Electric Energy Consumption of the Full Scale Research Biogas Plant “Unterer Lindenhof”: Results of Longterm and Full Detail Measurements

Abstract

This work thoroughly evaluates the electric power consumption of a full scale, 3 × 923 m 3 complete stirred tank reactor (CSTR) research biogas plant with a production capacity of 186 kW of electric power. The plant was fed with a mixture of livestock manure and renewable energy crops and was operated under mesophilic conditions. This paper will provide an insight into precise electric energy consumption measurements of a full scale biogas plant over a period of two years. The results showed that a percentage of 8.5% (in 2010) and 8.7% (in 2011) of the produced electric energy was consumed by the combined heat and power unit (CHP), which was required to operate the biogas plant. The consumer unit agitators with 4.3% (in 2010) and 4.0% (in 2011) and CHP unit with 2.5% (in 2010 and 2011) accounted for the highest electrical power demand, in relation to the electric energy produced by the CHP unit. Calculations show that 51% (in 2010) and 46% (in 2011) of the total electric energy demand was due to the agitators. The results finally showed the need for permanent measurements to identify and quantify the electric energy saving potentials of full scale biogas plants.

Effect of substrate pretreatment on particle size distribution in a full-scale research biogas plant

“…The setup, the mass and flow schemes of the research BGP have been described in full detail by various authors (Lemmer et al, 2008;Naegele et al, 2012;Naegele et al, 2013a;Naegele and Lemmer, 2011;Naegele et al, 2013b;Thomas and Wyndorps, 2012). The two digesters used for the experiment are made of concrete and are covered with insulated concrete.…”

“…Samples of input substrates and fermenting substrate were taken on a fortnightly basis and analyzed for DM, organic dry matter (oDM), pH, volatile organic acids/total inorganic carbon (VOA/TAC) and volatile fatty acids (VFA) content in the biogas laboratory of Hohenheim University according to the standard methods of the Federation of German Agricultural Investigation and Research Institutes (VDLUFA, 2007). Furthermore, the electrical energy demand is measured for every key consumer unit (Naegele et al, 2012). As a unique feature in biogas research, each of the BGP digesters is set up with 12 probe sampling holes, installed crosswise in the concrete roof at a distance of 1.75 m from the digester wall to the outer ring, 3.3 m to the center ring and 3.75 m to the inner ring.…”

“…This process forms a suspension of liquid and solid parts, which avoids sedimentation or floating of particles, enables gas lift, ensures uniform heat distribution and prevents foam formation (Hennig et al, 2011;Hopfner-Sixt and Amon, 2006;Reinecke et al, 2012;Weiland, 2010;Wu, 2012). As a result, the consumption of electric energy by stirring accounts for approximately 50% of the electric energy consumption in agricultural BGP fed with energy crops, thus having a direct impact on the profitability of the BGP operation (Naegele et al, 2012). An increase in the use of substrates, such as energy crops with high fiber content, caused the dry matter (DM) content in the digester to increase significantly .…”

Co-digestion of Wastewater-Grown Filamentous Algae With Sewage Sludge Improves Biomethane Production and Energy Balance Compared to Thermal, Chemical, or Thermochemical Pretreatments

“…Input is the other electricity consumption (e.g. lighting, automation), (3.6 W m −3 ); E CHP Input is the electricity for operation of the CHP unit (74 W per m 3 of methane) (Naegele et al, 2012); and E reagents Input is the electricity for production of chemical reagent (1,500 kW ton −1 ) (Worrell et al, 2000;Scheme, 2010).…”

Advancement in Biogas Digester

“…Due to guaranteed feed-in tariffs for "green" electricity under the Renewable Energy Sources Act (EEG) of 2001 and its amended versions of 2004, 2009, and 2012, the number of biogas plants has grown rapidly and reached 5,905 in 2010, with an installed electrical capacity of 2291 MW. According to certain predictions, the number of biogas plants in Germany will increase approximately to 7521, with an installed electrical capacity of 3185 MW by the end of 2012 (Naegele et al 2012). The share of biogas in electricity supplied from renewable energy sources reached 14.4 % in 2011.…”