Catalytic effect of iron on sequential Fenton oxidation, hydrothermal treatment, and enzymatic hydrolysis to produce monosaccharide from lignocellulosic biomass

Abstract

In this study, Fenton oxidation, hydrothermal treatment, and enzymatic hydrolysis were performed in sequence to produce monosaccharide from lignocellulosic biomass. The biomass obtained from each process was washed or unwashed in order that the effect of Fe remaining in the biomass could be investigated further processing. After Fenton oxidation, the Fe remaining in the biomass (washed biomass: 306.74–823.46 ppm, unwashed biomass: 729.58–2456.45 ppm) was found to improve the hydrothermal treatment efficiency and demonstrated degradation rate of 28.94–31.16 % and 34.16–34.75 % in the washed and unwashed biomass, respectively. Hemicellulose was mainly degraded by hydrothermal treatment, which was confirmed by chemical composition and FT-IR analysis. Meanwhile, the Fe remaining in the biomass (washed biomass: 53.38–124.13 ppm, unwashed biomass: 98.25–249.85 ppm) after hydrothermal treatment negatively affected the enzymatic hydrolysis. After 96 h of enzymatic hydrolysis, the cellulose conversion yield differed depending on the condition, with a range of 78.85%–91.08%. The yield was 80.32–91.80 % for washed biomass used in the enzymatic hydrolysis, whereas the yield was low at 78.85–83.53 % for unwashed biomass.