Discussion Forum

Hi


I am dealing with a microreactor which can be specified as a plug flow
reactor. The bottom of this reaction contains platin as the catalyst
towards the reaction of CO oxidation:

2CO+O2->2CO2

Indeed this is a catalytic reaction one must also consider the elemental
reactions as following

1) CO+*<=>CO*

2) O2+2*<=> 2O2*

3) CO*+O*->CO2*+*

4) CO2*<=> CO2 + *

A) The sign '*' accomodate for platin due to the surface reaction which
occurs on the platinum. Every reaction has specified Activation energy Ea
and reaction constant, ki and a reaction rate. I have two models in my
system. The first one is with reaction engineering interface, and in the
second model I have transport of dilluted species and laminar flow
interfaces.

The question I have is that I have plenty of equations to take account
for. These a coverages of every componenet in the reactions, rate
equations, conversion and selectivity. Eventually after implementing those
equation I will have a lot of results in terms of graphs. As a general
thing in every plot, concentrations (or parial pressures), temperature and
time will be my variables. Is it appropriate to define my equations as
global or local variables in order to create "plot conbinations" as
selectivity vs time, selectivity vs temperature, conversion vs. time ect?
Can I define the variables (time, temperature and concentrations) without
using parametric sweep? Just a note to these questions, my purpose is to
plot for instance the coverage of one component as a "surface plot" (the
equations of the coverage indludes the changing concentration of one
component).

B)Appearantly, if one want to implement reactions in comsol, comsol always
use the component concentrations (I think this is default in comsol). Can
I exchange this with partial pressures due to gasses in my system?

C)Some of my elementary reactions are reversible. Unfortunately, I cannot
choose reversibel in "surface reactions" in reaction engineering
interface. As a default comsol i set to irreversibel. what can I do to
change this?


Thanks in advance.

BR

Zubeyr