Biodiesel is an excellent source of fuel: not only does it come from renewable sources, but it also burns cleaner, producing less pollution than fossil fuels. But it can be expensive to produce. That is set to change, however, as South Korean researchers recently developed a new way to source fuel from sewage sludge at a fraction of the cost of regular sources.
Although biodiesel from sludge has been researched before, South Korean researchers at the Research Institute of Industrial Science and Technology figured out a new way to extract lipids, the compounds used to create biodiesel, using sludge at a local wastewater treatment plant. The process involves using heat to extract the lipids, rather than using catalysis, the method previously used.
According to Kwon, one of the researchers involved in the study, the process opens up new options in recycling waste. “Waste is not simply waste—it can be converted into useful resources like biodiesel,” says Kwon. Rafael Hernandez of Mississippi State University, who has also worked on producing biofuel from sludge, cautions that due to the varying concentration of lipids from treatment plant to treatment plant, the cost could vary and notes that the new process seems to be “very encouraging.”
Today, biofuel is created using vegetable oils, like rapeseed oil or soybean oil, or animal fat, which costs an average 80 cents to make. Sewage sludge, on the other hand, costs only 3 cents due to its high lipid content – a difference that makes it an attractive option.