COMSOL 6.3 - Syngas Combustion in a Round-Jet Burner

This model simulates turbulent combustion of syngas (synthesis gas) in a simple round jet burner. Syngas is a gas mixture, primarily composed of hydrogen, carbon monoxide and carbon dioxide. The name syngas relates to its use in creating synthetic natural gas.

The model setup corresponds to the one studied by Couci and others in Ref. 1. The temperature and composition resulting from the nonpremixed combustion in the burner setup have also been experimentally investigated by Barlow and coworkers (Ref. 2 and Ref. 3) as a part of the International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames (Ref. 4). The model is solved in COMSOL Multiphysics by combining a Reacting Flow and a Heat Transfer in Fluids interface.

Model Definition

The burner studied in this model consists of a straight pipe placed in a slight coflow. The gas phase fuel is fed through the pipe using an inlet velocity of 76 m/s, while the coflow velocity outside of pipe is 0.7 m/s. At the pipe exit, the fuel gas mixes with the coflow, creating an unconfined circular jet. The gas fed through the tube consists of three compounds typical of syngas: carbon monoxide (CO), hydrogen (H2), and nitrogen (N2). The coflow gas consists of air. At the pipe exit, the fuel is ignited. Since the fuel and oxidizer enter the reaction zone separately, the resulting combustion is of the nonpremixed type. A continuous reaction requires that the reactants and the oxidizer are mixed to stoichiometric conditions. In this setup, the turbulent flow of the jet effectively mixes the fuel from the pipe with the coflowing oxygen. Furthermore, the mixture needs to be continuously ignited. In this burner the small recirculation zones generated by the pipe wall thickness provide the means to decelerate hot product gas. The recirculation zones hereby promote continuous ignition of the oncoming mixture and stabilizes the flame at the pipe orifice. In experiments (Ref. 4), no lift-off or localized extinction of the flame has been observed.

In the current model, the syngas combustion is modeled using two irreversible reactions:

(1)

This assumption of a complete oxidation of the fuel corresponds to one of the approaches used in Ref. 1. The mass transport in the reacting jet is modeled by solving for the mass fractions of six species: the five species participating in the reactions and nitrogen N2 originating in the coflowing air.

The Reynolds number for the jet, based on the inlet velocity and the inner diameter of the pipe, is approximately 16,700, indicating that the jet is fully turbulent. Under these circumstances, both the mixing and the reactions processes in the jet are significantly influenced by the turbulent nature of the flow. To account for the turbulence when solving for the flow field, the k-ω turbulence model is applied.

Taking advantage of the symmetry, a two-dimensional model using a cylindrical coordinate system is solved.

Turbulent reaction rate

When using a turbulence model in a Reacting Flow interface, the production rate (SI unit: kg/(m3·s)) of species i resulting from reaction j is modeled as the minimum of the mean-value-closure reaction rate and the eddy-dissipation-model rate:

The mean-value-closure rate is the kinetic reaction rate expressed using the mean mass fractions. This corresponds to the characteristic reaction rate for reactions that are slow compared to the turbulent mixing, or the reaction rate in regions with negligible turbulence levels. This can be quantified through the Damköhler number, which compares the turbulent time scale (τT) to the chemical time scale (τc). The mean-value-closure is appropriate for low Damköhler numbers:

The reaction rate defined by the eddy-dissipation model (Ref. 5) is

(2)

where τT (SI unit: s) is the mixing time scale of the turbulence, ρ is the mixture density (SI unit: kg/m3), ω is the species mass fraction, ν denotes the stoichiometric coefficients, and M is the molar mass (SI unit: kg/mol). Properties of reactants of the reaction are indicated using a subscript “r,” while product properties are denoted by a subscript “p”.

The eddy-dissipation model assumes that both the Reynolds and Damköhler numbers are sufficiently high for the reaction rate to be limited by the turbulent mixing time scale τT. A global reaction can then at most progress at the rate at which fresh reactants are mixed, at the molecular level, by the turbulence present. The reaction rate is also assumed to be limited by the deficient reactant; the reactant with the lowest local concentration. The model parameter β specifies that product species is required for reaction, modeling the activation energy. For gaseous nonpremixed combustion the model parameters have been found to be (Ref. 5):

In the current model the molecular reaction rate of the reactions is assumed to be infinitely fast. This is achieved in the model by prescribing unrealistically high rate constants for the reactions. This implies that the production rate is given solely by the turbulent mixing in Equation 2.

