Coal Calculator
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NOTE: This feature is currently in BETA with limited release. Please contact us (support@syscad.net) if you are interested in using this model. This page is currently under development and details may change. Use with caution - we do not guarantee compatibility between different BETA versions. |
Navigation: Main Page ➔ Process Control Models ➔ Coal Calculator
Available from Build 139.37014.
General Description
The purpose of the coal calculator is to generate parameters for thermodynamic functions (G, H, S, and Cp) for a specific coal sample. This is based on typical chemical analyses, including ultimate analysis, proximate analysis, volatiles, and gross heat value.
Two species and corresponding thermodynamic parameters will be created:
- Coal: species representing the coal sample (solids + volatile matter)
- CoalVM: volatile matter component of coal
To use the coal calculator in SysCAD, the following species and elements must be present in the project in addition to the default species:
- Required Elements in the project are: C, S, N
- Required Species in the project include: CO2(g), SO2(g), CO(g), S2(g), C(s), N2(g), O2(g), H2(g)
Diagram
The diagram shows the default drawing of the Coal Calculator controller.
Inputs and Outputs
There are no connections to this unit.
Model Theory
Gross Heat Value (GHV): Gross heat value represents the total amount of energy released by 1 kg of fully combusted coal with stoichiometric air, with all products of combustion cooled down to 25°C.
- [math]\ce{ Coal(s) + Air(g) ->[\ce{T=25°C}] CO_{2}(g) + H_{2}O(l) + SO_{2}(g) + N_{2}(g) + Ash(s) }[/math]
The above equation, expressing coal as its contents defined by proximate analysis, is:
- [math]\ce{ C_{fix}(s) + V_{M}(g) + Air(g) ->[\ce{T=25°C}] CO_{2}(g) + H_{2}O(l) + SO_{2}(g) + N_{2}(g) }[/math]
Note that ash and free moisture content of coal do not contribute to the gross heat value calculation, as they are present at the same temperature as the reactants and products and are removed from the equation.
How to use the Coal Calculator Control
To use the Coal Calculator, user will provide the following specifications:
- Typical contents for coal analysis in mass basis. The Proximate analysis (wt%) in wet basis include:
- Fixed Carbon
- Ash
- Volatile Matter
- Moisture
- Ultimate analysis (dry basis, excluding Ash):
- Total Carbon
- Total Hydrogen
- Total Sulphur
- Total Nitrogen
- Total Oxygen
- Gross heat value
Based on the above specifications, SysCAD will iterate for the apparent or equivalent chemcial formula of Coal and VM species, assuming the chemical formula of these species being:
- Coal: CmHnSoNpOq(s), where m, n, o, p and q are moles of C, H, S, N and O respectively.
- VM: CmVMHnSoNpOq(g), where mVM, n, o, p and q are moles of Volatile Matter, H, S, N and O respectively.
- The number of moles for the two chemical formulas need to be rounded to 3 decimal places, the elemental compositions are in wt% and the molecular weights, in gmol for an assumed 100g of coal basis.
- The resulting species composition and enthalpy data are displayed on the Results tab.
Using the results to add the Coal and VM species to the Species database:
- The species data definition and the derived thermodynamic property equations can be found on the Database tab.
- User can copy these data to the clipboard, then paste into a text file or MS Excel, so you can then copy and paste the relevant data into the SysCAD species database editor.
- Edit the SysCAD species database, add or update the Coal and VM species properties in the SysCAD species database.
TBC
Data Sections
- Coal Calculator tab - This is where user can enter the coal analysis data and gross heating value.
- Results tab - Contains the calculated chemical formula and heating values for the Coal and VM material.
- DataBase tab - Contains the chemical formula and heating values for the Coal and VM material, in the form suitable for entering into the SysCAD species database.
- Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
Unit Type: CoalCalculator - The first tab page in the access window will have this name.
