It may sound like science fiction, but in the not too distant future, wastewater treatment plants may become a source of pyrolysis biofuels, reminiscent of crude oil. Wastewater treatment technology was developed at the Department of the US National Energy Laboratory.
The hydrothermal liquefaction technology imitates the natural geo-conditions in which oil is formed in the bowels of the Earth. In other words, what nature spends millions of years on can be obtained in a matter of minutes. The result is a crude oil-like product with little water and oxygen.
Every day, 34 billion liters of wastewater pass through the treatment facilities of a country like the United States. Their processing can yield up to 30 million barrels of oil per year. According to experts, each person is capable of "producing" up to four liters of biofuel in the same period of time.
For a long time, wastewater was considered unsuitable as an ingredient for fuel production due to its high humidity. Using hydrothermal liquefaction, it was possible to divide the wastewater into simpler chemical compounds. For this, a pressure of 206.8 bar is created, that is, 100 times more than in a car tire.
Then the sludge under pressure enters the reactor system, where it is heated to a temperature of about 350 ° C. High temperature and pressure separate the waste into two fractions - pyrolysis fuel and water.
It is assumed that in 2017 the design and manufacturing phase of equipment will be completed, and in 2018 a pilot biofuel production system will start operating.