Sewage sludge is the last place where you’d expect to find something valuable. But the brains behind Israeli startup BioPetrol say it is exactly the place where it is possible to find gasoline and natural gas.
The company has developed a method of extracting oil out of sewage sludge, and converting it into various petroleum products. “Sludge is a huge environmental problem all over the world and we have a good actual solution for it,” says Hillel Lerman, BioPetrol’s business development director.
The US produces 5.3 million metric tons of sewage sludge each year (dry weight, not including the water that carries it). According to the GreenLeft website, about 16% of sewage sludge is incinerated, and the ashes are buried in landfills; 38% of sludge is landfilled directly; 36% is spread onto farmland or forest land or otherwise mixed into soils; and 10% is handled in other ways (piled on the land and abandoned, for example).
BioPetrol’s technology provides a solution for recycling sewage sludge via a thermo-chemical process called pyrolisis. This recovers the hydrocarbons in the sludge, producing oil, gas and char products. In addition the process also extracts valuable chemicals that can be used as chemical feedstock.