Scientists have found a way to effectively turn "fatbergs," a congealed fat and grease that turn solid and clog the sewage system, into energy.
According to a team of experts from the University of British Columbia, the same fatty deposits that often stick to garbage and block pipes can still be broken down and repurposed as a source of biofuel.
Turning Fatbergs Into Sources Of Energy
These gross fatbergs that lurk within sewers are made up of cooking oil, grease, fat, and other similar waste that get dumped from kitchen sinks. They have become a major nuisance: aside from clogging up pipes and blocking sewage systems, experts warned that these congealed mass of discarded waste can become breeding grounds of superbugs that are resistant to antibiotics.
Scientists, however, figured out how to make these slabs of fat into methane, a valuable renewable energy that releases the lower amount of carbon dioxide compared to fossil fuels. In order to turn fatbergs into useful biofuel, the team heated a sample of fat, oil, and grease or FOG to temperatures ranging from 90 to 110 degrees Celsius. They also added hydrogen peroxide to break down the sample.
The scientists discovered that this process can reduce the solids in the FOG to as much as 80 percent. The data was published in Springer in June 2018.
"FOG is a terrific source of organic material that microorganisms can feed on to produce methane gas, which is a valuable, renewable energy source," said research associate Asha Srinivasan. "But if it's too rich in organics, bacteria can't handle it and the process breaks down. By preheating it to the right temperature, we ensure that the FOG is ready for the final treatment and can make the maximum amount of methane."
The biggest chunk of the infamous congealed fat has been found in London and weighs about 130 tons or as much as 10 double-decker buses. A sample of it is now on display at the Museum of London.
Eliminating Fatbergs
Srinivasan said that the method developed in the study can already be used to dislodge fatbergs.
"Anaerobic digestion systems commonly exist in municipal sewage treatment plant," she told Inverse. "So, it would be advantageous to make use of the existing infrastructure to produce methane."
She added that their findings can also hopefully encourage farmers to load more FOG into biogas digesters, the tanks used to treat farm wastes to produce methane. Now that FOG can be broken down into simpler forms, farmers can recycle more oil waste up to 75 percent of the overall biogas digesters.
