 0.000164 - 0.000166
PETRO_9 0.004654 0.002991 0.000074 - 0.000140
PETRO_10 0.004411 0.002434 0.000018 - 0.000105
PETRO_11 0.003687 0.001648 2.38E-06 - 0.000079
COMP1 0.002344 0.002528 0.003821 5.63E-09 0.001855
COMP2 0.004319 0.004378 0.004518 1.06E-06 0.002232
COMP3 0.594647 0.621946 0.761958 6.10E-07 0.373053
COMP4 0.064187 0.065363 0.065147 1.48E-10 0.032225
COMP5 0.057369 0.057435 0.049935 2.08E-13 0.024901
COMP6 0.033973 0.033108 0.024641 1.44E-16 0.012424
COMP7 0.013206 0.012940 0.009982 4.84E-17 0.005019
COMP8 0.010395 0.010115 0.007215 9.29E-20 0.003649
COMP9 0.015588 0.014942 0.009813 6.80E-20 0.004997
COMP10 0.015740 0.014890 0.008625 2.60E-23 0.004442
COMP11 0.026786 0.025126 0.013396 1.24E-26 0.006956
COMP12 0.025084 0.023153 0.010866 1.95E-30 0.005723
COMP13 0.016487 0.015099 0.006511 1.99E-34 0.003464
H2O 0.000537 0.000502 0.000377 0.999998 0.505309
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As a small reminder of the flash algorithm, you basically solve the flash at a fixed number of phases starting from a good initialization and using the stability analysis, you check if you need to introduce a new phase or not. The introduction of a new phase is done if we find a phase which introduced in a very small amount will reduce the Gibbs energy of the system. Here we introduce not only a phase which reduces by a very small amount the Gibbs energy of the system (G/RT = 1x10^-18 where normally we are in the order of 1x10^-4 to 1) but which is also really close to an existing phase. Because it is really close to an existing phase, it is very easy for the solution to converge to the trivial solution of the existing phase. And what you cannot see, is that after one of the stability calls, the convergence needs to overcome a local minima barrier to reach the good minimum and convergence.
So, today I am happy. This is the kind of work I am really proud to do for my customers.