Living the pipe dream

Waste Management (WM), headquartered in Houston, has implemented a number of unique and potentially game-changing ideas for recovering and using its landfill gas as a resource.

The waste management services company now has 134 landfill projects using landfill gas to generate electricity, produce renewable gas or displace fossil fuel.

One of those projects, arguably its most cutting edge venture, is the one in which its landfill gas is purified and piped right alongside traditional natural gas. Ultimately the two products become one and the same.

It’s a partnership that also has impressed WM’s natural gas delivery partner, Ameren Illinois of Collinsville, Illinois, because of the level of cooperation, innovation and sustainability the companies have been able to achieve.
 

From landfill to pipeline

The cutting edge project begins at the North Milam Landfill in Fairmont City, Illinois, where the company has constructed a renewable natural gas facility (RNGF) capable of processing, purifying and compressing landfill gas to a quality that makes it suitable for injection into a natural gas pipeline.

The North Milam landfill, which was expanded in 2013, has been creating enough methane gas to support an existing landfill-gas-to-energy plant. In an effort to harness the remaining landfill gas, WM has partnered with electricity and natural gas delivery company Ameren Illinois to deliver processed landfill gas through one of its major pipelines. For its part, WM is purifying and compressing the landfill gas, so it can be injected into Ameren Illinois’ nearby pipeline.

Lisa Disbrow, spokesperson for WM of Illinois, says the new RNGF is the first such facility the company has built from the ground up and is an innovative project for the company, which never before processed landfill gas for delivery through a natural gas pipeline. But via processing through the RNGF, the purified gas is upgraded to pipeline quality, making it suitable to heat homes and businesses and fuel equipment and truck fleets that run on compressed natural gas (CNG), including WM’s own.

“It’s actually closing the loop, by linking our own demand for CNG to fuel our own trucks,” says Disbrow. “We’re able to collect trash, place it in the landfill and withdraw the landfill gas to clean it up to pipeline quality, and run our trucks on that gas.”

Disbrow says the process exemplifies a core principle of creating renewable energy from waste. “The trash is collected and then through decomposition and other processes, the trash becomes capable of running our vehicles,” she observes.

Scott Glaeser, vice president of gas operations and development for Ameren Illinois, observes that accepting and transporting gas sourced from a landfill in its pipeline sets a precedent for the utility too.

“This is the first time we’ve received biogas from a landfill facility,” he says, noting that while the company has received natural gas from small natural gas producers and wells in Illinois, it has never before tapped into a landfill.

Plenty of gas

The idea to generate pipeline-worthy gas from North Milam was appealing to the company as a better way to utilize and manage the landfill gas generated there, Disbrow explains. The 180-acre landfill, located across the river from St. Louis, has been operated by WM of Illinois since 1984. The landfill accepts municipal solid waste (MSW) and industrial waste from around the greater metropolitan St. Louis and Southern Illinois regions.

A landfill-gas-to-energy plant has been operating on the site since 1991, and it is capable of producing 2.4 megawatts of energy. The power was originally fed into the local electricity grid, while excess landfill gas had to be flared from the site.

“Either you collect it and develop gas to energy, or use a flare mechanism to manage the gas,” Disbrow explains. “When we looked at the landfill gas generation, we realized we had enough gas to develop this renewable natural gas facility,” she says.

The new RNGF, constructed adjacent to the landfill-gas-to-energy (LFGE) plant, is now powered by that facility. “We have connected [the gas-to-energy facility] to the renewable natural gas facility for its electricity needs, to run the compressors, dehydrators and the other equipment used to clean up the landfill gas to pipeline-quality natural gas,” Disbrow explains.

Disbrow says the landfill gas generated by the decomposing waste is collected in a network of wells and pipes that move it to central locations, in this case the LFGE plant and the RNGF. As the gas is collected, she says a small amount of air enters the system, adding as contaminants carbon dioxide, nitrogen and oxygen to the methane gas.

“What we’re doing at the renewable natural gas facility is processing the landfill gas by removing carbon dioxide, nitrogen and oxygen to produce the high purity methane that meets the natural gas pipeline specifications,” Disbrow says. “It’s this renewable natural gas that’s compressed and injected into the adjacent natural gas pipeline.”

Disbrow adds that Ameren Illinois was considered to be a natural partner for WM, as the company’s natural gas pipeline runs right through WM’s Milam property.

“It made perfect sense when we started to look at this,” Disbrow says. “We were thinking, ‘we can clean up and pipe the natural gas, and tap right into the Ameren pipeline, because it’s right there.’”

Ameren Illinois agreed to the idea, considering it an opportunity for itself as well. “We are investing in new technology upgrades to our natural gas delivery system, so when we were approached by Waste Management for this first-of-its-kind collaboration, it made perfect sense to us,” explains Richard Mark, president of Ameren Illinois.

