Agricultural methane is responsible for 41% of New Zealand’s greenhouse gas emissions, but researchers want to change that by harnessing help from tiny living organisms.

University of Canterbury Chemical and Process Engineering Professor Peter Gostomski’s research will explore the use of on-farm biofilters to remove methane from the atmosphere.

Professor Gostomski’s pioneering research would use methane-eating microbes (microscopic organisms that live all around us) to convert methane back to CO2, which is considered carbon neutral as it is taken up by grass as it grows – a process known as photosynthesis.

“Currently, commercial options for reducing the methane released by cows is limited to changing the herd genetics or expensive supplements. Biofilters could complement these technologies,” Professor Gostomski says.

Methane represents 63% of New Zealand’s carbon footprint (including non-agricultural sources) and 90% of this is agricultural methane. Aotearoa New Zealand has pledged to decrease its biogenic (cow-produced methane) methane emissions by 10% by 2030, however there is no existing economically viable solution.

“The biofilter options we are exploring already exist, but they are too large and too expensive to be used on farms, our research aims to prove that we can remove agricultural methane in a cost efficient and sustainable way.

“For these biofilters to work the methane must be captured so microorganisms can eat it, this requires cows to be in barns for all or part of the year, ideally this would be over winter which would also prevent nitrate leaching into the ground and waterways.”

The microorganisms in the biofilter don’t die from too much methane, in fact they perform best when there is too much methane.

“These microbes in the biofilter like to gorge themselves, they prefer having an abundance of food available as they will continue to eat methane until they are full, they then convert the methane to CO2 which is released back into the atmosphere,” Professor Gostomski says.

“The CO2 is carbon neutral however it can’t be captured and reused as the microbes will be releasing such small amounts it would not be cost effective.”

Not only is this research important for New Zealand’s environment and economy, it could also be sold and used across the world, particularly in places like the United States where there are more barn-housed animals.

Source:  University of Canterbury