Effect of Corn Stover Concentration on Rheological Characteristics

Pimenova, Natalia V.; Hanley, Thomas R.

doi:10.1385/abab:114:1-3:347

Cited by 72 publications

(31 citation statements)

References 8 publications

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“…The fibers of bagasse tend to align parallel to current lines, thereby reducing the flow resistance [25] and generating behavior typical of a Newtonian fluid. The same rheological behavior was reported by Pimenova and Hanley [18] for corn stover suspensions (5-30% dry matter). However, when considering a constant 10% dry matter concentration, the steam-pretreated sugarcane bagasse slurries presented a very high apparent viscosity (2.6 Pa s at 100 s -1 ) as compared to acid-pretreated corn stover suspensions (0.02 Pa s at 100 s -1 ).…”

Section: Rheology Datasupporting

confidence: 86%

Sugarcane bagasse enzymatic hydrolysis: rheological data as criteria for impeller selection

Pereira

Teixeira

et al. 2010

J Ind Microbiol Biotechnol

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The aim of this work was to select an efficient impeller to be used in a stirred reactor for the enzymatic hydrolysis of sugar cane bagasse. All experiments utilized 100 g (dry weight)/l of steam-pretreated bagasse, which is utilized in Brazil for cattle feed. The process was studied with respect to the rheological behavior of the biomass hydrolysate and the enzymatic conversion of the bagasse polysaccharides. These parameters were applied to model the power required for an impeller to operate at pilot scale (100 l) using empirical correlations according to Nagata [16]. Hydrolysis experiments were carried out using a blend of cellulases, β-glucosidase, and xylanases produced in our laboratory by Trichoderma reesei RUT C30 and Aspergillus awamori. Hydrolyses were performed with an enzyme load of 10 FPU/g (dry weight) of bagasse over 36 h with periodic sampling for the measurement of viscosity and the concentration of glucose and reducing sugars. The mixture presented pseudoplastic behavior. This rheological model allowed for a performance comparison to be made between flat-blade disk (Rushton turbine) and pitched-blade (45°) impellers. The simulation showed that the pitched blade consumed tenfold less energy than the flat-blade disk turbine. The resulting sugar syrups contained 22 g/l of glucose, which corresponded to 45% cellulose conversion.

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Section: Rheology Datasupporting

confidence: 86%

Sugarcane bagasse enzymatic hydrolysis: rheological data as criteria for impeller selection

Pereira

Teixeira

et al. 2010

J Ind Microbiol Biotechnol

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“…The rheological behavior of unhydrolyzed [18] and hydrolyzed [1] biomass slurries has been shown to be non-Newtonian in nature, which is also the case here (Fig. 7).…”

Section: Viscosity Trendssupporting

confidence: 78%

Enzymatic Saccharification and Viscosity of Sawdust Slurries Following Ultrasonic Particle Size Reduction

Rezania

Berson

2009

Appl Biochem Biotechnol

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Results in a previous study showed up to a 55% increase in saccharification rates when the initial particle size range decreased from 590 < x < 850 microm down to 33 < x < 75 microm. The smaller particle sizes also lowered the viscosity of the slurry 50-fold (for an equivalent initial solids concentration). In this study, ultrasonic irradiation was employed to further reduce the particle size of sawdust slurries below the ranges in the previous study in an attempt to further increase enzymatic saccharification rates and lower the slurry viscosity. Average particle sizes were reduced to less than 1 microm under the conditions tested. Surprisingly, the amount and rates of sugar released in this study with the approximately 1 microm particles is comparable (maximum glucose release of 30%) to, but no better than that seen for particle sizes in the range of 33 < or = x < or = 75 microm (maximum glucose release of 31%). Also surprisingly, the viscosity increased as the average particle sizes in the slurries decreased, which is opposite to the trend in the previous study. For example, there was an approximately threefold increase in the viscosity between unsonicated samples with a range of 10 < or = x < or = 75 microm and sonicated samples with a range of 0.05 < or = x < or = 12 microm. This is attributed to the variations in surface characteristics of the particles which were characterized here using X-ray diffraction profiles and SEM pictures.

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“…Pimenova and Hanley [12,13] measured the apparent rheological properties of pretreated corn stover suspensions (average fiber length 120 μm) using a Brookfield viscometer with a helical impeller. The shear stress-shear rate data exhibited plastic-type rheological behavior with an apparent yield stress.…”

mentioning

confidence: 99%

Rheology of Dilute Acid Hydrolyzed Corn Stover at High Solids Concentration

Ehrhardt

Monz

Root

et al. 2009

Appl Biochem Biotechnol

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The rheological properties of acid hydrolyzed corn stover at high solids concentration (20-35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction temperature, acid concentration, and rheometer temperature. Plastic viscosities increase with increasing solids concentration and tend to decrease with increasing reaction temperature and acid concentration. The solids concentration dependence of the yield stress is consistent with that reported for other fibrous systems. The changes in yield stress with reaction conditions are consistent with observed changes in particle size. This study illustrates that torque rheometry can be used effectively to measure rheological properties of concentrated biomass.

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Effect of Corn Stover Concentration on Rheological Characteristics

Cited by 72 publications

References 8 publications

Sugarcane bagasse enzymatic hydrolysis: rheological data as criteria for impeller selection

Sugarcane bagasse enzymatic hydrolysis: rheological data as criteria for impeller selection

Enzymatic Saccharification and Viscosity of Sawdust Slurries Following Ultrasonic Particle Size Reduction

Rheology of Dilute Acid Hydrolyzed Corn Stover at High Solids Concentration

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