Acknowledgements
We deeply thank ICCTI (Portugal) and
CONICYT (Chile) for sponsoring a scientific and
technological co-operation between our universities
in 2001, which made possible this work to be
carried out, as well as the staff of the Chemical
Engineering Department of Conception University,
with a special remark to Javier Ferrer and Ana
Barriga for their support throughout the experiments
and analysis.