Sewage sludge can be converted into biofuel, but it has long been considered a poor source for fuel because it is too wet. This may change with a new Pacific Northwest National Laboratory (PNNL) hydrothermal liquefaction process funded by the U.S. Department of Energy’s Bioenergy Technologies Office (BETO). 

The PNNL process uses high pressure and temperature to convert wet sewage sludge to biocrude oil in less than 60 minutes. The process eliminates the need to dry the sewage first, which is what made converting wastewater to fuel too expensive and energy intensive. Read more from the PNNL news release.

PNNL has licensed its hydrothermal liquefaction technology to Utah-based biofuels company Genifuel Corporation, which is working to build a demonstration plant with Metro Vancouver—a federation of 23 local authorities that plan for and deliver regional-scale services in British Columbia, Canada. Metro Vancouver plans to move to design phase in 2017 and to start up in 2018.  The same hydrothermal liquefaction technology is used to convert algae to biocrude, also in less than 60 minutes. PNNL first developed the technology in 2013. 

Wastewater treatment plants in the United States treat enough sewage daily to produce approximately 30 million barrels of oil per year, and PNNL estimates that two to three gallons of biocrude per year could come from a single person.

PNNL is one of eleven Energy Department national laboratories that receive BETO funding to conduct bioenergy research. This project is part of BETO’s Conversion Research and Development Program, which develops viable technologies for converting biomass feedstocks into cost-competitive biofuels and bioproducts through biological and chemical processes.