Landfill Operator Turns Gas to Renewable Energy

From food and dairy operations to landfills, Kupper Engineering is helping companies convert waste and related byproducts into renewable natural gas (RNG.) Made from biogas emitted from organic waste, RNG is processed to pipeline quality standards and used as a substitute for fossil fuels.

Kupper Engineering, a system integrator in the Rockwell Automation PartnerNetwork™ program, is a member of the Asplundh Infrastructure Group, a national alliance of infrastructure services and solutions for utilities, power producers and energy-intensive customers in the United States.

The firm provides professional engineering, engineering support, equipment procurement, and automation controls integration, from planning and design to implementation and commissioning.

Kupper was one of the first firms to provide electrical engineering services for RNG production facilities. The company has supported about 30 RNG projects and has another 30 planned over the next three years. These include RNG sourced from landfill gas (LFG), and animal and food waste using anaerobic digester systems.

“Rather than digging natural gas out of the ground, which is ‘non-renewable,’ we’re taking a byproduct of human processes and turning it into a resource for people to use in their everyday lives,” explains Jude Matteo, principal systems integrator, Kupper Engineering.

“What makes us unique is that as both an engineering and controls firm we understand how all the pieces fit together in these highly specialized projects,” adds William Moss, a Kupper senior project manager. “We’re intimately involved from the initial design to implementation and support throughout the life of these sites.”

Supporting the Conversion Process

Kupper is helping one of North America’s largest landfill operators aggressively expand its RNG infrastructure as part of its growth and sustainability strategies.

“Historically, as trash was buried in landfills, it decomposed. This created off gases that smelled, could be extremely dangerous when accumulating, and negatively impacted the environment and ozone,” Matteo explains. “The original way operators dealt with that was to remove the landfill gas and flare it — just burn it off. Now, through a series of processes, they can take that gas out of the landfill, clean it and turn it into what is essentially natural gas.”

This operator plans to use the RNG generated to help fuel its transportation fleet and then return the remainder to the natural gas pipeline. Process control is paramount as stringent guidelines govern the process of converting LFG to pipeline-quality gas.

“Landfill gas typically is 50% methane, a large amount of carbon dioxide (CO₂) and a smaller amount of trace components,” notes Michael Markham, a Kupper senior project manager.

“The CO₂ and trace amounts must be stripped away so the final product is 98% pure methane. There are several processes to go through, and each stage may require compression, cooling, heating and filtration,” he says.

It’s a complex system to design, connect and control. Rockwell Automation technologies, including ControlLogix^® and CompactLogix™ control systems, intelligent motor control centers, variable-frequency drives and other components help operate the dozens of actuators, motors, valves, pumps and sensors in the system integrator’s LFG-to-RNG projects.

These technologies are also key to employee and system safety. They help facilities monitor and detect gas leaks, control ventilation, adjust fans and shut systems down if needed.

Standardized Plant Design & Equipment

“We were asked to get involved with this client because they wanted to standardize plant design and equipment across various project sizes so they would be safe, reliable and consistent,” shares Markham.

“Whether it’s a digester or a landfill, as in this case, they're always making gas that must be dealt with continuously,” Matteo adds. “Any time a plant isn’t running, they must do something with the gas and usually that means flaring it. So, any increase in reliability is hugely beneficial.”

Between now and 2026, the client plans to build 20 RNG plants in four sizes ranging from 16,000 to 30,000 sq. ft., handling between 3,000 and 8,000 standard cubic feet per minute (CFM) of LFG.

“These facilities will run fast-acting, complex processes with hundreds of components that need to be installed, configured and integrated,” notes Matteo. “Since we know we’re going to build more of these plants, we try to template them. The ability to standardize and modularize programming has been straightforward.”

Potential Economic and Environmental Benefits

Kupper’s first standardized LFG to RNG site for this client went online in spring 2023. About eight more are expected in 2024, and the remainder by 2026.

An average site has the potential to recover and produce more than 780,000 MMBtu per year of RNG. MMBtu is the common metric used to measure heating content and fuel value. That amount equals serving more than 26,000 homes or 676 heavy-duty trucks annually and is the equivalent of more than 5.3 million gallons of diesel fuel.

Using RNG from this sized plant, instead of fossil fuels, has the potential to eliminate more than 50,000 tons/year of greenhouse gas emissions (GHGs).

“We’re helping this client turn a nuisance gas byproduct into usable energy,” Markham says. “Instead of them having to spend capital and annual funds for disposal, they’ll produce a viable energy source that’s better for the environment and generates a profitable income.”

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