Upgrading of sugar cane bagasse by thermal processes - 10. Catalytic liquefaction in aqueous medium

This work presents the results of a study of a process of direct catalytic liquefaction of sugar cane bagasse, in aqueous medium, using different pH v alues. The experiments were conducted in the absence as well as in the pres ence of commercial catalysts. In the absence of catalyst the results showed that the conversion of sugar cane bagasse into liquefied products is not i nfluenced by the pH of the reaction mixture. An increase in the temperature augments the yield of liquefied products. The utilization of different com mercial catalysts permits an increase in the yields of liquefied products u p to 92.4%, obtained with 10% palladium on activated carbon powder as catal yst. The liquefied products were fractionated into eight different chemical classes by preparative liquid chromatography (PLC-8 method). In the absenc e of catalyst, high conversion yields into light-oils and resins (fractions F1 to F6) was observed only at pH = 9. When the catalysts were used (at pH = 9 and at 370 degrees C) an important increase (from 29 to 78%) of resins (fraction F6) was observed Under this condition the proportion of asphalte nes and asphaltols (fractions F7 and F8) decreases from 70 to 20%.