It should be noted that the eddy-dissipation model is a robust but simple model for turbulent reactions. The reaction rate is governed by a single time scale, the turbulent mixing time-scale. For this reason, the reactions studied should be limited to global one-step (as in Equation 1) or two-step reactions.

thermal properties — heat of reaction and heat capacity

In this model, a thermodynamic system including all present species is set up. The system is used to define species as well as mixture properties dependent on temperature and composition. When coupling the Chemistry interface to the Thermodynamic system, all thermodynamic and transport properties needed are automatically defined.

Two of the thermal properties needed are the heat of reaction and the heat capacity of the mixture. Figure 1 shows the variation of enthalpy of formation with temperature for all individual species. The enthalpy of formation is seen to increase with temperature for all species, and accurate results will be obtained by taking the temperature-dependence into consideration.

Figure 1: Enthalpy of formation for all individual species.

The heat capacities for all species in the system plotted against temperature are seen in Figure 2. As for the enthalpy of formation, all species’ heat capacities increase with temperature, making it relevant to also take the temperature-dependence on heat capacity into consideration.

Figure 2: Heat capacity for all individual species.

The heat of formations for each species at T = 298 K are given in Table 1 and the heat capacities at T = 300 K and T = 2000 K are given in Table 2. Both tables compare data based on Ref. 6 and Ref. 7 to calculated values from COMSOL. By using these values in Equation 3, the heat of formation at T = 298 K can be calculated. Since the heat of formation of the products is lower than that of the reactants, both reactions are exothermic and release heat:

(3)

Table 1: Species enthalpy of formation at 298.15 K from both reference data and comsol.
Species	ΔHf (kJ/mol) T = 298.15 K (Ref. 6)	ΔHf (kJ/mol) T = 298.15 K (COMSOL)
N2	0	0
H2	0	0
O2	0	0
H2O	-241.84	-241.82
CO	-110.54	-110.53
CO2	-393.55	-393.98

Table 2: Species heat capacity at 300 K and 2000 K from both reference data and comsol.
Species	Cp (J/mol/K) T = 300 K (Ref. 6, Ref. 7 for CO and CO2)	Cp (J/mol/K) T = 300 K (COMSOL)	Cp (J/mol/K) T = 2000 K (Ref. 6)	Cp (J/mol/K) T = 2000 K (COMSOL)
N2	29.075	29.142	35.987	36.368
H2	28.878	28.857	34.238	34.528
O2	29.330	29.395	37.790	37.882
H2O	33.468	33.602	51.145	51.193
CO	29.035	29.136	33.254	36.591
CO2	37.101	37.225	54.363	61.078

Results and Discussion

The resulting velocity field in the nonisothermal reacting jet is visualized in Figure 3. The expansion and development of the hot free jet is clearly seen. The turbulent mixing in the outer parts of the jet acts to accelerate fluid originating in the co-flow, and incorporate it in the jet. This is commonly referred to as entrainment and can be observed in the co-flow streamlines which bend toward the jet downstream of the orifice.

Figure 3: The velocity magnitude and flow paths (streamlines) of the reacting jet.

The temperature in the jet is shown in Figure 4 where a revolved dataset has been used to emphasize the structure of the round jet. The maximum temperature in the jet is seen to be approximately 2150 K. The carbon dioxide mass fraction in the reacting jet is plotted in Figure 5. The formation of CO2 takes place in the outer shear layer of the jet. This is where the fuel from the pipe encounters oxygen in the coflow and reacts. The reactions are promoted by the turbulent mixing in the jet shear layer. It is also seen that the CO2 formation starts just outside of the pipe. This is also the case for the temperature increase in Figure 4. This implies that there is no lift-off and the flame is attached to the pipe.

In Figure 6, Figure 7, and Figure 8 the results reached in the model are compared with the experimental results of Barlow and coworkers (Ref. 2, Ref. 3, and Ref. 4). In Figure 6 the jet temperature is further examined and compared with the experiments. In the left panel the temperature along the centerline is plotted. It is seen that the maximum temperature predicted in the model is close to that in the experiment. However in the model the temperature profile is shifted in the downstream direction. This is most likely due to the fact that radiation has not been included in the model.

