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Specialty Chemistry Forums => Chemical Engineering Forum => Topic started by: df1 on December 11, 2017, 08:16:22 PM

Title: Modelling Gasifier in Aspen Plus
Post by: df1 on December 11, 2017, 08:16:22 PM
Hi there,

I have a working model for the entrained flow gasifier specifically for coal

Trying to adapt the model to accept waste plastic input instead of coal, but end up with a warning for my pyrolysis reactor (RYIELD)

The error reads as:

THE FOLLOWING ELEMENTS ARE NOT IN ATOM BALANCE:
   C     H     S     N

Has this problem ever occured for you, trying to run simulation in Aspen Plus
Title: Re: Modelling Gasifier in Aspen Plus
Post by: sjb on December 12, 2017, 04:20:55 AM
No, but I'm not sure plastics would generally have sulfur in them, at least not common ones.

Are you trying e.g. to balance an equation of the form CwHxOySz -> CO2 + H2O + SO3?

Sorry, not familiar with what Aspen actually is, in this instance
Title: Re: Modelling Gasifier in Aspen Plus
Post by: df1 on December 12, 2017, 08:33:28 PM
In that case,

Is there any tutorial/ solved problem for modelling entrained gas flow gasifier for Aspen Plus software that I can refer to?
Title: Re: Modelling Gasifier in Aspen Plus
Post by: df1 on December 12, 2017, 11:46:32 PM
I have done a quick diagnostic check of the atomic balance and this is the result



   Block: PYROLYS  Model: RYIELD
            MOLES IN    MOLES OUT   MASS IN     MASS OUT    REL DIFF
            KMOL/SEC    KMOL/SEC    KG/SEC      KG/SEC
      C     0.5415E-02  0.4717E-02  0.6504E-01  0.5665E-01  0.1481     *
      O     0.5899E-04  0.7161E-04  0.9437E-03  0.1146E-02  0.2140     *
      H     0.6303E-02  0.4761E-02  0.6353E-02  0.4799E-02  0.3239     *
      S     0.3387E-04  0.4223E-04  0.1086E-02  0.1354E-02  0.2471     *
      N     0.2331E-04  0.3878E-04  0.3265E-03  0.5432E-03  0.6635     *
      CL     0.000      0.7985E-05   0.000      0.2831E-03  0.7985E-05
      ASH                           0.2908E-02  0.1188E-01   3.085
  *   WARNING
      THE FOLLOWING ELEMENTS ARE NOT IN ATOM BALANCE:
      C     H     S     N
Title: Re: Modelling Gasifier in Aspen Plus
Post by: df1 on December 15, 2017, 10:34:59 PM
Quote from: sjb on December 12, 2017, 04:20:55 AM
No, but I'm not sure plastics would generally have sulfur in them, at least not common ones.

Are you trying e.g. to balance an equation of the form CwHxOySz -> CO2 + H2O + SO3?

Sorry, not familiar with what Aspen actually is, in this instance

No SO3 but it does have CO, H2, CO2, H20, H2S, N2, CH4 and C6H6