title: In situ rheometry of concentrated cellulose fibre suspensions and relationships with enzymatic hydrolysis.
abstract: This work combines physical and biochemical analyses to scrutinize liquefaction and saccharification of complex lignocellulose materials. A multilevel analysis (macroscopic: rheology, microscopic: particle size and morphology and molecular: sugar product) was conducted at the lab-scale with three matrices: microcrystalline cellulose (MCC), Whatman paper (WP) and extruded paper-pulp (PP). A methodology to determine on-line viscosity is proposed and validated using the concept of Metzner and Otto (1957) and Rieger and Novak's (1973). The substrate suspensions exhibited a shear-thinning behaviour with respect to the power law. A structured rheological model was established to account for the suspension viscosity as a function of shear rate and substrate concentration. The critical volume fractions indicate the transition between diluted, semi-diluted and concentrated regimes. The enzymatic hydrolysis was performed with various solid contents: MCC 273.6 gdm/L, WP 56.0 gdm/L, PP 35.1 gdm/L. During hydrolysis, the suspension viscosity decreased rapidly. The fibre diameter decreased two fold within 2 h of starting hydrolysis whereas limited bioconversion was obtained (10-15%).
authors: Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (Université de Toulouse, INSA, INRA UMR792, CNRS UMR5504), Toulouse, France. tcnguyen@insa-toulouse.fr
authors: Tien-Cuong
authors: TC
authors: Nguyen
authors: Dominique
authors: D
authors: Anne-Archard
authors: Véronique
authors: V
authors: Coma
authors: Xavier
authors: X
authors: Cameleyre
authors: Eric
authors: E
authors: Lombard
authors: Cédric
authors: C
authors: Binet
authors: Arthur
authors: A
authors: Nouhen
authors: Kim Anh
authors: KA
authors: To
authors: Luc
authors: L
authors: Fillaudeau
mesh_terms: D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D004560:Electricity; D006868:Hydrolysis; D010316:Particle Size; D012212:Rheology / Q000379:methods*; D013535:Suspensions; D013997:Time Factors; D014783:Viscosity
chemical_list: D013535:Suspensions; D002482:Cellulose; D002480:Cellulase; C109691:microcrystalline cellulose