In the right panel of Figure 6 temperature profiles at 20 and 50 pipe diameters downstream of the pipe exit are compared with the experiments. The axial velocity of the jet is compared with the experimental results in Figure 7, using the same down stream positions. The axial velocity is found to compare well with the experimental values at both positions.

In Figure 8 the species concentration along the jet centerline is analyzed and compared with the experimental results. For some species, N2, and CO2, the axial mass fraction development agrees well with the experimental results. For the fuel species CO and H2 a fair agreement is observed. For the remaining species, O2 and H2O, the trend appears correct but the profiles are shifted downstream, as was the case with the temperature. The reason for the discrepancy in the mass fractions can in part be attributed to the fact that radiation is not included, but the accuracy is probably also significantly influenced by the simplified reaction scheme and the eddy-dissipation model.

Figure 4: Jet temperature shown using a revolved dataset.

Figure 5: CO2 mass fraction in the reacting jet.

Figure 6: Jet temperature along the centerline (left), and radially at two different positions downstream of the pipe exit (right) scaled by the inlet temperature. The centerline and radial distance is scaled by the inner diameter of the pipe. Model results are plotted using lines, while experimental results are indicated using symbols. The downstream positions are defined in terms of the inner diameter of the pipe (d).

Figure 7: Axial velocity at two different positions downstream of the pipe exit, scaled by the inlet velocity. The radial distance is scaled by the inner diameter of the pipe. Model results are plotted using lines, while experimental results are indicated using symbols.

Figure 8: Species mass fractions along the jet centerline. The centerline distance is scaled by the inner diameter of the pipe. Model results are plotted using lines, while experimental results are indicated using symbols.

References

1. A. Cuoci, A. Frassoldati, G. Buzzi Ferraris, T. Faravelli, and E. Ranzi, “The ignition, combustion and flame structure of carbon monoxide/hydrogen mixtures. Note 2: Fluid dynamics and kinetic aspects of syngas combustion,” Int. J. Hydrogen Energy, vol. 32, pp. 3486–3500, 2007.

2. R.S. Barlow, G.J. Fiechtner, C.D. Carter, and J.-Y. Chen, “Experiments on the Scalar Structure of Turbulent CO/H2/N2 Jet Flames,” Comb. and Flame, vol. 120, pp. 549–569, 2000.

3. M. Flury, Experimentelle Analyse der Mischungsstruktur in turbulenten nicht vorgemischten Flammen, PhD Thesis, ETH Zurich, 1998 (in German).

4. R.S. Barlow and others, “Sandia/ETH-Zurich CO/H2/N2 Flame Data - Release 1.1”, https://tnfworkshop.org/wp-content/uploads/2019/02/SANDchnDoc11.pdf, 2002.

5. B.F. Magnussen and B.H. Hjertager, “On Mathematical Modeling of Turbulent Combustion with Special Emphasis on Soot Formation and Combustion,” 16th Symp. (Int.) on Combustion. Comb. Inst., Pittsburgh, Pennsylvania, pp. 719–729, 1976.

6. A. Frassoldati, T. Faravelli, and E. Ranzi, “The Ignition, Combustion and Flame Structure of Carbon Monoxide/Hydrogen Mixtures. Note 1: Detailed Kinetic Modeling of Syngas Combustion Also in Presence of Nitrogen Compounds,” Int. J. Hydrog. Energy, vol. 32, pp. 3471–3485, 2007.

7. B.E. Poling, J.M. Prausnitz, and J.P. O’Connell, The Properties of Gases and Liquids, McGraw Hill, 2001.

Chemical_Reaction_Engineering_Module/Reactors_with_Mass_and_Heat_Transfer/round_jet_burner

Modeling Instructions

From the menu, choose .

New

In the window, click

Model Wizard

In the window, click

In the tree, select > > > ω.

Click .

In the tree, select .

In the text field, type 6.

In the table, enter the following settings:


wCO
wO2
wCO2
wH2
wH2O
wN2

Click

In the tree, select > .

Click

Global Definitions

Parameters 1

In the window, under click .

In the window for , locate the section.

Click

Browse to the model’s Application Libraries folder and double-click the file round_jet_burner_parameters.txt.

