PRE-TREATMENT WITH HYDROCHLORIC ACID AND ENZYMATIC HYDROLYSIS OF SUGAR CANE BAGASS TO OBTAIN GLUCOSE

• DOI: 10.22533/at.ed.3173332325099

• Palavras-chave: laccase; Cellulases; Lignocellulosic biomass.

• Keywords: laccase; Cellulases; Lignocellulosic biomass.

• Abstract:

  Pretreatment and enzymatic hydrolysis are two important steps within the process of converting lignocellulosic biomass into glucose. In this work, sugarcane bagasse (BCA) ground into particles smaller than 40 mesh (< 425 µm) was pre-treated with hydrochloric acid (HCl) in different concentrations (0.75, 1.0 and 1.25 mol/L), in time varying from 30 to 90 min by autoclaving (121 ºC / 1 atm) in solid ratio :net 1:10. The pretreated BCA was subjected to hydrolysis with commercial enzymes at a solid:liquid ratio of 1:30, with100 µL of cellulase mixtures and 100 µL of Aspergilus niger laccase, in citrate-phosphate buffer (50 mM; pH 4.8) for 72h at 50 ºC under agitation at 150 rpm. Pre-treatment with HCl showed an efficiency in delignification of BCA of 59.2% and the glycan fraction increased to 64.48% in the solid residue of BCA recovered after pre-treatment carried out with HCl 1.25 mol/L, time 30 min. Within these operational parameters, enzymatic hydrolysis continued for 72h. Within a mass balance analysis, a solids recovery of 42.8% was observed for the pre-treatment stage with HCl. Therefore, for every 100 g of pre-treated BCA, within the process, residue with 64.48 g of glycan and 9.23 g of lignin was recovered and for every 100 g of BCA recovered after pre-treatment and enzymatically treated with cellulases and laccase it was possible to obtain 12.0g of glycan hydrolyzed into glucose. It is concluded that pre-treatment with dilute acid and hydrolysis with commercial enzymes showed efficiency in converting BCA glycan into glucose.