Landfill Gas Collection Systems by Mark Henricks

Every million tons of municipal solid waste that goes into a landfill is equivalent to approximately 432,000 cubic feet per day of landfill gas. If it’s left alone to leak out through the landfill cover into the atmosphere, that gas can become a significant source of odor and a contributor to smog, ozone depletion and global warming.

But landfill gas does have value. It’s about 45 percent carbon dioxide and about 55 percent methane. Both of these are greenhouse gases, but methane is a much more serious contributor to global warming than carbon dioxide. Methane can also be burned to create energy. The end result is that if it is collected and treated properly, landfill gas can turn from a problem into a long-term source of renewable energy. In fact, that same daily output of gas from a ton of waste can, if used to power a generator, be converted to approximately 800 kilowatts of electricity. Gas can also be used to fuel industrial plants.

These facts are driving a growing market for products that help landfills collect their gas and either convert it into energy or burn it to reduce its polluting effect. At LFG Specialties, LLC in Findlay, Ohio, vice president Dan DeArment says the company supplies extraction systems and flaring systems for landfill gas applications. Its parent, Shaw Group, provides a wide range of offerings, from pipe distribution to design and building gas collection systems. “We have the whole gamut of services to the landfill gas industry. LFG Specialties is the products group,” DeArment says.

LFG Specialties focuses on providing gas flares to landfills. The company has more than 600 flares operating, nationally and internationally, according to DeArment. “We also build gas compression systems,” he says. These take landfill gas, dry it and compress it and feed it to a pipeline. This can supply a boiler system for a business such as an asphalt plant. “We also compress it, put it in a pipeline and feed a reciprocating engine that would spin a turbine and generate power they can sell on the grid,” DeArment says.

LFG Specialties has two new products for landfill gas applications. E-Vap is an evaporator system for treating landfill leachate. The system uses an LFG gas flame to evaporate the water from leachate, then returns the sludge to the landfill. “We have had the product for 10 years but we’ve completely redone the technology,” DeArment says. “Now it’s much cleaner and more efficient and uses a lot less gas and so it’s much more competitive.”

The second is a joint venture with a European company that has a low-emission flare widely used there for oilfield and landfill gas. The low-emission flare is needed here because regulation of emissions from flares is getting more and more stringent, DeArment says. LFG Specialties has a test unit up and running in the United States and is rolling out the product in March, he says.

At Landfill Service Corporation in Apalachin, New York, their business has been built around flares, says president David Hansen. “In the old days the gas was simply vented raw to the atmosphere, but relative to climate change, methane gas is about 25 times more damaging than the carbon dioxide created by burning the gas. So it’s much better to burn the gas,” he says. Burning also helps with odor control.

Landfill Service’s main flare customers are smaller landfills. “In larger landfills where they have active gas collection with a blower putting suction on pipe and wells, our vents are often used for standby purposes,” Hansen says. Flares are also used on wells that haven’t been connected to the collection system, and if there is a problem with the collection systems. “We sell thousands of them in North America,” Hansen says. “It’s widely used.”

Landfill Service’s Solar Spark flare is a solar-ignited landfill gas vent flare. “The advantage of this product is we have a dual expansion carbureting flare head so it can take a wide performance envelope of both flow rate and gas quality,” Hansen explains. “Typically the flow rate will change widely over the day or the month, according to barometric pressure and so forth. Also the gas quality will change. The flare head we have developed works very well over a wide range of flow rates and gas quality.”

A new Landfill Services product is its Hi-X Universal Terminal Station. This is a specially designed terminal station to connect with horizontally buried gas collection conduits. “A lot of landfills are now going to horizontally buried conduits in order to capture gas in real time,” Hansen says. “With wells, you have to wait until the landfill is closed. But the problem with horizontal wells is that a lot of water is released. So, our horizontal terminal station is made to separate liquid and gas and allow you to tune the horizontal well the same as you could with a vertical well.”

Pushed by numerous forces ranging from higher energy prices to regulatory controls, landfill gas collection is a booming business for equipment providers. That’s especially true when it comes to waste-to-energy products. “Nobody wants to flare their gas any more,” says DeArment. “There’s so much value in that gas. And everybody wants green energy.”