VATIS UPDATE Article

Researchers at the Department of Energy’s Pacific Northwest National Laboratory (PNNL), the United States, have created a method to turn ordinary sewage and other organic waste into biocrude oil. The researchers have developed a novel process, which they call hydrothermal liquefaction, that mimics the geological conditions involved in creating crude oil. Using high pressures and temperatures, they only need a few minutes and the stuff we flush down our toilets to create a liquid that takes millions of years to form in nature.

Organic matter is pressurized to 3,000 pounds per square inch (about 100 times the pressure in a car tire), then fed into a reactor system which cooks it to 660 °F (350 °C). These extreme conditions break the matter down to its simple chemical compounds – the cells in the material rip apart, forming biocrude and an aqueous-liquid phase. “There is plenty of carbon in municipal waste water sludge and interestingly, there are also fats,” said Corinne Drennan, at PNNL.

The method may also be used to make fuel from other types of wet organic feedstock, such as agricultural waste. In addition to the biocrude, the liquid phase can be treated to create other fuels and chemical products. A small amount of solid material is also generated, which contains important nutrients. For example, early efforts have demonstrated the ability to recover phosphorus, which can replace phosphorus ore used in fertilizer production.