 Biogas
can provide a clean, easily controlled source of renewable energy from organic waste
materials, replacing fossil fuels with a sustainable carbon neutral fuel option.
What is Biogas?
Biogas is generated when bacteria degrade biological material in the absence of oxygen, in a process known
as anaerobic digestion. Biogas is primarily a mixture of methane (also known as marsh gas or natural gas)
and carbon dioxide (CO2), and is a renewable fuel.
Landfill gas is biogas produced by organic waste decomposing under anaerobic conditions in a landfill.
The waste is covered and compressed mechanically by the weight of the material that is deposited from
above. This material prevents oxygen from accessing the waste and anaerobic microbes thrive. This gas
builds up and is slowly released into the atmosphere if the landfill site has not been engineered to
capture the gas.
What is Biomethane?
Municipal solid waste landfills account for over one quarter of the total methane emissions in the U.S.
Landfill gas is a particularly attractive natural gas supply option because it is a low-cost feedstock
source due to the minimal processing required to remove the impurities to produce biomethane.
Biogas is normally rich in methane (about 65%) and impurities of hydrogen sulfide (H2S),
CO2 and water. Technology is commercially available to remove H2S, CO2
and water contaminants present in the biogas and landfill gas through processing to produce high-purity
natural gas (biomethane) suitable for vehicles.
Therefore, biomethane is simply pipeline quality natural gas that can be used directly or added to existing
supplies.
Biomethane Benefits
Capturing landfill gas or biogas for processing into biomethane suitable for vehicles has significant
benefits.
- Using biomethane as a renewable fuel has significant greenhouse gas (GHG) benefits.
- Unlike naturally occurring methane emissions, biomethane is converted to CO2 during
combustion (a 21 times greenhouse gas savings).
- Biomethane is a renewable resource that can displace fossil fuel by 100%.
- Biomethane does not compete with food production.
- The biomethane that is used as fuel in place of fossil fuels produces less GHG than the fuel it
replaced.
Using natural gas and biomethane as a low-carbon fuel addresses not only global warming, but also the
problems of high oil prices and foreign oil dependence.
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