Problem 6.3:
You are responsible for a high-temperature process that produces two exhaust streams, stream A at 600 °C, 10 bar, with molar flow rate 100 mole/s; and stream B at 200 °C, 20 bar, with molar flow rate 50 mole/s. A young engineer in your team comes to you with an idea to utilize these streams to produce heat and work which will save costs in your process. She quickly puts together a sketch (see below) for a process that produces 220 kW of heat, 1700 kW of work, and delivers the exhaust gases as a
single stream at 1 bar. The heat will be used to produce saturated steam at 1 atm by boiling the saturated liquid.
a) What is the temperature of the exit stream?
b) Should you take this idea to your superiors for further discussions?
c) Could you use the heat from this process to boil water at 10 bar?
Additional information: Assume the exhaust gases can be treated as an ideal gas with CP = 30 J/mole K.