#*---------------------------------------------------------------------
* 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 a Gibbs reactor
*----------------------------------------------------------------------
*
*   Description:
*       Thermodynamic equilibrium modeling of a reactor using Gibbs
*	free energy minimization approach.
*
*   Assumptions:
*		* single-phases involved
*       * thermodynamic equilibrium
*		* steady-state
*
*	Specify:
*		* inlet stream
*		* number of elements related to components
*		* matrix of elements by components
*		* equilibrium temperature
*
*----------------------------------------------------------------------
* Author: Rodolfo Rodrigues
* $Id$
*--------------------------------------------------------------------*#

using "tank_basic";


#*---------------------------------------------------------------------
*	only vapour phase
*--------------------------------------------------------------------*#
Model gibbs_vap as tank_vap
	ATTRIBUTES
	Pallete = true;
	Icon 	= "icon/cstr"; 
	Brief 	= "Model of a generic vapour-phase Gibbs CSTR";
	Info 	= "
== Assumptions ==
* thermodynamic equilibrium
* steady-state

== Specify ==
* inlet stream
* number of elements related to components
* matrix of elements by components
* equilibrium temperature
";

	PARAMETERS
outer NElem			as Integer 		(Brief="Number of elements", Default=1);
	Rg				as Real			(Brief="Universal gas constant", Unit='J/mol/K', Default=8.314);
	na(NElem,NComp)	as Real			(Brief="Number of elements per component");
	fs(NComp) 		as pressure 	(Brief="Fugacity in standard state", Default=1, DisplayUnit='atm');
	To				as temperature  (Brief="Reference temperature", Default=298.15);
	
	VARIABLES
out Outlet			as vapour_stream(Brief="Outlet stream", PosX=1, PosY=1, Symbol="_{out}");

	G(NComp)		as energy_mol 	(Brief="Gibbs free-energy change of formation");
	lambda(NElem)	as energy_mol 	(Brief="Lagrangian multiplier", Symbol="\lambda");
	activ(NComp)	as Real 		(Brief="Activity", Symbol="\hat{a}", Lower=0);
	
	rate(NComp) 	as reaction_mol (Brief="Overall component rate of reaction");
	conv(NComp)   	as Real 		(Brief="Fractional conversion of component", Symbol="X", Default=0);
	Fi(NComp)		as flow_mol		(Brief="Component molar flow rate");

	EQUATIONS
	"Outlet stream"
	Outlet.F*Outlet.z = Outletm.F*Outletm.z + rate*Tank.V;
	
	"Mechanical equilibrium"
	Outlet.P = Outletm.P;

	"Steady-state"
	Outlet.F = sum(Fi);

	"Component molar flow rate"
	Fi = Outlet.F*Outlet.z;
	
	"Energy balance"
	Outlet.F*Outlet.h = Outletm.F*Outletm.h;

	"Element balance"
	sumt(Fi*na) = sumt(Outletm.F*Outletm.z*na);

	"Gibbs free-energy of formation"
	G = PP.IdealGasGibbsOfFormation(Outlet.T);

#	"Gibbs free-energy of formation without Cp correction"
#	G = PP.IdealGasGibbsOfFormationAt25C()*Outlet.T/To
#		+ PP.IdealGasEnthalpyOfFormationAt25C()*(1 - Outlet.T/To);

	for i in [1:NComp]
	"Lagrangian multiplier"
		G(i) + sumt(lambda*na(:,i)) = -Rg*Outlet.T*ln(activ(i));

	  if (Outletm.z(i) > 0) then
	    "Molar conversion"
	    Fi(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
	
	"Activity"
	activ = PP.VapourFugacityCoefficient(Outlet.T,Outlet.P,Outlet.z)
		*Outlet.P*Outlet.z/fs;
end


#*---------------------------------------------------------------------
*	only liquid phase
*--------------------------------------------------------------------*#
Model gibbs_liq as tank_liq
	ATTRIBUTES
	Pallete = true;
	Icon 	= "icon/cstr"; 
	Brief 	= "Model of a generic liquid-phase Gibbs CSTR";
	Info 	= "
== Assumptions ==
* thermodynamic equilibrium
* steady-state

== Specify ==
* inlet stream
* number of elements related to components
* matrix of elements by components
* equilibrium temperature
";

	PARAMETERS
outer NElem			as Integer 		(Brief="Number of elements", Default=1);
	Rg				as Real			(Brief="Universal gas constant", Unit='J/mol/K', Default=8.314);
	na(NElem,NComp)	as Real			(Brief="Number of elements per component");
	Ps				as pressure		(Brief="Pressure of standard state", Default=1, DisplayUnit='atm');
	To				as temperature  (Brief="Reference temperature", Default=298.15);
	
	VARIABLES
out Outlet			as liquid_stream(Brief="Outlet stream", PosX=1, PosY=1, Symbol="_{out}");

	G(NComp)		as energy_mol 	(Brief="Gibbs free-energy change of formation");
	lambda(NElem)	as energy_mol 	(Brief="Lagrangian multiplier", Symbol="\lambda");
	activ(NComp)	as Real 		(Brief="Activity", Symbol="\hat{a}", Lower=0);
	
	rate(NComp) 	as reaction_mol (Brief="Overall component rate of reaction");
	conv(NComp)   	as Real 		(Brief="Fractional conversion of component", Symbol="X", Default=0);
	Fi(NComp)		as flow_mol		(Brief="Component molar flow rate");

	EQUATIONS
	"Outlet stream"
	Outlet.F*Outlet.z = Outletm.F*Outletm.z + rate*Tank.V;
	
	"Mechanical equilibrium"
	Outlet.P = Outletm.P;

	"Steady-state"
	Outlet.F = sum(Fi);

	"Component molar flow rate"
	Fi = Outlet.F*Outlet.z;
	
	"Energy balance"
	Outlet.F*Outlet.h = Outletm.F*Outletm.h;

	"Element balance"
	sumt(Fi*na) = sumt(Outletm.F*Outletm.z*na);
	
	"Gibbs free-energy of formation"
	G = PP.IdealGasGibbsOfFormation(Outlet.T);

#	"Gibbs free-energy of formation without Cp correction"
#	G = PP.IdealGasGibbsOfFormationAt25C()*Outlet.T/To
#		+ PP.IdealGasEnthalpyOfFormationAt25C()*(1 - Outlet.T/To);

	for i in [1:NComp]
	"Lagrangian multiplier"
		G(i) + sumt(lambda*na(:,i)) = -Rg*Outlet.T*ln(activ(i));

	  if (Outletm.z(i) > 0) then
	    "Molar conversion"
	    Fi(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
	
	"Activity"
	activ = PP.LiquidFugacityCoefficient(Outlet.T,Outlet.P,Outlet.z)*Outlet.z
		*exp(PP.LiquidVolume(Outlet.T,Outlet.P,Outlet.z)*(Outlet.P - Ps)/Rg/Outlet.T);
end