Print: | ISSN 0256-1115 |
Online: | ISSN 1975-7220 |
Korean Journal of Chemical Engineering,
Vol.38, No.12, 2493-2499, 2021 The effect of enzymatic hydrolysis of pretreated wastepaper for bioethanol production
Enzymatic hydrolysis of waste biomass for bioethanol production is considered a decades old traditional, inexpensive, and energy-effective approach. In this study, waste office paper was pretreated with diluted sulfuric acid (H2SO4) and hydrolyzed with one of the most available and cost-effective enzymes, cellulase derived from Trichoderma reesei, under submerged static condition. Three different pretreatment approaches--cut into 2 cm2, blended with distilled water, and pretreated with diluted H2SO4--have been implemented, and pretreatment with diluted H2SO4 was the most effective. Hydrolysis with different concentrations--0.5M, 1.0M, 1.5M, 2.0M of H2SO4--was performed. The maximum glucose content was obtained at 2.0M H2SO4 at 90 min reaction time, and glucose yield was 0.11 g glucose/ g wastepaper. The cut paper, wet-blended, and acid-treated wastepaper was hydrolyzed with cellulase enzyme for 2, 4, and 5 consecutive days with 5mg, 10mg, 15mg, and 20mg enzyme loadings. The maximum glucose content obtained was 9.75 g/l from acid-treated wastepaper, after 5 days of enzymatic hydrolysis with 20mg enzyme loading and a glucose yield of a 0.5 g glucose/g wastepaper. The wastepaper hydrolysate was further fermented for 6, 8, and 10 hours continuously with Saccharomyces cerevisiae (yeast), and at 10 hours of fermentation, the maximum glucose consumption was 0.18 g by yeast. Further, HPLC analysis of the fermented medium presented a strong peak of bioethanol content at 16.12min. The distillation of bioethanol by rotary evaporator presented 0.79ml bioethanol/fermented solution, which indicated the conversion efficiency of 79%.
Keywords:
Acid Pretreatment; Bioethanol from Wastepaper; Enzymatic Hydrolysis; Wastepaper Utilization
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