That sounded good when I first read it but the more I think about it the more I don't believe it. Certain portions of gas will be in the scrubber longer and correspondingly others will be in it for less time. The total flow must average out unless the pressure in the loop is seriously different in different places.

N kilos of sorb has X litres of space within it. If gas moves round on whatever tidal profile the quantity of gas within the scrubber is constant so the fraction of the loop in the scrubber is constant so how can it be there 'longer' dependant on geometry? The only thing you can do with the geometry is make it worse by providing dead spots that never get used.

The idea that gas moves faster on the walls is interesting. I'm just trying to see how this can be more than a film effect and the flow will adhere to the wall and probably be slower.