Ethanol is the liquid combustible that has become the most promising alternative substitute for gasoline because of the experience gained in its production, the possibility of mixing it with gasoline in different proportions, the possibility of using the existing gasoline distribution infrastructure, and the fact that major changes in engines are not required for its use. Lignocelluloses offer great potential as a biomass source for ethanol production, although their use still requires in-depth analysis with an objective and holistic focus that includes present and future technologic implications. The present article reviews current knowledge about the characteristics and sources of vegetable biomass, as well as the development and possibilities for obtaining ethanol from lignocellulosic sources.

-Results are presented on the hot water prehydrolysis of sugar cane bagasse for obtaining ethanol by fermentation. The experimental study consisted of the determination of the effect of temperature and time of prehydrolysis on the extraction of hemicelluloses, with the objective of selecting the best operating conditions that lead to increased yield of extraction with a low formation of inhibitors. The study, carried out in a pilot plant scale rotational digester, using a 3 2 experimental design at temperatures of 150-190°C and times of 60-90 min, showed that it is possible to perform the hot water prehydrolysis process between 180-190°C in times of 60-82 min, yielding concentrations of xylose ≥ 35 g/L, furfural ≤ 2.5 g/L, phenols from soluble lignin ≤ 1.5 g/L, and concentrations ≤ 3.0 g/L of hemicelluloses in the cellolignin residue. These parameters of temperature and prehydrolysis time could be used for the study of the later hydrolysis and fermentation stages of ethanol production from sugar cane bagasse.

This work presents the results of a study of kinetic and adsorption isotherms of a cationic polyamine on bleached pulp of sugar cane bagasse. Polyamine was synthesized at laboratory scale and used in an experimental trial for the production of wet strength paper. In the isotherms and kinetic adsorption studies, pulp dispersions were used with the addition of KCl or aluminum sulfate. The concentration of the unadsorbed polyamine was determined by the polyelectrolyte titration. It was found that the polyamine adsorption in KCl at different pH values, and in the presence of Al3+, shows adsorption isotherms of the high affinity solute-adsorbent type, which satisfactorily adjust to the Langmuir adsorption isotherm equation. In systems in the presence of KCl, the polyamine adsorption is approximately four times higher than in the presence of aluminum sulfate. The speed constants of the fast stages are higher than the slow ones.