Por favor, use este identificador para citar o enlazar este ítem:http://uvadoc.uva.es/handle/10324/31390
Título
Redefining conventional biomass hydrolysis models by including mass transfer effects. Kinetic model of cellulose hydrolysis in supercritical water
Autor
Año del Documento
2018
Editorial
Elsevier
Descripción
Producción Científica
Documento Fuente
Chemical Engineering Journal 350, 2018, 463-473
Resumo
Conventional kinetic models of cellulose hydrolysis in supercritical water do not accurately represent the operation with concentrated suspensions since they neglect the mass transfer effects. This work proposes a kinetic model which is able to reproduce cellulose hydrolysis at high concentrations providing the opt imum reaction conditions to obtain nanocellulose particles and oligomers of controlled size. The basic idea of the model, which is applicable to other lignocellulosic materials, is that the hydrolysis of the cellulose particles generates an oligosaccharides layer which creates a mass transfer resistance. Therefore, it considers both the diffusion of the water molecules from the bulk phase to the surfaces of the cellulose particles and the superficial hydrolysis kinetics. Experimental points were obtained working with two different cellulose types (Dp=75 μm and Dp=50 μm) at 390 °C and 25 MPa, residence times between 50 ms and 250 ms and initial cellulose suspension concentration from 3% to 7% w/w (1% to 2.3% w/w at the inlet of the reactor). The average deviation between the experimental points and the theoretical values is lower than 10% proving the applicability of the kinetic model. The experimental and theoretical results demonstrated that increasing the total number of cellulose particles, either increasing the initial concentration or decreasing the average particle diameter, reduces the hydrolysis rate.
Palabras Clave
Mass transfer
Shrinking Core Model
particle surface
oligosaccharides layer
covering conversion
ISSN
1385-8947
Revisión por pares
SI
Version del Editor
Idioma
eng
Derechos
openAccess
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