UBC researchers have developed a method to turn pesky and harmful fatbergs into energy using heat and hydrogen peroxide.

A UBC method to break down fats, oil and grease can be used in municipal FOG management programs. (Source: Clare Kiernan/UBC)

A fatberg is cooking oil, fats, grease and other waste that clogs pipes and creates masses in sewage systems which can end up clogging the whole system. The new method breaks up these fatbergs and turns the remaining waste into energy.

To create the method, fat, oil and grease (FOG) samples are heated between 90 to 110° Celsius. After the FOG samples are heated up, the researchers added hydrogen peroxide which kick starts the breakdown of the samples. This method reduces the volume of FOGs by up to 80%. The fatty acids that were released from the mixture can then be further broken down by bacteria.

"FOG is a terrific source of organic material that microorganisms can feed on to produce methane gas, which is a valuable, renewable energy source. 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," says research associate Asha Srinivasan.

The UBC developed methods would allow farmers to load FOG masses into biogas digesters. Digesters are large tanks used by farmers to treat farm waste.

"Farmers typically restrict FOG to less than 30 percent of the overall feed. But now the FOG can be broken down into simpler forms, so you can use much more than that, up to 75 percent of the overall feed. You would recycle more oil waste and produce more methane at the same time."

This technology can be used in municipal FOG management programs around the world.

"The principle would be the same: you pretreat the FOG so it doesn't clog the pipes, and add it to sewage sludge to produce methane from the mix. To the best of our knowledge, this type of pretreatment for FOG has not been studied before, although simple chemical methods do exist to break down FOG," added Victor Lo, emeritus professor of civil engineering at UBC, "We're hoping to do more research to find the optimal ratio of FOG to dairy manure so that they can be pretreated together."

The paper on this research was published in Water, Air & Soil Pollution.