source: mso/sample/optimization/ammonia.mso @ 78

#* Sample file showing how to model a ammonia process
* Using EMSO with the VRTherm thermodynamic and physical
* property prediction.
*
* This file is free distributed without any guarantee.
* VRThech Tecnologias Industriais Ltda.
*#

using "stage_separators/flash";
using "mixers_splitters/splitter";

# A simple ideal compressor
Model Compressor
        PARAMETERS
ext PP as CalcObject;
ext NComp as Integer;
        
        VARIABLES
in      Inlet as stream;
out     Outlet as stream_therm;

        EQUATIONS
        "Isentropic expansion"
        PP.VapourEntropy(Outlet.T, Outlet.P, Outlet.z) = 
                PP.VapourEntropy(Inlet.T, Inlet.P, Inlet.z);
        
        "Global Molar Balance"
        Inlet.F = Outlet.F;
        "Component Molar Balance"
        Inlet.z = Outlet.z;
        
        "vaporization fraction "
        Outlet.v = 1.0;
end

# A simple 2 Inlet mixer.
Model Mixer
        PARAMETERS
ext PP as CalcObject;
ext NComp as Integer;
        
        VARIABLES
in      Inlet1 as stream;
in      Inlet2 as stream;
out     Outlet as stream_therm;

        EQUATIONS
        "Energy Balance"
        Outlet.F * Outlet.h = Inlet1.F * Inlet1.h + Inlet2.F * Inlet2.h;
        
        Inlet1.P = Outlet.P;
        
        "Global Molar Balance"
        Inlet1.F + Inlet2.F = Outlet.F;
        "Component Molar Balance"
        Inlet1.z*Inlet1.F + Inlet2.z*Inlet2.F = Outlet.F * Outlet.z;
        "vaporization fraction"
        Outlet.v = Inlet1.v;
end

# A simple 'conversion' based reactor.
Model Reactor
        PARAMETERS
ext PP as CalcObject;
ext NComp as Integer;
        NReac as Integer(Default=1);
        stoic(NComp, NReac) as Real (Brief = "Stoichiometric Matrix");
        comp(NReac) as Integer(Default=1, Brief = "Key Component of the reaction");
        
        VARIABLES
in      Inlet as stream;
out     Outlet as stream_therm;
        Outletz(NComp) as fraction;
        X(NReac) as fraction(Brief="Convertion of the key component");
        
        EQUATIONS
        "Energy Balance"
        Outlet.F * Outlet.h = Inlet.F * Inlet.h;
        
        "Global Molar Balance"
        Outlet.F = Inlet.F * (1 - sum(Outletz));
        
        for i in [1:NComp]
                "Component Molar Balance"
                Outletz(i) = Inlet.z(i) + sum(stoic(i,:)*X*Inlet.z(comp));
        end
        
        "Normalize the outlet composition"
        Outlet.z * sum(Outletz) = Outletz;

        Outlet.P = Inlet.P;
        
        "vaporization fraction"
        Outlet.v = Inlet.v;
end

# Ammonia Process
FlowSheet Ammonia
        PARAMETERS
        PP      as CalcObject(Brief="Physical Properties", File="vrpp");
        NComp   as Integer;
        SET
        PP.Components = ["hydrogen", "nitrogen", "argon", "methane", "ammonia"];
        PP.LiquidModel = "APR";
        PP.VapourModel = "APR";
        NComp = PP.NumberOfComponents;
        
        DEVICES
        FEED   as streamTP;
        C101   as Compressor;
        R101   as Reactor;
        F101   as flash_Steady;
        F102   as flash_Steady;
        S101   as splitter;
        M101   as Mixer;
        M102   as Mixer;
        C102   as Compressor;

        VARIABLES
        purity as fraction(Brief="Purity of the product");
        production as flow_mol(Unit = "lbmol/h", Brief="Ammonia in the product");
        loose as flow_mol(Unit = "lbmol/h", Brief="Ammonia in the purge");
        Q1 as heat_rate;
        Q2 as heat_rate;

        CONNECTIONS
        FEED           to   M101.Inlet1;
        M101.Outlet    to   C101.Inlet;
        C101.Outlet    to   M102.Inlet1;
        M102.Outlet    to   R101.Inlet;
        R101.Outlet    to   F101.Inlet;
        F101.OutletL   to   F102.Inlet;
        F102.OutletV   to   M101.Inlet2;
        F101.OutletV   to   S101.Inlet;
        S101.Outlet1   to   C102.Inlet;
        C102.Outlet    to   M102.Inlet2;
        
        Q1             to   F101.Q;
        Q2             to   F102.Q;     
        
        SET
        R101.comp = 2; # Key component of the reaction
        R101.stoic = [-3, -1, 0, 0, 2]; # Stoichiometry of the reaction

        SPECIFY
        FEED.F = 2000 * "lbmol/h";
        FEED.T = (27 + 273.15) * "K";
        FEED.P = 10 * "atm";
        FEED.z = [0.74, 0.24, 0.01, 0.01, 0.0];
        
        C101.Outlet.P = 200 * "atm";
        C102.Outlet.P = 200 * "atm";
        
        R101.X = 0.4; # Convertion of the reactor
        
        F101.OutletV.P = 199 * "atm";
        F101.OutletV.T = (-34 + 273.15) * "K";
        
        F102.OutletV.P = 10 * "atm";
        F102.Q = 0 * "kJ/h";
        
        # We can choose between one of the following specs
        S101.frac = 0.78; # Recycle fraction
        #loose = 1 * "lbmol/h"; # Ammonia in the purge
        
        EQUATIONS
        production = purity * F102.OutletL.F;
        purity = F102.OutletL.z(5);
        loose  = S101.Outlet2.F * S101.Outlet2.z(5);
        
        OPTIONS
        mode = "steady";
        relativeAccuracy = 1e-5;
end