Question

Organic materials (such as food scraps and yard waste) in landfills can decompose and produce landfill gas ( LFG ) over time. About 50% of LFG is methane, a greenhouse gas with a global warming potential 25 times higher than that of carbon dioxide over a 100 -year period. LFG can be collected and burned to produce electricity.
i. Explain a process during which LFG is burned to produce electricity.
ii. The Puente Hills Landfill in California contains about 123 million tons of landfill waste and burns LFG to produce electricity. In a typical landfill, one million tons of landfill waste emits approximately 432,000 cubic feet of LFG per day. Calculate how much LFG is emitted at the Puente Hills Landfill per year.
iii. Burning LFG for electricity produces the additional benefit of preventing methane from entering the atmosphere. Calculate how much methane is prevented from entering the atmosphere by burning LFG to produce electricity at the Puente Hills Landfill over a 10-year period.
iv. All of the landfills in the United States that burn LFG to produce electricity produce a total of about 15 billion kilowatt-hours ( kWh ) of electricity per year. The average house in the United States uses about 30.3 kWh of electricity per day. Calculate how many households can have their total electricity needs provided by these landfills.

Answer 1

Based on the data provided:

• LFG is used to produce electricity by using it as fuel in combustion turbines

• the Puente Hills Landfill will emit 1.94 * 10¹⁰ cubic feet of LFG per year

• 9.7 * 10¹⁰ cubic feet of methane is prevented from entering the atmosphere.
• the number of households that can have their total electricity needs provided by these landfills is 1,368,925 households.

What is the process of electricity generation from LFG?

Landfill gas, LFG can be used to generate electricity.

It contains 50% methane which is used as fuel for energy generation.

The process of generating electricity from LFG is as follows:

• It is processed to produce methane.
• The methane produced is combined with natural gas
• The mixture is used as fuel for combustion turbines which then drives energy generation.

How much LFG is emitted at the Puente Hills Landfill per year?

From the data given:

ii) 1 million tons of landfill emits  432,000 cubic feet of LFG per day

123 million tons of landfill waste will emit 123000000 * 432000/1000000 cubic feet of LFG per day

The Puente Hills Landfill will emit 53136000 cubic feet of LFG per day

1 year = 365.25 days

Amount of LFG emitted in 1 year = 53136000 * 365.25 cubic feet of LFG per day

Amount of LFG emitted in 1 year = 1.94 * 10¹⁰ cubic feet of LFG per year

Therefore, the Puente Hills Landfill will emit 1.94 * 10¹⁰ cubic feet of LFG per year

What is the amount of methane prevented from entering the atmosphere by burning LFG to produce electricity at the Puente Hills Landfill over a 10-year period?

Volume of LFG produced in Puente Hills Landfill in 10 years is calculated below:

1.94 * 10¹⁰ cubic feet of LFG per year * 10 years = 1.94 * 10¹¹ cubic feet of LFG

Volume of methane in 1.94 * 10¹¹ cubic feet of LFG = 1.94 * 10¹¹ * 50% Volume of methane in 1.94 * 10¹¹ cubic feet of LFG = 9.7 * 10¹⁰ cubic feet of LFG

Therefore, 9.7 * 10¹⁰ cubic feet of methane is prevented from entering the atmosphere.

How many households can have their total electricity needs provided by these landfills in the United States?

Average yearly household electricity need = 30 kWh * 365.25 days

Average yearly household electricity need = 10957.5 kWh per year

Number of households = total electricity from LFG / average household electricity use per year

Number of households = 15000000000/10957.5

Number of households = 1,368,925 households

Therefore, the number of households that can have their total electricity needs provided by these landfills is 1,368,925 households.

Learn more about LFG and electricity generation at: brainly.com/question/14391018