Ground-breaking for the facility occurred in the fall of 2013, and construction took about a year, with the facility up and running in November of 2014. The $19 million cost of the project was partially funded by a grant of $2.4 million from the Illinois Department of Commerce and Economic Opportunity and the Illinois Energy Office.
 

Many benefits

While this renewable natural gas facility is unique for WM, the company has at least two similar projects underway.

In California, for example, WM collaborated in what the company says is the world’s largest plant to convert landfill gas to ultra-low-carbon liquefied natural gas (LNG). And in Ohio, WM is processing about 3,000 standard cubic feet per minute (SCFM) of landfill gas for delivery to a natural gas pipeline used by a single entity for its natural gas needs. Those are in addition to 130 other projects where the landfill gas is used to generate electricity, produce renewable gas or displace fossil fuel.

While those projects have benefits for WM and the greater community, the North Milam renewable natural gas project brings a collection of positive effects that may be greater than the sum of its parts. Besides being able to help fuel its own fleet of CNG trucks, WM also has reduced North Milam’s carbon emissions, since excess landfill gas is no longer flared.

“That is the biggest benefit, as we help to reduce our own emissions and that in turn helps improve the air quality in the region,” Disbrow observes.

Using the CNG in its trucks is another tangible benefit. “We’re able to reduce our dependence on fossil fuels,” she adds. Yet another benefit of running CNG trucks is lower emissions, because CNG trucks “emit nearly zero air particulates,” she says.

As part of the deal, WM has to option to either sell its CNG to Ameren Illinois or to have Ameren transport CNG to the local gas utility serving WM’s Midwest fueling facilities.

Since operations began, Disbrow says processes are running well as the facility is continuing to ramp up to full capacity.

Designed to process about 3,500 SCFM of incoming landfill gas, at that level the RNGF could contribute enough CNG to fuel about 200 of WM’s CNG collection trucks per day, or around 5 percent of the daily natural gas usage for the company’s entire CNG fleet.

“We’re successfully cleaning the landfill gas to meet the pipeline specification and we’re delivering the produced gas to Ameren Illinois,” says Disbrow, who notes that WM continues to ramp up processing. “We’re probably at about 50 percent capacity,” she says, noting that accelerating the process must be done in measured steps to ensure the processed gas continues to meet specifications.

Ameren Illinois’ Glaeser explains that even though Milam’s cleaned and compressed gas is being fed into Ameren’s pipeline, the gas is owned by WM, which pays a fee for transporting the gas.

The high-pressure, 12-inch-diameter pipeline serves as a main transmission line supplying the greater St. Louis metro east area. As such, accepting Milam’s biogas involves a constant process of quality control, Glaeser explains.

“We require Waste Management to really clean and scrub the gas until it is pipeline quality to meet our specifications to pure natural gas,” says Glaeser. This cleaning and treatment, which occurs at the RNGF, is monitored continually at the injection point where Ameren Illinois systems meter and measure gas pressure, quality and moisture content, he explains.

“It is cleaned up to the point where it looks just like natural gas, and it burns exactly like natural gas,” Glaeser says.

If at any time monitoring indicates specifications are not being met, the system can be halted at the injection point until the problem is corrected, Glaeser says, noting that the two companies work very closely in terms of meeting and monitoring specifications.

“That’s the way we maintain the quality and the blend of that gas with our natural gas,” he says. “We manage our metering system for the purposes of controlling the system,” says Glaeser. “We also make that [information] available to WM.”

Glaeser notes that the pipeline moves a tremendous amount of gas, with the landfill gas comprising only a very small percentage of the total flow. Even so, the project benefits the distribution company and is a win-win-win for the companies and residents in the area, he says.

“Waste Management is an important power customer of Ameren Illinois,” Glaeser says, “and we wanted to make them a natural gas customer.”

Further, Glaeser says, Ameren Illinois supports such renewable energy projects. “Reduced emissions from the landfill is important for our customers that live in that area,” she says. Another benefit is the recovery of a resource that previously was wasted.

Both companies also point to the cooperative effort that has allowed the North Milam project to be a success and one that can serve to inspire additional projects.

“We’ve had a great partnership with Waste Management,” says Glaeser. “All the people at Milam and Ameren Illinois are working together for this common cause and recovering this resource, which has been a really neat part of this project.”

Meanwhile, Disbrow says the project is ideal for a company that currently operates the largest fleet of heavy duty CNG trucks in North America, now numbering more than 4,000. Furthermore, she says the project is also contributing to the company’s long-term mission to reduce greenhouse gas emissions and increase fuel efficiency.

“This fits so perfectly into our own sustainability goals,” she observes.

The author is a managing editor with the Recycling Today Media Group and can be reached via email at lmckenna@gie.net.