3. (from 2.41) In 2010 landfills in the US produced approximately 107.8 Tg CO2e

Question

3. (from 2.41) In 2010 landfills in the US produced approximately 107.8 Tg CO2e of methane
emissions. Wastewater treatment plants emitted 16.3 Tg CO2e of methane. (a) How many pounds and
metric tons of methane (reported as CO2 equivalents) did landfills and wastewater plants emit in
2010? What percent of the total 2010 methane emissions (and greenhouse gas emissions) do these two
sources contribute (total methane emissions in 2010 were 666.5 Tg CO2e, and total greenhouse gas
emissions in 2010 were 6,821.8 CO2e).    

Explanation / Answer

To calculate pounds and metric tons of methane (reported as CO2 equivalents) did landfills and wastewater plants emit in 2010 uses the following steps:

CH4 + 2O2 -àCO2 + 2H2O

One mole methane produce one mole of methane gas.

First calculate the number of mole

107.8 Tg CO2e = 107.8 *10^12 g CO2

the number of mole CO2 = 107.8 *10^12 g CO2 / 44.01 g/mol = 2.45 *10^12 mol CO2

from the above reaction 2.45 *10^12 mol CO2 produce from 2.45 *10^12 mol CH4 then mass of methane:

Mass of CH4 = 2.45 *10^12 mol CH4 *16.00 g / mol = 39.2 *10^12 g CH4

Convert the unit of mass from g to pounds and metric tons as follows:

1 Pound = 453.592 g

39.2 *10^12 g CH4 *1 Pound / 453.592 g = 86.42*10^10 Pound CH4.    

1 metric ton = 10^6 g

39.2 *10^12 g CH4 *1 metric ton / 10^6 g = 39.2 *10^6 metric ton CH4

  First calculate the number of mole

16.3Tg CO2e = 16.3 *10^12 g CO2

The number of mole CO2 = 16.3*10^12 g CO2 / 44.01 g/mol = 0.37 *10^12 mol CO2

From the above reaction 0.37 *10^12 mol CO2 produce from 0.37 *10^12 mol CH4 then mass of methane:

Mass of CH4 = 0.37 *10^12 mol CH4 *16.00 g / mol = 5.93 *10^12 g CH4

Convert the unit of mass from g to pounds and metric tons as follows:

1 Pound = 453.592 g

5.93 *10^12 g CH4 *1 Pound / 453.592 g = 1.30 *10^10 Pound CH4.

1 metric ton = 10^6 g

5.93 *10^12 g CH4 *1 metric ton / 10^6 g = 5.93 *10^12 metric ton CH4

What percent of the total 2010 methane emissions (and greenhouse gas emissions) do these two
sources contribute (total methane emissions in 2010 were 107.8 Tg CO2e, and total greenhouse gas
emissions in 2010 were 6,821.8 CO2e).

Now calculate the percent of the total 2010 methane emissions (and greenhouse gas emissions as follows:

The percent of the total 2010 methane landfills

= 107.8 Tg CO2e /666.5 Tg CO2e *100

= 16.17 %

The percent of the total 2010 methane from wastewater plants

= 16.3 Tg CO2e /666.5 Tg CO2e *100

= 2.45 %

total greenhouse gas emissions in 2010 were 6,821.8 g CO2e, first change it into Tg as follows:

1 tg = 10^12 g

6,821.8 g CO2e *1 tg / 10^12 g = 6.821810^-12 tg

The percent of the total 2010 methane from greenhouse gas

= 6.821810^-12 tg CO2e /666.5 Tg CO2e *100

= 1.02*10^-9 %

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.