A mathematical procedure for determination of the driving force distribution in a chemical reactor, that gives minimum entropy production for a given production rate, is applied to oxidation of SO2. The solution for the force is calculated from known reaction kinetics, and compared to the actual force. A large difference is found. Two practical ways that do not include changes the apparatus, are suggested for moving the process towards minimum entropy production. Reductions of 5 and 21 in lost work %, and an increased production of SO3 are obtained. The ideal results suggest that there is room for further improvements, especially if the apparatus is changed.