Effects of partial maize silage substitution with microalgae on viscosity and biogas yields in continuous AD trials.

•Substitution of maize silage with 20% microalgae reduced viscosities up to 53%.•Biogas yields were significantly lower at a substitution ratio of 20% microalgae in continuous anaerobic digestion trials.•Ultrasonication of A. obliquus biomass did not increase digestibility in continuous anaerobic digestion trials.