News

Methane Methods: Converting Harmful Gas to Renewable Energy

May 23, 2024 by Emily Newton

Companies are innovating ways to capture harmful methane from hydropower, sewers, and landfills and use it as renewable energy.

Methane comprises nearly half of greenhouse gas emissions, a proportion equal to carbon dioxide. Yet naturally occurring methane gas can also become a viable renewable energy source. 

Methane capture techniques have been developed to harvest methane emissions from landfills and agricultural waste for electricity generation. However, several other methane sources, including hydropower—which releases 3 billion tonnes of methane into the atmosphere annually—are still undeveloped.

Three startups are implementing innovative ways to capture methane from landfills, sewage, and hydropower facilities. Their strategies could reduce or offset hydro’s harmful gases while generating renewable energy.

 

Hydroelectric power plant.

Hydroelectric power plant. Image used courtesy of Adobe Stock

 

Methane as a Power Source

Previous efforts to eliminate methane have involved taking it from sources such as landfills to run reciprocating generator sets. The landfill gas for this power production is approximately 50% methane, and peak production occurs up to seven years after garbage arrives at a location. Landfill gas usage is a longer-term solution, while other methods give shorter payoffs.

Methane is a byproduct of dam-created hydropower reservoirs. Decomposing vegetation on the reservoir’s bottom releases gases into the atmosphere by natural diffusion or turbine generation. The dissolved greenhouse gases flow through the hydroelectric turbines along with the water. The process disturbs the liquid, causing a degassing effect in methane emissions.

 

Methane extraction from landfill gasses

Methane extraction from landfill gasses. Image used courtesy of Environmental Protection Agency

 

Methane Extraction from Sewage

Japanese general contractor Taisei has created a method to turn sewage plants’ greenhouse gas emissions into electricity and thermal energy. The technique involves using a film, minerals, and a gas engine. Internal experiments showed this approach reduced emissions by 30% while equaling the water quality achieved by other methods.

Additionally, the extracted methane generated more electricity than this method required to run. Taisei indicated existing sewage plants could adopt this option, and it was a viable solution for food processing facilities.

 

Capturing Methane

Bluemethane, the creator of an intelligent methane-monitoring platform, has innovated an approach to directly connect to methane as a renewable power resource. It uses a proprietary separation technology to prevent emissions while generating energy. The approach supports an overarching goal of capturing 1 billion tonnes of greenhouse gasses from water, whether associated with wastewater, hydropower reservoirs, or agricultural activities.

Its methane-capture method has two parts. First, the gravity-powered in-line degassing unit removes the methane. Then, the water flows into a light vacuum system. If necessary, it can undergo additional treatment steps. Finally, people collect the methane from a biogas stream and turn it into energy.

 

Methane processing

Methane processing. Image used courtesy of Bluemethane
 

Water and wastewater company United Utilities is testing the commercialization potential of Bluemethane’s methane-capturing technology. The modular, patent-pending innovation uses a gravity-fed design that does not require active pumping. 

 

Solar and Hydropower

Enel Green Power plans to install a one-kilometer-long solar panel over a hydroelectric power plant’s diversion channel near Macerata, Italy. Estimates suggest this 1 MW photovoltaic roof will generate enough power for 450 households and conserve approximately 300,000 cubic meters of methane consumption.

The solar roof will feature fiber-optic cables connecting hydraulic sensors to increase safety. Additionally, automated flood-prevention measures will stop any upstream flow when leaks occur.

 

Collaborating for a Renewable Future

Although methane removal techniques have become more common over time, people have increasingly examined how to use gas as an energy source. Such open-mindedness will improve the chances of finding long-term energy solutions while targeting hydropower and sewage methane emissions. Engineers and others can benefit from previous efforts, expanding those based on what worked well or needed improvements.