Oil shale ash is increasingly finding use in construction materials manufacturing and agriculture. Eesti Energia subsidiary Enefit Power more than doubled its ash sales last year to over 100,000 tons.
Enefit Power hopes to boost sales of ash further this year. One new market for the company is the Nordics where oil sale ash is fast replacing cement industry waste as a component in construction materials.
"We sent a test shipment of 4,000 tons to Scandinavia last year. Now, we are about to sign a project continuance where we want to dispatch at least one such ship to Scandinavia every month. Mostly for construction materials manufacturing," Enefit Power CEO Andres Vainola said, adding that oil shale ash is made attractive by the fact it is an industrial byproduct.
Oil shale ash has also become popular as a lime fertilizer in Estonia. However, soil researchers warn that individual fields need to be analyzed in terms of whether oil shale ash is a good fit for them. The high sulfur content of oil shale ash has already damaged around ten fields in Estonia.
"Before using lime, soil samples need to be taken, which allows the soil to be diagnosed and the proper treatment, or quantities, determined. If the soil is too acidic, has a pH level of 5.5 or less, oil shale ash should be mixed with lime meal or other types of lime fertilizers preferred. Oil shale ash is good for soil that does not need a lot of lime – there its rapid effect is beneficial," said Priit Penu, head of soil research at the Center of Estonian Rural Research and Knowledge (METK).
In all, Enefit Power generated over four million tons of oil shale ash last year, with selling it a good way to turn expenses into revenue as simply piling it up in hills is subject to a depositing fee.
Editor: Marcus Turovski