Modeling of Rheological Behavior of Egyptian Cane Molasses
S. JR. Mostafa
Department of Chemical Engineering -Faculty of Eng. -Cair o University
Abstract
The rheological properties of Egyptian cane molasses were studied at a
temperature range of 30-60°C at a shear rate of 1.1 to 5.5 sec’1
for solid
concentrations 6G%,70%, 75% and 80%. Results indicated that the power law
model fitted well the shear stress-shear rate data. The molasses behaved as a
shear-thinning fluid with a flow behavior index less than one. Dependence of
the apparent viscosity on the temperature was related through the Arrhenius
model for which the values of activation energy of molasses were estimated at
■investigated shear rates. The Krieger-Dougherty model, for concentrationviscosity relationship, fairly fitted the viscosity data. A hysteresis loop between
forward and backward cycle of the flow curve indicated thixotropic behavior
and was quantified by Weltman model. Other two models were applied, based
on analytical approach using time-independent power law models modified to
include a structural parameter, h These models were used to account for timedependent effects as well as reproduce experimental results “of shear rateviscosity to evaluate their validity. Finally, the values of X with time were
plugged in Tiu and Boger kinetic model to obtain the constants of that model.