CHEMCAD Seminar
Reactions
John Edwards, P&I Design Ltd
January 2015
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REACTIONS CHEMCAD MODELS
Kinetic
- Plug flow reactor
- Continuous stirred tank reactor
Stoichiometric - Single stoichiometric reaction
Gibbs
- Minimizes Gibbs free energy at equilibrium
- Combustion process
SIMULATION SUITE
- Fast reactions
CHEMCAD SOFTWARE
Equilibrium
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- Reactions with specified conversions
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Engineering advanced
REACTIONS
KINETIC
CRYOGENIC
BATCHREACTOR
REACTOR
BIO-MASS OXIDATION
REACTION
OPTIMISATION
Section 7 page xxx, Case 7.07 (Edition 3)
Exercise Objectives
Stoichiometric reactor to simulate a bio-mass process
Process Description
Glucose and benzene degradation to form a biomass, carbon dioxide and water
Some of the biomass will decay. The reactions are as shown.
Simulation
Isothermal at 25°C mass bases stoichiometry with user based specified rate equations
Continuous stirred tank reactor (CSTR) with volume 1698 m3
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Engineering advanced
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REACTORBATCH
SEMINAR
CRYOGENIC
REACTOR
BIO-MASS KINETIC
OXIDATION REACTION
OPTIMISATION
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Engineering advanced
REACTIONS
STOICHIOMETRIC
REACTOR
CRYOGENIC
BATCH REACTOR
USER SPECIFIED
FUEL CELL
OPTIMISATION
Exercise Objectives
1. Stoichiometric reactor to generate H2 from H2O = H2 + 0.5O2
2. User UnitOp carries out two reactions H2 → 2H+ +2e− + O → H2O ∆q=48.7 kJ/mol
(Faraday = 96485 coulomb or amp sec 1 mol/sec = 3.6 kmol/h = 96485 amp/cell)
3. Controllers to drive reaction rate and cell power output
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Engineering advanced
REACTIONS
STOICHIOMETRIC
REACTOR
CRYOGENIC
BATCH REACTOR
USER SPECIFIED
FUEL CELL
OPTIMISATION
Section 15 page 513 Case 15.03
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Engineering advanced
REACTIONS
REACTOR
CRYOGENICGIBBS
BATCH
REACTOR
ANTHRACITE
GASIFICATION
OPTIMISATION
Exercise Objectives
1. Create combustion solid user component
2. Set up Gibbs reactor for coal gasification
Process Description
1. Gasify anthracite coal in presence of oxygen using Gibbs Reactor
Reaction Phase Vapor or mixed phase
Operating isothermally at 800°F and 14.7 psia
Specify solids
Carbon Anthracite Silicon Dioxide
2. Gases cooled to 230°F
Case Data
Coal Specification
MW 500
Composition (weight %) C 83
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H 2.5
O 3.0
S 0.5
N 0.9
Si 10.1
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Engineering advanced
REACTIONS
REACTOR
CRYOGENICGIBBS
BATCH
REACTOR
ANTHRACITE
GASIFICATION
OPTIMISATION
New component composition as weight %
Reactor Component Element Matrix converts to
stoichiometric values
Solid heat capacity changes with temperature
mean value used
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Engineering
Engineeringadvanced
advanced
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REACTIONS BATCH
GIBBS REACTOR
CRYOGENIC
REACTOR
ANTHRACITE
GASIFICATION
OPTIMISATION
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Engineering advanced
REACTIONS
GIBBS BATCH
WITH EQUILIBRIUM
CRYOGENIC
REACTOR
COAL GASIFICATION
& SYNGAS PRODUCTION
OPTIMISATION
Section 16 page xxx Case 16.07 Edition 3
1.
2.
3.
4.
5.
1.
2.
3.
4.
4.
Exercise Objectives
Create combustion solid user component
Gibbs reactor for coal gasification
Component separator to remove slag
SCDS column to cool and scrub gases
Equilibrium reactor for gas shift reaction
Process Description
Gasify coal in presence of oxygen using Gibbs Reactor in Reaction Phase Vapor or
mixed phase whilst operating isothermally at 2400°F and 812 psia
Separate SiO2 slag in Component Separator split basis 0.466
Cool to 1100°F and scrub hot gas in SCDS column based on VLE model
Equilibrium reactor carries out the water gas shift reaction (WGSR)
CO + H2O ↔ CO2 + H2 isothermally at 410°F with approach fraction 1.0
Gases cooled to 100°F
Coal Specification (weight %) MW 500
C 69.56
H 25.11
N 0.502
Cl 0.046
S 0.44
O 2.42
Si 1.94
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Engineering
Engineeringadvanced
advanced
COAL GASIFICATION
CRYOGENIC
BATCH REACTOR
USER COMPONENT
COMBUSTION SOLID
OPTIMISATION
Section 15 page 513 Case 15.03
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Engineering
Engineeringadvanced
advanced
REACTIONS
COAL
GASIFICATION
CRYOGENIC
BATCH
REACTOR
FLOWSHEET
OPTIMISATION
Section 15 page 513 Case 15.03
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Engineering advanced
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REACTIONS
GIBBS
CRYOGENIC
BATCH
REACTOR
GAS TURBINE
SIMULATION
OPTIMISATION
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Engineering advanced
REACTIONS
GIBBS
CRYOGENIC
BATCH
REACTOR
GAS TURBINE
SIMULATION
OPTIMISATION
Section 16 page xxx Case 16.06 Edition 3
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Engineering advanced
REACTIONS
GIBBS
CRYOGENIC
BATCH
REACTOR
GAS TURBINE
SIMULATION
OPTIMISATION
Section 16 page xxx Case 16.06 Edition 3
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