Year: 2005
Type: article
Abstract: The importance of forage as a feed supply for dairy and beef cattle stocks is decreasing.Therefore, interest is rising in alternative use of grasslands.An ecologically sound option is the anaerobic digestion of the biomass as co-substrates in biogas plants.Three fresh and ensiled grass species were investigated in lab-scale batch experiments at 35° C to determine their maximum biogas production potential.The volatile solid-based biogas and methane yield were observed to be in the range of 0.65-0.86 and 0.31-0.36m 3 /(kg VS), respectively.Semi-continuous experiments were conducted to examine biomethanation of grass and cattle slurry at two organic loading rates (OLR) of 0.7 and 1.4 kg VS/(m 3 d).The anaerobic digestion was carried out in completely stirred tank reactors at 35° C with a mixture of three fresh grass species as mono-substrate, cattle slurry and a mixture of both as co-digestion.The biogas yield observed from the grass as mono-substrate at OLR of 0.7 and 1.4 kg VS/(m 3 d) was 0.61 and 0.56 m 3 /(kg VS), respectively.However, for both, co-digestion and cattle slurry digestion, the impact of OLR in the range of 0.7 and 1.4 kg VS/(m 3 d) on biogas yield was small.At this range of OLR, the averaged biogas yield obtained to 0.5 and 0.38 m 3 /(kg VS), respectively.The biogas yield in case of co-digestion was proportional to the amount of VS from grass in a mixture with cattle slurry.Moreover, the methane content decreased from 59-63% to 53-59% with the increasing proportion of grass.
Source: eCommons (Cornell University)
Authors: Mahnert, Pia, Heiermann, Monika, Linke, Bernd
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1665850622