ESTONIAN ENVIRONMENTAL REVIEW 2009

5.2. Emissions
5.2.1. Emissions of acidifying substances
Sulphur and nitrogen compounds react with moisture
in the air to form acids that fall as acid rain and cause
damage to the environment, including forests, water
ecosystems as well as buildings and materials.
Acidification is caused by sulphur dioxide (SO 2
),
nitrogen oxides (NO x
) and ammonia (NH 3
) emitted
into the air due to human activity. The largest sources
of sulphur dioxide emissions are the energy sector and
industry. Nitrogen oxide emissions primarily originate
from transport and the energy sector, while ammonia
emissions come mainly from animal husbandry and
use of fertilizers. Acidification is expressed in terms of
acidification equivalent. The emissions of each pollutant
are converted into acidification potential: SO 2
– 0.03125,
NO x
– 0.02174, NH 3
– 0.05882 A . The emissions reduction
programme requires that emissions not exceed the following
limits by 2015: SO 2
– 43,350 tonnes, NO x
– 36,240
tonnes and NH 3
– 7,330 tonnes. The limits established by
in regulation no. 299 of the Government of the Republic of
20 September 2004, “Limits for total emissions of sulphur
dioxide, nitrogen oxides, volatile organic compounds
and ammonia discharged from stationary and mobile
pollution sources and terms for achieving them” for 2010
(SO 2
– 100,000 t, NO x
– 60,000 t and NH 3
– 29,000 t)
had for the most part been achieved by 2007, while the
other targets depend on the measures to be implemented
(renovation of power plants, reducing use of oil shale,
developing renewable energy etc) (figure 5.1).
Sulphur dioxide SO 2
In 2007, a total of 2,766 tonnes of sulphur dioxide in
acidification equivalent was emitted into Estonia’s ambient
air, of which the bulk was generated in the combustion
of fuel in the energy and transformation industries (about
92%) and in the manufacturing industry (about 6%). SO 2
primarily originates from oil-shale-fired power plants
in Ida-Viru County. Thus reduction of sulphur dioxide
emissions is in direct dependence on measures implemented
at power plants (renovation of energy generation
units). A small quantity of SO 2
emissions was given off
from non-industrial fuel combustion and transport (use
of motor fuels hat contain sulphur).
Compared to 1990, SO 2
emissions have dropped by
67.5%. The changes were occasioned by economic restructuring
that took place at the beginning of the 1990s, as
a result of which the amount of electricity consumed in
industry dropped significantly. The extent of the use of
other fuels also changed – a transition has occurred from
use of heavy oil with a high sulphur content to combustion
of natural gas and wood. Use of lower-sulphur shale
oil and light fuel oil has increased.
The changes of recent years are due to renovation of
energy units at Eesti and Balti power plants, where the
old dust burning technology was replaced with the new
fluidized bed technology. The new technology means a
rise in the efficiency of the boilers and a reduction in the
amount of oil shale needed. Besides the renovation of the
energy units, emissions reduction was also impacted by
the decommissioning of old energy units at Balti power
plant.
Compared to 2005–2006, sulphur dioxide emissions
increased in 2007. The increase in emissions can be
explained by a 22% increase in the output of Narva Elektrijaamad
AS compared to 2006, owing to the export of
electricity to Finland via the Estlink submarine cable.
Nitrogen oxides NO x
In 2007, around 749 tonnes of nitrogen oxides in
acidification equivalent was discharged into ambient
air in Estonia. Of this, one-half was generated by mobile
sources of pollution (vehicles) from use of motor fuel.
The transport topic is dealt with more thoroughly in
the section on ozone (chapter 5.2.2). The rest of the NO x
emissions was discharged in the process of combustion
of fuels in the energy and transformation industries and
in the manufacturing industry. The primary polluters in
the case of both sulphur dioxides and nitrogen oxides are
power plants in Ida-Viru County.
Compared to 1990, nitrogen oxide emissions have
dropped by 53%. There were no material changes in
nitrogen oxide emissions in specific economic sectors.
Compared to 2005 and 2006, nitrogen oxide emissions
increased in 2007.
Ammonia NH 3
In 2007, a total of 570 tonnes of ammonia in acidification
equivalent was emitted into Estonia’s ambient air,
of which the bulk was generated by agriculture. A small
part of the ammonia was discharged into ambient air
from transport and production processes. In agriculture,
pollution of ambient air with ammonia is primarily due to
animal farming buildings, manure storage facilities and
fields fertilized with manure and mineral fertilizers.
Compared to 1990, ammonia emissions have dropped
by nearly 63%, namely due to a reduction in the share of
agriculture. In the last decade, ammonia emissions have
remained stable.
Compared to other European Union member states,
Estonia’s emissions of pollutants per capita are high, much
greater than the average for the European Union (figure
5.2). The amount of pollution per capita is only exceeded
by Bulgaria, which has heavy industry and burns coal.
Estonia’s high position in the rankings can be attributed
to the large percentage of oil shale with a high-sulphur
and ash content in the Estonian energy sector and the
small population. At the same time, the emissions of SO 2
,
NO x
and NH 3
in Estonia make up only 0.5% of the total
emissions in the European Union.
A
The larger the number, the stronger the oxidant.
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