Department of Energy scientists at the Pacific Northwest National Laboratory say they’ve reduced nature’s million year process of turning algae into crude oil to one than takes less than an hour. The engineers created a chemical process that produces crude oil minutes after it is poured into harvested algae. The reaction is not only fast, but also continuous since it produces a recyclable by product containing phosphorus that can then be used to grow more algae. Watch a video of the process after the jump.
While algae has long been considered a potential source of biofuel, PNNL scientists and engineers say they’ve sped up production using a chemical reactor. In the PNNL process, a slurry of wet algae that has the consistency and appearance of pea soup is poured into the front end of a chemical reactor. Inside the reactor, the algae undergoes a combining process known as hydrothermal liquefaction and catalytic hydrothermal gasification. After stewing in conditions at 350 degrees Celsius (662 degrees Fahrenheit) and a pressure of around 3,000 PSI for less than an hour, crude oil comes pouring out along with a water and phosphorus byproduct.
“It’s a bit like using a pressure cooker, only the pressures and temperatures we use are much higher,” Douglas Elliott, the laboratory fellow who led the PNNL team’s research, said in a release. “In a sense, we are duplicating the process in the Earth that converted algae into oil over the course of millions of years. We’re just doing it much, much faster.”
The scientists say with additional conventional refining, the crude algae oil can be converted into avariety of fuels for aviation, gasoline burning cars, or diesel vehicles. Meanwhile, the wastewater can also be used to yield burnable gas or elemental substances like potassium and nitrogen, which, along with the cleansed water, can grow more algae.
The new process promises to reduce time and save money compared to other techniques by combining several chemical steps and skipping the process of drying out the algae. Instead, the new process uses a slurry that contains as much as 80 to 90 percent water while eliminating the need for complex processing solvents like hexane to extract the energy rich oils from the algae. Elliott said in addition to saving time, “there are bonuses, like being able to extract usable gas from the water and then recycle the remaining water and nutrients to help grow more algae, which further reduces costs.”