Chapter 19, Problem 3P

Consider a 400-MW, 32 percent efficient coal-fired power plant that uses cooling water withdrawn from a nearby river (with an upstream flow of 10-m3/s and temperature 20 °C) to take care of waste heat. The heat content of the coal is 8,000 Btu/lb, the carbon content is 60% by mass, and the sulfur content is 2% by mass. How much electricity (in kWh/yr) would the plant produce each year? How many pounds per hour of coal would need to be burned at the plant? Estimate the annual carbon emissions from the plant (in metric tons C/year). If the cooling water is only allowed to rise in temperature by 10 °C, what flow rate (in m3/s) from the stream would be required?  What would be the river temperature if all the waste heat was transferred to the river water assuming no heat losses during transfer?  Estimate the hourly SO2 emissions (in kg/h) from the plant assuming that all the sulfur is oxidized to SO2 during combustion.

Which emits more SOx per unit amount of electricity produced; a coal-fired plant with a 90% efficient SO2 scrubber or an oil-fired plant with m scrubber? Assume the coal has a heat content of 13,000 Btu/lb and contains 3.5% sulfur, and that the oil has a heat content of 6.0(10)* Biu/barrel (42 gallons) and contains 0.9% sulfur, Assume the oil has a specific gravity of 0,92.

Use second law of thermodynamics to explain global warming,why battery runs down and why rusting is inevitable