Poop may be the power of the future if scientists at the US Department of Energy’s Pacific Northwest National Laboratory have anything to do with it. Researchers have developed a way to convert sewage sludge into a form of crude oil called biocrude by pumping it through a pressurized tube, the PNNL recently announced.
Here’s how it works: inside the tube, the pungent mixture is heated to about 650 degrees Fahrenheit and squeezed at pressures of 3,000 pounds per square inch, according to a report the scientists published over the summer. Fats already in the wastewater help lubricate its path. What comes out is a watery liquid and the biocrude that’s apparently close enough to petroleum to be refined the same way.
Called hydrothermal liquefaction, what these researchers are doing is a smaller scale, sped up version of the same process that converts organic matter into petroleum deep in the Earth over millions of years. It’s similar to the technique researchers at the PNNL developed a few years ago to generate fuel from algae.
We’ve been seeing promises of a fecal future for awhile now. Scientists at Stanford created a microbial battery powered by poop in 2013, and many research teams are working on ways to convert poop to methane, a component in natural gas. None of these seem to have really taken off.
But the scientists at the PNNL think their technique stands a chance because of its efficiency, estimating that about 60 percent of the carbon in the sludge winds up in the biocrude. In fact, we could be seeing it in municipal wastewater plants soon. According to a news release, a company called Genifuel Corporation licensed the technology and is working on rolling out a test facility in Vancouver as soon as 2018. (The project’s estimated to cost less than $7 million American dollars.)
Of course, burning a fuel made from poop would still generate carbon emissions. But if our supply of fossil fuels came from local wastewater facilities rather than from oilfields across the country, it could help reduce our dependance on leaking pipelines, leaking ships, exploding oil rigs, exploding trains, and destructive mining practices.
Correction November 15th 10AM ET: A previous version of this story incorrectly referred to poop biocrude as a fossil fuel. We regret the error.