Biomass Magazine, Nov. 7, 2016.
http://biomassmagazine.com/articles/13895/pnnl-researchers-convert-sewage-into-biofuel

"It may sound like science fiction, but wastewater treatment plants across the United States may one day turn ordinary sewage into biocrude oil, thanks to new research at the Department of Energy's Pacific Northwest National Laboratory. The technology, hydrothermal liquefaction, mimics the geological conditions the Earth uses to create crude oil, using high pressure and temperature to achieve in minutes something that takes Mother Nature millions of years."