title: Effects of thermo-chemical pre-treatment of grass silage on methane production by anaerobic digestion.
abstract: Dried grass silage (GS) was pre-treated at different NaOH loading rates (1%, 2.5%, 5% and 7.5% by volatile solids (VS) mass in grass silage) and temperatures (20 °C, 60 °C, 100 °C and 150 °C) to determine effects on its bio-degradability in terms of the hydrolysis yield and degradation of ligno-cellulosic materials for biogas production. At 100 °C and the four NaOH loadings, up to 45% of the total COD was solubilised and up to 65.6%, 36.1% and 21.2% of lignin, hemicellulose and cellulose were removed, respectively; biological methane production potentials obtained were 359.5, 401.8, 449.5 and 452.5 ml CH₄/g VS added, respectively, being improved by 10-38.9% in comparison with untreated GS. VS removals following anaerobic digestion were 67.6%, 76.9%, 85.3%, 95.2% and 96.7% for untreated GS and GS treated at the four NaOH loadings, respectively. 100 °C and the NaOH loading rate of 5% is recommended as a proper GS pre-treatment condition.
authors.affiliation: Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Xie
authors.forename: J P
authors.initials: JP
authors.lastname: Frost
authors.forename: P G
authors.initials: PG
authors.lastname: Lawlor
authors.forename: G
authors.initials: G
authors.lastname: Wu
authors.forename: X
authors.initials: X
authors.lastname: Zhan
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002482:Cellulose / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D008697:Methane / Q000096:biosynthesis*; D006109:Poaceae; D011134:Polysaccharides / Q000378:metabolism; D012820:Silage / Q000032:analysis*; D012972:Sodium Hydroxide; D013696:Temperature
chemical_list: D011134:Polysaccharides; D012972:Sodium Hydroxide; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin; D008697:Methane