How should I adjust it if the tower doesn’t converge?

Simulate each tower one by one, :)

1 Do not create too many models at once; it is better to build one tower first, wait for convergence, and then build a second tower, and so on. 2 Also, the control conditions shouldn’t be too strict at first; they can start from lenient and gradually become stricter. For example, the purity requirement can be set at 98% first, and then at 99%. 3 Increase the number of iterations. 4 If the specific parameters are not clear, you can start by using the shortcut module; then use the results obtained from that shortcut to determine that Tower Pro2 does not converge well – more practice will help in this case

What’s the use of the shortcut module?

Let’s first address the “shortcut” module; this module is used when performing design calculations, as it helps estimate values such as the number of plates based on the initial values you provide. Then you can go to the “distillation” module to perform specific calculations for the distillation tower. Now, to answer the original poster’s question: The reason for non-convergence in the PROii software in certain situations depends mainly on what errors and warnings are reported; by identifying those, it is possible to determine the root cause. In short, it’s likely mainly because your requirements are too high, and the number of plates or the reflux ratio in your system are not sufficient to meet your separation needs ； It’s possible that the requirements specified in your \"specifications\" are in conflict with the design of other parts of your distillation tower ； Or conservation is violated after adding the loop ； It could also be a problem with your thermodynamic model ； It might also be that you didn’t choose the gas-liquid phase properly. That’s roughly all for now. If you have any questions, feel free to ask, or you can send me your ERROR message so I can take a look at it

Pro/II convergence seems quite troublesome; it’s not as fast as Hysys and Aspen. The main issue is that the initial values are hard to determine. There are several ways to speed up the convergence of towers in Pro/II. The key is to have good initial values, an appropriate initial value generation algorithm, a method for the tower to converge, and reasonably specified parameters for tower calculations. By using step-by-step adjustments, taking the previous convergence result as the initial value for the next simulation, and other such methods, in short, towers do not converge well in Pro/II.

Short Cut can also be used as a module for side-line stripping towers. Personally, I find that Pro2 converges more easily than AspenPlus; during simulation, it’s possible to relax the requirements initially and then gradually move toward the desired results

In simple terms, don’t simulate them all at once; calculate them one by one in sequence, rather than trying to process them all together

Adjust the initial values and operating conditions, give it a few more tries – you’ll probably get used to it soon