Different that shale oil—i.e., liquids produced from shale formation via techniques such as hydraulic fracturing—oil shale is a sedimentary rock containing up to 50% organic matter rich in hydrogen, known as kerogen. The extracted rock can be used directly as a power plant resource or it can be processed to produce shale oil, which in turn can be refined into gasoline, diesel or jet fuels. However, the direct combustion of oil shale, or its transformation into shale oil and then other fuels, emits more CO₂ than any other primary fuel.

Estonia has more than 4 billion tonnes of estimated reserves—just over 1.1% of global and 17% of European reserves. In 2012, 70% of Estonia’s total primary energy supply (TPES) came from oil shale. Just over 85% of mined oil shale was used to produce electricity and heat generation; the rest was turned into shale oil, retort gas and other valuable chemicals.

The new IEA publication Energy Policies of IEA Countries – Estonia 2013 describes how the country is trying to slow its mining of oil shale amid environmental concerns. In 2012, Estonia mined 15.86 million tonnes. However, the National Development Plan for Oil Shale Use for 2008-15 calls for reducing annual extraction while preserving the country’s strong energy security. Estonia is also working to halve energy sector-related CO₂ emissions in 2020 from the 15.7 million tonnes emitted in 2007.

Estonia is relying on technological improvements to maximize oil shale yield to generate more electricity, heat and shale oil so as to maintain necessary levels of electricity and heat for the economy, which remains one of the OECD’s strongest performers.

In 2011, public research, development and demonstration (RD&D) expenditures exceeded €9.4 million (US$12.8 million), with the oil shale sector accounting for one-third. That spending demonstrates how RD&D is an economic priority, with the national research and development and innovation system enjoying one of the highest growth rates in gross RD&D domestic expenditure among OECD member countries in recent years.

The aim is to improve technologies for greater efficiency throughout the oil shale cycle, from mining to consumption. The research concentrates on two aspects: maximizing the production of liquid fuel and reducing the carbon intensity of oil shale-based power and heat generation.

The recently launched ENEFIT280 technology of the state-owned company Eesti Energia highlights Estonia’s achievements in reducing emissions and increasing efficiency for the oil shale industry, the IEA article says. ENEFIT280-equipped plants utilize 100% of mined oil shale, producing shale oil, electricity and retort gas with higher efficiency and improved environmental performance than other models.

Overview of Enefit280. Click to enlarge.

Enefit280 was developed by Enefit Outotec Technology using Enefit’s extensive experience in Solid Heat Carrier shale oil technology and Outotec’s world-leading process and plant engineering solutions.

Enefit Technology comprises a novel combination of processing units, each of them serving special purposes such as drying and pyrolysis of oil shale, combustion of semi-coke, as well as the dedusting and cleaning of vapors and gases. Enefit’s modular design allows easy maintenance, process optimization and streamlined adaptability to the individual characteristics of different oil shale deposits.

The efficiency of the technology comes from its 100% use of the mined oil shale. All organic matter is fully utilized, and high performance in oil extraction is further aided by additional revenue streams associated with utilisation of excess heat and gas generated in the process. Waste heat is used to generate electricity, making Enefit shale oil plants net producers of electricity.

Ash, as a processing residue, is clean and has several applications in cement production and the construction industry.

Estonia produced the first barrel of ENEFIT280 shale oil in December 2012.

Renewable energy is another solution. Renewables, particularly biomass for heat, provided 14.6% of Estonia’s TPES in 2012, a share which would rank tenth among IEA members.

The European Union Renewable Energy Directive calls for sourcing one-quarter of Estonia’s gross final energy consumption from renewable sources. To increase and improve the sector, Estonia is not only spending heavily on RD&D for biomass-based energy, wind and solar power, but it is also pursuing solutions such as fuel cells and electrolyzers as well as computer-based energy management technologies for buildings, power storage and grid development.

Oil shale. The US tops the list of the richest oil shale reserves, accounting for more than 60% globally, with the most concentrated deposits located in the Green River Formation that lies in western Colorado, eastern Utah and southern Wyoming.

Besides Estonia, countries with large oil shale reserves include Australia, Brazil, China and Russia. There are also significant reserves in Jordan, Morocco, Sweden, Syria and Turkey.

Estonia’s latest technological breakthrough could catalyse a new approach to exploring the vast global reserves of this fossil fuel frequently perceived as a significant pollutant, the IEA article suggests.

Eesti Energia started its international oil shale activities in 2006, and has oil shale operations in Jordan and the United States. Eesti Energia’s subsidiary Enefit is developing two parallel oil shale projects in Jordan, where it acquired the exclusive right to develop, design, finance, construct and operate a 500 megawatt oil shale-fueled power station.

In the US state of Utah, Eesti Energia purchased Oil Shale Exploration Company in 2011. Properties owned or controlled by Enefit contain an estimated 2.6 billion barrels of recoverable oil that can be unlocked safely with conventional mining, mineral processing and refining methods.