RHEOLOGICAL BEHAVIOUR OF VINASSES FROM A MEXICAN BIOETHANOL FACTORY

D. CANTÚ-LOZANO1, M.V. VELÁZQUEZ MACARIO1, N.A. VALLEJO CANTÚ1,
M.A. MAURO2, V.L. DEL BIANCHI2 and J. TELIS-ROMERO2
1División de Estudios de Posgrado e Investigación-DEPI,
Instituto Tecnológico de Orizaba, Orizaba, México
2Instituto de Biociências, Letras e Ciências Exatas-IBILCE,
Universidade Estadual Paulista-UNESP, São José de Rio Preto, Brazil
dcantu@itorizaba.edu.mx

KEYWORDS: Rheology, Vinasses, Bioethanol,
Viscoelastic, Energy of Activation.

Abstract

THE KNOWLEDGE of the rheological behaviour of vinasses is very important for the operation
and design of a sugarcane bioprocess.
This study characterised rheological behaviour of residues from a bioethanol process
that uses final molasses as the carbohydrate source.
For this, we used a rotational rheometer Anton Paar MCR 301, concentric cylinder
system, Peltier plate for temperature control and software Rheoplus for date capture. The
temperature effect was compensated with an Arrhenius model, which measures the activation
energy of vinasses in the range 298–310 K.
The results showed an activation energy of 2.496 × 103 Cal/g-mol, a non-Newtonian
behaviour with viscoelastic characteristic, i.e. at low shear rate range (0–387 L/s) as fluid or
viscous (pseudo plastic) flow.
After this, there is an inflection point at high shear rate as solid or elastic flow
(dilatant), because the vinasses presented a material restructure.
This behaviour is due to the complex chemical composition of vinasse from final
molasses, which is a by-product of the sugarcane process.
To confirm this behaviour, it was compared with the rheological behaviour of vinasse
from sugarcane juice as the carbon source that showed a dilatant behaviour, i.e. as a fluid
flow.
These results showed that, depending on the substrate chemical composition
(complex/simple), similar rheological behaviour (complex/simple) is obtained.

Co-Products Posters Proc. Int. Soc. Sugar Cane Technol., Vol. 27, 2010
http://www.atamexico.com.mx/PDF/Abstract.pdf