Theoretical air URGENT

Carlo09

Ok I need to work out the air needed to supply to my reaction.

It's partial combustion since there is 17ppm co in the flue gas. I have my equation for complete and for patrial .... and i know that i have 1kmol of butane going into the reaction .. and the composition of air is 21% o2 ... how can i work out the air needed to be supplied? I can do this fo complete combustion, but partial gets me! Thanks