Steam Reforming of Propane
Steam Reforming of Propane
Steam reforming is a method for producing hydrogen and carbon dioxide starting from hydrocarbons. In this Demonstration, a feed stream, composed of propane and steam, enters a reactor at 150 °C and 1 atm. We assume that the propane molar flow rate in the feed stream is 1 mol/s and that the steam/propane molar ratio in the feed stream is 9.
Using a nickel-based catalyst placed in tubes, steam reforming of propane (reaction R1) occurs according to the following reaction:
C
3
H
8
H
2
H
2
Another reaction, the water-gas shift reaction (reaction R2) also takes place in the reactor and produces more hydrogen according to
CO(g)+O(v)→(g)+(g)
H
2
CO
2
H
2
The standard heat of reaction R1 is . Thus, this reaction is endothermic. On the other hand, reaction R2 is mildly exothermic, and its standard heat of reaction is . Thus, heat must be added to the reformer, using burners to heat the tubes. You can set the value of the heat added (in kW) to the reactor >0, as well as the temperature of the outlet stream. The outlet stream's pressure is equal to 1 atm. Assume that the propane is entirely consumed, so that the extent of reaction R1 is =1mol/s.
497.73kJ/mol
-41.15kJ/mol
Q
ξ
1
The graphic shows the labeled process flowchart and , the extent of reaction R2. For this purpose, we make use of the energy balance equation for reactive systems: =Δ=- (i.e. the heat of formation method). The specific enthalpies of all components are computed using the temperature-dependent expressions of the constant-pressure heat capacities given in [1, Appendix B2]. In addition, we chose as reference states the elemental species (g), (g) and at 25 °C and 1 atm. All of the heat requirements for the formations are obtained from [1, Appendix B1].
ξ
2
Q
H
∑
i
out
n
i
H
i
∑
i
in
n
i
H
i
H
2
O
2
C(s)