Vancouver B.C. will soon use science from the Pacific Northwest National Laboratory in Richland, Wash., to create biofuels out of sewage — a.k.a., a lot of poop, with plenty of toilet paper, plus some grease, fats and oils mixed in.
Biofuels result in fewer carbon emissions than petroleum-based fuels. And the Pacific Northwest National Laboratory (PNNL) believes that a single person can produce two to three gallons of biocrude oil annually just by doing what comes naturally and inevitably to each one of us.
PNNL has been tinkering on and off with biofuels since the 1970s. The lab’s scientists ended up focusing on the grease, fats and oils in sewage as a potential source of biocrude oil. The problem has always been that sewage sludge is too soggy to produce usable biocrude oil. And until recently, engineering issues have kept scientists from drying the sewage sludge into a biocrude-oil-friendly substance.
Those engineering problems have been solved — at least in the laboratory.
— PNNL (@PNNLab) November 30, 2016
The process is called hydrothermal liquidification. In English, that means the sludge in a lab setting flows through a long, narrow tube — 1/3-inch to 1/2-inch in diameter — under a pressure of 3,000 pounds per square inch while being heated to 660 degrees Fahrenheit. The resulting biocrude can then be refined into usable biofuel, possibly for use in jet planes and other machinery.
Corinne Drennan, PNNL’s head of bioenergy technologies research, said 100 million gallons of sewage can produce 100 tons of dry biocrude sludge. The nation’s sewage plants treat roughly 34 billion gallons of sewage every day, which could translate to approximately 30 million 42-gallon barrels of oil a year, according to PNNL figures.
Metro Vancouver has an $8 million to $9 million pilot project planned for its Annacis Island wastewater treatment plant, with construction expected to be complete by the end of 2018. The plant serves roughly 1 million people with 175 billion liters of wastewater going in each year, resulting in 16,000 metric tons of mixed sewage sludge being produced annually.
“Hydrothermal processing could be as dramatic as when the steam locomotive displaced the horse and carriage,” wrote Metro Vancouver spokeswoman Sarah Lusk in an email.
The airline industry and the federal government are aiming to cut commercial aviation carbon emissions to 50 percent of 2012 levels by 2050. In the case of jet fuel, biofuels are blended with petroleum-based fuels to cut down carbon emissions. ASTM International — a more-than-a-century-old organization that sets technical standards for numerous industries worldwide — tests the blended fuel to see if it meets its requirements for jet fuel. ASTM has certified five biofuels for jet fuel use since 2011.
Drennan speculated that Metro Vancouver might send its biocrude to an existing Northwest refinery for the final processing. She acknowledged that the economics of sewage-based biofuel still need be studied and improved to make it financially feasible.
The video below explains how PNNL converts sewage waste into biocrude oil:
Biofuels refer to a wide range of fuels created by different processes for a wide variety of purposes. They are created with sugar, or with cover crops such as camelina, or with wood wastes such a leftover slash of downed trees, among other sources. A July 2016 U.S. Department of Energy report concluded that the nation has the partly-untapped potential to produce at least 1 billion tons of crops, biomass from forests and other waste materials capable of replacing 30 percent of the United States’ 2005 petroleum consumption.
A major hurdle in getting airlines to use biofuels is the cost difference between biofuels and petroleum-based fuels. Right now, petroleum-based jet fuels are cheaper. Biofuels do not totally replace petroleum-based fuels when used in jets. Instead, they are mixed with petroleum-based fuels to reduce carbon emissions.
Another problem is that the prices of biofuels and petroleum-based fuels are constantly fluctuating. Also there are several processes — with varying expenses — for creating biofuels. And there are several sources for raw materials for biofuels: sugars, corn, other crops and wood. These sources have their own constantly shifting economic pictures.
Recently, the Port of Seattle, the sustainable jet fuel company SkyNRG and Sir Richard Branson’s nonprofit Carbon War Room announced that they are partnering on a study to find out how to compensate airlines for the difference in fuel prices. Backers of the study hope to have some results by February.
Their goal to set up a way so all airlines at SeaTac International Airport can economically use biofuel for their passenger jets. They want SeaTac to become the first American airport to provide biofuel for all of its passenger planes. Worldwide, only the airport in Oslo, Norway, does that. In the United States, United Airlines uses biofuel in its airplanes leaving Los Angeles International Airport.
But another unknown is where the money will come from to compensate airlines for the greater cost of using biofuels. A central question is how the production of more biofuels can be spurred so it becomes more economical at larger volumes.
The nation uses roughly 23 billion gallons of aviation fuel a year, according to the Commercial Aviation Alternative Fuels Initiative, a national coalition of airlines, biofuel producers and government agencies. CAAFI has set a target of manufacturing 400 million gallons of biofuels a year by 2020, or 1.7 percent.