Geometry 1

Rectangle 1 (r1)

In the toolbar, click

In the window for , locate the section.

In the text field, type GeomW.

In the text field, type GeomH.

Click

Rectangle 2 (r2)

In the toolbar, click

In the window for , locate the section.

In the text field, type Pth.

In the text field, type Pl.

Locate the section. In the text field, type Di/2.

Click

Chamfer 1 (cha1)

In the toolbar, click

On the object , select Points 3 and 4 only.

It might be easier to select the points by using the window. To open this window, in the toolbar click and choose . (If you are running the cross-platform desktop, you find in the main menu.)

In the window for , locate the section.

In the text field, type Pth*0.15.

Click

Click the

button in the toolbar.

Polygon 1 (pol1)

In the toolbar, click

In the window for , locate the section.

From the list, choose .

In the text field, type GeomW GeomW*1.5 GeomW*1.5 GeomW.

In the text field, type 0 GeomH GeomH GeomH.

Click

Union 1 (uni1)

In the toolbar, click

and choose .

Select the objects and only.

In the window for , locate the section.

Clear the checkbox.

Click

Difference 1 (dif1)

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and choose .

Select the object only.

In the window for , locate the section.

Click to select the

toggle button for .

Select the object only.

Click

Line Segment 1 (ls1)

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and choose .

In the window for , locate the section.

From the list, choose .

In the text field, type Pl-0.15*Pth.

Locate the section. From the list, choose .

In the text field, type Di/2.

In the text field, type Pl-0.15*Pth.

Click

Line Segment 2 (ls2)

In the toolbar, click

and choose .

In the window for , locate the section.

From the list, choose .

In the text field, type Di/2+Pth.

In the text field, type Pl-0.15*Pth.

Locate the section. From the list, choose .

In the text field, type GeomW+0.5*(Pl-0.15*Pth)*GeomW/GeomH.

In the text field, type Pl-0.15*Pth.

Click

Line Segment 3 (ls3)

In the toolbar, click

and choose .

In the window for , locate the section.

From the list, choose .

In the text field, type Di/2.

In the text field, type Pl-0.15*Pth.

Locate the section. From the list, choose .

In the text field, type Di/2+(GeomH-Pl+Pth*0.15)*tan(pi/180).

In the text field, type GeomH.

Click

Line Segment 4 (ls4)

In the toolbar, click

and choose .

In the window for , locate the section.

From the list, choose .

In the text field, type Di/2+Pth.

In the text field, type Pl-0.15*Pth.

Locate the section. From the list, choose .

In the text field, type Di/2+Pth+(GeomH-Pl+Pth*0.15)*tan(5*pi/180).

In the text field, type GeomH.

Click

Form Union (fin)

In the window, click .

In the window for , click

Mesh Control Edges 1 (mce1)

In the toolbar, click

and choose .

On the object , select Boundaries 4, 8, 13, and 14 only.

In the window for , click

Click the

button in the toolbar.

Form Composite Edges 1 (cme1)

In the toolbar, click

and choose .

On the object , select Boundaries 3 and 11 only.

In the window for , click

Define a that can be used for several physical properties in the model. The system is in gas phase and consists of water, hydrogen, oxygen, nitrogen, carbon monoxide and carbon dioxide.

Global Definitions

In the toolbar, click

and choose .

Select System

Go to the window.

Click in the window toolbar.

Select Species

Go to the window.

In the list, select .

Click

In the list, select .

Click

In the list, select .

Click

In the list, select .

Click

In the list, select .

Click

In the list, select .

Click

Click in the window toolbar.

Select Thermodynamic Model

Go to the window.

Click in the window toolbar.

Global Definitions

Gas System 1 (pp1)

As stated in the section, the heat of reaction and heat capacity of the mixture are dependent on temperature and composition. To display their dependence, plots where the enthalpy of formation and heat capacity are plotted against a temperature span between 298.15 and 2000 K are later created. The functions necessary for these plots will now be obtained.

Right-click > > and choose .

Select Properties

Go to the window.

In the list, select .

Click

In the list, select .

Click

Click in the window toolbar.

Select Phase

Go to the window.

Click in the window toolbar.

Select Species

Go to the window.

Click

Click in the window toolbar.

Species Property Overview

Go to the window.

Click in the window toolbar.

Chemistry (chem)

Reaction 1

In the window, under right-click and choose .

