OREANDA-NEWS. April 16, 2013. In the past 10 years, Eesti Energia has significantly reduced environmental impacts in the oil shale industry. For instance, the emission of sulphur has decreased by nearly a factor of three.

In 2002, the emission of sulphur was about 70 000 and in 2012, about 24 000 tonnes, meaning that the emission has decreased 66%. The change occurred because of new technologies being introduced over the years.

Narva Power Plant, more specifically, the four energy blocks of the Eesti Power Plant were equipped with unique sulphur treatment equipment, resulting from five years of research and experimental work. “Thanks to this equipment, the production capability of Narva Power Plants will remain at the current level of 9 TWh per year and Estonia’s greatest electricity provider can produce electricity even after 2016, when the environmental rules are once again made stricter,” says Olavi Tammemae, the Environmental Manager of Eesti Energia, adding that in the past ten years electricity production increased about 30%.

The decrease of emissions into the air has also been influenced by the replacement of some pulverised oil shale firing boilers with more modern circulated fluidised bed boilers. Pulverised combustion has so far been the most common combustion method, during which the supplementary trapping of carbon dioxide and nitrogen emissions is required. In this case, the emissions can be reduced by adding rubble to the oil shale that is used as a fuel. The combustion temperatures in circulated fluidised bed boilers are lower and when oil shale is burnt, a considerable amount of sulphur is bound, resulting in almost no sulphur dioxide emissions.

Eesti Energia uses resources efficiently and economically, trying to recycle as much as possible. For instance, both mine waste and oil shale ashes are recycled. Oil shale ashes are mainly recycled as an ingredient in cement or dry mixes and as a raw material for building blocks when producing building materials.

Mine waste that is created during oil shale enrichment is used both in processed and unprocessed form. The processing of mine waste generates high-quality limestone rubble that can be used in various building projects. “We have used lots of the mine waste for building facilities that develop the environment of Ida-Viru County. This has created an opportunity to reduce the establishment of new quarries that would be made especially for producing rubble. Last year, about a million tonnes of mine waste rubble was used for different purposes,” says Tammemae.

Former mining areas always gain a new value after they are closed down. The former Kohtla mine industrial territory and the underground complex are popular tourist destinations, while the soon-to-be-closed Aidu quarry is being made into an unconventional water landscape with opportunities for sports and recreation. The Sirgala quarry that is situated in an area away from human population houses a polygon for military shooting practices.

In addition, throughout the years Eesti Energia has been one of the largest forest planters. Since 1960, approximately 13 000 hectares of forest has been planted to rehabilitated open pit areas and 169 hectares of arable land has been rehabilitated.