Basic Information about Landfill Gas | US EPA (2023)

FAQs

What are the basic information about landfill gas? ›

Landfill gas contains many different gases. Methane and carbon dioxide make up 90 to 98% of landfill gas. The remaining 2 to 10% includes nitrogen, oxygen, ammonia, sulfides, hydrogen and various other gases. Landfill gases are produced when bacteria break down organic waste.

Landfill gas (LFG) is a natural byproduct of the decomposition of organic material in landfills. LFG is composed of roughly 50 percent methane (the primary component of natural gas), 50 percent carbon dioxide (CO₂) and a small amount of non-methane organic compounds.

Three processes—bacterial decomposition, volatilization, and chemical reactions—form landfill gas. Bacterial decomposition. Most landfill gas is produced by bacterial decomposition, which occurs when organic waste is broken down by bacteria naturally present in the waste and in the soil used to cover the landfill.

Potential to Pose an Explosion Hazard

At some landfills, methane can be produced at sufficient quantities to collect in the landfill or nearby structures at explosive levels. Carbon dioxide is not flammable or explosive. Nitrogen dioxide is not flammable or explosive.

Landfill gas is collected and vented through a filter of bacterial slime. As long as oxygen is present, bacteria will decompose landfill gas under aerobic conditions, producing carbon dioxide and water. See the example below of odor controls used at a landfill in California.

Landfill gases are fed into a collection system which consists of a series of wells drilled into a landfill through a plastic piping system to later produce electricity. These gases could cause fire and explosions in some landfills, promoting close monitoring by the California Environmental Protection Agency.

WHAT IS THE COMPOSITION OF A LANDFILL? There are four critical elements in a secure landfill: a bottom liner, a leachate collection system, a cover, and the natural hydrogeologic setting. The natural setting can be selected to minimize the possibility of wastes escaping to groundwater beneath a landfill.

Landfill gas is composed primarily of 50 percent methane and 50 percent carbon dioxide and other gases produced at less than 1 percent. Methane and carbon dioxide are generated through the biological decomposition of waste.

Generally, it is accepted that landfills undergo at least four phases of decomposition, (1) an initial aerobic phase, (2) an anaerobic acid phase, (3) an initial methanogenic phase, and (4) a stable methanogenic phase (Christensen and Kjeldsen, 1995).

Biogas is produced naturally by anaerobic bacteria in municipal solid waste landfills and is called landfill gas. Landfill gas with a high methane content can be dangerous to people and the environment because methane is flammable. Methane is also a strong greenhouse gas.

What are the emissions from burning landfill gas? ›

Combusting the LFG also destroys organic compounds, including methane and non-methane organic compounds (NMOCs). During combustion, these organic compounds chemically react with oxygen in the presence of heat, breaking apart to form water vapor, carbon dioxide, and other less volatile compounds.

Reduce Air Pollution by Offsetting the Use of Non-Renewable Resources. Create Health and Safety Benefits. Benefit the Community and Economy. Reduce Environmental Compliance Costs.

Landfill gas consists primarily of methane and is produced when organic materials in large landfills decompose. Methane is 20 times more potent than carbon dioxide at trapping heat in the atmosphere. Capturing methane and using it as fuel is a more sustainable alternative to burning it as a waste product.

In May, the EPA implemented a 2016 Obama-era rule that will extend existing requirements for methane collection systems to 93 additional landfills. It lowers the emissions threshold for when landfills must install gas collection systems. Once in place, the rule will cut landfill methane emissions about 7% nationally.

Gas collection efficiencies ranged between 13 and 86% with an average of 50% – a value lower than for Swedish (58%), UK (64%) and US (63%) landfills.

Environmental Impact of Landfills

Along with methane, landfills also produce carbon dioxide and water vapor, and trace amounts of oxygen, nitrogen, hydrogen, and non methane organic compounds. These gases can also contribute to climate change and create smog if left uncontrolled.

Municipal Solid Waste Landfills (MSWLFs) – Specifically designed to receive household waste, as well as other types of nonhazardous wastes. Bioreactor Landfills – A type of MSWLF that operates to rapidly transform and degrade organic waste.

There are 3 main categories of landfills: Municipal Solid Waste Landfills (MSWLFs), Industrial Waste Landfills, and Hazardous Waste landfills. MSWLFs were created to dispose of household waste and other types of nonhazardous waste. Bioreactor landfills are a subcategory of MSWLFs.

