Pioneering Cleaner Technology Set to Transform Agricultural Emissions

An inside view of the MEPS reactor (Methane Eradication Photochemical System) reveals how chlorine atoms, generated by UV light, engage with methane gas. Credit to Morten Krogsbøll for the image.

In a groundbreaking study, the University of Copenhagen’s team has harnessed light and chlorine to effectively remove low-concentration methane from the air. This breakthrough paves the way for potentially eradicating greenhouse gases from settings like livestock enclosures, biogas facilities, and wastewater treatment plants, thus aiding the climate.

The Intergovernmental Panel on Climate Change (IPCC) acknowledges that curtailing methane emissions is crucial for immediately slowing global temperature rises. Methane, up to 85 times more impactful as a greenhouse gas compared to CO2, is predominantly emitted by human activities, notably from cattle and fossil fuel production.

Innovative Approach to Reduce Methane

The University of Copenhagen’s Department of Chemistry, along with Ambient Carbon, a spin-out company, has developed a novel method for extracting methane from the air.

Professor Matthew Stanley Johnson from UCPH, a leader in atmospheric chemistry, stated, “A significant portion of methane emissions originates from numerous low-concentration sources like cattle and pig barns, previously challenging to mitigate. However, our latest advancement demonstrates the feasibility of methane removal using our custom-built reaction chamber.”

The team engineered a reaction chamber that expedites methane’s natural breakdown process. This system, named the Methane Eradication Photochemical System (MEPS), accelerates methane degradation by 100 million times compared to its natural rate.
Credit goes to Michael Skov Jensen of SCIENCE/KU for this information.

Professor Johnson has shared these findings at COP 28 in Dubai and the National Academy of Sciences in Washington D.C., which advises the U.S. government on science and technology.

Methane Purification via Reactor

Typically, methane in air can be burnt off if its concentration is above 4 percent, but most emissions caused by humans are under 0.1 percent, making them unburnable.

To tackle this, the researchers developed a reaction chamber, resembling an elongated metal box equipped with numerous hoses and instruments. This chamber facilitates a chemical reaction sequence that eventually breaks down methane.

The MEPS mechanism employs UV light and chlorine gas generated through electrolysis to eradicate methane on site. Credit to Matthew Stanley Johnson, Department of Chemistry, University of Copenhagen.

“Recent experiments have shown that our chamber can eliminate 58 percent of methane from the air, with laboratory improvements pushing this figure to 88 percent,” notes Matthew Stanley Johnson.

The Role of Chlorine

Chlorine is central to this discovery. Its combination with light allows for a more efficient methane removal from the air than the atmospheric process, which usually spans 10-12 years.

In the MEPS reactor, chlorine molecules interact with methane gas in a chamber, and UV light exposure leads to the splitting of these molecules, forming chlorine atoms.

“These chlorine atoms initiate a reaction, disintegrating methane approximately 100 million times quicker than naturally,” explains Johnson.

Method Overview

This method, named MEPS, drastically speeds up methane’s natural degradation process.

Chlorine atoms generated in the chamber snatch a hydrogen atom from methane, leading to its decomposition. The resultant chlorine product (hydrochloric acid) is then captured and reused in the chamber.

Methane is transformed into carbon dioxide (CO2), carbon monoxide (CO), and hydrogen (H2), mirroring the atmospheric process.

Future Prospects: Tackling Emissions in Agriculture and Waste

The Department of Chemistry is set to receive a 40ft shipping container, which will house a larger prototype of the laboratory-built reaction chamber. This “methane cleaner” could potentially integrate into ventilation systems in livestock barns.

“Given that modern livestock farms already extract ammonia from the air, incorporating methane removal into these air purification systems is a logical step,” suggests Professor Johnson.

This approach is also applicable to biogas and wastewater treatment plants, significant methane emission sources in Denmark after cattle production.

The preliminary phase of this research involved measuring methane leakage from various cattle stalls, wastewater treatment plants, and biogas plants across Denmark.

“Denmark, a leader in biogas production, faces a challenge as even minor methane leaks from this process can negate climate benefits,” concludes Johnson.

This research has been published in the journal Environmental Research Letters.

Additional Information on Methane (CH4)

Methane requires a concentration above 4%, or 40,000 ppm, to be flammable and thus removable by burning. Most human-induced emissions fall below 0.1 percent.

The IPCC confirms that reducing methane emissions will immediately slow the increase in global temperatures.

Methane, a natural byproduct from sources like wetlands and human activities like food production and natural gas, is responsible for a third of the climate-affecting greenhouse gases.

It takes about 10-12 years for methane to naturally decom

Frequently Asked Questions (FAQs) about Methane Reduction Technology

More about Methane Reduction Technology

• University of Copenhagen
• Environmental Research Letters
• Intergovernmental Panel on Climate Change (IPCC)
• Methane Eradication Photochemical System (MEPS)
• Methane Emissions and Climate Change
• Greenhouse Gas Reduction Technologies
• Innovations in Environmental Science
• Livestock Emissions Management
• Biogas Production and Methane Control
• Wastewater Treatment and Methane Emission Reduction
• Matthew Stanley Johnson’s Research on Methane Reduction