In the window for , locate the section.

In the text field, type CO+O2=>CO2.

Click .

Since all species in the reaction are written using their chemical formulas, their molar masses are predefined to come from thermodynamics. Moreover, the reaction can also be balanced using the button.

Click in the upper-right corner of the section.

Reaction 2

In the toolbar, click

and choose .

In the window for , locate the section.

In the text field, type H2+O2=>H2O.

Click .

Click in the upper-right corner of the section.

Species 1

In the toolbar, click

and choose .

In the window for , locate the section.

In the text field, type N2.

Since a is defined earlier, the checkbox can be selected that uses the values for density and heat capacity from the system.

In the window, click .

In the window for , locate the section.

Select the checkbox.

Locate the section. Find the subsection. From the list, choose .

In the table, enter the following settings:


Species	Type	Mass fraction	Value (1)	From Thermodynamics
CO	Variable	wCO	Solved for	CO
CO2	Variable	wCO2	Solved for	CO2
H2	Variable	wH2	Solved for	H2
H2O	Variable	wH2O	Solved for	H2O
N2	Free species	wN2	Solved for	N2
O2	Variable	wO2	Solved for	O2

Click to expand the section. From the list, choose .

In the k text field, type k_mix.

From the list, choose .

In the μ text field, type mu_mix.

Set the two reactions in to be turbulent reactions.

1: 2 CO + O2 => 2 CO2

In the window, click .

In the window for , locate the section.

From the list, choose .

Select the checkbox.

Click to expand the section. Select the checkbox.

2: 2 H2 + O2 => 2 H2O

In the window, click .

In the window for , locate the section.

From the list, choose .

Select the checkbox.

Locate the section. Select the checkbox.

Transport of Concentrated Species (tcs)

In the window, under click .

In the window for , locate the section.

From the list, choose .

Locate the section. From the list, choose .

Reaction Sources 1

In the toolbar, click

and choose .

The reaction rates are defined in .

Select Domain 1 only.

In the window for , locate the section.

From the RwCO list, choose .

From the RwO2 list, choose .

From the RwCO2 list, choose .

From the RwH2 list, choose .

From the RwH2O list, choose .

Initial Values 1

In the window, click .

In the window for , locate the section.

In the ω0,wCO text field, type 0.

In the ω0,wO2 text field, type wcf_O2.

In the ω0,wCO2 text field, type 0.

In the ω0,wH2 text field, type 0.

In the ω0,wH2O text field, type 0.

Inflow 1

In the toolbar, click

and choose .

Select Boundary 2 only.

In the window for , locate the section.

From the list, choose .

In the x0,wCO text field, type x0_CO.

In the x0,wO2 text field, type x0_O2.

In the x0,wCO2 text field, type x0_CO2.

In the x0,wH2 text field, type x0_H2.

In the x0,wH2O text field, type x0_H2O.

Inflow 2

In the toolbar, click

and choose .

In the window for , locate the section.

In the ω0,wCO text field, type 1e-5.

In the ω0,wO2 text field, type wcf_O2.

In the ω0,wCO2 text field, type 1e-5.

In the ω0,wH2 text field, type 1e-5.

In the ω0,wH2O text field, type 1e-5.

Select Boundaries 9 and 10 only.

Outflow 1

In the toolbar, click

and choose .

Select Boundary 3 only.

Turbulent Flow, k-ω (spf)

Fluid Properties 1

In the window, under > ω (spf) click .

In the window for , locate the section.

Click in the upper-right corner of the section.

Locate the section. From the ρ list, choose .

From the μ list, choose .

Inlet 1

In the toolbar, click

and choose .

Select Boundary 2 only.

In the window for , locate the section.

From the list, choose .

Locate the section. In the Uav text field, type Ujet.

Inlet 2

In the toolbar, click

and choose .

Select Boundaries 9 and 10 only.

In the window for , locate the section.

Click the button.

Specify the u0 vector as


0	r
Ucf	z

Locate the section. From the IT list, choose .

From the LT list, choose .

In the text field, type 0.1*Di.

Outlet 1

In the toolbar, click

and choose .

Select Boundary 3 only.

In the window for , locate the section.

Select the checkbox.

Heat Transfer in Fluids (ht)

Initial Values 1

In the window, under > click .

