I'm trying to simulate a purifier in Aspen Plus in a cryogenic system. This purifier is just meant to change the pressure of the outlet stream based on the inlet flow and pressure (we are using the purest xenon money can buy and making it several orders of magnitude purer, so I'm just modeling it as pure xenon hence the purifiers only being pressure changers). I have tried using calculator blocks around different components (namely compressors and pipes) but none are allowing me to simulate a pressure drop the way I'd like. I figure the correct way to simulate this pressure drop would be with one of the custom user models, namely User2 (I've been eyeing it because I already have an excel sheet with the relevant formulae), however I'm sure any user model would work. I'm not exactly sure of how these user models work, however. Could anyone walk me through how to create a custom user model in Aspen, or point me to a tutorial? The section of the User Models documentation relevant to User and User2 hasn't been especially helpful to me.
Which property package are you using? What type of mixture are you purifying?
Because if it is non-ionic I would much better recommend you to use HYSYS and you can use a custom model in BVA and excel workbook for AspenHYSYS. Calculator blocks and spreadsheets are often not the best options because they seek to solve the balance on its entirety and it favors the property package (which seeks to minimize error regardless of the results you seek).
I would happily help if you give me conditions for the Xenon you are trying to use and the pressure drop you are attempting.