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3.10. Pre Reformer - PR
3.10 Pre Reformer - PR
Figure 3.13: Pre Reformer component
The most important function of the pre reformer is to break down
large carbon chains into methane, hydrogen, and carbon oxides. All the
components in the model have, however, only been made to accept 7
different species (not including other hydro carbons than C H 4 ). So in this
model, the pre reformer only reforms methane into carbon oxides and
hydrogen by the ”Reforming” and ”Water Gas Shift” process:
C H 4 + H 2 O → CO + 3H 2
CO + H 2 O ⇋ CO 2 + H 2
∆H ◦ f
∆H ◦ f
kJ
= +206,10
mol
kJ
= −41,16
mol
(3.60)
(3.61)
The degree to which these two reactions occur, is set by the two
parameters ´´FR´´ (Fraction of Reforming) and ”FW” (Fraction of Water
gas shift). FR determines how many times the reforming process runs
per molecule of C H 4 that is sent into the pre reformer:
F R =
ṙre f
ṅ C H4 ,i
(3.62)
FW determines how many times the water gas shift reaction runs per
molecule of CO present after the reforming process
FW =
ṙ W GS
ṙ re f + ṅ CO,i
(3.63)
Since reforming is endothermic while water gas shift is exothermic, the
temperature can either raise or fall during reformation, depending on
how large FW and FR are relative to each other. The pressure loss is
given by the parameter ∆p.
p o =p i + ∆p (3.64)
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