Page 82 - Process simulation and control using Aspen

74 PROCESS SIMULATION AND CONTROL USING ASPENT

As stated, the reaction
C6H5NH2 + 3H2 C6HnNH2

is first-order in aniline and hydrogen. Also, the reaction rate constant is defined with
respect to aniline. Accordingly, we may use the follow ing information to specify the
reaction (see Table 2.2).

TABLE 2.2
Component Coefficient Exponent

aniline -1 1
hydrogen -3 1
cyclohexylamine 1 0

Recall that in Aspen Plus terminology, coefficients must be negative for reactants
and positive for products. As we fill up the form, it looks like Figure 2.30.

i ' lltiliiii ESS
aj}. f*, Fe> iw tup Tcotr

"
BoacMrNo.: |7i 3 Reaction type: 3
r
RuctMi - Poduct!
f
Comnonent Coeficient Enponent 1 CompafieW Coelficient Ej<ponent
ANILINE 1 j ; CYCLO-01 1
- IYDR0GEN . 3
j *
* 1 i
t
Cote

Bock,
y Reactiom
-
r J Chemolry
B Peacuons Edt Delete
ft R-I
1 Convefgcnce
fj Rowaheetng Onions
1
.r
Reojad tipul hcowMe
r
IT Mam pKen | Sepaators | HeatEndiangen | Cokams Haachm | PtenueOiaven ] SoUt UnModeb
1.0 .y-U-U-
KWariel
STREAMS RSIoic RYieU HMj RStb. RCStfl BPIm Rieldi
"
ForHec .weMfl !C\ i,fi*ta.vW«iHi.111 , HUH - ReuMtnO
f
« « b3
FIGURE 2.30
If we do not specify the exponent for a species, Aspen Plus takes a default value of
zero. In Figure 2.31, the resulting relation is displayed in the stoichiometry sheet.
In the subsequent step (see Figure 2.32), we move on to Kinetic tab.