Recent research findings at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) has shown that wastewater treatment plants may have the potential to produce biocrude oil, which is a petroleum-substitute synthetic fuel, from ordinary sewage (1).
The technological process being considered is called hydrothermal liquefaction (HTL) (2). In HTL, a wet biomaterial is depolymerized under high pressure and temperature to create a crude, petroleum-like bio-oil (2). The starting material, organic matter such as human waste, is first pressurized to 3,000 pounds per square inch (2). The resulting sludge is then heated at 660 degrees Fahrenheit in a reactor (2). The high intensity of heat and pressure decomposes the organic matter into a biocrude oil and an aqueous liquid (2).
A total of approximately 34 billion gallons of sewage can be treated in a single day by wastewater treatment plants scattered across the United States (1). This amount could generate approximately 30 million barrels of oil per year (1). The main flaw of sewage that has prevented it from being used as a component of biofuel is that it is too wet. Many current thermal technologies require the need for drying, which is not only costly, but also time consuming. PNNL has managed to eliminate this need for drying (2).
Not only can HTL create a practical fuel source, but it also can decrease government spending by removing the need for sewage residuals processing, transport and disposal. Corinne Drennan, a lead member of the bioenergy technologies research at PNNL, emphasized the advantage of their HTL approach, claiming the process to be very simple because “the reactor is literally a hot, pressurized tube” (2).
PNNL has given Utah-based Genifuel Corporation access to its online casino real money HTL technology. The corporation is currently attempting to implement HTL into the Metro Vancouver treatment plant. Darrell Mussatto, the chair of Metro Vancouver’s Utilities Committee, stated that they hope to be the first wastewater treatment utility in North America to utilize HTL (2). After the necessary funding is met, Metro Vancouver looks to transition to the design phase in 2017, followed by equipment fabrication, with start-up taking place in 2018.
(1) Pacific Northwest National Laboratory (2016). Pacific Northwest National Laboratory. N.p., n.d. Retrieved from https://www.pnnl.gov/ .
(2) Pacific Northwest National Laboratory (2016). Fuel from sewage is the future — and it’s closer than you think: Technology converts human waste into bio-based fuel. ScienceDaily. Retrieved November 2, 2016 from www.sciencedaily.com/releases/2016/11/161102134504.htm .