I am working on urea production from liquid ammonia and CO2. I used the SR-Polar thermo. property. However, whenever the simulation is ran, the urea reactor (modeled as Rplug) does not solve. It says DGFORM and DHFORM is missing. How can go about specifying these enthalpy and Gibbs energy of formation? What's the way around this problem?
Hi Mister Ojelade.
You can add the databank Combust to try solving your problem.
The way to do it is: Aspen Properties-Components Tab-Specifications-Enterprise Database. You have to move the Combust database from Available Databanks to Selected Databanks.
Regards.
Also, you can find in the books, for instance, Perry´s Handbook the values of DHFORM and DGFORM and adding into the Aspen Properties:
Methods tab-Parameters-Pure components-New-Scalar.
You have to choose the DHFORM and DGFORM, the units and write the numerical value.
Regards.
Hello, I have the same problem. Some people say, that there are problems with the MS SQL-Server. However, I can't fix it. So if I want to solve this problem manually, I should use Perry's Chemical Engineers Handbook? I don't have this book right now, but is there some data concerning DHFORM, DGFORM or DHAQFM?
Thanks for your help.
I have the same problem here:
* WARNING IN PHYSICAL PROPERTY SYSTEM
POLAR PARAMETERS CANNOT BE ESTIMATED FOR UREA
DEFAULT VALUES OF ZERO ASSUMED
->Table Generation begins ...
VAPOR PRESSURE MODEL PL0XANT HAS MISSING PARAMETERS:
PLXANT/1ST ELEMENT (DATA SET 1) MISSING FOR COMPONENT UREA
****PROPERTY PARAMETER ERROR
ERRORS ENCOUNTERED IN CALCULATION OF VAPOR-LIQUID K-VALUES USING
OPTION SET SR-POLAR FOR KVL.
! Calculations stopped because of missing property parameters
And I don't really know the best way to solve it.
Thank you guys in advance for any sort of help