Research report Organofinery biogas production AAU

Summary

Organically grown red clover was investigated as a resource for organic feed by combination of protein extraction and anaerobic digestion of the sub-products. Extraction of proteins revealed a very favorable amino acid composition for the use as poultry feed. The residual 89% of organic matter, as solid press cake and brown juice was subjected to anaerobic digestion to produce biogas and fertilizer. Specific methane yields of 225±62 and 487±30 ml CH4/g VS were obtained for press cake and brown juice, respectively. No distinct inhibition was detected but adaptation of microorganisms in the case of the press cake and gradual increase of the substrate load in the case of the brown juice were beneficial to achieve efficient conversion of both fractions during the anaerobic digestion process.