Applied Biochemistry and Biotechnology

, Volume 114, Issue 1, pp 723–732

Measurement of rheology of distiller's grain slurries using a helical impeller viscometer

Session 3—Bioprocessing, Including Separations

DOI: 10.1385/ABAB:114:1-3:723

Cite this article as:
Houchin, T.L. & Hanley, T.R. Appl Biochem Biotechnol (2004) 114: 723. doi:10.1385/ABAB:114:1-3:723


Current research is focused on developing a process to convert the cellulose and hemicellulose in distiller's grains into fermentable sugars, increasing both ethanol yield and the amount of protein in the remaining solid product. The rheologic properties of distiller's grain slurries were determined for concentrations of 21, 23, and 25%. Distiller's grain slurries are non-Newtonian, heterogeneous fluids subject to particle settling. Traditional methods of viscosity measurement, such as cone-and-plate and concentric cylinder viscometers, are not adequate for these fluids. A helical impeller viscometer was employed to measure impeller torque over a range of rotational speeds. Newtonian and non-Newtonian calibration fluids were utilized to obtain constants that relate shear stresses and shear rates to the experimental data. The Newtonian impeller constant, c, was 151; the non-Newtonian shear rate constant, k, was 10.30. Regression analysis of experimental data was utilized for comparison to power law, Herschel-Bulkley, and Casson viscosity models with regression coefficients exceeding 0.99 in all cases.

Index Entries

Distiller's grain slurriesrheologic propertieswet grainscalibration fluidshelical impeller

Copyright information

© Humana Press Inc. 2004

Authors and Affiliations

  1. 1.Department of Chemical EngineeringUniversity of LouisvilleLouisville
  2. 2.Office of the ProvostAuburn UniversityAuburn