Kitchen vent

I'm working on installing a new kitchen dwv, running the vent up thru the top plate, then running the vent over 30' to the main stack. I was looking at the old setup, and there is a 1 1/2" iron vent on the opposite side of the window that goes directly up thru the roof. IF I can cut this pipe, can I use this for my vent instead of running pipe all thru the attic? IF I can get this pipe to budge, I may be able to replace the iron vent, but I have had ZERO luck trying to remove iron vent pipe (see my post on the main stack vent iron pipe).
The old system was a prob, cause the vent was at the same level as the drain.

 

Sure.. but you might want to identify what all is currently being vented by it already. You should just cut it off with a sawzall and install a fernco from iron to a pvc sanitary tee.