Nano-Tubular Cellulose for Bioprocess Technology Development

Delignified cellulosic material has shown a significant promotional effect on the alcoholic fermentation as yeast immobilization support. However, its potential for further biotechnological development is unexploited. This study reports the characterization of this tubular/porous cellulosic material, which was done by SEM, porosimetry and X-ray powder diffractometry. The results showed that the structure of nano-tubular cellulose (NC) justifies its suitability for use in “cold pasteurization” processes and its promoting activity in bioprocessing (fermentation). The last was explained by a glucose pump theory. Also, it was demonstrated that crystallization of viscous invert sugar solutions during freeze drying could not be otherwise achieved unless NC was present. This effect as well as the feasibility of extremely low temperature fermentation are due to reduction of the activation energy, and have facilitated the development of technologies such as wine fermentations at home scale (in a domestic refrigerator). Moreover, NC may lead to new perspectives in research such as the development of new composites, templates for cylindrical nano-particles, etc

Influence of lithium on the kind of cobalt-species formed on γ-Al2O3

The effects of calcination temperature and lithium content on the kind of cobalt species formed on the surface of γ-Al2O3 have been studied using diffuse reflectance spectroscopy(D.R.S) and X-ray powder analysis (X.R). Six specimens with various amounts of lithium, all containing 2.8% Co3O4, have been prepared by pore volume impregnation of γ-Al2O3 with lithium nitrate aqueous solutions, followedby pore volume impregnation of the resulting supports with cobalt nitrate aqueoussolutions. A considerable inhibition of the solid-state transformation of Co3O4 into CoAl2O4 with thelithium content wasobserved by R.S.A determination of activation energies, using various models, for the above mentioned solidstatetransformation allows us to shed some light on lithium effects; the practical consequences, from a catalytic point of view, of these effects are also discused. © by Akademische Verlagsgesellschaf