2 replies to this topic

[f.pasquini]

Hi guys! I'm building an electrolyzer block on Aspen Plus (please see attached figure for a better understanding). For that I'm using a RStoic reactor (equation H2O -> H2 + 0.5 O2) followed by a separator (creating two stream: one is hydrogen and the other is oxygen + water). Later I add a flash to separate water from oxygen. The reactor asks for a fraction conversion, which I believe is the amount of water that will be splitted. I've tried to use 0.35 and it worked great. However, I calculated the exact number later and it's very small for my system (0.00045). When I try to run using this small number the software says that the O2 stream is 0, which I believe is because a small amount of oxygen is produced. Is there a way to increase the accuracy? In other words, make the software give me a very low value instead of zero?

I hope you understand my problem. Thanks!

 

 

Attached Files

•  Capture.JPG   31.21KB   2 downloads

Edited by f.pasquini, 03 September 2021 - 10:00 AM.

[latexman]

What I found when using F1 (Help):

 

RStoic Convergence Form

See Also

Working with RStoic

Use the Flash Options sheet on the RStoic Convergence form to specify temperature and pressure estimates and convergence parameters for flash calculations.

 

The default is 0.0001 for "Error tolerance".

[SilverShaded]

Is the O2 remaining in the water os is there actually a small model balance error?