Changes in greenhouse gas balance and resource demand of biogas plants in southern Germany after a period of three years

Abstract

For five agricultural biogas plants with a high share of energy crops in the input material, a detailed balance of greenhouse gas emissions (GHG) and cumulated energy demand (CED) was calculated for the years 2007 and 2010. The results vary considerably between plants and over time. In 2010 compared with 2007, all of the five biogas plants reduced their impact on climate change and four of them also reduced their consumption of fossil energy. The strongest influence was from the enhanced utilization of surplus heat energy, whereas variations of environmental impact due to direct emissions from the biogas plants were less distinctive. Compared with a reference system based on fossil resources, electricity production in the biogas plants avoided GHG emissions of 603 g to 940 g carbon dioxide equivalents (CO2-eq)•kilowatt hours electrical energy (kWhel (-1)) and saved 2.48 to 3.23 kilowatt hours primary energy from fossil energy carriers (kWhfossil)•kWhel (-1) CED (results for 2010).

Anaerobic digestion of different feedstocks: Impact on energetic and environmental balances of biogas process

“…The result of our study are in accordance with the literature (Bachmaier et al, 2013;Pöschl et al, 2010Pöschl et al, , 2012Wulfa et al, 2006;Bacenetti et al, 2012aBacenetti et al, , 2012bSchumacher et al, 2010;Meyer-Aurich et al, 2012), which shows that electricity production from biogas has huge potential for energy savings and a reduction of GHG emissions.…”

Environmental assessment of two different crop systems in terms of biomethane potential production

“…Considering that it is essential that the production of feedstock is carried out under sustainable conditions, in recent years, several LCA studies have been carried out to evaluate the environmental impact of energy crops cultivation (Dressler et al, 2012;Goglio et al, 2012;González-García et al, 2012b;Bachmaier et al, 2013;Ghahderijani et al, 2013). Our results are in agreement with this literature.…”

Biogas Biorefineries

“…Here, degrees of efficiency in the implemented machinery generate even more variations. 21,22 Biogas production out of organic wastes, residues from food production, and from manure based installations show even a negative GHG balance. Table 6.5).…”