A new coal-fired power plant with a heat rate of 9000 Btu/kWh burns coal with an energy content of 24,000 kJ/kg. The coal content includes 62% carbon, 2% sulfur and 10% unburnable minerals called ash. a. Knowing that 1 Btu/kWh is equivalent with 1.055 kJ/kWh, what will be the carbon emission rate (g C/kWh)? b. What will be the uncontrolled sulfur emission rate (g S/kWh)? c. If 70% of the ash is released from the stack (called fly ash), what would be the corresponding uncontrolled emission rate (g fly ash/kWh)? d. Since the Clean Air Act restricts SO2 emissions to 130 g of sulfur per 106 kJ of heat into the plant, what removal efficiency does the corresponding equipment need to have for the plant? What is the name of this equipment? (1 kWh = 3600 kJ) e. What efficiency does the removal equipment need to have to meet the Clean Air Act standard of no more than 13 g of fly ash per 106 kJ of heat input? What is the name of this equipment? f. If 80% of thermal losses are taken away by cooling system (i.e., condenser and cooling tower), calculate the thermal losses up at the stack (kJ) after burning 100 kg of fuel.
A new coal-fired power plant with a heat rate of 9000 Btu/kWh burns coal
with an energy content of 24,000 kJ/kg. The coal content includes 62%
carbon, 2% sulfur and 10% unburnable minerals called ash.
a. Knowing that 1 Btu/kWh is equivalent with 1.055 kJ/kWh, what will
be the carbon emission rate (g C/kWh)?
b. What will be the uncontrolled sulfur emission rate (g S/kWh)?
c. If 70% of the ash is released from the stack (called fly ash), what would
be the corresponding uncontrolled emission rate (g fly ash/kWh)?
d. Since the Clean Air Act restricts SO2 emissions to 130 g of sulfur per
106 kJ of heat into the plant, what removal efficiency does the
corresponding equipment need to have for the plant? What is the name of
this equipment? (1 kWh = 3600 kJ)
e. What efficiency does the removal equipment need to have to meet the
Clean Air Act standard of no more than 13 g of fly ash per 106 kJ of heat
input? What is the name of this equipment?
f. If 80% of thermal losses are taken away by cooling system (i.e.,
condenser and cooling tower), calculate the thermal losses up at the stack
(kJ) after burning 100 kg of fuel.
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