13.79 Methane (CH4) at 77°F, 1 atm enters an insulated reactor operating at steady state and burns completely with air entering in a separate stream at 77°F, 1 atm. The products of combustion exit as a mixture at 1 atm. For the reactor, determine the rate of entropy production, in Btu/°R per lbmol of methane entering, for combustion with (a) the theoretical amount of air. (b) 200% of theoretical air. effects