There are three main reasons that landfills are bad for the environment: toxins, leachate, and greenhouse gases. First of all, many materials in the landfill contain toxic substances.

Waste minimization can be achieved in an efficient way by focusing primarily on the first of the 3Rs, "reduce," followed by "reuse" and then "recycle."

What makes a landfill different than a dump? ›

Dumps allowed leachate to soak into the ground and contaminate the groundwater. Landfill liners prevent leachate from passing into groundwater. Modern landfills have leachate collection systems and the leachate is transported to treatment plants where clean water is produced and pollutants are removed.

The four Rs - Rethink, Reuse, Reduce, Recycle - are a lifestyle for a sustainable future. ways to reuse items whenever possible; reduce consumption to reduce waste. Purchase only items that can be recycled.

Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.

Landfill gas is a type of biomass energy categorized as "waste energy." The process of decomposition—when organic material is broken down by microorganisms—generates methane gas, a greenhouse gas that can be hazardous.

Because of its explosive potential, methane is the primary concern at landfills. Methane is lighter than air and tends to migrate upwards and escape to the atmosphere.

But once it's in the landfill, it will take a really long time to decompose! How long? Between 450 and 600 years.

Methane is a flammable toxic greenhouse gas twenty times more damaging to the climate than carbon dioxide. Instead of going into the atmosphere and becoming a greenhouse gas which is harmful to the environment, it can be collected in every landfill and used to produce renewable energy.

RNG derived from LFG is considered a cellulosic biofuel eligible for D3 Renewable Identification Number (RIN) credits under EPA's Renewable Fuel Standard (RFS).

Landfill gas is a safe and renewable energy source. Using landfill gas reduces the need to use more polluting forms of energy. Using landfill gas reduces health and community risks, such as air pollution.

Which fuel source is considered the most pollution when burned? ›

These are not just the emissions from the burning of fuels, but also from the mining, transportation and maintenance over a power plant's lifetime. Coal, again, is the dirtiest fuel. It emits much more greenhouse gases than other sources – hundreds of times more than nuclear, solar, and wind.

Diverting organic waste through incentives and educational awareness. Policies can incentivize organic waste diversion through source separation of organic materials, large-scale deployment of organics recovery technologies, and development of organics processing infrastructure.

Landfill methane can be tapped, captured, and used as a fairly clean energy source for generating electricity or heat, rather than leaking into the air or being dispersed as waste. The climate benefit is twofold: prevent landfill emissions and displace coal, oil, or natural gas that might otherwise be used.

Typically, one million tons of landfill waste emit approximately 432,000 cubic feet of LFG per day, enough to produce either 0.78 MW of electricity or 216 MMBtu of heat.

With a heating value of about 500 British thermal units (Btu) per standard cubic foot, LFG is a good source of useful energy, normally through the operation of engines or turbines.

Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities.

Much of the 25% to 45% that remains consists of gaseous methane—produced by bacterial breakdown—and a solid residue which, if dried and concentrated, has an energy content similar to that of coal.

The largest source of greenhouse gas emissions from human activities in the United States is from burning fossil fuels for electricity, heat, and transportation.

Landfill gas utilization is a process of gathering, processing, and treating the methane or another gas emitted from decomposing garbage to produce electricity, heat, fuels, and various chemical compounds. After fossil fuel and agriculture, landfill gas is the third largest human generated source of methane.

Landfill gas is a safe and renewable energy source. Using landfill gas reduces the need to use more polluting forms of energy. Using landfill gas reduces health and community risks, such as air pollution. Landfills that use their landfill gas tend to be better managed and make better neighbors.

Why is landfill gas bad for the environment? ›

Environmental Impact of Landfills

Along with methane, landfills also produce carbon dioxide and water vapor, and trace amounts of oxygen, nitrogen, hydrogen, and non methane organic compounds. These gases can also contribute to climate change and create smog if left uncontrolled.

Waste-to-energy cons

They include the pollution and particulates it generates, the destruction of useful materials, and the potential to disincentivize more sustainable waste management solutions and renewable energy sources.

When it comes to converting landfill gas to electricity, the combustion engine is one of the major components to the process. Otherwise known as a biogas generator, a combustion ene does all the hard work when it comes to converting landfill gas to electricity.

Carbon dioxide is widely reported as the most important anthropogenic greenhouse gas because it currently accounts for the greatest portion of the warming associated with human activities.