Methane emissions in biogas production - The Biogas: Science, Production and Applications - page 261

depends on the upgrading technology, numbers for each of the

technologies should be measured.

. Emissions from digestate storage. A wide range of emissions from

digestate storage tanks has been reported: roughly from 0.5 to 11.0% of
the total methane production in one study and around 7% in another
study. Some of the results came from measurements using closed tanks.
The captured production in these closed tanks is considered representa-
tive of emissions from storage in open tanks.

.

Overall emissions. Considering the above-mentioned sources, including
the uncertainties, the total emission from a biogas plant could be as low
as 1% or as high as tens of percent. One study measured the overall

emissions of a plant with a downwind concentration measurement. This
resulted in an estimated 3% which is, not surprisingly, within the
aforementioned range.

<

. Data sources. This chapter is based on a relatively small number of

articles. There is more information available, but this is not to be found
in the open literature. Given the wide ranges in the reported emissions, it
would be sensible for anyone interested in quantifying emissions from
biogas plants to seek additional information. Therefore, the authors of
this chapter recommend a more extensive search to include unpublished
reports as well, before drawing final conclusions or planning measure-
ments.

11.6 References

Amon B., Kryvoruchko V., Amon T. and Zechmeister-Boltenstern S. (2006)
Methane, nitrous oxide and ammonia emissions during storage and after
application of dairy cattle slurry and influence of slurry treatment. Agriculture,
Ecosystems and Environment, 112, 153-162.
Bu ¨ eler E. (2011a) CH4-Emissionen bei EPDM-Gasspeichern und deren
wirtschaftlichen und o ¨ kologischen Folgen. Report for Swiss Bundesamt fu ¨ r
Energie (BFE), Switzerland.
Bu ¨ eler E. (2011b) CH4-Emissionen bei EPDM-Gasspeichern. Presentation, based on
Bu ¨ eler (2011a).
Burgstaler J., Wiedow D., Godlinski F. and Kanswohl N. (2011) Verminderung des
Restgaspotentials

￿ ￿ ￿ ￿ ￿ ￿

und gasfo¨ rmiger Emissionen aus Ga¨ rresten der

Biogasproduktion. vTI Agriculture and Forestry Research, 2(61), 127-140.
de Zwart M., van Dijk G. and Klimstra J. (2011) Methane emissions from gas
engines driving combined heat and power installations. Proceedings of the 6th
International Symposium on Non-CO2 Greenhouse Gases, Amsterdam, The
Netherlands, 2-4 November 2011 .
Engelen P. A. C. (2009) Overzichtsrapportage vervolgonderzoek methaanemissies bij
gasmotoren op continu vollast - Voorjaar 2009. Update of Oltuis and Engelen
(2007).