That's correct. It's a good point to bring up. ProMax uses the residence time (calculated by the column internals and flow rates) to rigorously calculate the progression of the reactions. I like that because there are no fudge factors to deal with. ProTreat uses "enhancement factors" to deal with the non-equilibrium effect. Both approaches work, but since amine sweetening is primarily limited by reaction kinetics, I trust the ProMax approach slightly more.
The residence time in ProMax is an interesting and tricky thing. I don't think ProMax is really a rate-base column model. RockDock, do you have some research literature in that? The rigorous model should solve the mass transfer rate using a series of ODEs, like what used in ProTreat. The rigorous model may have problems in convergence. The stage efficiency / enhancement factor is also a rigorous rate-base approach, which is used by the DBR amine. There are tons of research in the rigorous rate-base model and in the enhancement factor model. These two models are really the models that rigorously calculate the reaction kinetics. I personally don't think the DBR amine is a marketing ploy by big companies. On the contrary, I think ProMax is more successful in marketing their products.
I thought one does not to provide the residence times for the packed columns. ProMax calculates the residence times for the trayed columns, but not so for the packed columns. I typically solve for the packed column, copy the residence time, convert it to packed columbn and use the residence times copied earlier. If there is a way to calculate the residence time for the packed columns as well, I am not aware of it.
One area where I have issues is to calculate the # of trays needed, and the packing ht for the packed column. If anyone has any tips on this, please share.
Thanks
-AC