State-owned energy giant Eesti Energia annually produces 7 million tons of ash as a byproduct of oil shale processing, yet manages to reuse only 2 percent, a problem the company discussed at a recent conference.
“We would like to increase the amount of ash recycled by five-fold in the next few years,” said Tõnis Meriste, environmental manager at the company, at a conference organized by Eesti Energia last week.
Meriste said the company turns each ton of oil shale into 125 kilograms of shale oil or about 850 kilowatt hours of electricity, and is left with 450 kilograms of ash.
The vast majority of the byproduct is transported to ash heaps, while only 150,000 tons is sold, mostly to be made into building materials.
During the Soviet era, the ash was used in the construction of buildings, including in Tallinn's TV Tower, and roads. It was also used in agriculture to neutralize soil. At that time, the company managed to reuse much more of the ash.
A project to find uses for oil shale ash, OSAMAT, was launched in 2010, and according to Aleksander Pototski, who is responsible for selling oil shale ash at Eesti Energia, the preliminary testing results have been positive.