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Posted on on April 29th, 2013
by Pincas Jawetz (

April 15-21, 2013, I participated on a trip to Baltic Sea States of the KPV (Komunal Politische Vereignigung) of the Politische Akademie of the Austrian Peoples Party (OEVP). Above took us to Estonia  Saturday April-20 to Sunday April 21-st. This was a weekend and it might have been a too short time for serious learning about matters of Energy Policy. But I was fortunate to come back with enough information because I had the chance to meet very helpful people and I was prepared ahead with my questions.

We drove from St. Petersburg in Russia to Narva in Estonia and then continued to the capital – Tallinn. We had the luck of having a very good Estonian guide and were honored that evening with a reception at the residence of Austrian Ambassador H. E. Ms. Renate Kobler who invited as well local and Austrian resource people and made sure to establish contacts according to our interests.

I had in effect two different set of interests. One was in regard to a transportation policy instituted this year by the city of Tallinn that offers free rides on the electric street-cars to documented residents of the city while having increased charges for the out-of-towners. The idea behind this being that people will be moving back to the city from the suburbs and increase the tax roles thus making up for some of the losses and allow for gains in air quality by getting out of their cars. I learned that though nice in theory, seemingly it did not work in practice because it applied mainly to the poor – so it did not result in enhanced income from taxes leaving just the lower income from the tram-rides. The topic was originally brought to my attention by the Austrian Standard of April 5, 2013.

This was the minor interest of my two suggested topics.

The other topic – and that one of major interest these days – dealt with the use of oil-shales for energy – an issue of global importance  when Shale-Gas has become the energy interests’ battle cry. It was brought out of obscurity in the United States, and Europe is talking as if it was going to follow suit. Austria has also shales and at present media battles rage between business interests and the environmentalists – with the Eurosolar monthly table all convinced that Austria can become energy self-sufficient without touching the shales.

Estonia, as well as Spain, are countries with experience in what can happen when energy is obtained from these shales.

Under the Soviets, the shales were mined and used like a lower grade coal in thermal power plants. What was left are mountains of ash from the combustion process and mountains of  spent shales from the retorting process in which the product was a synthetic crude oil. These mountains of by-product contain heavy metals and when washed by rains these heavy metals poisoned the underground water, thus making it unusable for drinking and agriculture. Everybody I talked to told me the same thing – the losses around Narva are immense.

Wikipedia tells us: “Oil shale in Estonia is an important resource for the national economy. Estonia‘s oil shale deposits account for just 17% of total deposits in the European Union but the country generates 90% of its power from this source. The oil shale industry in Estonia employs 7,500 people—about one percent of the national work force—and accounts for four percent of its gross domestic product.[1]


There are two kinds of oil shale in Estonia – Dictyonema argillite (claystone) and kukersite.[2] The first attempt to establish an open-cast oil shale pit and to start oil production was undertaken in 1838.[3] Modern utilization of oil shale commenced in 1916. Production began in 1921 and the generation of power from oil shale in 1924.[4]


In 2005 Estonia was the leading producer of shale oil in the world. Of all the power plants fired by oil shale, the largest was in this country.[1][5] As of 2007, six mines (open cast or underground) were extracting oil shale in Estonia.[2]”

Kukersite, named after the Kukruse settlement in Estonia, is the better quality shale. Estonian kukersite deposits are one of the world’s highest-grade shale deposits with more than 40% organic content and 66% conversion ratio into shale oil and oil shale gas. They have relatively a lower content of heavy metals.

in the 1830s, although the attempt of shale oil distillation failed, oil shale was used as a low-grade fuel. Then studies of Estonian oil shale resources and mining possibilities intensified in the beginning of 20th century because of industrial development of Saint Petersburg and a shortage of fuel resources in the region. Finally – the world’s two largest oil shale-fired power stations – Balti Power Plant and Eesti Power Plant (known as the Narva Power Plants) – were opened in 1965 and in 1973. Because of the success of oil shale-based power generation, Estonian oil shale production peaked in 1980 at 31.35 million tonnes.[3] In 2004, two power units with circulating fluidized bed combustion (CFBC) boilers were put into operation at Narva Power Plant.[4] In 1984, the scientific-technical journal Oil Shale was founded in Estonia.[15]

Some of the spent shale is used in cement manufacturing and Uranium is a by-product.

