What gases are released by landfills?
Landfills consist of a complex mix of gases and VOCs, and are a source of major pollution, and potential revenue… which we will address later in this article. Dangerous gases like methane (CH4), carbon dioxide(CO2), sulfides (SOx), and ammonia, are created by the decomposition and evaporation of organic compounds, as well as chemical reactions between waste components. Methane and carbon dioxide are the most prevalent, making up between 90 and 98% of all gases and VOCs released.
Why are these chemicals a concern?
These gases and VOCs are considered greenhouse gases, and play a huge role in global warming. According to the EPA, in the United States, landfills are the third most prevalent source of methane, and other greenhouse gases. Another risk when dealing with methane is the flammability of the gas, which is incredibly high. When condensed into a small space, methane is considered an explosive, and should be handled with extreme caution. Landfill gas explosions are not uncommon.
In addition to pollution and the risk of exploding, these VOCs pose a serious risk to human health. They have been linked to eye, throat and lung irritation, nausea, headache, nasal blockage, sleeping difficulties, weight loss, chest pain, and even asthma. Some recent studies indicate a connection between air pollution, and Alzheimer’s, diabetes, and slow fetal development.
There are a couple steps to abating landfill gases and VOCs. The first step that must be taken is the removal of the H2S. H2S, or hydrogen sulfide, is a very corrosive VOC, can be destructive to common machinery. The best way to abate hydrogen sulfide is by using a carbon absorber, or a dry scrubber (sometimes in the form of an iron sponge system). The second step is to remove the CO2, using sieves and other technologies to ‘clean’ the gas. Once these steps are complete, you are left with a product that is actually considered a renewable natural gas, which can be used as a fuel source in many operations or to produce electricity and heat.
Waste gas from the landfill gas cleaning needs to be treated prior to atmospheric discharge. The waste gas is processed using thermal oxidization. Depending upon concentrations, and the presence of additional VOCs, equipment options include a direct fire thermal oxidizer, a regenerative thermal oxidizer, or a catalytic oxidizer.
What is RNG?
RNG stands for renewable natural gas. Renewable natural gas, also known as sustainable natural gas (SNG), or biomethane, is a biogas that can now be used as a pipeline energy source. Natural gas and energy companies can purchase the waste gas from landfill gas abatement, and sell it to their customers. RNG qualifies as an advanced biofuel under the Renewable Fuel Standard.
The RNG created by landfill gas abatement are incredibly valuable, because they can be used interchangeably with natural gas, and the US government incentivizes energy companies to purchase and use them. As of March 2015, there were about 645 operational Landfill Gas projects in the United States through the Landfill Methane Outreach Program (LMOP), and that number was expected to steeply rise. Because of this, these gases often sell at a higher rate, than conventional natural gas. The end result of RNG development takes dangerous gases, and turns them into valuable sources of energy, while aiding in the prevention of global warming. Landfill companies benefit financially, in a big way, with the expertise of the Gulf Coast Environmental Systems team.
Why choose GCES for your Landfill project?
Gulf Coast Environmental Systems is a full-service pollution control company. We offer a variety of solutions to customers looking to process and abate VOCs and gases, produced by dozens of industries including landfills. Our mission: For the environment, and the economy, we are inspired to develop innovative solutions, which better the lives of our employees, customers, and communities. Our engineering team has taken a special interest in landfill projects, because of the massive global benefits, and in doing so, we have come up with several abatement options. By designing and custom manufacturing pollution control equipment in-house, we are able to provide the best solution for each unique operating condition.
Our units have been proven in some of the most challenging environments. The vast majority of units we install operate 24 hours a day, 7 days a week in facilities across the world. Our systems consistently perform at greater than 99% uptime in rendering facilities, chemical mixing plants, petrochemical facilities, landfills and other harsh process environments.
If you are considering the value of abating landfill gases, and would like to speak with one of our experts, please give us a call at 1.832.476.9024, or email us at email@example.com.
To learn more about GCES’ involvement in Landfill RNG Products, see our Landfill-RNG Presentation PDF