Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
solving ODE..set of differential equations
Posted 2016年7月10日 GMT-4 10:35 Chemical Reaction Engineering Version 4.4 2 Replies
Please login with a confirmed email address before reporting spam
( dH)/dt=-R_H ; where R_H=A_H*H*exp((-E_H)/RT)
dM/dt=2/3 R_H-R_(M ) ; where R_M=A_M*M*exp((-E_M)/RT)
dW/dt=3R_M-R_(W ) ; where R_W=A_W*W*exp((-E_W)/RT)
( dF)/dt=-R_(W );
dC/dt=-( 1/3 R_H+R_(M )+R_(W )) ;
ρC_P ∂T/∂t=∂/∂x(K_eff ∂T/∂x)+∑_(i=H,M,W,C)▒〖R_i 〖∆H〗_i 〗
at top
- K_eff ∂T/∂z= 0
at bottom
- K_eff ∂T/∂z= σ ε (T_a^4- T^4 )
2 Replies Last Post 2016年7月15日 GMT-4 01:39
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Hello Sooraj,
You may want to clarify for Discussion Forum users what questions you have.
Jeff
You may want to clarify for Discussion Forum users what questions you have.
Jeff
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Hematite to magnetite: 3Fe2O3 + CO = 2Fe3O4 + CO2
Magnetite to wustite: Fe3O4 + CO = 3FeO + CO2
Wustite to iron: FeO + CO = Fe + CO2
Boudouard reaction: CO2 + C = 2CO
these reactions should be solved using chemical reaction engineering module.
First order kinetics has been assumed here. ie using Arrhenius equation. as defined in that module. values of the constant has been defined below,
A_H=10^19/s A_M=10^18/s A_W=10^14/s
E_H=580 KJ/mole E_M=580 KJ/mole E_W=390 KJ/mole
∆H (H→M)=-16 KJ/mole
∆H (M→W)=42 KJ/mole
∆H (W→Fe)=-17 KJ/mole
∆H (C-gasification)=172 KJ/mol
σ=5.667×10^(-8) watt/m^2-K
ε=0.8
T=1,500K
Density (kg/ m3):
H= 5,200; M= 5,160; W=5,500; Fe= 7,800; C= 2,267
Heat capacity Cp (J/ kg-K):
H= 100; M= 100; W=80; Fe= 65; C= 80
where H= Hematite, M=Magneite, W=Wustite, F=Iron, C =Carbon.
I have already posted the set of first order kinetics eqs earlier
Magnetite to wustite: Fe3O4 + CO = 3FeO + CO2
Wustite to iron: FeO + CO = Fe + CO2
Boudouard reaction: CO2 + C = 2CO
these reactions should be solved using chemical reaction engineering module.
First order kinetics has been assumed here. ie using Arrhenius equation. as defined in that module. values of the constant has been defined below,
A_H=10^19/s A_M=10^18/s A_W=10^14/s
E_H=580 KJ/mole E_M=580 KJ/mole E_W=390 KJ/mole
∆H (H→M)=-16 KJ/mole
∆H (M→W)=42 KJ/mole
∆H (W→Fe)=-17 KJ/mole
∆H (C-gasification)=172 KJ/mol
σ=5.667×10^(-8) watt/m^2-K
ε=0.8
T=1,500K
Density (kg/ m3):
H= 5,200; M= 5,160; W=5,500; Fe= 7,800; C= 2,267
Heat capacity Cp (J/ kg-K):
H= 100; M= 100; W=80; Fe= 65; C= 80
where H= Hematite, M=Magneite, W=Wustite, F=Iron, C =Carbon.
I have already posted the set of first order kinetics eqs earlier