title: Optimization of the co-digestion of catch crops with manure using a central composite design and reactor operation.
abstract: This study investigates the effect of catch crops as co-substrate on manure-based anaerobic digestion. Batch experiments were carried out for two catch crops, namely Italian ryegrass (IR) and oil seed radish (OSR), in co-digestion with manure. Methane yields in the range of 271-558 and 216-361 ml CH4/g volatile solids (VS) were obtained for OSR and IR in co-digestion, respectively. OSR co-digestion was chosen for semi-continuous reactor experiments. The addition of 50 % of OSR to manure (on VS basis) in semi-continuous anaerobic digestion resulted in a methane yield of 348 ml CH4/g VS, an improvement of 1.46 times compared to manure alone. Adaptation to OSR was observed, and no ammonia or volatile fatty acid-mediated inhibition was detected. The results prove that it is feasible to use catch crops as co-substrate for manure-based biogas production, obtaining a stable process with significantly higher methane yields than that of manure alone.
authors.affiliation: Section for Sustainable Biotechnology, Aalborg University Copenhagen, A C Meyers Vænge 15, 2450, København SV, Denmark, bms@bio.aau.dk.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Molinuevo-Salces
authors.forename: Birgitte K
authors.initials: BK
authors.lastname: Ahring
authors.forename: Hinrich
authors.initials: H
authors.lastname: Uellendahl
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D002417:Cattle; D018556:Crops, Agricultural / Q000737:chemistry*; D005232:Fatty Acids, Volatile / Q000032:analysis; D008129:Lolium / Q000737:chemistry; D008372:Manure / Q000032:analysis*; D008697:Methane / Q000096:biosynthesis; D031224:Raphanus / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D013223:Statistics as Topic; D034421:Sus scrofa; D014865:Waste Disposal, Fluid
chemical_list: D005232:Fatty Acids, Volatile; D008372:Manure; D008697:Methane