STUDY OF THE REMOVAL OF FERMENTATION INHIBITORS AFTER ACID AND ENZYMATIC TREATMENT OF CANE STRAW

Abstract

It was studied the removal of toxic inhibitors produced during dilute-acid pretreatment of lignocellulosic biomass. Different sulfuric acid concentrations (1%, 2.5% and 5%) and reaction times (15, 30 and 60 minutes) were analyzed for the pretreatment process, and, 1% w/w H₂SO₄ and 15-minute reaction time have proven to be the most proper condition. With the experimental data, purification and concentration operations were simulated. For C5 stream (xylose, furfural and water) three different unit operations have been explored: a flash drum, a distillation column and a distillation column followed by multiple-effect evaporators. The distillation column with five multiple-effect evaporator system achieved the best energy efficiency (0,85 kW/kg xylose) and removal of furfural. For C6 stream (glucose and water), a four multiple-effect evaporator system simulated showed that the energy requirements not change significantly within the range of sugar concentration used (14% to 20%).