Solid carbon is burned with stoichiometric air in an SSSF process. The reactants at T0, P0 are

Question:

Solid carbon is burned with stoichiometric air in an SSSF process. The reactants at T0, P0 are heated in a pre-heater to T2 = 900 R with the energy given by the products before flowing to a second heat exchanger, which they leave at T0. Find the temperature of the products T4 and the heat transfer per lb mol of fuel (4 to 5) in the second heat exchanger.