Kerogen (from Greek for wax + -gen, that which produces)[1]  is a mixture of organic chemical compounds that make up a portion of the organic matter in sedimentary rocks.[2] It is insoluble in normal organic solvents because of a huge molecular weight. The soluble portion is known as bitumen. When heated to the right temperatures in the Earth’s crust, (oil window ca. 60–160 °C, gas window ca. 150–200 °C, both depending on how quickly the source rock is heated) some types of kerogen release crude oil or natural gas, collectively known as hydrocarbons (fossil fuels). When such kerogens are present in high concentration in rocks such as shale they form possible source rocks. Shales rich in kerogens that have not been heated to a warmer temperature to release their hydrocarbons will eventually  form oil shale deposits. (The name “kerogen” was introduced by the Scottish organic chemist Alexander Crum Brown in 1906.)

What above tells us is that the organic matter in shales is in the form of very large molecular weight polymers. These can be deconstructed at high temperature in retorts, and then the quality of the remaining ash (or spent shale) can be investigated and the potential damage to the environment assessed. An alternative could be to create a fire underground and collect above ground the released oil or gas created by breaking up the kerogen polymer. In such case the damage from the ash cannot be assessed without knowing the underground conditions and where the underground waters will take the released heavy metals. The Shale Gas operations now in the United States are underground production sites explained as examples of Hydro-Fracking which sounds incoherent when we do not know the operating temperatures which are needed to break chemical bonds of that polymer. Neither the new American production companies nor the EU Shale Gas production interests give us such technology details as they did not even obtain patents that would have required transparency.

This present posting has an added purpose.

I learned that  June 10-13, 2013, the Estonian users of shale-for-energy intend a Shales Symposium in Tallinn as a follow up to the 2006 Symposium that was held in Ammann, Jordan.

The Symposium in Tallinn will be followed by a Field Trip to Estonian oil shale processing industry – an extraordinary opportunity to visit the most important sites of Estonian oil shale industry, including the new, recently completed Enefit280 Oil Plant.

I would like to hope that the European Commission send some inquisitive people to that symposium in order to learn about the side-effects or the environmentally harming “externalities” that could cause harm to the underground aquifers.

Further, as mentioned at the beginning, another European location were there was experience with Oil Shale Retorting is Puertollano, in the Ciudad Real region of Spain. With information from these  sites the EU could be in a better position to judge the issues involved.

I was personally involved with the Purtollano plant of the Empressa Nacional de Pisara Bituminosa Calvo Sotelo in 1959. That plant was producing lubricants or viscous petroleum product alternatives in huge retorts and leaving behind mountains of spent shale as well. Looking at the remains of those mountains – in Puertollano and in Narva, could help the decision making process at the EU.

We realize the importance of the energy independence goal – but as it can be reached in various ways, it is important to start out with open eyes.


Estonia and Sweden Oil Shale Estonia and Sweden Oil Shale Map

Map of kukersite deposits in northern Estonia and Russia (locations after Kattai and Lokk, 1998; and Bauert, 1994). Also, areas of Alum Shale in Sweden (locations after Andersson and others, 1985).


Estonia and Sweden Oil-Shale Deposits

Reprint of: United States Geological Survey Scientific Investigations Report 2005-5294
By John R. Dyni


The Ordovician kukersite deposits of Estonia have been known since the 1700s. However, active exploration only began as a result of fuel shortages brought on by World War I. Full-scale mining began in 1918. Oil-shale production in that year was 17,000 tons by open-pit mining, and by 1940, the annual production reached 1.7 million tons. However, it was not until after World War II, during the Soviet era, that production climbed dramatically, peaking in 1980 when 31.4 million tons of oil shale were mined from eleven open-pit and underground mines.

The annual production of oil shale decreased after 1980 to about 14 million tons in 1994-95 (Katti and Lokk, 1998; Reinsalu, 1998a) then began to increase again. In 1997, 22 million tons of oil shale were produced from six room-and-pillar underground mines and three open-pit mines (Opik, 1998). Of this amount, 81 percent was used to fuel electric power plants, 16 percent was processed into petrochemicals, and the remainder was used to manufacture cement as well as other minor products. State subsidies for oil-shale companies in 1997 amounted to 132.4 million Estonian kroons (9.7 million U.S. dollars) (Reinsalu, 1998a).

