WOLFRAM|DEMONSTRATIONS PROJECT

Combustion Reactions in a Furnace

​
fuel:
methane
ethane
acetylene
propane
butane
furnace operation
adiabatic flame temperature calculation
temperature of exaust gas
900
inlet molar flow rate:
oxygen
1000
nitrogen
1000
Fuel is fed to a furnace at
25°C
and a molar flow rate of
100moles/hr
. This fuel is one of these hydrocarbons: methane, ethane, acetylene, propane, or butane. The fuel is subject to a combustion reaction in the furnace:
fuel+
ν
oxygen
O
2
⇄
ν
carbondioxide
CO
2
+
ν
water
H
2
O(v)
, where
ν
species
is the stoichiometric coefficient of the chemical species. An excess of oxygen entering at
150°C
is used for the combustion reaction, so that the conversion of the fuel is total. You can select the value of the inlet molar flow rate of oxygen and nitrogen. We apply the energy balance for reacting systems using the heat of reaction method [1]. The Demonstration determines:
1. the heat duty in
kJ/hr
(labeled
▪
Q
in the process flowchart) for user-set values of exit temperature of the exhaust gases
or
2. the adiabatic flame temperature (i.e., for
▪
Q
=0
) labeled
T
ad
in the process flowchart.
By specifying the exit temperature of the furnace, the enthalpy balance at steady operation requires that excess heat (denoted by
▪
Q
) from the exothermic reaction has to be removed. By specifying adiabatic operations, the heat released by the reaction raises the temperature of the exhaust gases. You can change the inlet molar flow rate of nitrogen and observe its effect on both on
▪
Q
and
T
ad
.