title: Intensification of hemicellulose hot-water extraction from spruce wood in a batch extractor--effects of wood particle size.
abstract: The effect of five different wood particle size fractions between 0.5 and 12.5 mm on hot-water extraction of acetylated water-soluble hemicelluloses from spruce wood with a batch extraction setup at 170 °C was investigated. Extraction kinetics, with regard to particle size, was also studied. The purpose was to intensify the hemicellulose extraction for high molar mass hemicelluloses at high yield and purity. About 30% of the wood was dissolved and basically all the hemicelluloses could be extracted. The average molar masses of the extracted hemicelluloses decreased rapidly during the first 10 min of the extraction, but were not much affected by the difference in wood particle sizes. Smaller particles resulted in higher extraction rates. The reaction order was established to be of pseudo-first order for particles above 2mm and 1.5st order for particles smaller than 2mm. The effective diffusion coefficient was determined to be 9.11×10(-10) m(2)/s.
authors.affiliation: Åbo Akademi Process Chemistry Centre, c/o Laboratory of Wood and Paper Chemistry, Porthansgatan 3, FI-20500 Åbo, Turku, Finland. jekrogel@abo.fi
authors.forename: Jens
authors.initials: J
authors.lastname: Krogell
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Korotkova
authors.forename: Kari
authors.initials: K
authors.lastname: Eränen
authors.forename: Andrey
authors.initials: A
authors.lastname: Pranovich
authors.forename: Tapio
authors.initials: T
authors.lastname: Salmi
authors.forename: Dmitry
authors.initials: D
authors.lastname: Murzin
authors.forename: Stefan
authors.initials: S
authors.lastname: Willför
mesh_terms: D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010316:Particle Size; D028222:Picea; D011134:Polysaccharides / Q000302:isolation & purification*; D014867:Water; D014934:Wood
chemical_list: D011134:Polysaccharides; D014867:Water; C007916:hemicellulose
keywords: Extraction kinetics; Hemicellulose; Hot-water extraction; Particle size; Spruce wood