Well; go to Reaction tab, chose "New"

In the opened window select your reaction type: for your case "LHHW" is Langmuir type reaction.

Define "New" reaction, select your reactants and in "Kinetic" tab enter Langmuir parameters.

B term will be determined by experiment. You just enter this parameter in the required positions. In case of regression a sensitivity analysis must be done

Thank you Sajad for the insight.

Actaully that was what i did. I entered all the data. I have not run Langmuir before but from the reference I used, the person considered activation energy for each species in determining the adsorption constants. However, i have always known activation energy to be for a reaction and not a species. But well, I did what i could and the simulation seems to be working good.

The problem I encounter is that, the reaction is suppose to be partial oxidation but my simulation shows all the oxygen feed is consumed in the reaction. I have tried to control reaction parameters and increase the oxygen feed or decrease the other reactant amount, and none of them leaves unreacted oxygen. So It makes me feel not convinced about the reference I used. have you run a partial oxidation reaction in Aspen Plus before?

Yes, before I've  run partial oxidation reaction for production of propylene from propane in a fixed bed reactor. For controlling reaction rate I used staged reactor; in other words oxygen was injected in several segments of the bed in lieu of complete O2 injection at beginning of the reactor order to slow down oxidation rate and reducing ill-favored products such as CO and CO2.

In case of your process, it is recommended to use staged reactor to control the reaction.

For activation energy let me do some research about these type of reactions. If possible can you send me your reference?

Thanks for your time and effort. I will stage it and let you know how it goes.

This is the reference I used, is a youtube video I watched.

link: https://www.youtube.com/watch?v=AJikn76yhhk