In the window for , locate the section.

In the T text field, type T0.

Fluid 1

In the window, click .

In the window for , locate the section.

Click in the upper-right corner of the section.

Locate the section. From the u list, choose .

Locate the section. From the k list, choose .

Locate the section. From the ρ list, choose .

From the Cp list, choose .

Inflow 1

In the toolbar, click

and choose .

Select Boundaries 2, 9, and 10 only.

In the window for , locate the section.

In the Tustr text field, type T0.

Outflow 1

In the toolbar, click

and choose .

Select Boundary 3 only.

Mesh 1

Mapped 1

In the toolbar, click

In the window for , click to expand the section.

Clear the checkbox.

Distribution 1

Right-click and choose .

Select Boundaries 2 and 15 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 20.

In the text field, type 4.

From the list, choose .

Distribution 2

In the window, right-click and choose .

Select Boundaries 11, 16, and 17 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 200.

In the text field, type 250.

From the list, choose .

Distribution 3

Right-click and choose .

Select Boundaries 9 and 18 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 20.

In the text field, type 400.

From the list, choose .

Select the checkbox.

Distribution 4

Right-click and choose .

Select Boundaries 1, 4, and 8 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 20.

In the text field, type 200.

From the list, choose .

Select the checkbox.

Distribution 5

Right-click and choose .

Select Boundary 12 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 20.

In the text field, type 8.

From the list, choose .

Distribution 6

Right-click and choose .

Select Boundaries 3 and 13 only.

In the window for , locate the section.

From the list, choose .

In the text field, type 20.

In the text field, type 4.

From the list, choose .

Click

In the toolbar, click

Study 1

Solution 1 (sol1)

In the window, expand the node.

In the window, expand the > > > > node, then click .

In the window for , click to expand the section.

In the text field, type 0.40.

Global Definitions

The enthalpy of formation and heat capacity plots will now be created (Figure 1 and Figure 2).

Gas System 1 (pp1)

In the window, expand the > > > node.

Enthalpy of formation 1 (EnthalpyF_carbon_dioxide_Gas12, EnthalpyF_carbon_dioxide_Gas12_Dtemperature, EnthalpyF_carbon_dioxide_Gas12_Dpressure)

In the window, expand the > > > > node, then click > > > > > .

In the window for , click to expand the section.

In the table, enter the following settings:


Argument	Lower limit	Upper limit
temperature	298.15	2000

Click

Results

Enthalpy of Formation

When working with the functions, they tend to load for a while. By choosing to manually save data in the model under , it will be possible to enable under each plot group and therefore shorten the loading time.

In the window, click .

In the window for , locate the section.

From the list, choose .

In the window, click .

In the window for , type Enthalpy of Formation in the text field.

Locate the section. Select the checkbox.

1D Plot Group 2

In the window, expand the > node.

Function 1

In the window, expand the > node, then click .

Function 2

Drag and drop below > .

Drag-drop all functions into the same plot group to plot them in the same graph.

Since - are empty now, delete them.

1D Plot Group 2, 1D Plot Group 3, 1D Plot Group 4, 1D Plot Group 5, 1D Plot Group 6

In the window, under , Ctrl-click to select , , , , and .

Right-click and choose .

The same procedure will now be performed for the heat capacity functions. As before, start by creating plots for each of the heat capacity functions.

Global Definitions

Heat capacity (Cp) 1 (HeatCapacityCp_carbon_dioxide_Gas11, HeatCapacityCp_carbon_dioxide_Gas11_Dtemperature, HeatCapacityCp_carbon_dioxide_Gas11_Dpressure)

In the window, under > > > > click .

In the window for , locate the section.

In the table, enter the following settings:


Argument	Lower limit	Upper limit
temperature	298.15	2000

Click

Results

Heat Capacity

In the window for , type Heat Capacity in the text field.

Locate the section. Select the checkbox.

Repeat creating plots for the functions - using the same temperature limits.

1D Plot Group 3

In the window, expand the > node.

Function 1

In the window, expand the > node, then click .

Function 2

Drag and drop below > .

Repeat the drag-dropping of functions 3-6 into the plot group.

1D Plot Group 3, 1D Plot Group 4, 1D Plot Group 5, 1D Plot Group 6, 1D Plot Group 7

Since - are empty now, delete them.

