Salvaged energy

Currently ranked as the third-largest source of human-related methane emissions in the U.S., municipal solid waste (MSW) landfills have been the subject of increased scrutiny and government intervention in recent years.

Under the most recent adaption of New Source Performance Standards (NSPS) and Emission Guidelines (EG), which was drafted by the U.S. Environmental Protection Agency (EPA) in 2016, MSW landfills are expected to cut methane emissions by approximately 334,000 tons a year starting in 2025.

In addition, the EPA lowered its non-methane organic compound emission threshold from 50 megagrams per year to 34 megagrams or more per year as part of the new standards, thus requiring landfills to install and operate a gas collection control system within 30 months of meeting this threshold.

Given these circumstances, landfills across the country have begun the process of establishing landfill gas (LFG) collection technology to meet federal emission guidelines. However, some sites have gone the extra mile to further benefit the environment.

Amid widespread pressure to adopt more responsible landfill management practices, the conversation surrounding converting LFG to energy (LFGTE) has gained significant traction. Several major waste management players, including Casella, Rumpke and Meridian Waste, have publicly partnered with renewable natural gas (RNG) providers to develop LFG-to-RNG projects just this year—proving by example that the conversion technology can provide a viable end market for the once problematic byproduct.

“Ingenco’s most important partners are the landfills we work with. An opportunity to help reduce their costs, protect the environment and also achieve a financial return is an ideal project.” – Sam Lewis, manager of Commercial Strategy and Data Engineering, Ingenco

Photos courtesy of INGENCO

CLOSING THE LOOP

In order to compete within the fast-growing green energy field of LFG electricity generation, companies like Richmond, Virginia-based Ingenco have worked to establish themselves as a pioneer for unique LFGTE technology.

With nearly 20 sites throughout the mid-Atlantic region, the company has created a viable business model through the process of converting LFG into renewable energy with the use of Detroit diesel engines.

“[Ingenco] was first formed in 1989 and is [currently] the mid-Atlantic’s largest LFG-to-energy company,” says Sam Lewis, manager of commercial strategy and data engineering for Ingenco. “The founders [of the company] believed they could compete under PURPA (Public Utility Regulatory Policies Act) by offering lower capital costs and lower operating costs than the incumbent utilities.

“Ingenco experimented with many waste fuels, such as perfumes, waste oils, animal fats, greases, etc. Landfill gas [has been] an extension of those efforts and proved to be a fuel stock of relatively high supply and of low costs on an energy equivalent basis.”

According to Lewis, the old diesel engines Ingenco uses to help power its LFGTE operations were previously used in tractor-trailers to transport goods within the U.S. As the engines are retired from the road, the company takes them and incorporates the engines into its fleet of gensets (a diesel engine connected to a generator), creating a closed loop.

“Our expertise, developed from over 30 years of operating in the industry, has allowed us to refine our technology and accentuate the effectiveness of our technology across various market conditions. Traditional LFGTE projects use engines specifically manufactured and designed for LFG rather than recycled from a previous, entirely different industry,” says Lewis.

Once gas is collected from the landfill and piped into one of Ingenco’s LFGTE facilities, it is distributed amongst the gensets. The engine then combusts the fuel, or LFG, to turn the generator, which converts the resulting energy into electricity that is sent to the grid via a distribution line.

“Rather than burning the methane through a flare, landfills [such as Charles City] seek beneficial use projects if feasible. This allows them to monetize the methane produced at the landfill and turn it into something beneficial for the environment.” – Sam Lewis, manager of Commercial Strategy and Data Engineering, Ingenco

Ingenco works with a wide variety of partners within the waste industry for its LFGTE operations, most of which are municipal landfills. Currently, the company has 14 designated LFGTE sites located throughout North Carolina, Virginia, Maryland and Pennsylvania.

A notable facility within this portfolio of LFGTE sites is the Charles City Landfill in Virginia, which was opened in 2003. Owned and operated by Houston-based Waste Management, the massive 629-acre landfill produces enough LFG to create roughly 70,000 megawatt hours (MWhs) of electricity annually.

“Rather than burning the methane through a flare, landfills [such as Charles City] seek beneficial use projects if feasible,” says Lewis. “This allows them to monetize the methane produced at the landfill and turn it into something beneficial for the environment.”

Considering the large scale of the Charles City site, Lewis says it was a challenge throughout the COVID-19 pandemic to ensure the facility had the required labor to keep operations running smoothly.

“For us, running over 30 gensets 24/7 at our facility is a lot to manage. Fortunately, our remote monitoring via central dispatch allowed us to operate with minimal labor and continue to produce green energy for the largest power market in the U.S,” Lewis explains.

Ingenco sells the energy it creates directly into the Eastern Interconnection grid operated by PJM Interconnection LLC (PJM), as well as to retail customers, such as colleges and businesses.

BROADENING HORIZONS

In addition to LFGTE operations, Ingenco is also in the process of expanding its operations into the LFG-to-RNG marketplace.

According to Lewis, Ingenco developed one of the nation’s first LFG-to-RNG facilities in Cedar Hills, Washington, in 2009, but it has since been divested to Bio Energy Washington. Now, the company has plans to covert four landfills in North Carolina and Virginia to create RNG.

“We view RNG as a great supplement to Ingenco’s traditional power business, and we see some landfills as more suitable currently for RNG,” says Lewis. “As our partner landfills’ collected gas volumes grow, EPC (engineering, procurement and construction) technology becomes more commonplace. And as virtual pipelines continue to evolve, we hope to continue to pivot the company towards RNG at the landfills where it makes economic sense. These elements make the physical and economical constraints easier to overcome and provide a more efficient market for companies or individuals to achieve their ESG (environmental, social and governance) goals.”

The company’s newest foray into the LFG utilization space has been through the creation of leachate evaporation systems. By using LFG to evaporate water content off of leachate, Ingenco hopes to provide its partners with a more cost-effective and environmentally friendly method to manage their leachate.

“Ingenco’s most important partners are the landfills we work with. An opportunity to help reduce their costs, protect the environment and also achieve a financial return is an ideal project,” says Lewis. “Essentially, [our systems] use the gas in the same manner you would use your stove to boil water. We combust the gas in a controlled manner to heat a vessel containing the leachate solution, and the vessel evaporates off additional water content in the leachate mixture.”

Through this process, Lewis says landfill operators can reduce disposal costs, decrease the risk of contaminants leaking into local environments and water supplies and cut emissions.

The author is the assistant editor of Waste Today and can be reached at hrischar@gie.net.