The Possibility of Biogas Production from Anaerobic Co-digestion of Hemp and Manure– A perspective in Germany

Abstract

Replacement of fossil-based resources with renewable resources to offset the use for heating and electricity production are important for today’s social and economic growth and energy security. Anaerobic fermentation and the production of biogas generates an alternative, carbon-neutral, renewable fuel that easily can be generated from local, low-cost organic waste materials and used as replacement for fossil fuel based gaseous products. The anaerobic digestion experiments ran for 240 hours at a temperature of 39°C ± 2°C for the duration of the experiment. The combined biogas production of hemp residues and hemp stems showed that the average reduced volatile solids content for hemp residue 1 and 2 was 0.98 g with a combined biogas production of 231.31 ml/g. For the hemp stems 1 and 2 the average reduced volatile solids content was 4.06 g and the combined biogas production was 64.90 ml/g respectively. Cow manure showed average reduced volatile solids content of 0.76 g and a combined biogas production of 305.69 ml/g respectively. The biogas content without CO2 was 62% for the manure samples, 55% for the hemp stems, and 57% for the hemp residues. The application of co-digestion utilizing cow manure and hemp-based waste material, as feedstock could be an option, helping to increase energy security, biological diversity, and sustainability.