Chemical engineers at Michigan Tech University have released a study examining the carbon footprint of redirecting methane into a usable energy source.
The study, published in the journal “Environmental Progress and Sustainable Energy,” analyzed anaerobic digestion, or the composting of organics without air, and how that effects the environment. Researchers found that bio-methane produced through this digestion emits far less than its fossil natural gas equivalent.
Mtu.edu states that studying each product’s carbon footprint is a way to assess its social, environmental and economic impact — in other words, “how sustainable it is,” said Swarth Ankathi, the paper’s lead author and a PhD student at Michigan Tech. He says this is “defined as helping current generations without compromising their needs or the needs of future generations.”
To get to their findings, Ankathi and his faculty advisor David Shonnard dug into piles of organic waste coming into Colorado’s Heartland Biogas Facility and assessed the process that turns food waste from restaurants in Denver and manure from dairy farms near the facility into bio-methane, an energy source. This is the first study that looks at the entire anaerobic digestion life cycle of both food waste and dairy manure and that includes avoided landfill emissions.
According to the site, the research team found that bio-methane produced from all available food waste and dairy manure in the US annually would offset about .74% of annual natural gas demand. The bigger savings come in mitigated methane emissions; around 100 Heartland-scale anaerobic digestion facilities can eliminate about 0.41% annually of the approximately seven billion tons of overall US greenhouse gas emissions.
Converting food and animal waste into an energy source has become a hot topic among energy managers and academic researchers. During the 2017 Environmental Leader Conference and Energy Management Summit, William Gill, vice president of environmental affairs at Smithfield Foods, shared how his company is working to convert pig manure into energy.
Also in the waste-to-energy game is BMW. The automaker recently announced that manure from a South African organic cattle farm gets turned into biogas to power BMW’s Rosslyn Plant north of Pretoria.