Rate of emission of particulates from a power plant

[mbm]

Homework Statement

What is the rate of emission (kg/h) of particulates from a power plant with a thermal output of 3000MW that burns coal with and ash content of 2%? How much is emitted if an electrostatic precipitator of 95% efficiency is used? if the ash contains 1ppM of mercury, how many tons fo mercury will be emitted by this plant per year?

Homework Equations

The Attempt at a Solution

I'm really clueless on how to solve this problem!

 

[mark726]

Hello,

To calculate the rate of emission of particulates from a power plant, we first need to determine the amount of coal being burned per hour. We can do this by using the thermal output of 3000MW.

Power (P) = Energy (E) / Time (t)

3000MW = Energy (E) / 1 hour

Energy (E) = 3000MW x 1 hour = 3000 MWh

Next, we need to convert the energy (E) into a unit of mass, such as kilograms (kg). To do this, we need to know the specific energy of coal, which is typically measured in joules per kilogram (J/kg). For the purposes of this calculation, we will assume an average specific energy of 25,000,000 J/kg for coal.

Energy (E) = Mass (m) x Specific Energy (SE)

3000 MWh = m x 25,000,000 J/kg

m = 3000 MWh / 25,000,000 J/kg

m = 0.12 kg

This means that 0.12 kg of coal is being burned per hour in the power plant.

Next, we need to determine the amount of ash being emitted. We know that the ash content of the coal is 2%, which means that 2% of the coal being burned is converted into ash.

Ash Mass = 0.12 kg x 2% = 0.0024 kg

Therefore, the rate of emission of particulates from the power plant would be 0.0024 kg/h.

If an electrostatic precipitator with 95% efficiency is used, it will capture 95% of the particulates emitted, leaving only 5% to be released into the environment.

Emissions with Electrostatic Precipitator = 0.0024 kg x (1 - 0.95) = 0.00012 kg/h

This means that using an electrostatic precipitator would reduce the rate of emission to 0.00012 kg/h.

Finally, to determine the amount of mercury emitted per year, we need to know the total mass of coal burned in a year and the concentration of mercury in the ash.

Mass of Coal Burned in a Year = 0.12 kg/h x 24 hours x 365 days = 1051.2 kg/year

Concentration of Mercury in