초록
Pinus radiata is an appropriate feedstock for the production of second-generation bioethanol through a biochemical platform due to its high content of fermentable sugars. However, because of this tree's recalcitrance, a suitable pretreatment is necessary. In this paper, the effect of the concentration of H<SUB>2</SUB>SO<SUB>4</SUB> as a catalyst for the organosolv pretreatment for this raw material was studied. It was determined that a concentration of 1.1% of H<SUB>2</SUB>SO<SUB>4</SUB> promotes structural and morphological changes, such as the formation of lignin droplets, which increase the digestibility of the pretreated material to achieve an efficient conversion of cellulose to glucose of 94% using the proper dosage of a last-generation cellulase complex. Because of the good digestibility of the pretreated material obtained, it was possible to obtain high concentrations of ethanol, reaching 85.01g/L after 72h of reaction, working with fed-batch simultaneous saccharification and fermentation at 40<SUP>o</SUP>C at high substrate loadings using the thermotolerant strain of Saccharomyces cerevisiae IR2-9a. The importance of obtaining high concentrations of ethanol is that if the concentrations are above 4%, the cost of the distillation process is decreased.