A steam boiler heats liquid water at 200 ºC to superheated steam at 4 MPa and 400 ºC. Coal fuel from Utah which has an ultimate analysis (by mass) as 61.40 percent C, 5.79 percent H2, 25.31 percent O2, 1.09 percent N2, 1.41 percent S, and 5.00 percentash (non-combustibles) is burned steadily with 50 percent excess air. The fuel and air enter the boiler at 25 ºC and the products of combustion leave at 227 ºC. Determine the amount of steam generated per unit of fuel mass burned, the change in the exergy of the combustion streams, in kJ/kg fuel and the steam stream, in kJ/kg steam, and the lost work potential, in kJ/kg fuel. Neglect the effect of the sulfur in the energy and entropy balances.