Coal Calculator Tab
| Tag (Long/Short) | Input / Calc | Description/Calculated Variables / Options |
| Tag | Display | This name tag may be modified with the change tag option. |
| Condition | Display | OK if no errors/warnings, otherwise lists errors/warnings. |
| ConditionCount | Display | The current number of errors/warnings. If condition is OK, returns 0. |
| GeneralDescription / GenDesc | Display | This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the UnitType or SubClass. |
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| Inputs (Basis of Calculus) | ||
| Proximate analysis (wet basis): | ||
| FixedCarbon / FixC | Input | The mass fraction of the fixed carbon. |
| Ash | Input | The mass fraction of the ash. |
| Volatile | Input | The mass fraction of the volatile matter. |
| Moisture | Input | The mass fraction of the free moisture. |
| Ultimate analysis (dry basis, excluding Ash): | ||
| TotalCarbon / Ctot | Input | The mass fraction of the total carbon. |
| Hydrogen / H | Input | The mass fraction of the total hydrogen. |
| Sulphur / S | Input | The mass fraction of the total sulphur. |
| Nitrogen / N | Input | The mass fraction of the total nitrogen. |
| Oxygen / O | Input | The mass fraction of the total oxygen. |
| Gross heat value: | ||
| GrossHeatValue / GHV | Input | The measured Gross Heat Value, represents the total amount of energy released by 1 kg of fully combusted coal with stoichiometric air and all products of combustion cooled down to 25°C. Note that ash and free moisture content of the coal do not contribute to the gross heat value calculation. |
Results Tab
| Tag (Long/Short) | Input / Calc | Description/Calculated Variables / Options |
| Coal composition: CmHnSoNpOq | ||
| Coal.m | Display | Coal composition: number of moles of Carbon in the Coal species. [math]\displaystyle{ \frac{C_{tot}}{MW_C} }[/math] |
| Coal.n | Display | Coal composition: number of moles of Hydrogen the Coal species. |
| Coal.o | Display | Coal composition: number of moles of Sulphur the Coal species. |
| Coal.p | Display | Coal composition: number of moles of Nitrogen the Coal species. |
| Coal.q | Display | Coal composition: number of moles of Oxygen the Coal species. |
| Coal.MW | Display | The molecular weight Coal of the Coal species. |
| Volatile Material composition: CmHnSoNpOq | ||
| VM.m | Display | Volatile Material composition: number of moles of Carbon in the Volatile Material species.
[math]\displaystyle{ Coal.m − \frac{C_{fix}}{(C_{fix} + VM) ·MW_C}· 100 }[/math] |
| VM.n | Display | Volatile Material composition: number of moles of Hydrogen in the Volatile Material species. |
| VM.o | Display | Volatile Material composition: number of moles of Sulphur in the Volatile Material species. |
| VM.p | Display | Volatile Material composition: number of moles of Nitrogen in the Volatile Material species. |
| VM.q | Display | Volatile Material composition: number of moles of Oxygen in the Volatile Material species. |
| VM.MW | Display | The molecular weight Coal of the Volatile Material species. |
| Coal reference enthalpy | ||
| Coal.MCO2 | Display | Mass of CO2 / mass Coal |
| Coal.MH2O | Display | Mass of H2O / mass Coal |
| Coal.MSO2 | Display | Mass of SO2 / mass Coal |
| hf_CO2 | Display | The heat of formation of CO2(g) at reference T, P |
| hf_H2Ol | Display | The heat of formation of H2O(l) at reference T, P |
| hf_SO2 | Display | The heat of formation of SO2(g) at reference T, P |
| Coal.Hf@25 | Display | Coal specific enthalpy of formation at 25°C
[math]\displaystyle{ H^o_{coal,298} [kJ] = −GHV·\left[\frac{kJ}{kg}\right] . 1[kg \; coal] + H^o_{CO_2,298} + H^o_{H_2O(l),298} + H^o_{SO_2,298} }[/math] |
| Specific Heat | ||
| Coal.Cp | Input | The user specified the coal specific heat value. |
| VM.OverrideCp | Tickbox | Checking this box will allow the user to specify a user defined VM specific heat value. |
| VM.UserCp | Input | Only visible if the VM.OverrideCp box is checked. The user specified VM specific heat value. |
| VM.Cp | Display | The derived specific heat of the volatile material species.
[math]\displaystyle{ Cp_{VM} \left[\frac{kJ}{kg}\right] = \frac{m_{CO} · Cp_{CO} + m_C · Cp_C + m_{O_2} · Cp_{O_2} + m_{H_2} · Cp_{H_2} + m_{S_2} · Cp_{S_2} + m_{N_2} · Cp_{N_2}} {m_{{VM}_{charr}}} }[/math] |
| Mass Fractions | ||
| MF.FixedCarbon / MF.FixC | Display | The mass fraction of fixed carbon in coal. |
| MF.VolatileMatter / MF.VM | Display | The mass fraction of volatile matter in coal. |
| Calculations | ||
| CalcOptions | Calc H_VM_298 | |
| Calc Gibbs Energies | ||
| Calculate | Calculate Button | Use this button to calculate the properties at the user specified temperature. |
| CharTemperature / CharT | Input / Display | If the CalcOptions = Calc H_VM_298, this is a user input value. |
| Offset | Input | Only visible when CalcOptions = Calc Gibbs Energies. Target GVM + GFix - GCoal at 25°C |
| VM.Hf@25 | Display | Volatile Matter enthalpy of formation at 25°C
[math]\displaystyle{ H^o_{VM,298} [kJ] = −GHV\left[\frac{kJ}{kg}\right] . 1[kg \; coal] + H^o_{CO_2,298} + H^o_{H_2O(l),298} + H^o_{SO_2,298} }[/math] |
| Results at Temperature | ||
| T | Input | Only visible when CalcOptions = Calc Gibbs Energies. This specific enthalpy of formation value (next two variables) will be displayed for this temperature when the calculate button is pressed. |
