Abstract
The free-liquid fraction of slurries is strongly correlated with other slurry properties, especially the rheological and transport properties. Measuring free-liquid fraction can be problematic with lignocellulosic materials, and many studies to-date have instead used the total mass-fraction of liquid as a surrogate measure. This study presents two bench-scale methods for determining the free-liquid content of lignocellulosic biomass slurries. One is based on centrifuge-filtration of biomass for increasing time intervals until an asymptote is observed. The other uses solute exclusion methods and includes a proper accounting for unavoidable adsorption of the tracer solute molecules on the biomass solids. Overall, we found both methods gave reasonable results for washed pretreated corn stover. Among our controls, the centrifuge dewatering method tends to enable better results for large, rigid particles, and can give unrealistic results for small, compressible particles. This tendency is also reflected in the results for different pretreated corn stover slurries, where the quality of the results varied with the particle size distribution of the slurries. The solute exclusion method gives physically realistic results for all of our control materials and for washed pretreated materials, but produced physically unrealistic results for one unwashed pretreated corn stover sample. Further, we show that blue dextran interacts chemically with lignocellulosic material via adsorption and suspected degradation reactions.
Original language | American English |
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Pages (from-to) | 2261-2269 |
Number of pages | 9 |
Journal | Cellulose |
Volume | 21 |
Issue number | 4 |
DOIs | |
State | Published - 2014 |
Bibliographical note
Publisher Copyright:© 2014, Springer Science+Business Media Dordrecht (outside the USA).
NREL Publication Number
- NREL/JA-5100-60471
Keywords
- Centrifuge filtration
- Dewatering
- Free liquid
- Lignocellulosic biomass
- Solute exclusion