Is this a problem of a boring loop? How should it be handled?
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It’s my first time running a simulation, and there is a cycle that occurs during execution due to boredom (similar to how CO2 is absorbed by the MEA and then released back again; I’m not sure how to handle this). The following error occurred during operation: ->Processing input specifications... Flowsheet Analysis: Block $OLVER01 (Method: WEGSTEIN) has been defined to converge streams: 4B 4A 6A. COMPUTATION ORDER FOR THE FLOW SHEET: $OLVER01 EXHEAT1 COOLER FORM MEMBRANE PUMP EXHEAT2 DECOMP (RETURN $OLVER01) DRIER COMPRESS ->Calculations begin... ****PROPERTY PARAMETER ERROR: ERRORS WAS FOUND IN THE CALCULATION OF VAPOR-LIQUID K-VALUES USING THE UNIFAC OPTION FOR KVL! Calculations were stopped due to missing property parameters. I would appreciate it if someone could give me some advice – is this a problem related to material circulation? If that’s the case, how should it be handled? (Is it necessary to add other equipment, such as mixers, for material circulation?) Thank you!
The hint contains cyclic information, but the error is caused by the gas-liquid equilibrium calculation in unifac. It is recommended that the original poster start by doing some simple simulations first
Reply to 2# laipi*ao*n: Thank you for the suggestion from the second floor; it’s clear that you’re an expert. I hope you can give me more guidance, as I’m in a hurry to work on this project – it’s one of those projects I’m taking on despite not having much experience with it. I can adjust the gas-liquid handling aspects, but my question is whether, when simulating the actual circulation in Aspen, it’s not necessary to represent it as a closed loop diagram, or something like that. I’m really confused about this issue. Thank you again!
A cycle certainly requires a closed loop; the key lies in setting the initial value. There are many discussions on this topic in forums, so the original poster can search for them.
It is recommended to first streamline the process and establish a cycle. Additionally: if your amine stream is completely sealed, convergence will not occur ever, because the gas at the top of the regeneration tower will contain MEA during regeneration, resulting in an imbalance in the mass of the entire system