Question: Regarding Aspen’s simulation of electrolyte systems, what is the format in which the stream results are displayed?

Properties->Methods->Specifications->Global->Uncheck \"Use true components\"

If the checkbox is unchecked, the calculation does not converge. I looked into it further to see if checking or not would affect the calculation process. And what I mainly request is the output report format for the calculation results.

I’ve only tried simple flash equilibrium calculations; when convergence is achieved, the data remains the same. It’s hard to say about other cases, but I personally think the results should be identical. You can give it a try

Trouble. This problem has been bothering me for several years. If that doesn’t work, the only option is to use a crude method and handle it manually later

Based on your English text, I found the original text in the help material. Because my English is average and my theoretical knowledge is limited, I could only understand it half-baked. The overall feeling is that there is a difference between the two. And the difference lies not only in the format of the output results

Specifically, that passage says there is a difference, but the text I posted seems to indicate no difference; it states that the thermodynamic properties of the apparent components derive from those of the actual components. Taking ammonia as another example, the liquid fugacity coefficient of ammonia is calculated based on the actual components; since the source is the same, there shouldn’t be much difference. There might be slight variations in the calculation process, but I have also checked a single equilibrium stage and got the same result. I’m not sure exactly which part you refer to as being different; you can paste it here so I can take a look

In true species electrolyte systems, the heat capacity cannot be calculated precisely. It is determined as a numerical derivative of enthalpy using temperatures close to those of the system. However, in electrolyte systems, the actual composition can change significantly even with slight temperature variations. In both the true species approach and the apparent species approach, the actual composition is calculated separately for each temperature; therefore, an approximation of this effect is taken into account in the heat capacity calculation. This issue does not affect any other properties or the model results, aside from the calculated heat capacity.

My English isn’t very good either, but I have the feeling that this sentence doesn’t convey what you meant What I understand from this passage is that in a real electrolyte system (referring to those in real life, not the actual or hypothetical compositions used in Aspen), it is difficult to calculate the heat capacity accurately. The reason is that slight changes in temperature can sometimes lead to significant variations in the composition within a real electrolyte system. He goes on to mention that under both the real and hypothetical approaches, its true composition is calculated oppositely at each temperature point (in order to approximate a real electrolyte system), but this issue does not affect other physical properties (except heat capacity). So, in my opinion, there is no difference between these two methods of using hypothetical substances; the only difference is that when calculating the heat capacity, there will be deviations compared to real electrolyte systems (it’s not a method based on actual components), but he is doing his best to avoid such deviations.

In the composition table, it is necessary to distinguish between apparent components and actual components; for example, NaCl is an apparent component, while NaCl(s) is an actual component

When ions are generated in the process simulation, Aspen identifies it as an ionic process, and thus defaults to using the true component method for simulation and representation. What you are asking for is to change the display format to the apparent component method, and the implementation method was explained earlier in 2L. As for the issue of non-convergence, you need to consider your simulation process; for certain processes involving ions, it is not possible to use apparent components, as simulating such ion-related processes by treating them as apparent components requires meeting certain conditions. These conditions can be found in Aspen’s Help documentation. Furthermore, when considering the composition of a stream, one should take into account not only simplicity but also the properties of the ionic solution. The various ions in the solution need to be replaced by apparent components, which can be expressed as combinations of multiple salts, such as NaCl+KNO3 and NaNO3+KCl. In such cases, using the true component method allows for a more accurate representation of the component characteristics of this solution; moreover, when dealing with issues related to concentration and precipitation, the apparent component approach cannot be used.