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Aspen Plus Simulation Error!

simulation error aspen plus surfactant defining new chemicals

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#1 sukanta87

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Posted 27 June 2017 - 04:59 PM

Hi,

 

I am working on this simulation. I have defined a new chemical in this providing the molecular structure, and the properties data were generated by the NIST TDE in the Aspen. With two other chemicals (water, and glucose) in a mixure once It was solved properly.  Then I added another new chemical defining the molecular structure but When I am running the simulation it's showing error. I have reseted the things, done completely new simulation several times but the things are showing the almost same kind of error. Even later the first 'solved' program was created again but it's also showing the error! Some errors are coming surprisingly new and seems they should not be. The typical errors in this simulation are given below:

 

" << Run reinitialized 16:26:46 Tue Jun 27, 2017>>



->Processing input specifications ...

  *   WARNING IN PHYSICAL PROPERTY SYSTEM
      THE FOLLOWING CONVENTIONAL COMPONENTS WERE NOT IN A DATA BANK.
      CHECK DATA BANK NAMES FOR SPELLING.
      CID       DATA BANK NAME
        SURFACTA  N23E2

      STRUCTURE FOR COMPONENT SURFACTA HAS NOT BEEN DEFINED.
      PCES CANNOT USE GROUP-CONTRIBUTION METHODS TO ESTIMATE MISSING PROPERTIES
      USE THE STRUCTURES PARAGRAPH TO DEFINE STRUCTURES OF THIS COMPONENT.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINSON LINE
66
      STREAM NAME: GLUC
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINS
ON LINE 70
     
STREAMNAME:SURFA
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINSON LINE
74
      STREAM NAME: WATER
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  Flowsheet
Analysis :

 COMPUTATION ORDER FOR THE FLOWSHEET:
 MIX

->Calculations begin ...

      VAPOR PRESSURE MODEL PL0XANT HAS MISSING PARAMETERS:
      PLXANT/1ST ELEMENT (DATA SET 1) MISSING FOR COMPONENT SURFACTA

  ****PROPERTY PARAMETER ERROR
      ERRORS ENCOUNTERED IN CALCULATION OF VAPOR-LIQUID K-VALUES USING
      OPTION SET UNIFAC FOR KVL.

! Calculations stopped because of missing  property parameters
<reset scope>
<reset scope>


->Processing input specifications ...

  *   WARNING IN PHYSICAL PROPERTY SYSTEM
      THE FOLLOWING CONVENTIONAL COMPONENTS WERE NOT IN A DATA BANK.
      CHECK DATA BANK NAMES FOR SPELLING.
      CID       DATA BANK NAME
        SURFACTA  N23E2

      STRUCTURE FOR COMPONENT SURFACTA HAS NOT BEEN DEFINED.
      PCES CANNOT USE GROUP-CONTRIBUTION METHODS TO ESTIMATE MISSING PROPERTIES
      USE THE STRUCTURES PARAGRAPH TO DEFINE STRUCTURES OF THIS COMPONENT.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINS
ON LINE 66
      STREAM NAME: GLUCOSE
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINS
ON LINE 70
      STREAM NAME: SURFACTA
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  *   WARNING IN THE "STREAM" PARAGRAPH WHICH BEGINS
ON LINE 74
      STREAM NAME: WATER
      COMPONENT MOLE FLOWS OF SUBSTREAM: "MIXED"
      ARE NORMALIZED TO THE TOTAL MOLE FLOW VALUE.

  FlowsheetAnalysis :

 COMPUTATION ORDER FOR THE FLOWSHEET:
 MIX

->Calculations begin ...

      VAPOR PRESSURE MODEL PL0XANT HAS MISSING PARAMETERS:
      PLXANT/1ST ELEMENT (DATA SET 1) MISSING FOR COMPONENT SURFACTA

  ****PROPERTY PARAMETER ERROR
      ERRORS ENCOUNTERED IN CALCULATION OF VAPOR-LIQUID K-VALUES USING
      OPTION SET UNIFAC FOR KVL.

! Calculations stopped because of missing  property parameters"

 

 

Can anybody advice me how to solve this problem?

 

Regards,

 

 



#2 Mahdi1980

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Posted 27 June 2017 - 09:00 PM

Hi,

It seems that you have two problems; 1st is defining your third material since Aspen cannot find it in the data bank.

2nd is selecting an unsuitable property package.

 

You should find the material in the data bank of Aspen and according to the nature of the material and mixing with other materials, select the best property package/ EOS.



#3 sukanta87

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Posted 28 June 2017 - 05:03 PM

Mahdi, thank you for your reply. The chemical I was defining is a new chemical in the market, and is not mentioned in the aspen library. There is the 'User Defined' option in the 'Components' tab. This option was used. UNIFAC method was selected earlier and the simulation was solved then.

 

When I  defined another unknown component which isn't in the aspen library then the problem occurs. I can't even run the previous simulation which was okay earlier. I think somehow they are getting linked and making errors.

 

I have tried with UNIQUAC and NRTL methods also. Doesn't work. The guideline for the method selection in aspen was followed. A part of this is attached herewith.

 

 

Attached File  Method.PNG   37.24KB   4 downloads

 

In addition, the process is in low pressure.

 

 

 

 



#4 Saml

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Posted 28 June 2017 - 10:46 PM

You are using an activity coefficient model. So you calculate the liquid activity. To estimate the vapor liquid equilibrium it needs the ideal vapor pressure at T.  In your setup this is done by the Extende Antoine Equation, and the parameters are the PLXANT 1 to 9.

You only need to set the 1st one to a low value to declare the material as non volatile (say 1E-10)

This parameter being missing and not being able to calculate the VL equilibrim is what appears that Aspen is complaining about.

Search the web or Aspen Support site for ASpen Physical Property System document for an explanation of the different equations used by Aspen.



#5 sukanta87

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Posted 30 June 2017 - 10:36 PM

Hi Saml, thank you. I have changed the pressure to very low as you mentioned. The phases is also declared as 'Liquid-only'. I have used different methods for the thermodynamic properties. But could not solve the problem. 






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