| Coal.H | Display | Coal specific enthalpy of formation at the specified temperature. |
| VM.H | Display | Volatile Matter specific enthalpy of formation at the specified temperature. |
| Gibbs Energy | ||
| GCoal | Display | Gibbs Energy of Coal |
| GFix+GVM | Display | Gibbs Energy of fixed carbon plus gross heating value. |
| GFix | Display | Gibbs Energy of fixed carbon. |
| GVM | Display | Gibbs Energy of gross heating value. |
| Diff | Display | GVM + GFix - GCoal |
Database Tab
| Tag (Long/Short) | Input / Calc | Description/Calculated Variables / Options |
| ---Coal--- | ||
| Coal.ShortName | Input | User specified short name for the coal species. For example: TypeA_Coke |
| Coal.Definition | Display | The coal species elemental count. This value can be copied and pasted into the Definition field of the species table when defining the new species in the database. Species Definition. For example: C8.236H0.022O0.011N0.000S0.027 |
| Coal.H25 | Display | The heat of formation value at 25°C of the coal species. This value can be copied and pasted into the H25 field of the species table when defining the new species in the database. Species Table. For example: FromCp() |
| Coal.S25 | Display | The entropy value at 25°C of the coal species. This value can be copied and pasted into the S25 field of the species table when defining the new species in the database. Species Table. For example: FromCp() |
| Coal.CpEqn | Display | The heat capacity equation of the coal species. This equation can be copied and pasted into the Cp field of the species table when defining the new species in the database. Species Table. For example: Gibbs_Cp(-713327.265146, 0.000000, -99.984048, 0, 0, 0) : Range(K, 1.000000, 6000.000000) |
| Coal.Density | Input | User defined density value for the coal species. This value can be copied and pasted into the density field of the species table when defining the new species in the database. Species Table. |
| Coal | Copy Coal to Clipboard Button | Use this button to copy the above information to the clipboard, then paste it into a text file or similar. When adding the coal species to the SysCAD database, users can copy the relevant information into the required fields in the Edit Species database interface. Adding a New Species |
| ---Volatile Matter--- | ||
| VM.ShortName | Input | User specified short name for the volatile matter species. For example: TypeA_VM |
| VM.Definition | Display | The volatile matter species elemental count. This value can be copied and pasted into the Definition field of the species table when defining the new species in the database. Species Definition. For example: C0.013H0.022O0.011N0.000S0.027 |
| VM.H25 | Display | The heat of formation value at 25°C of the volatile matter species. This value can be copied and pasted into the H25 field of the species table when defining the new species in the database. Species Table. For example: FromCp() |
| VM.S25 | Display | The entropy value at 25°C of the volatile matter species. This value can be copied and pasted into the S25 field of the species table when defining the new species in the database. Species Table. For example: FromCp() |
| VM.CpEqn | Display | The heat capacity equation of the volatile matter species. This equation can be copied and pasted into the Cp field of the species table when defining the new species in the database. Species Table. For example: Gibbs_Cp(-325.956396, -1630.837058, -1.093263, 0, 0, 0) : Range(K, 1.000000, 6000.000000) |
| Voaltile | Copy VM to Clipboard Button | Use this button to copy the above information to the clipboard, then paste it into a text file or similar. When adding the volatile matter species to the SysCAD database, users can copy the relevant information into the required fields in the Edit Species database interface. Adding a New Species |
| ---Graph--- User can generate Gibbs values for plotting using the following: | ||
| Graph.Low | Input | Minimum temperature. |
| Graph.High | Input | Maximum temperature. |
| Graph.Points | Input | Number of data points. |
| Gibbs | Copy Graph to Clipboard Button | Press the button to copy the generated Gibbs value for the defined temperature range to the clipboard. See the example below. |
Example Data for plotting, using 0 to 1000 C, 10 data points:
| T(C) | GCoal | GFix+VM |
| 0.000000 | -8666.787975 | -4605.240968 |
| 100.000000 | -9344.197730 | -6296.983569 |
| 200.000000 | -10048.736720 | -8013.167623 |
| 300.000000 | -10774.570881 | -9753.770147 |
| 400.000000 | -11517.942098 | -11517.942098 |
| 500.000000 | -12276.223974 | -13304.432686 |
| 600.000000 | -13047.476256 | -15111.861775 |
| 700.000000 | -13830.206494 | -16938.852345 |
| 800.000000 | -14623.230801 | -18784.089547 |
| 900.000000 | -15425.587003 | -20646.343907 |
| 1000.000000 | -16236.477616 | -22524.477363 |
Adding this Model to a Project
Add to Configuration File
Sort either by DLL or Group:
| DLL: | Pyro.dll |
→ | Units/Links | → | Control 2: CoalCalculator | |
| or | Group: | General |
→ | Units/Links | → | Control 2: CoalCalculator |
See Model Selection for more information on adding models to the configuration file.
Insert into Project Flowsheet
| Insert Unit | → | Control 2 | → | CoalCalculator |
See Insert Unit for general information on inserting units.