Report - DCE - Nationalt Center for Miljø og Energi

associated with more uncertainty as it is estimated as a percentage (15 %) of
the meter differential. This assumption is based on expert judgement from
one of the town gas companies. It must be noted that more town gas distribution
companies are now closed (one in 2004 and another in 2006), and
therefore the data availability is scarce.
In Denmark there are two natural gas storage facilities. Both are obligated to
make an environmental report on annual basis. Data on gas input and withdrawal
are included and were 685 Mm 3 and 715 Mm 3 in 2010, respectively.
Until 2000 emissions from storage of gas were included in transmission in
the inventories.
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Venting at the two Danish gas storage plants are included in the inventory.
Venting of gas is assumed to be negligible in extraction and in refineries as
controlled venting enters the gas flare system. Venting rates are shown in
Figure 3.105. As venting rates are not available before 1995 the mean value
for the following three years are adopted as basis for the emission calculation
for the years 1990-1994.
Venting in gas treatment and storage plants, TJ
.
12
10
8
6
4
2
0
1990
1992
1994
1996
1998
2000
2002
2004
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Offshore flaring amounts are given in Denmark’s oil and gas production
(Danish Energy Agency, 2011a) while flaring in treatment/storage plants are
given in DONG Energy’s environmental reports (Dong Energy, 2010; Dong
Energy, 2011). Flaring rates for the two Danish refineries are given in their
environmental reports and additional data. From 2006 flaring amounts are
given in the EU ETS reporting.
The flaring rates are shown in Figure 3.106 and 3.107. Flaring rates in gas
treatment and gas storage plants are not available until 1995. The mean
value for the following ten years (1995 to 2004) has been adopted as basis for
the emission calculation for the years 1990-1994.
The large amount of flared gas in 2007 owe to a larger maintenance work at
the gas treatment plant.
2006
2008
2010
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