<b>Citric waste saccharification under different chemical treatments

Abstract

Second generation ethanol from lignocellulose materials has been used in applications for food processing wastes. Since Brazil has a leading position in orange juice exports, the influence of acid and alkali pretreatments on liquor saccharification, solubilization of solid fraction and mass yield was evaluated. Time and C_acid or C_alkaline at different concentrations of solids (low to moderate, 1 to 9%) and high catalyst concentrations were analyzed. A hydrothermal pretreatment was conducted under the same conditions of acid and alkaline treatments to investigate the relative selectivity increase in using the catalysts. The chemical analyses of wastes indicated a 70% total carbohydrate level denoting a promising raw material for bioethanol production. Pretreatment caused acid saccharifications between 25 and 65% in total reducing sugars (TRS) and mass yields (MY) between 30 and 40%. In alkaline pretreatment, these rates ranged between 2 and 22.5% and between 30 and 80, respectively. In hydrothermal pretreatment, solubilized TRS varied between 3 and 37%, whereas MY remained between 45 and 60%, respectively. C_biomass strongly influenced the three variables; in the same way, time affected MY.