Gasification

Discusses use of CAPE-OPEN compliant Process Modelling Components

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Gasification

Postby hiren » 31 October 2018, 16:41

Hello, in the attached file can i eliminate fixed conversion reactor and carry out the reactions currently happening in fixed conversion reactor to take place in CSTR and gibbs used ahead itself ....as it shows some equilibrium error?
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Re: Gasification

Postby jasper » 01 November 2018, 15:30

The warnings can be ignored for now - but I will check its cause.
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Re: Gasification

Postby hiren » 01 November 2018, 16:53

Sir what about the rections happening in fixed conversion reactor which i actually want to carry out in cstr & gibbs, and remove the fixed conversion reactor.
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Re: Gasification

Postby jasper » 02 November 2018, 08:38

The Gibbs reactor is not an option - phase changes are not accounted for in the Gibbs minimization.

The CSTR uses the reaction phase to calculate the equilibrium constants or reaction rates. In the next version of the reaction specification this will change and the CSTR may be adapted, but in the current version of the reaction specification these properties are associated with a phase. Therefore the CSTR is also not an option for multi-phase reactions like these.

What kinetics or equilibrium model do you have? Or do you want to perform a Gibbs minimization?
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Re: Gasification

Postby hiren » 03 November 2018, 15:14

The data which i have used and what i intend to do is given here
http://www.ep.liu.se/ecp/119/015/ecp15119015.pdf

my fsd file is also attached.
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Re: Gasification

Postby jasper » 05 November 2018, 08:46

The process type suggests that, as the concentration of CO2 is used in the kinetics, electrolyte thermodynamics should be used for an accurate description. However, the article itself states that SRK is used.

Modelling of the CSTR seems fairly straight forward, using e.g. Excel, Matlab or Scilab and a simple equation solver to solve for the reaction extents for which the reaction rates match the kinetic expression.

Modelling of the Gibbs reactor requires inclusion of a Gibbs term for carbon. The remaining terms can simply be obtained from G = H - T * S where H = enthalpyF and S is entropyF. Also this can be done in Excel, Matlab or Scilab, using a multi-dimensional minimization (e.g. modify reaction extents so that total Gibbs energy is minimized).
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Re: Gasification

Postby jasper » 05 November 2018, 08:47

Care should be taken that the Gibbs term for carbon uses the same reference state as the remaining Gibbs terms.
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