Metoder til forøgelse af biogasudbyttet fra de tungt omsættelige dele af det organiske stof i gylle og undersøgelser over svinegylles udrådningsegenskaber

Danish pig manure can be digested in thermophilic conditions with very low yield of roughly 65 ml methane CH4/g VS. Five methods had positive effect in the biogas process: longer duration, enrichment of biomass by sedimentation; granules addition; charcoal addition; glauconite or another ion exchanger.

Combination of charcoal with glauconite addition to fresh manure resulted in trebling of biogas yield, 195 ml CH4/g VS. Ammonium and sulfide ions inhibition is reduced this way. Manure fibers should be comminuted as much as possible. Processing of manure fibers by means of hemicellulose-degrading bacteria resulted in 30 % increase of the biogas potential.

Bases like NaOH, NH_4OH etc improved the biogas potential by 20 %. (EG).