In the window, under , Ctrl-click to select , , , , and .

Right-click and choose .

Now we have two plots: one contains all enthalpy of formation functions, one contains all heat capacity functions.

Enthalpy of Formation

In the window, under click .

In the window for , click to expand the section.

From the list, choose .

Locate the section.

Select the checkbox. In the associated text field, type Temperature (K).

Select the checkbox. In the associated text field, type Enthalpy of Formation (J/mol).

Locate the section. From the list, choose .

Function 1

In the window, click .

In the window for , click to expand the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
CO2

Function 2

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
CO

Function 3

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
H2

Function 4

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
N2

Function 5

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
O2

Function 6

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
H2O

In the toolbar, click

Heat Capacity

All datasets - contain the same information. Therefore, change the dataset to be the same as for the plot group.

In the window, under click .

In the window for , locate the section.

From the list, choose .

Locate the section. From the list, choose .

Locate the section.

Select the checkbox. In the associated text field, type Temperature (K).

Select the checkbox. In the associated text field, type Heat Capacity (J/mol/K).

Locate the section. From the list, choose .

Function 1

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
CO2

Function 2

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
CO

Function 3

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
H2

Function 4

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
N2

Function 5

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
O2

Function 6

In the window, click .

In the window for , locate the section.

Select the checkbox.

From the list, choose .

In the table, enter the following settings:


Legends
H2O

In the toolbar, click

The datasets that are not used can now be deleted.

Delete all datasets to .

Now are the graphs for enthalpy of formation and heat capacity finished and are presented as Figure 1 and Figure 2 in the section. To obtain the values presented in Table 1 and Table 2, are used, which gives the values for each function at the specific temperature.

Evaluation Group 1

In the toolbar, click

In the window for , locate the section.

Select the checkbox.

Enthalpy of Formation, 298 K

Right-click and choose .

In the window for , type Enthalpy of Formation, 298 K in the text field.

Locate the section. In the table, enter the following settings:


Expression	Unit	Description
EnthalpyF_carbon_dioxide_Gas12(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 1
EnthalpyF_carbon_monoxide_Gas14(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 2
EnthalpyF_hydrogen_Gas16(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 3
EnthalpyF_nitrogen_Gas18(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 4
EnthalpyF_oxygen_Gas110(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 5
EnthalpyF_water_Gas112(298.15[K],1.0133E5[Pa])	J/mol	Enthalpy of formation 6

If clicking the button now, no values will be given. This is because the datasets are empty. Using the feature under enables evaluation of the function values in .

Study 1

In the toolbar, click

Results

In the window, under > click .

In the toolbar, click

Heat Capacity, 300 K

In the window, right-click and choose .

In the window for , type Heat Capacity, 300 K in the text field.

Locate the section. In the table, enter the following settings:


Expression	Unit	Description
HeatCapacityCp_carbon_dioxide_Gas11(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 1
HeatCapacityCp_carbon_monoxide_Gas13(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 2
HeatCapacityCp_hydrogen_Gas15(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 3
HeatCapacityCp_nitrogen_Gas17(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 4
HeatCapacityCp_oxygen_Gas19(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 5
HeatCapacityCp_water_Gas111(300[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 6

In the toolbar, click

Heat Capacity, 2000 K

Right-click and choose .

In the window for , type Heat Capacity, 2000 K in the text field.

Locate the section. In the table, enter the following settings:


Expression	Unit	Description
HeatCapacityCp_carbon_dioxide_Gas11(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 1
HeatCapacityCp_carbon_monoxide_Gas13(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 2
HeatCapacityCp_hydrogen_Gas15(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 3
HeatCapacityCp_nitrogen_Gas17(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 4
HeatCapacityCp_oxygen_Gas19(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 5
HeatCapacityCp_water_Gas111(2000[K],1.0133E5[Pa])	J/(mol*K)	Heat capacity (Cp) 6

In the toolbar, click

The values in rows 7-12 in the table from are for 300 K, while the values for rows 13-18 are for 2000 K. Together with the values in rows 1-6, these are presented in Table 1 and Table 2.

Study 1

Solution 1 (sol1)

In the window, under > right-click and choose .

The default plots that are supposed to be generated when clicking were not generated this time because they had already been generated when performing the step. Therefore, they need to be reset.

In the toolbar, click