title: Effects of crop maturity and size reduction on digestibility and methane yield of dedicated energy crop.
abstract: The compositional changes of Napier grass (Pennisetum purpureum) with respect to maturity (namely, 2, 4, 6, and 8 months age), and its effect on anaerobic digestion was examined under three sieving regimes (6, 10, and 20mm). Significant changes in plant composition were observed with crop maturity. The highest methane yields of 219±4.9 NmL/g VS added was found for biomass harvested at 2 months old compared to 189±7.3, 131±4.7, and 104±2.3 NmL of methane/g VS added, respectively, for 4, 6, and 8 months old biomass. For all ages, feedstock passed through a 6mm sieve resulted in significantly higher methane yields compared to biomass passed through 10 and 20mm sieves. Additionally, 2 months old biomass exhibited the highest digestibility of cellulose and hemicellulose, whereas digestibility of cellulose and hemicellulose were lowest for the biomass harvested at 8 months of maturity.
authors.affiliation: Department of Molecular Biosciences and Bioengineering (MBBE), University of Hawai'i at Mānoa, 1955 East-West Road, Agricultural Science Building 218, Honolulu, HI 96822, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Surendra
authors.affiliation: Department of Molecular Biosciences and Bioengineering (MBBE), University of Hawai'i at Mānoa, 1955 East-West Road, Agricultural Science Building 218, Honolulu, HI 96822, USA. Electronic address: khanal@hawaii.edu.
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Khanal
mesh_terms: D000693:Anaerobiosis; D061249:Batch Cell Culture Techniques; D018533:Biomass; D018556:Crops, Agricultural / Q000254:growth & development* / Q000378:metabolism; D004736:Energy-Generating Resources; D008031:Lignin / Q000378:metabolism; D016014:Linear Models; D008697:Methane / Q000096:biosynthesis*; D006109:Poaceae / Q000254:growth & development; D012037:Refuse Disposal / Q000379:methods*
chemical_list: C036909:lignocellulose; D008031:Lignin; D008697:Methane
keywords: Anaerobic digestion; Compositional analyses; Digestibility; Lignocellulose; Tropical energy crops