On April 22 the world observes Earth Day, and plenty of organizations celebrate with tree planting or education on other sustainable methods. Why not throw our League of Women Voters hat in the ring, starting with a humorous hook. Some folks may remember that childhood shenanigan of attempting to light their flatulence on fire. While anyone who’s tried it may not have created a flame-thrower, but any flame they experienced proves a wild bit of science. Our guts produce small amounts of carbon dioxide and methane along with the hydrogen in human gases.
Those small amounts of this powerful greenhouse gas in our flatulence come from the organic compounds in our food. Livestock too billow out clouds of methane, producing up to 27% of the total amount in our atmosphere. Why so much? First, consumers demand meat, often every day at every meal. Why does it matter? “Because of its chemical composition, methane has a much higher global-warming potential than carbon dioxide does—up to 80 times as much—and is responsible for about a third of current global warming,” reports the Harvard School of Engineering. 32% of methane in our atmosphere comes from leaks during the extraction and distribution of fossil fuels - not just natural gas, but also oil wells and coal mines. Another 17% of methane in the atmosphere comes from municipal solid waste landfills, primarily from the organic waste we throw into them. That’s the equivalent of 23.1 million vehicle emissions or 13 million homes’ emissions from gas stoves, water heaters and furnaces. The University of Maryland reports that nearly a quarter of that comes from the leftovers that households, restaurants, and groceries throw out.
When organic materials end up in a landfill, they begin to break down anaerobically, that is, without nature’s recyclers, bacteria and microbes, which are required to return the organic material into useful compost. That’s how something fairly harmless - your leftover ravioli - turns into methane.
But creative problem solvers squeezed some good out of trash back in the early 2000s. Of the 2,600 landfills that the EPA tracks, nearly 500 have dedicated their landfill to generate renewable energy. Another 500 could become energy producers, according to the EPA. Here in the Wabash Valley, Waste Management of Indiana LLC, the Wabash Valley Power Association and Hendricks Power Cooperative have been producing electricity from landfill gases since the 2010s. By 2012, four gas-to-energy plants generated enough energy to power 14,000 homes near the Twin Bridges Recycling and Disposal Facility in Danville, IN. Overall Wabash Valley Power (WVP) operated 14 such landfill gas-to-energy facilities. By 2022, the exclusive partnership between Wabash Valley Power (WVP) and Waste Management of Indiana had produced 15 such facilities with 55.2 megawatts of generation capacity.
Because WVP is committed to renewable energy, it produces 199 megawatts of power via solar and another 219 via wind energy.
How many homes can that power? Rice University Associate Professor of Environmental Energy Daniel Cohensays it depends. Whereas the Electric Reliability Council of Texas conservatively estimates that 1 megawatt can power 200 homes at peak demand, he estimates it could be as high as 670 homes. That’s a wide margin for a region like the Wabash Valley; it could be as low as 44,000 to as much as almost 147,000 homes. But one landfill-to-gas plant, in combination with solar and wind could easily cover the demand of Montgomery County, all without creating emissions.
If you’ve read this far, you might be a science nerd wondering how landfill methane turns into electricity. The three-stage process begins with pipes into the landfill that remove moisture from the gas rising through the process of capture, filter, and blowing out the moisture. Second, the gas needs treated - there are still chemicals and further moisture - so it’s cooled and compressed to remove impurities including siloxane/sulfur (like the stuff that makes your human gas smelly) and others. After the secondary treatment, landfill gases can be used to generate electricity or as a medium-Btu fuel for arts and crafts, as the EPA reports. A third stage of advanced treatment removes additional impurities (CO2, N2, O2, and VOCs) and compresses the landfill gases into a high BTU gas that can be used for vehicles or a gas pipeline to be converted into electricity.
The promise of landfill-to-gas technology in Montgomery County could build the renewable energy portfolio in Crawfordsville, contributing to cleaner air and water, both of which locals can champion. We’ve made huge strides with cleaning up local drainage ditches (like the Shelley ditch). Friends of Sugar Creek put in great effort to clean up trash left by people canoeing, kayaking and tubing. We are producing a substantial bulk of our municipal energy from solar.
In other promising news, simple composting, including burying food waste and creating a compost bin can aerobically recycle food and organic waste. Properly composting other organic materials, like compostable “plastic” or fiber compostable food service products, paper, newspaper, can reduce methane.
What’s the why for all this methane concern? There’s nuance to consider. A third of all methane is naturally produced, two-thirds is created by human demand for food products and fuel - think meat production, rice paddies, fuel production and burning biomass like forest fires, wood-burning, and burning other organic materials. Atmospheric methane is up 162% since the 1860 kick-off to the Industrial Period. “Since it traps more heat within the earth’s atmosphere, it’s advisable to mitigate human influence in its production. The upside - that might not be the best word - is that “methane lingers in the atmosphere for much less time than carbon dioxide does - only about 10-20 years,”
as Harvard’s School of Engineering reports.
“What that means is that methane is responsible more for near-term climate change, but it also means that acting on methane can give us a short-term climate response,” says Daniel Jacob, the Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). “So, if we are trying to address climate change over the next decade or two, methane is a very powerful lever.”
https://www.smithsonianmag.com/smart-news/more-than-half-of-us-landfills-may-be-methane-super-emitters-study-finds-180984071/#:~:text=Landfills%20in%20the%20United%20States,potent%20greenhouse%20gas%20each%20hour.
https://www.epa.gov/land-research/quantifying-methane-emissions-landfilled-food-waste
https://www.epa.gov/land-research/food-waste-research#management
https://www.epa.gov/land-research/food-waste-research#processing
https://www.epa.gov/land-research/food-waste-research#prevention
https://www.epa.gov/land-research/food-waste-research#farm
https://www.epa.gov/land-research/food-waste-research
https://www.npr.org/2021/07/13/1012218119/epa-struggles-to-track-methane-from-landfills-heres-why-it-matters-for-the-clima