source: trunk/eml/reactors/equil.mso @ 403

#*---------------------------------------------------------------------
* EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC.
*
* This LIBRARY is free software; you can distribute it and/or modify
* it under the therms of the ALSOC FREE LICENSE as available at
* http://www.enq.ufrgs.br/alsoc.
*
* EMSO Copyright (C) 2004 - 2007 ALSOC, original code
* from http://www.rps.eng.br Copyright (C) 2002-2004.
* All rights reserved.
*
* EMSO is distributed under the therms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*
*----------------------------------------------------------------------
* Model of an equilibrium reactor
*----------------------------------------------------------------------
*
*
*
*----------------------------------------------------------------------
* Author: Rodolfo Rodrigues
* $Id$
*--------------------------------------------------------------------*#

using "tank_basic";


#*---------------------------------------------------------------------
*       only vapour phase
*--------------------------------------------------------------------*#

Model equil_vap as tank_vap
        ATTRIBUTES
        Pallete         = true;
        Icon            = "icon/cstr"; 
        Brief           = "Model of a generic vapour-phase Equilibrium CSTR";
        Info            = "
Requires the information of:
* number of reactions
* matrix of stoichiometric coefficients (compounds, reaction)
";

        PARAMETERS
        NReac           as Integer              (Brief="Number of reactions", Default=1);
    stoic(NComp,NReac) as Real  (Brief="Stoichiometric matrix");
        Rg                      as Real                 (Brief="Universal gas constant", Unit='J/mol/K', Default=8.314);
        fs(NComp)       as pressure     (Brief="Fugacity in standard state", Default=1, DisplayUnit='atm');
        T0                              as temperature  (Brief="Reference temperature", Default=298.15);

        VARIABLES
out Outlet              as vapour_stream; # Outlet stream

        Gs(NComp)       as energy_mol   (Brief="Gibbs energy in standard state");
        K(NReac)        as Real                 (Brief="Equillibrium constant",Default=1.5);
        activ(NComp)as Real             (Brief="Activity",Default=0.2);
        phi(NComp)      as fugacity             (Brief="Fugacity coefficient", Default=1);
        
        rate(NComp) as reaction_mol (Brief="Overall component rate of reaction");
        extent(NReac) as flow_mol       (Brief="Extent of reaction");
        conv(NComp) as Real             (Brief="Fractional conversion of component", Default=0); # Lower=-1e3, Upper=1e3);
        
        EQUATIONS
        "Outlet stream"
        Outlet.F*Outlet.z = Outletm.F*Outletm.z + rate*V;
        
        "Mechanical equilibrium"
        Outlet.P = Outletm.P;
        
        "Energy balance"
        Outlet.F*Outlet.h = Outletm.F*Outletm.h;
        
        "Steady-state"
        Outlet.F = Inlet.F+sum(sumt(stoic*extent));

        "Gibbs Energy of Formation"
        Gs = PP.IdealGasGibbsOfFormation(Outlet.T);

#       "Gibbs Energy of Formation without Cp correction"
#       Gs = PP.IdealGasGibbsOfFormationAt25C()*Outlet.T/T0+PP.IdealGasEnthalpyOfFormationAt25C()*(1-Outlet.T/T0);

        "Equilibrium constant"
        K = exp(-sumt(Gs*stoic)/(Rg*Outlet.T));
        
        for j in [1:NReac]
        "Equilibrium"
                K(j) = prod(activ^stoic(:,j));
        end

        for i in [1:NComp]
        "Outlet molar fraction"
                Outlet.F*Outlet.z(i) = (Inlet.F*Inlet.z(i) + sumt(stoic(i,:)*extent));
        end     

        for i in [1:NComp]
          if (Outletm.z(i) > 0) then
            "Molar conversion"
            Outlet.F*Outlet.z(i) = Outletm.F*Outletm.z(i)*(1 - conv(i));
          else if (Outlet.z(i) > 0) then
                        "Molar conversion"
                                conv(i) = 1;    # ?
                        else
                        "Molar conversion"
                                conv(i) = 0;    # ?
                        end
          end
        end

        "Fugacity coefficient"
        phi = PP.VapourFugacityCoefficient(Outlet.T,Outlet.P,Outlet.z);

        "Activity"
        activ = phi*Outlet.P*Outlet.z/fs;
end