How Much Work is Lost in This Thermodynamics Scenario?

[matthewsyq1995]

Homework Statement

A flue gas is cooled from 1100 C to 150 C and the heat is used to generate saturated steam at 100 C in a boiler. The flue gas has a heat capacity given by CP/R = 3.83 + 0.000551 T, where T is in K. Water enters the boiler at 100 C and is vaporized at this temperature. Its latent heat of vaporisation is 2256.9 kJ/kg. What is the lost work of this process

Homework Equations

The Attempt at a Solution

Basically i think i only need help in finding the rate of entropy generation of this qn. I believe i can finish the qn once i get that :)

I managed to equate mdot(steam) x ndot(gas) = -15.13g/mol by doing a simple energy balance
Tried to sub that into equation for summation of entropy but can't seem to solve it.
Sdot(g) = Sdotg(steam) + Sdotg(gas)
I have calculated ΔS(gas) and ΔS(steam) to be -41.835 and 6048 J/kgK but still can't seem to sub it in.Appreciate the help! Thks!

 

[Chestermiller]

Using the first law of thermodynamics, what do you get for the heat load?