The kukersite deposits occupy more than 50,000 km2 in northern Estonia and extend eastward into Russia toward St. Petersburg where it is known as the Leningrad deposit. In Estonia a somewhat younger deposit of kukersite, the Tapa deposit, overlies the Estonia deposit.

As many as 50 beds of kukersite and kerogen-rich limestone alternating with biomicritic limestone are in the Kõrgekallas and Viivikonna Formations of Middle Ordovician age. These beds form a 20- to 30-m-thick sequence in the middle of the Estonia field. Individual kukersite beds are commonly 10-40 cm thick and reach as much as 2.4 m. The organic content of the richest kukersite beds reaches 40-45 weight percent (Bauert, 1994).

Rock-Eval analyses of the richest-grade kukersite in Estonia show oil yields as high as 300 to 470 mg/g of shale, which is equivalent to about 320 to 500 l/t. The calorific value in seven open-pit mines ranges from 2,440 to 3,020 kcal/kg (Reinsalu, 1998a, his table 5). Most of the organic matter is derived from the fossil green alga, Gloeocapsomorpha prisca, which has affinities to the modern cyanobacterium, Entophysalis major, an extant species that forms algal mats in intertidal to very shallow subtidal waters (Bauert, 1994).

Matrix minerals in Estonian kukersite and interbedded limestones includes dominantly low-Mg calcite (>50 percent), dolomite (<10-15 percent), and siliciclastic minerals including quartz, feldspars, illite, chlorite, and pyrite (<10-15 percent). The kukersite beds and associated limestones are evidently not enriched in heavy metals, unlike the Lower Ordovician Dictyonema Shale of northern Estonia and Sweden (Bauert, 1994; Andersson and others, 1985).

Bauert (1994, p. 418-420) suggested that the kukersite and limestone sequence was deposited in a series of east-west “stacked belts” in a shallow subtidal marine basin adjacent to a shallow coastal area on the north side of the Baltic Sea near Finland. The abundance of marine macrofossils and low pyrite content indicate an oxygenated-water setting with negligible bottom currents as evidenced by widespread lateral continuity of uniformly thin beds of kukersite.

Kattai and Lokk (1998, p. 109) estimated the proved and probable reserves of kukersite to be 5.94 billion tons. A good review of the criteria for estimating Estonia’s resources of kukersite oil shale was made by Reinsalu (1998b). In addition to thickness of overburden and thickness and grade of the oil shale, Reinsalu defined a given bed of kukersite as constituting a reserve, if the cost of mining and delivering the oil shale to the consumer was less than the cost of the delivery of the equivalent amount of coal having an energy value of 7,000 kcal/kg. He defined a bed of kukersite as a resource as one having an energy rating exceeding 25 GJ/m2 of bed area. On this basis, the total resources of Estonian kukersite in beds A through F (fig. 8) are estimated to be 6.3 billion tons, which includes 2 billion tons of “active” reserves (defined as oil shale “worth mining”). The Tapa deposit is not included in these estimates.

The number of exploratory drill holes in the Estonia field exceeds 10,000. The Estonia kukersite has been relatively thoroughly explored, whereas the Tapa deposit is currently in the prospecting stage.

 -Dictyonema Shale

Another older oil-shale deposit, the marine Dictyonema Shale of Early Ordovician age, underlies most of northern Estonia. Until recently, little has been published about this unit because it was covertly mined for uranium during the Soviet era. The unit ranges from less than 0.5 to more than 5 m in thickness. A total of 22.5 tons of elemental uranium was produced from 271,575 tons of Dictyonema Shale from an underground mine near Sillamäe. The uranium (U3O8) was extracted from the ore in a processing plant at Sillamäe (Lippmaa and Maramäe, 1999, 2000, 2001).

The future of oil-shale mining in Estonia faces a number of problems including competition from natural gas, petroleum, and coal. The present open-pit mines in the kukersite deposits will eventually need to be converted to more expensive underground operations as the deeper oil shale is mined. Serious air and ground-water pollution have resulted from burning oil shale and leaching of trace metals and organic compounds from spoil piles left from many years of mining and processing the oil shales. Reclamation of mined-out areas and their associated piles of spent shale, and studies to ameliorate the environmental degradation of the mined lands by the oil-shale industry are underway. The geology, mining, and reclamation of the Estonia kukersite deposit were reviewed in detail by Kattai and others (2000).



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