title: Chemical characteristics and biofuels potentials of various plant biomasses: influence of the harvesting date.
abstract: BACKGROUND
  An optimal valorization of plant biomasses to produce biofuels requires a good knowledge of the available contents and molecular composition of the main chemical components, which changes with the harvesting date. Therefore, we assessed the influence of harvesting date on the chemical characteristics of various energy crops in the context of their conversion to biofuels.
  
  
  RESULTS
  We showed that the biomass chemical composition, enzymatic digestible organic matter, bioethanol and thermal energy production potential for each species are impacted by the harvesting date. The proportion of enzymatically digestible organic matter decreases as the harvesting date is delayed. This is related to the increase in cellulose and lignin contents. The suitability of the biomasses for bioethanol production increases with harvest stage, as the total carbohydrates content increases. The suitability of the biomasses as a source of thermal energy increases according to the harvesting date as the proportion of organic matter increases and the content of mineral compounds decreases. For all investigated energy conversions, the best harvesting period is autumn, because the significantly higher crop dry matter yield largely compensates for the sometimes slightly less favorable chemical characteristics.
  
  
  CONCLUSIONS
  While the biomass composition of energy crops changes with harvest stage, the dry biomass yield per unit area is the main factor that controls the total amount of chemical components, digestible organic matter, bioethanol and thermal energy that can be expected to be harvested per unit area. The biomass compositions presented in this paper are essential to investigate their suitability for bioenergy conversion.
authors.affiliation: Biomass, Bioproducts and Energy Unit, Valorisation of Agricultural Products Department, Walloon Agricultural Research Center (CRA-W), B-5030, Gembloux, Belgium; Bioengineering Group, Earth and Life Institute, Université catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Godin
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lamaudière
authors.forename: Richard
authors.initials: R
authors.lastname: Agneessens
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmit
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Goffart
authors.forename: Didier
authors.initials: D
authors.lastname: Stilmant
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Gerin
authors.forename: Jérôme
authors.initials: J
authors.lastname: Delcarte
mesh_terms: D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D002241:Carbohydrates / Q000032:analysis; D002482:Cellulose / Q000032:analysis; D000431:Ethanol; D008031:Lignin / Q000032:analysis; D009005:Monosaccharides / Q000032:analysis; D063245:Plant Development; D010940:Plant Proteins / Q000032:analysis; D010944:Plants / Q000737:chemistry*; D011134:Polysaccharides / Q000032:analysis; D013997:Time Factors
chemical_list: D056804:Biofuels; D002241:Carbohydrates; D009005:Monosaccharides; D010940:Plant Proteins; D011134:Polysaccharides; D000431:Ethanol; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin
keywords: cellulose; fibrous biomasses; hemicelluloses; plant maturity; renewable energy